-■r_"- . | • ■ s Si .«• tf CONTENTS Safe Handling of Pesticides 2 J. Blair Bailey, Extension Pesticide Safety Specialist, Berkeley. Calculations and Measurements 4 Wayne C. Morgan, former Farm Advisor (Turfgrass), Los Angeles. Weed Control 10 Clyde L. Elmore and W. B. McHenry, Extension Weed Control Specialists, Davis. Insect Pests 31 Andrew S. Deal, Extension Entomologist, R. N. Jefferson, Professor of Entomology and Entomologist in the Experiment Station, and F. S. Morishita, Laboratory Tech- nician, Riverside. Nematodes 38 John D. Radewald, Extension Plant Nematologist, Riverside. Diseases 42 Arthur H. McCain, Extension Plant Pathologist, Berkeley, Robert M. Endo, Associ- ate Professor of Plant Pathology, Riverside, and Robert D. Raabe, Professor of Plant Pathology, Berkeley. Rodents 46 Maynard W. Cummings, Extension Wildlife Specialist, Davis. Glossary of Terms 48 ' V >■ s +AP »;,' ^ PREFACE This manual is written so that anyone concerned with the growing of turfgrass can identify and control many of the serious pests invading turfgrasses. The authors have provided sufficient information and pictures to aid in identification of these pests. Calen- dars of pest activity and treatment will be useful in control measures. Correct identification and selection of the best pesticide for control is of utmost im- portance; but paralleling this is the correct use of these materials. The section on pesti- cide calculations will be of value in determining the correct amounts of chemical and water to use. The glossary provides information necessary for a clear understanding of terms used with pests and pesticides. Most pesticides are poisonous. The section on chemical safety should be read carefully and the directions followed closely. Knowledge is expanding at a rapid pace. Universities and private research agencies throughout the world continue to produce new information and chemicals to provide more effective pest control. Unfortunately, in spite of this new pests seem to somehow make their uninvited and unwelcomed appearance. As new pests are discovered and new control recommendations are made, they will be announced through the University of California Farm Advisor offices (see below). Many turfgrass authorities have stated that "a healthy grass is the best means of pest control.'' Before seeking chemical methods to control pests, the wise manager will also determine if better turfgrass management practices can be employed to help reduce pest problems. It should be emphasized that "as a chain is no stronger than its weakest link," pest control practices will be no more effective than the attention paid to the least detail. This publication was made possible by the work of many people. The authors express their appreciation to all persons who have contributed to the identification and control of the pests of turfgrasses. It is necessary to control some pests of turfgrass by using chemicals. However, devel- opments in the field of chemistry are taking place so rapidly that no specific recommen- dations for the use of chemicals can be made in this manual. Such recommendations are made in a free, leaflet-type publication that is revised and re-issued as needed. Copies may be obtained from the University of California Farm Advisor offices, or from Agricultural Publications University of California Berkeley, Calif. 94720 Ask for Leaflet 209. University of California • Division of Agricultural Sciences January 1971 [1] SAFE and EFFECTIVE USE of PESTICIDE CHEMICALS J. Blair Bailey Pesticides are not only useful, but in many cases abso- lutely necessary for production of pest-free turfgrass. We can benefit from their proper use. If misused, however, through carelessness or lack of knowledge, the result can be expensive and even dangerous. Before discussing the problems that can result from mis- use, let's first have clearly in mind what pesticides are, and in general terms, how they work. What is a pesticide? The term "pesticide," defined legally as an "economic poison,"' refers to any chemical or mixture of chemicals intended for controlling pests. For example: TYPES OF PESTICIDES USED Insecticides Fungicides Herbicides Nematicides Rodenticides TYPES OF PESTS CONTROLLED Insects Fungi and Bacteria Weeds Nematodes Rodents How they work In general, pesticides control both plant and animal pests by poisoning them. Thus all pesticides are toxic (poisonous) to one degree or another to plants or animals, and some- times to both. Since humans are animals, pesticides are poisonous to them too. Some pesticides are poisonous to, and can kill, helpful plants or animals such as livestock, pets, fish, and honeybees. Some pesticides are more toxic than others. All of the chemicals recommended in Leaflet 209 are given toxicity ratings so you will know which ones are most toxic. You should be especially careful with these materials and take the precautions outlined here and on the label of the pesti- cide container. Chemicals that present special problems will be discussed below. Follow recommendations carefully and do exactly what they say Before handling any pesticide read and understand all of the information on the pesticide label! If you need help ask for it! Know ulial to do in ease of an accident. The authors of each section of tins manual have given their recommendations for safel) and effectively controlling specific pe-t-. Follow them. Use the correct chemical It i- essential to your personal Bafet) and the safely of other-, as well as all beneficial plants and animals, that when a specific chemical is recommended, you use it. These chemicals have been tested and proven to be effective in controlling -pec ific pests. Use the correct amount When directions say use a given amount of the chemical, use only that amount. Adding "a little extra" will not con- trol the pest any better and it may cause injury to the treated area (burn the turfgrass) or result in serious drift or other contamination problems. Use at proper time and temperature When directions say to apply the chemical at a specific time of the day, or within a given temperature range, or at a certain stage of plant growth, they mean just that. Again, experiments and experience have shown these spe- cific times of application give safest and best control of the pest. Use recommended form of chemical Use only the formulation of the chemical recommended (wettable powder, dust, emulsifiable concentrate, granular, or gas fumigant). This is important for good pest control. In addition, plant injury (phytotoxicity) may result from the use of a different formulation of the same chemical. Use proper method of application Applying the chemical in a prescribed manner is likewise important for effective control and safety. For example, if you are applying a chemical with a tractor-powered unit, and directions are given to travel at a given speed, do just that. Increasing your speed will very likely result in less chemical being applied to a given area. This may result in poor, or no control of the pest. If you travel slower than prescribed, more chemical will be deposited in a given area and you may "burn" the turfgrass, and leave so much chemical residue that plant growth will be stunted. You could even prevent any plant growth in this soil for a long time afterward. Do not combine chemicals unless recommendations say it is safe Mixtures of certain chemicals can cause plant injury, run-off, reduced control of the pest, or clogging of appli- cation equipment. Mixtures sometimes even increase the toxicity of the chemicals. Check the label of the pesticide container or a compatibility chart before you combine pesticides. How toxic are the pesticides recommended? , 4 on don't have to be a chemist or a toxicologist to un- derstand approximately how toxic a pesticide is. This in- formation is given on the label of the pesticide container 2 I in the form of a symbol, or one or two words in extra large print known as signal words. SIGNAL WORD (s) OR SYMBOL APPROXIMATE TOXICITY "Danger," "Poison" and skull and crossbones symbol Highly toxic "Warning" Moderately toxic "Caution" Slightly toxic No special signal words or symbols Still less toxic NOTE: Even though you may find no special "signal words" printed on the label of the pesticide you plan to use, you should treat the chemical as a poison. Even those having a low toxicity rating can cause toxic reactions in you if used in large quantities and often. Splashes and spills of chemicals As an applicator you are not likely to eat or drink a pesticide unless by accident. You may, however, acciden- tally splash or spill the chemical on your skin or in your eyes. This is by far the most common source of poisoning to those handling pesticides. Therefore, your greatest con- cern should be how toxic (poisonous) the chemical will be to you if it gets on your skin or in your eyes. This is re- ferred to as "Dermal Toxicity." The effects a pesticide will have on you are mainly determined by : • How much gets on you. • How long you let it stay on you. • Concentration of the chemical. • Toxicity of the chemical. • Formulation of the chemical. A few drops of a highly toxic, highly concentrated, liquid formulation can be highly toxic to you, if it splashes or spills on your skin or in your eyes. If this occurs, stop immediately and rinse your eyes with clean water for 10-15 minutes. If the chemical gets on your skin, wash thoroughly with soap and water. Then call your doctor and tell him what happened giving him the name of the chemical, as printed on the package. Remember, the longer you leave the chemical on your skin the more damage it can do to you. Liquid formulation containing solvents, such as xylene, oils, and other petroleum hydrocarbons are absorbed by the eyes and skin much more rapidly than are dusts, wet- table powders, or granular forms of these chemicals. Use special caution when pouring and weighing con- centrated materials. They are most hazardous before dilu- tion. However, even diluted chemicals can accumulate on your skin, hair, clothing, and shoes, so wash and change your clothing after application. If you are given a choice of chemicals to control a pest, select the one that is least hazardous to you, and that will still control the pest. Before handling any pesticides wear clean, protective clothing, waterproof hat, boots, and goggles. Avoid inhaling (breathing) chemicals, especially those in dust and gas form. Wear a clean, well-fitted, approved respirator when handling sprays and dusts. Wear approved gas mask when handling fumigants. Check the labels on the pesticide con- tainer for these precautions before you handle any pesti- cide. A list of approved respirators and gas masks may be found in the University of California Pesticide Information and Safety Manual. What to do after a pesticide application Clean your application equipment and put it back in good working order Store your pesticides properly: In the original, labeled container; never in or near food, feed, or drinking containers. In a locked, well-marked storage cupboard or building, never where they will get hot, or freeze. Dispose of used pesticide containers properly: Return 30 and 55 gallon drums to original supplier or have a drum reconditioner pick them up as soon as possible. Store them in a place where no unauthorized person can get to them until you can get rid of them safely. Rinse all non- returnable, glass, metal, and plastic containers with soap and water. Make sure you pour the rinse water in a place where it won't contaminate water supplies or damage crops. Then break or puncture them so they cannot be reused. Empty containers that will burn, should be burned. But make sure it is legal to burn in your area, and stand out of the smoke fumes. Never burn containers that held hor- mone-type (2,4-D) weed killers. The fumes from these can drift for miles and injure plants. Keep good records of all pesticide applications Do this immediately after the application, before you forget the details. Record what was treated; the pest treated; the location and amount of area treated; time of day, date of application; exact name of pesticide used, in- cluding type of formulation; amount used per gallon or unit of area treated; and the weather conditions. For more detailed information on these and other pesti- cides you are referred to the University of California Pesti- cide Information and Safety Manual which is available at $2.50 from the University of California Agricultural Ex- tension Service, Berkeley, California 94720. For large spraying or dusting jobs the operator should wear protective clothing — of material that can be easily washed off. [3] CALCULATIONS and MEASUREMENTS Wayne C. Morgan This manual is mainly for operators and caretakers of large areas of lawn and turf and many of the directions given for applying chemicals will state ". . . apply at the rate of (so much) per acre." The same may be true in other turfgrass publications or on the labels of containers of chemicals bought in large quantities. But many times, the area to be treated is relatively small and the margin between using enough of a material to be effective and too much material (which might damage the turf) is rather narrow. So it is important that measure- ments and directions be followed as closely as possible when applying chemicals. This section tells how to calculate and measure chemicals for different size plots when the directions tell only how much to apply on large areas. Any rates given here are examples only; they are not recommendations. How to convert from large areas and/or amounts to smaller ones Because many recommendations are made on a per-acre basis, the amounts of a pesticide required are often in larger amounts, such as pints (pts.) or pounds (lbs.) . First, the area conversion should be reduced to a convenient one and then the materials amounts changed to other equiva- lents usable for smaller areas. When using acre figures, round off an acre (43,560 sq. ft.) to 44,000 square feet Isq. ft. (.Often for turfgrasses, recommendations are on a "per 1.000 sq. ft." basis; there- fore, this is %4 of an acre. Dividing the acre rates by 44 will give the amounts needed for 1.000 sq. ft. To further reduce areas or amounts to 100 sq. ft. units, divide by 10. Any other measurements can then be easily adjusted from this basis by additional multiplication or division. If 1 lb, 1 16 dry oz. by weight) or 1 pt. (16 fluid oz. by volume) were recommended for 1,000 sq. ft., this would be 1.6 oz. per 100 sq. ft. (16-4-10= 1.6). For an area 350 sq. ft. in size, this is 5.6 oz. ( 1.6 x 3.5 = 5.6 oz.) . Recommendations are sometimes made for the main in- gredient of a mixture in terms of active or actual ingredi- ent. Pesticides are usually sold under trade names contain- in:' onl) certain percentages and/or pounds of the active ingredient. The rest of the mixture will be "inert" or non- A small gram scale and/or household scale with divisions of ounces will be needed for small measure- ments. When liquid materials are used, it would be well to have measuring cups with divisions of ounces, measuring spoons, and a graduated cylinder in milli- liters, obtainable for a small cost at most drug stores. active ingredients. These must be adjusted to the amounts of material needed to make one whole unit active ingredient such as a pint or pound. The labels of most pesticides not only state the per- centage concentration but also the number of ounces of active ingredient per gallon of the formulation. The latter is more important in computing dosages. To determine how many units of active ingredient are in the container when only a certain percentage of the active ingredient is given, multiply the size or weight of the con- tainer by the percentage written as a decimal for this infor- mation. Thus 1 gal. x 0.40 = 0.4 gallons, or since there are 128 ounces in a gallon, this is 128 ounces x 0.40 = 51.2 ounces of active ingredient in one gallon of 40Cr material. Formulations of the same pesticides often vary in con- centration of active ingredients depending upon the manu- facturer, so it is necessary for the person using the pesti- cide to compute the amount of formulation needed to give the amount of active ingredient called for in the recom- mendation. The various emulsifiable pesticide concentrates usually contain the following amounts of active ingredients per gallon (by weight) : 15% - 18.5% = 1.5 lb. per gallan 20% - 25% = 2 lb. per gallon 40% - 45% = 4 lb. per gallan 50% - 57% = 5 lb. per gallon 58% - 67% = 6 lb. per gallon 72% - 78% = 8 lb. per gallon Tables 1 and 2 will be helpful if you are called upon to convert from printed directions that say "Use (so many) pounds per acre," and you wish to apply the material to an area of from 100 to 1.000 square feet. Measuring small amounts For treating small areas with chemicals it is often nec- essary to measure out V44 of a pint or %4 of a pound. This will require you to have the gram scale or the cylinder graduated in milliliters discussed in box at left. Then by consulting the table of conversion figures given below the job becomes easier. As an example: If a dosage recommendation calls for applying 1.6 oz. to 100 square feet of turf, convert the ounces to grams. (1.6x28.4 = 45.44 grams.) You could round off the 15.1 I grams to 45.5 for con- venience, but if you rounded off the 1.6 oz. to 1.5 it would amount to a reduction in dosage that might affect the efficiency of the treatment. Rounding off measures Even small rounding off of figures can make substantial changes in the rale of application, especially when small quantities per acre are used or the units of measurement [4 Table 1 GRAMS TO USE PER 100 SQUARE FEET FOR DRY MATERIALS AT CERTAIN PERCENTAGES 01 ACTUAL INGREDIENTS, WHEN RECOMMENDATIONS ARE GIVEN IN POUNDS PER ACRE Recomm. in pounds Per cent of actual ingredient given on label per acre 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 5% No. of grams to use per 100 sq. ft. 1 1 04 2.08 3.12 4.16 5 20 6.24 7.28 8.32 9.36 10.40 1.15 2.30 3.45 4.60 5 75 6.90 8 05 9.20 10.35 11.50 1.3 2.6 3.9 5.2 6 5 7.8 9.1 10 4 11,7 13.0 1.49 2.98 4.47 5.96 7 45 9.94 11.43 11.92 13 41 14.90 1.73 3.46 5.19 6.92 8 65 10.38 12.11 13.84 15.57 17.30 2.08 4,16 6,24 8.32 10.40 12.48 14.56 16.64 18.72 20.80 2.6 5.2 7.8 10 4 13.0 15 6 18.2 20.8 23.4 26.0 3.47 6.94 10 41 13.98 17.45 20.82 24.29 27.96 31 23 34.70 5.2 10 4 15.6 20.8 26.0 31.2 36.4 41.6 46.8 52.0 10 4 20.8 31 2 41.6 52 62.4 72.8 83.2 93.6 104.0 20.8 41.0 62.4 83.2 104.0 124 8 2 3 4 5 6 7 145 6 8 166.4 187 2 9 10 208.0 Table 2 CUBIC CENTIMETERS TO USE PER 100 SQUARE FEET FOR LIQUID MATERIALS WHEN ACTIVE INGREDIENT IS STATED IN POUNDS PER GALLON, AND RECOMMENDATIONS ARE GIVEN IN POUNDS PER ACRE Recomm. in pounds Pounds per gallon active ingredient given on label per acre 10 9 8 7 6 5 4 3 2 1 .5 No. of CC to use per 100 sq. ft. 1 2 0.84 1.68 2 52 3 36 4 20 5 04 5.88 6.72 7 56 8 40 0.96 1.92 2.88 3 84 4.80 5.76 6.72 7.68 8.64 9 60 1.08 2.16 3.24 4,32 5 40 6,48 7.56 8.64 9.72 10.80 1.23 2.46 3.69 4.92 6.15 7.38 8.61 9.84 11.07 12.30 1.43 2.86 4.29 5,72 7.20 8,58 10 01 11 44 12.87 14.30 1.68 3.36 5.04 6.72 8,40 10.08 11,76 13.44 15.12 16.80 2.15 4,30 6.45 8.60 10.75 12.90 15.05 17.20 19.35 21.50 2.88 5.76 8.64 11.52 14 40 17.28 20.16 23.04 25.92 28.80 4.30 8.60 12.90 17.20 21.50 25.80 30.10 34.40 38.70 43.00 8.6 17.2 25.8 34 4 43.0 51.6 60.2 68.8 77.4 86.0 17.2 34.4 3 51 6 4 68.8 5 86.0 6 103.2 7 120.4 8 9 137.6 154 8 10 172.0 are larger. This may seriously alter the effectiveness of the pesticide or subject desirable plants to injury. If 12 pints or pounds to the acre were recommended, the following is how rounding off of rates for 200 sq. ft. would affect the amounts being applied: 1.6 oz. to 1.5 oz. = a reduction of 20 oz. per acre or only 10.75 pints or pounds being applied per acre rather than the 12 pints or pounds recommended. 3.17 tbsp. to 3 tbsp. = a reduction of 34 tbsp. or 17 oz., a little over a pint less than the 12 pints recommended. 9.6 tsp. to 9.5 tsp. = a reduction to 20 tsp. or about 7 tbsp. ilV-2 oz.). This would be about 11.75 (11% pts.) to the acre being used. 47.4 ml. or gms. to 47.5 ml. or gms. = an increase of 20 ml. or gms. per acre, which is less than .1 or 1% in- crease. In using the teaspoon, milliliter, or gram measurements, the differences in rates applied would not have been sig- nificant. Examples Here are some typical examples of conversion from figures where the recommendations are given for large areas but only a relatively small area needs treatment. Problem 1. A recommendation calls for the rate of 4 oz. (0.25 lb.) active ingredient per 1.000 sq. ft. The material is available as a 25% emulsifiable concentrate Table 3 CONVERSION FIGURES DRY WEICHT 1 pound (lb.) = 16 ounces (oz.) 1 pound = 454 grams (gms.) 1 ounce =28.4 grams (gms.) LIQUID MEASURK ( VOLUME ) 1 gallon (gal.) - 128 ounces 1 quart (qt.) = 32 ounces lpint(pt. ) = 16 ounces 1 cup = 8 ounces 1 tablespoon (tbsp.) = % ounce 3 teaspoons (tsp.) = 1 tablespoon 16 fluid ounces = 473 milliliters* 1 fluid ounce = 29.57 milliliters* 1 qt. water/100 sq.ft. = HO.gals./acre * 1 milliliter is equivalent to 1 cubic centimeter. Note: It may be helpful to determine how many level teaspoons of material are needed to make 1 ounce or how many grams there are in a teaspoonful, and then use volume measurements for ease in future use. [5] (contains 2 lbs. per gal.). How much of this formulation will he needed to provide the 4-oz. active ingredient for 200 sq. ft. of lawn area? How much water would be needed if this was to be applied in 110 gals, per acre? Solution. First use this formula Lbs. active ingredient desired per unit of area x fluid ounces in one gallon Lbs. active ingredient in the emulsifiable concentrate - Fluid ounces of formulation needed per unit of area 25 v 1 98 1^1— ^T = 16 fl. oz. or 473 ml (16 x 25.47 ml/oz = 473 ml) per 1,000 sq. ft. As 200 sq. ft. is 20% of 1,000 sq. ft. (200 ~ 1,000 = 0.20 or 20%) then by multiplying each measure by 0.20 the amount needed for the 200 sq. ft. -area is found: 16 oz. x 0.20 = 3.2 oz. or 473 ml x 0.20 = 94.6 ml. Using teaspoon and tablespoon equivalents this would be 3.2 oz. = about \8 l /± tsp. or 6 tbsp. + about ^4 tsp. Since 1 qt. of water per 100 sq. ft. is equal approximately to 110 gals, per acre, then 2 qts. of water would be needed for the 200 sq. ft. of lawn area. Problem 2. The recommendation is for 18 pounds of active ingredient per acre. A dry granular material contain- ing 45% active ingredient is to be used. How much is needed for 740 sq. ft. area? Solution. 18 pounds equal 288 oz. or 8,172 gms. For 1,000 sq. ft. this would be about 6.5 oz. (288 -f- 44 = approximately 6.5 oz.) or 186 gms (8172 -f- 44 = approxi- mately 186 gms.). Since 740 sq. ft. is almost % of 1,000 sq. ft. this means about 4.9 oz. (6.5 oz. x 0.75 = approxi- mately 4.9 oz.) or 139.5 gms (186 gms. x 0.75 = 139.5 gms.) of active ingredient would be needed for the 740 sq. ft. area. The granular material contains only 45% active ingre- dient, so to have 1 oz. of active ingredient, about 2.2 oz. (100 -f- 45 = about 2.2 oz.) of the 45% material would be required. With 4.9 oz. or 139.5 gms. of active ingredient being needed, about 10.70 (4.9 oz. x 2.2 = 10.78 oz.) or 307 gms. (139.5 gms. x 2.2 = 307 gms.) of the 45% dry granular material would be needed for the 740 sq. ft. area. If it had been determined that 8 tsp. of the 45% mate- rial equalled 1 oz. or there were 3^2 gms. in 1 tsp., this would be 86.4 tsp. (10.78 x 8 tsp. = 86.4 tsp.) . Rounding off to 29 tbsp. or a 15-oz. volume measure would not signifi- cantly affect the results. Problem 3. Same problem as above, using "constants" in a simplified formula. .03673 xRx A % = per cent of active ingredient in material to be used (taken from label) .03673 x 18 x 740 jr = 10.76 oz. of 45 per cent material ap- plied to 740 sq. ft. is equal to 18 lbs. of active ingredient per acre Problem 3b. Same problem as above but a liquid material with 3 lbs. active ingredient per gallon is used rather than a 45% active granular material. Solution. A simplified formula for liquid materials is: .0029xRxA = fluid oz. of liquid material needed for given area lbs/ gal = lbs. of active ingredient per gallon (taken from label) lbs. /gal. = oz. of per cent material needed for given area, \\ here H rate needed in lbs. per acre A = given area .0029 x 18 x 740 o = 1-29 fluid oz. of a 3 lbs. active per gal- lon material applied to 740 sq. ft. is equal to 18 lbs. active ingredient per acre. Note : if pints or quarts are used, multiply lbs. active per pint by 8 or lbs. active per quart by 4 to change to lbs. active per gallon. Problem 4. (Using Table 4.) (a) If the label on a liquid pesticide called for 1 gal. of the material to be applied in 100 gals, of water per acre, how much would be needed for a 430 sq. ft. area? (b) How much would be needed for a 1,500 sq. ft. area? Solution, (a) (Using Table 4.) — Since 430 sq. ft is approximately Vino of an acre (44,000 -=- 430 = approxi- mately 100), then only 1 gal. of water with 2 1 /2 tbsp. or 37.9 ml. of the material need be applied, (b) (Not using table)— The 1,500 sq. ft. is about % 9 . 3 (44,000 -f- 1,500 = 29.3) of an acre. By dividing the number of gallons of water needed by the area being used (100 gal. -7- 29.3) and the amount of material by the area to be covered (1 gal. or 128 oz. -r- 29.3) it is found that 3.41 gals. (3 gals. + 1 qt. + 1 pt. and 4V2 oz.) of water with 4.37 oz. (about 8 tbs. + 2 tbs.) of the liquid pesticide would be needed for a 1,500 sq. ft. area. Problem 5. (Using Table 5.) (a) A wettable powder is to be used at the rate of 3 lbs. in 25 gal. of water to cover 10,000 sq. ft. What would be needed for a 2,000 sq. ft. area? (b) What would be needed for a 100 sq. ft. area? Solution, (a) (Using Table 5.) Since 2,000 sq. ft. is 20% of 10,000 sq. ft. (2,000 -*- 10,000 = .20 or 20%) and 20% of 25 gals, is 5 gals, by looking across the 5-gal. row to the 3 lbs. column, it is seen that 2.4 oz. or 68 gms. would be the rate for 2,000 sq. ft. (b) (Not using table) — One hundred sq. ft. is Vi,,,, of 10,000 sq. ft. Twenty-five (25) ^als. equals 3.200 oz. Three (3) lbs. equals 1,362 gms. Kadi 100 sq. ft. would then need 32 oz. (3,200 -4- 100 = 32 oz.) of water with 13.62 gms. (1.362 : 100 = 13.62) of wettable powder. Table 4 PROPORTIONATE AMOUNTS OF LIQUID CHEMICALS NEEDED WHEN RECOMMENDATION- IS GIVEN FOR 100 GALLONS OF WATER* Quantity of water needed Quantity of liquid chemical needed 100 gallons 1 cup 1 pint 1 quart 2 quarts 1 gallon 25 gallons 4 tablespoons (59.2 ml.) Yi cup 1 cup 1 pint 1 quart 10 gallons 5 teaspoons (23.7 ml.) 3 tablespoons (47.3 ml.) 6Y tablespoons (94.6 ml.) 13 tablespoons (189.3 ml.) 114 cups (378.5 ml.) 5 gallons 2M teaspoons (11.8 ml.) i}4 teaspoons (23.7 ml.) 3 tablespoons (47.3 ml.) 6Y: tablespoons (94.6 ml.) 13 tablespoons (189.3 ml.) 3 gallons \\4 teaspoons (7.1ml.) 3 teaspoons (14 2ml.) 5J4 teaspoons (28.4 ml.) 3^j tablespoons (56.8 ml.) 7Yi tablespoons (113.6 ml.) 1 gallon Yi teaspoon (2.4 ml.) 1 teaspoon (4.7 ml.) 2 teaspoons (9.5 ml.) 4 teaspoons (18.9 ml.) 2\4 tablespoons (37.9 ml.) Ji( — ) teaspoon (1.2ml.) Y2 teaspoon (2.4 ml.) 1 teaspoon (4.7ml.) 2( — ) teaspoons (9.5 ml.) * Adapted from "Handbook of Agricultural Pest Control" by S. F. Bailey and L. M. Smith. Table 5 PROPORTIONATE AMOUNTS OF POWDERED MATERIALS NEEDED WHEN RECOMMENDATION IS GIVEN FOR 100 GALLONS OF WATER* Quantity of water needed Quantity of powdered material needed 100 gallons 1 pound 2 pounds 3 pounds 5 pounds 25 gallons 4 ounces 8 ounces 12 ounces 20 ounces 10 gallons 1.6 ounces (45 4 grams) 3.2 ounces (90. 7 grams) 4.8 ounces (136.1 grams) 8 ounces (226.8 grams) 5 gallons 0.8 ounce (22.7 grams) 1 . 6 ounces (45.4 grams) 2.4 ounces (68.0 grams) 4 ounces (113.4 grams) 3 gallons J'2 ounce (— ) (13.6 grams) 10 ounce (— ) (27.2 grams) 1.4 ounces (40.8 grams) 2.4 ounces (68.0 grams) 1 gallon 4 5 grams 9 1 grams 13.6 grams 22.7 grams 1 quart 1 . 1 grams 2.3 grams 3.4 grams 5 7 grams * Adapted and L. M. Sm from "Handbook of Agricultural Pest Control" by S. F. Bailey ith. Problem 6. (Using Table 6.) (a) The recommenda- tion called for a dilution of 1 part material to 600 parts of water. If 225 gals, of water per acre are to be used, how much material would be needed? (b) How much water and material would be needed for 1,000 sq. ft.? Solution, (a) (Using Table 6.) A dilution of 1 to 600 for 100 gals, is % qt. (1% pt.) and for 25 gals, is % pt. Two-hundred gals, would then be 2% pts. (1% pt. x 2 = 2% pts.) ; and by adding */& pt. for 25 gals, this equals 3 pts. (2% + y 3 - 3 pts.) which would be needed in the 225 gals, for 1 acre, (b) (Using Problem (a) results) — One- thousand sq. ft. is about Y\\ of an acre. Changing the 3 pts. to oz., this equals 48 oz. The amount of water needed per 1.000 sq. ft. would be 5.1 gals, or 5 gals., 13 oz. (225 -f- 44 = 5.1 gals. ) with about 1.1 oz. (48 oz. -f- 44 = about 1.1 oz.) of the liquid material. Problem 6. (Using Table 7.) (a) A recommen- dation calls for 2.75 pounds of material per 100 gals, of spray. How much would be needed for 15 gals.? (b) If 64 oz. of spray are needed in 100 gals, to cover Y2 acre, how much material would be needed and how many gallons of Table 6 EQUIVALENT QUANTITIES OF LIQUID MATERIALS FOR DILUTION IN PARTS OF WATER* Quantity of water Dilution (parts) in gallons 1 to 200 1 to 400 1 to 600 1 to 800 1 to 1000 1 to 1600 100 2 quarts 1 quart % quart 1 pint. IY2 cups 1 2 pint 25 1 pint 1 cup \4 pint Yi cup 614 tablespoons 4 tablespoons 5 614 tablespoons 314 tablespoons 6K teaspoons 5( — ) teaspoons %% teaspoons 2 1 ■> teaspoons 1 4 teaspoons (18.9 ml.) 2 teaspoons (9.5ml.) \\i teaspoons (6.3 ml.) 1 teaspoon (4.7 ml.) % teaspoon (3.8ml.) l 2 teaspoon (2.4 ml.) * Adapted from "Handbook of Agricultural Pest Control" by S. F. Bailey and L. M. Smith. [7] Table 7 AMOUNTS OF POWDERED MATERIAL (BY WEIGHT) NEEDED TO PREPARE DIFFERENT AMOUNTS OF SPRAY MIXTURE AT GIVEN DOSAGE LEVELS Recommended dosages Amount of powdered material needed to prepare: per 100 gallons 50 gallons 20 gallons 10 gallons 5 gallons 1 gallon lb. oz. gm. oz. gm. oz. gm. oz. gm . oz. gm. 02. gm. 0.25 4 113 1 56 0.8 23 0.4 11 20 6 0.04 1 0.50 8 227 4 113 1.6 45 8 23 0.40 11 0.08 2 1.00 16 454 8 227 3.2 91 16 45 0.80 23 0.16 5 1.50 24 681 12 340 4.8 136 2.4 68 1.20 34 0.24 7 2.00 32 908 16 454 6.4 182 3.2 91 1.60 45 0.32 9 3.00 48 1362 24 681 9.6 272 48 136 2.40 68 48 14 4.00 64 1816 32 908 12 8 363 6 4 182 3 20 91 0.64 18 5.00 80 2270 40 1135 16 454 8.0 227 4 00 113 0.80 23 spray for ^4 acre? (c) How much material and spray are needed for each 100 sq. ft. of Problem (b) ? Solution, (a) (Using Table 7.) — DOSAGES PER 100 GALLONS AMOUNT OF MATERIAL lb. 10 gals. 5 gals. 2.00 91 gm. or 3.2 oz. 45 gm. or 1.6 oz. = 136 gm .50 23 gm. or 0.8 oz. 11 gm. or 0.4 oz. = 34 gm .25 11 gm. or 0.4 oz. 6 gm. or 0.2 oz. = 17 gm 2.75 125 gm. or 4.4 oz. 62gm.or2.2oz. = 187 gm For 15 «als. of spray that calls for 2.75 lbs. of material per 100 gals, of spray, this would require 187 gm. or 6.6 oz. lb) (Using Table 7.) — If the 64 oz. in 100 gals, of water would cover Mi acre, then Y± acre is one-half of this ; so 50 gals, of spray with 32 oz. of materials are needed, (c) (Not using table) — One-half of an acre is 22,000 sq. ft., so 100 sq. ft. is j , L .,, of this (22,000 ~ 100 = 220) . For each 100 sq. ft. then, about .29 oz. (64 -f- 220 = 0.29 oz.) of material is needed. The water requirements would be .45 gals (100 gals. ^-220 = 0.45 gals.) or 57.6 oz. (128 x 0.45 = 57.6 oz.) for 100 sq. ft. How to measure the area to be treated Few. if any areas that need treating will be in nice, regular geometric designs. Practically all such areas will be irregular in shape and may even resemble something like i he area shown in blue at the top of column 2. While it would be difficult for anyone to measure an area like this to within one or two square feet, it is fairly simple to figure it closely enough for practical purposes. Chemicals arc expensive and it is well to avoid wasting them by measuring as accurately as you can. Probabl) the simplest way to measure an odd-shaped area like the one shown above is to reduce it to simple, geometrical figures, then work out the areas of these from the formulas given below. Sec bottom of column 2. Note- thai you have roughly a triangle, a rectangle, and a circle. If you drive small -take- into the ground at the points indicated l>\ letters it is easy to make the measure- ments needed. I'll' area <>i the triangle FDE can be arrived at with the formula base fline EF) multiplied bj altitude (line DD') 8] 40' x 15' = 600' divided by 2. or AB. In this case - 300' is the area of the triangle. Note that line DD' is drawn from point D so that it is perpendicular (at right angles) to line EF. It is easy to find a right angle with a very simple device you can make with a cord or rope. Use any convenient stick of wood; measure off three lengths of the stick on your cord and tie a knot at that point. Measure off four more lengths on the cord and tie another knot. Then measure off five lengths and either tie a knot or cut the cord (see diagram) . 5 lengths 3 lengths 4 lengths Bring the end you started measuring from over to the last knot you tied and hold these two points together. Pull the cord out, as shown in the diagram and the angle formed at the second knot you tied will be a right angle. (This trick is thought to have been known to the ancient Egyptians and it still works.) The area of the rectangle ABCD can be found by multi- plying the length (50') by the width (20') and comes out to 1,000 square feet. The remaining plot is almost a perfect circle so to find its area measure the radius (half of the diameter) and use the formula ttt 2 I radius times itself) where the symbol -n represents the number 3.14. Table 8 AMOUNTS OF LIQUID OR DRY MEASURE TO USE PER 100 SQUARE FEET WHEN RECOMMENDATION IS FOR POUNDS OR GALLONS PER ACRE Pounds or gallons recommended Quantity to use per 100 sq. ft. per acre Dry measure Liquid measure 50 100 200 :soo 400 500 Ounces v-> 7 1 ■> 11 14 :i 4 18', Tablespoons 7 14J4 22 29' , :i7 Example: The recommendation is for 200 pounds of a dry material per acre and you want to treat 350 square feet. Multiply 11 oz. by 3.5 = 38.5 oz. or 2 lbs. and 6.5 oz. Example: The recommendation is for 100 gallons of a liquid material per acre and you want to treat 300 square feet. Multiply 7 tablespoons by 3 = 21 tablespoons. In column 2, this page you will find that 1 tablespoon = l A a ounce so you may use one-half of 21 ounces, or 10J-S ounces. So this circle having a radius of 15' has an area 3.14 x 15 x 15 or 706.5 sq. ft. You could round that off to 700. Reduction from Amounts Per Acre to 100 Square Feet Areas Most directions on labels of chemicals are given in con- venient round numbers. To determine the exact calculations for your requirements use Table 8 and some simple arithmetic. MEASUREMENTS Linear Measure 1 inch (in.) — 2.54 centimeters (cm.) 12 inches = 1 foot (ft.) 3 feet = 1 yard (yd.) 5,280 feet = 1 land mile 1,760 yards =1 land mile NOTE: For extreme accuracy in measuring distance, a 50- or 100-foot steel tape is indispensable. However, in many cases distances can be paced off by walking and the resulting figures will be close enough for small areas. Most men of average height (5'8" to 5'10") will take a 30-inch (2%-foot) stride. Square Measure 144 square inches (sq. in.) = 1 square foot (sq. ft.) 9 square feet = ] square yard (sq. yd. ) 43,560 square feet = 1 acre ( 165 ft. x 264 ft.) (198 ft. x 220 ft.) (660 ft. x 66 ft.) 4,840 square yards = 1 acre 640 acres - 1 square mile Liquid Measure 1 fluid ounce (fl.oz. " 29.5' " cubic centimeters (cc.) 8 fluid ounces = 1 cup 2 cups = 1 pint (pt.) 16 fluid ounces = 1 pint 1 pint = 473 milliliters (ml.) 2 pints = 1 quart (qt.) 4 quarts = 1 gallon (gal.) fluid Dry W eight 28.4,grams =1 ounce (oz.) 454 grains =1 pound (lb.) 16 ounces = 1 pound 2,000 pounds = 1 ton * One cubic centimeter (cc.) is equivalent to one milliliter (ml.) Household Measure Where only reasonable accuracy is required. Where teaspoons, tablespoons and cups are used, they should be of the measuring type, not that for tableware use. 1 teaspoon (tsp.) =% fluid ounce 3 teaspoons = 1 tablespoon (tbs.) 1 tablespoon = % fluid ounce 1 teaspoon = 5 milliliters 1 tablespoon = 15 milliliters 16 tablespoons = 1 cup [9] WEED CONTROL in LARGE TURF AREAS Clyde L. Elmore and W. B. McHenry Turf quality depends largely upon one's point of refer- ence. Turf texture and color are usually the important characteristics — the more uniform the texture, the more pleasing the effect. Uniform texture, in addition to a deep green color, is a highly sought after feature of golf course and howling green turf because it influences the course traveled by the ball. This kind of turf quality requires intensive management to maintain. For economic reasons, management is less intensive in larger turf areas such as parks thus a mixture of plant species having less uniform texture results. In large areas a turf composed even of nearly all crabgrass has a uniform though coarse texture, and presents a pleasing over-all appearance. Irregular areas or patches of weeds in turf reduce the beauty and utility. Turf weeds recover from mowing more rapidly than the turfgrass, causing a rough texture in a matter of a few days. Annual bluegrass or ryegrass in the winter; tall fescue or buckhorn plantain in the summer, are examples of weeds that require frequent mowing to main- tain a uniform turf species. Weed problems can be reduced or in certain cases eliminated with treatments of herbicides prior to turf establishment. Preplant fumigation of a turf site can kill bermudagrass, nutsedge, other perennials as well as all existing annual plants and many seeds. Management practices Weedy turf often results from a breakdown somewhere in the management program. Over or underwatering, mow- ing too short, low fertility, excessive wear, diseases, insects, soil compaction, excessive shade; all of these allow weeds to invade turf. Any condition tbat exposes the soil surface to additional light tips the competitive balance in favor of invading weeds. Mismanagement may include frequent, relatively light irrigations that encourage germination of seeds of annual shallow-rooted weeds such as crabgrass and annual blue- grass. It discourages deep rooting of the turf and weakens its resistance to invasion. Mowing Kentucky bluegrass turf short (below IV2 inches) weakens this turf species and encourages weed growth. Soil that is wet for long periods of time, often resulting from poor drainage, favors red -oriel and annual bluegrass. When weeds have resulted from poor management, A GLOSSARY . . . of terms used not only in this manual, but by pro- fessional turfgrass operators generally, appears on page 48. herbicides can be introduced as a management tool to pro- vide a decisive and rapid means of swinging the weed-grass- competition in favor of the turf species. However, unless deficient management practices which encouraged weed invasion are remedied, weeds will again encroach. Herbi- cides become an important tool in turf management where high-quality turf is desired. Characteristics and habits of weeds A weed is a plant growing where its presence is objection- able. Dichondra, a highly prized turf, may be considered an unwelcome intruder, hence a weed in grass turf. Tall fescue is well suited as turf for areas receiving high wear, such as play fields, but when it appears as clumps in Kentucky blue- grass or bermudagrass turf, uniform texture is destroyed and it becomes a weed. Occasionally the terms grasses and weeds are used as two kinds of weeds, but this is unneces- sary. Whether a plant is a grass or broadleaf, if it is out of place and objectionable it is a weed. There are about 500 species of weeds in California; the great majority of them are flowering plants, the higher forms of plant life that produce seed. Most of the plants of great economic importance to mankind including wheat, corn, cotton, bluegrass and soybeans are seed-producing plants. Botanists recognize two natural divisions called the monocotyledonae and the dicotyledonae, or more briefly the monocots and the dicots. A familiarity with these plant groups is important to anyone conducting weed control programs.* Since there are only the two plant groups the * Assistance with weed species identification may be obtained at the local county office of the University of California Farm and Home Advisors Office, or Agricultural Commissioners Office. Local nurserymen are usually acquainted with common weeds in the area. NAKROWLEAF PLANT (MOMOCOTVUPON s a) Method of propagation Z£%55 >XX >55 X£ 55* >55 XX Bentgrass — Agrostis spp. P b,bt ■ Dallisgrass — Paspalum dilatatum P S,R ■ ■■ XX 55 X Cutleaf geranium — Geranium dissectum A S «6& 555 !XX >55 Postrate knotweed — Polygonum aviculare A S III III IO XX ?xx « XX c*x Dichondra — Dichondra rcpens P S.Sl «fc XX «x £# XX $xx as 552 $55 >9 Dandelion — Taraxacum officinale P,B S « 5?X #5 55? S55; 556 JXX 55 XX 5^X >55 »C White clover — T ri folium repens P S «* XX «x XS sxx «« 55* KS X52 55J California hurclover — Medicago polymorpha A S II mi 119 55< XX 55* >55 XX5 a Black medic — Medicago lupulina A.P S X >65 XX Growth Method of ?| g^^g^wHS g g type propagation -^ i£ 3* < 3; -^ -^ < OZQ Pennywort — Hydrocotyle umbellata P S.Rs *x *x>< »C «*: < >x «w ("VV Wvvy vSft Curly dock — Rumex crispus P S 5*S XX 5« XX> »< »00 Buckhorn plantain — Plantago lanceolata P S XX 55 XX 55* W XX> XX 5 55* >56 XX 55< XX5 55* »& Soliva — Soliva sessilis A S 55* >5*s x» 55* ^X>< XX -XX » Spotted spurge — Euphorbia maculata A S III lie XX ><» XX «X 55* XX 5X Spotted catsear — Hypochoeris radicata P S Healall — Prunella vulgaris P S,Rs ■■ 552 5X S55 55* >55 5*X XX S$ Henbit — Lamium ample xicaule A S Field madder — Sherardia arvensis A S Yarrow — Achillea millefolium P S.Rs ■■ 5*X 5$ XX5 55* ■■ MM Southern Brass buttons — Cotula australis A S Wartcress — Coronopus didymus A S Prickly lettuce — Lactuca scariola A S » Cudweed — Gnaphalium chilense A.B S inn >X *> XX fV, ^Ofc "v- T \ SCARLET PIMPERNEL Anagallis arvensis L. Annual; low growing, branched with 4-angled stems. Leaves op- posite or in whorls of three. Flowers are salmon colored about 1 /4- 1 /3 inch in diameter, opening only under a clear sky. BROADLEAF PLANTAIN Plantago major L. Perennial; leaves large 3-6 inches long, smooth. Conspicuous flower stalks 3-6 inches in length. Roots fibrous and shallow. May be dis- tinguished from buckhorn plantain by the broader leaf and shorter flower stalks. BUCKHORN PLANTAIN Plantago lanceolata L. Perennial; long narrow leaves with parallel veins, 3-12 inches in length, slightly hairy, brownish hairs surround the base of leaves. Growth habit similar to broadleaf plantain. Long seed stalks, much longer than leaves. BIRDSEYE PEARLWORT Saginu procumbent L. Perennial; stems prostrate forming mats, rooting at the nodes, found in coastal areas. Looks like moss. 24 CHICKWEED Stellaria media (L.) Vill. Annual; slender much branched stems with a line of white hairs along on one side. Leaves smooth and pointed. Grows in cool weather or in winter in sheltered area. CURLY DOCK Rumex crispus L. Perennial; growing from a large brownish taproot. Normally found as a rosette in turf but will attain a height of 2 to 3 feet. Leaves are large, reddish-green in color, curly and wavy along the margins. RED SORREL (SHEEP SORREL) Rumex acetosella L. Perennial; similar to curly dock, leaves are arrow shaped. Roots are a slender running rootstock, reddish in color. PENNYWORT Hydrocotyle umbellata L. Perennial; creeping, rooting at nodes of slender rootstocks. Trouble- some in southern California. Round leaves approximately V2 inch in diameter with wavy margin. Can be distinguished from dichondra by wavy leaf margins. [25] BIRDSEYE SPEEDWELL (BYZANTINE SPEEDWELL) Veronica persica Poir. Annual; stems 4" to 16" tall, leaves roundish or oval. Small deep blue flower with white center on stalks %" to 1" long. Plants covered with hairs. ENGLISH DAISY Bellis perennis L. Perennial ; low growing, with oval basal leaves. Prominent upright flower stalks throughout season with showy white or pinkish daisy- like flowers. FIELD BINDWEED Convolvulus arvensis L. Perennial; deep rooted, prostrate or twining stems with arrow shaped leaves. Flowers conspicuous white or pink. Plant can take many forms and shapes. SOLIVA Soliva sessUis R.&P. Annual; small plant with dissected leaves. Foliage covered with fine hairs. When seed has formed it appears as a small 3-spined bur which can bo readily felt when pressing a clump with your hand. r 26] SPOTTED SPURGE Euphorbia macula ta L. Annual; grows prostrate on ground, stems forming circular mats from single taproot, non-rooting at the nodes; aggressive — milky sap in leaves — may be green or reddish but easily identified by red spot on upper center of leaflet. PROSTRATE KNOTWEED Polygonum aviculare L. Annual; grows prostrate forming circular mats; found in hard worn turf areas of high traffic, slender wiry stems, non-rooting, at the nodes, leaves bluish-green and smooth, no purple spotting as found on spotted spurge; white inconspicuous flowers. MOUSEEAR CHICKWEED Cerastium vidgatum L. Perennial; sticky-hairy leaves and stems, leaves rounded on end; prostrate, forming dense patches. Small white inconspicuous flowers. SPOTTED CATSEAR HAIRY CATSEAR Hypochoeris radicata L. Perennial; with thick fleshy taproot, normally found as a rosette in turf. Leaves lobed or saw-toothed with coarse yellow hairs on both upper and lower surfaces. Flower yellow, may have several flowers from each stem. [27] HEALALL (selfheal) Prunella vulgaris L. Perennial; gray, hairy or smooth green plant, with spreading root- stocks. Usually found in patches. Also a silvery, hairy form. HENBIT Lamium amplexicaule L. Annual; several upright 4-angled stems that root at the lower nodes, rounded coarsely toothed leaves are whorled up the stem. Irregular purple flower, the lower lips of the flower spotted. Difficult to control. SOUTHERN BRASS BUTTONS (AUSTRALIAN BRASS BUTTONS) Cotula australis (Sieber) Hook. f. Annual; strong scented, low growing. Looks similar to soliva or wart-cress. Has small, yellow flowers, leaves deeply toothed and covered with fine hairs. FIELD MADDER Shcrardia arvensis L. Annual; with slender, square, hairy stems. Low growing, forming mats. Leaves in whorls, strong odor. Flowers small, blue, pinkish in clumps at ends of the stems. r 28 COMMON YARROW Achillea millefolium L. Perennial; plants hairy, with spreading rootstocks. Leaves somewhat like a carrot. Flowers white or yellow in dense flat clusters at the end of stems. Flowers are not normally found in turf. CARPET WEED Mollugo verticillataL. Annual, with whorls of leaves on many branched stems 4 to 6 inches in length. Mat forming. Leaves about V2 inc h long with 5 to 6 in a whorl around the stem. Inconspicuous white flowers on short stalk at each joint of the stem appearing in May to November. Somewhat similar to four-leaved all-seed. WART- CRESS Coronopus didymus (L. ) Sm. Annual; low growing, strong smelling, looks very similar to Soliva. Seeds are borne in two lobed wrinkled pods. LOW AMARANTH Amaranthus deflexus A low, prostrate annual with the end of the stem turning upward. Stems l-l 1 /^ iee t long. Leaves short petioled, oval, Vi to 1 inch long and about V2 inch broad. Flowers inconspicuous, in dense clusters at the ends of the stem, appearing from May to November. Another pigweed, prostrate pigweed, is very similar except it forms a small dense mat. [29 WHITESTEM FILAREE Erodium moschatum (L.) L'Her Annual; with leaves forming a low rosette. Stems generally whitish, leaves up to 10 inches in length with several toothed leaflets. Flowers small purple-bluish. Seed pods form a storksbill. BRISTLY MALLOW Modiola caroliniana (L.) G. Don. A low perennial, with spreading stems, 6—18 inches long. Leaves round with coarse-cut margins 1 to 1% inches across, may look similar to cut-leaved geranium. Flowers dull red, round, less than y% inch in size in summer. May be found almost throughout Cali- fornia. BRISTLY OXTONGUE Picris echioides L. A coarse, rough biennial, 4 to 6 inches tall in turf. Leaves 2 to 6 inches in length, ^2 to 1% inches wide, rough-hairy on upper and lower surfaces. Flower heads yellow about V2 bich broad occurring in clusters near the top of the stem. Flowers appear from June to December. COTTON BATTING PLANT ( CUDWEED) Gnaphalium cliilcnse Spreng. Annual or biennial; white silk-hairy plant; leaves long, narrow, rounded at tip on base and more pointed at top of plant. Small in- conspicuous flowers in clusters. I 30 INSECT and RELATED PESTS of TURFGRASS Andrew S. Deal, R. N. Jefferson, and F. S. Morishita This section tells how to identify insects and related pests, either by inspection of the pest or the damage it causes, and gives recommendations for the types of treatment that should be applied. Because the information on chemicals to use changes very rapidly, actual recommendations for chemicals should be obtained from the leaflet "Guide to Turfgrass Pest Control." revised annually and available at the office of your local University of California Farm Advisor. Make regular inspections Regular inspections of lawn areas are very important if injury from insect pests is to be avoided. Insects may cause such disorders as die-back, stunting or distortion of growth, browning, yellowing, or bleaching of leaves. If such symp- toms are noted, action should be taken rapidly because insect populations can build up in a very short period of time if conditions are right. Some pests feed only at night and unless a special effort is made to look for them they may go undetected for some time. Identifying the trouble Some of the symptoms of trouble discussed above may be caused by disease, unfavorable soil conditions, or poor cultural practices, and these possibilities should be inves- tigated before pest control measures are taken. In fact, the first line of defense against turfgrass pests is a program of good cultural practices; poorly kept turf shows pest injury sooner and recovers more slowly than vigorous, well-kept turf. Regular thatch removal and aeration discourages in- sect pests and aids in penetration with sprays if and when treatment is needed. One method used in detecting the presence of insect pests of lawns is the "pyrethrum test." Mix one tablespoon of one of the commercial garden insecticides containing 1 to 2 per cent pyrethrins in one gallon of water. Mark off one square yard of lawn area, including some damaged and some undamaged grass, and apply the entire gallon of mix- ture as evenly as possible to that area with a sprinkling can. Pyrethrum is very irritating to many insects and will bring them to the surface within ten minutes where they may be seen. Insects which may be detected in this way are cutworms, sod webworms, lucerne moth larvae, skipper larvae, and vegetable weevil larvae. White grubs or the larvae of billbugs will not respond to the pyrethrum test, but may be found, if present, by carefully digging around the roots of the grass. In heavy infestations the grass roots will be eaten away and the grass can be rolled back like a carpet. If an average of more than five cutworms, 10 skipper larvae or 15 sod webworms per square yard, or more than one white grub or billbug larva per square foot of established lawn area are found, control measures should be taken. Leafhoppers, scale insects, leaf bugs, spider mites, and flea beetles can be found, if present, by carefully examining the leaves, stems and crowns of the grasses or dichondra. In large lawn areas, such as parks, golf courses and me- morial parks, the pyrethrum test or other inspections for pests should be made at several locations in order to deter- mine the extent of the infestation. In some cases the prob- lem may be localized and treatment of the entire area may not be necessary. Accurate identification of insects in lawns is important because many insects may be found that are not pests at all, and thus control measures will not be necessary. Also, different pests require different chemical treatments and application methods, for effective control. Application of insecticides Lawns to be treated to control most pests that feed on the leaves, stems, and crowns of the plants should first be irrigated well. As soon as the plants have dried the insecti- cide should be applied and further irrigation withheld until necessary to prevent wilting. This allows the insecti- cide to remain on the plants for the longest possible period and thus increases the effectiveness of the treatment. When lawns are to be treated for pests that feed below ground on the roots, such as white grubs, or the larvae of billbugs, the treatment should be applied and then followed with a heavy irrigation to carry the insecticide into the soil. Do not apply insecticides to dichondra needing water or when the temperature is above 90°F, In general, sprays are preferred to other methods of ap- plication for the control of turfgrass and dichondra pests. Granular formulations are also suitable for control of white grubs, billbugs, chinch bugs, cutworms, skipper larvae, sod webworms, and slugs and snails. Most of the insecticide dosages given in the "Guide" refer to the amount of active ingredient needed per 1000 square feet of lawn area. This can be applied in any con- venient amount of water provided enough is used to thor- oughly wet the grass or dichondra down to the ground. Most operators use about 20 gallons of spray per 1000 square feet. For control of spider mites greater volume may be required and the dosage is given in terms of the amount of formulated material per 100 gallons of diluted spray. (See section on calculations.) [31] ZL > 3 fc x ^ CO _S (9 -o - X H s ■ - — 3 sj ca x - j; -o r x o j: - i > a 3 PhS £.£ CO t- o J3 — a *^ -. - — - o B ai U o r - — ti. at ■O -3 - o a - X tf p — o • "?£.*. o .3. ~ u b 3 u e o s 2 '5 g a 8 S S .1 a M en _ eu — . t. eg a. H en - « c > ♦; u2 3 § g - CO c B -a "3 - X! £• ix.2 < Co™ (8 « B es ^ 3 .2 b w x O >- Q ,U C u -o CO ft c o ua sses. 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CQ Q SC K U u- Z Q O w Oh W > (-( 2 H U < H W < CO W cc fc* H 4) T3 O >- .§ g s * a. l. o o -C~ >. c o E (D O o -a o o 0) la E -„ O a> ■£ o C 'i/l •- >. £ a -si 1j a 0) o D o a wi n a D r o - a n> -C o D a — J £ | •a •- -a ■- a a> V fli *- Si i> » u Si j, 4> a ••= c a> a> >- > D 0) j2 a o ^ a £ "c a t- o o I 36 | Lawn moth larva Lawn moth adult Flea beetle damage to dichondra (leaves greatly enlarged) Frit fly adults (millimeter scale in background) Billbug pupa (left) and legless larvae Billbug injury to turf (trowel shows comparative size) Legless larva of vegetable weevil Adult vegetable weevil [37] NEMATODE DISEASES ofTURFGRASS John D. Radewald Disease is one of the most limiting factors in turfgrass production in California. A plant disease is defined as "a continuous abnormality which in some way interferes with structure, function, or economic value of a plant." Many parasitic and nonparasitic agents may cause plant diseases. A parasite is a living organism that obtains its food from another living organism. A parasite is not necessarily a pathogen (a cause of disease). The recognized parasites that may cause plant diseases are: higher plants (mistletoe, dodder, broomrape), insects, nematodes, fungi, bacteria, and viruses. Frequently two or more pathogens act simultaneously on a plant and are re- ferred to as "disease complexes." The association or finding of any one of these potential parasitic disease-causing organisms, including nematodes, with the root system of a given turf plant does not prove that the turf is diseased and the nematode is the pathogen. The only thing that is proven by these associations is that a possible turf disease does, or eventually may, occur, de- pending upon the host, the parasite I in this case, the nema- Intesti Adull Femole Nematode (actual length of Nematode is 1 30 inch) Enlargement of Head Enlargement of Male Tall tode), and environment. "Guilt by association" means find- ing nematodes in soil around the roots of a turf plant and immediately concluding they are causing a turf disease. Whether the nematode is causing a disease or not must be proven by reliable methods of experimentation. Only when this experimental proof is obtained does proof of patho- genicity of the nematode on the turf exist. Nematological research on turfgrass has produced a large number of reports from the United States and other parts of the world on nematode associations with roots of turf species. These reports are of value as they establish a basis on which more detailed work may establish the true importance of a given nematode on a given turfgrass species. Unfortunately, only a very few associations be- tween a nematode and a specific turfgrass have been studied in enough detail to actually prove that a nematode does cause a disease to a given turf species. Some species of nematodes are injurious to turf in other parts of the Tjnited States but these nematodes are not known to occur on turf in California. Therefore, the turf grower in Cali- fornia has little information on which to base a decision with regards to a nematode control program. However, investigations on this problem are underway. What is a nematode? Nematodes are roundworms, sometimes called eelworms. or nemas. Most plant-parasitic nematodes are microscopic in size and can only be identified by a trained technician with the aid of specialized equipment. A nematode feeds by inserting the hollow spear (stylet) into the plant cells and sucks out the cellular contents. Some nematodes inject substances into the plant before they feed. The esophagus contains a pumping mechanism that aids in the ingestion of plant cell contents, and glands that pro- duce digestive materials. The gut is a simple tube that terminates at the anus. A nematode feeds by inserting the hollow spear (stylet) into the plant cells and withdraws the cellular contents. Some nematodes inject substances into the plant before I hey feed. The esophagus contains a median bulb that aids in the ingestion of plant cell contents, and glands that pro- duce digestive materials. The gut is a simple tube that terminates at the anus. The female nematode lays eggs either singly or in egg masses, depending on the species. A single female of some nematodes may lay 500 eggs or more. Plant-parasitic nematodes, being obligate parasites, can complete their life cycles when the roots or oilier portions of a susceptible host planl arc present for them to feed upon. The life histories, feeding habits, and methods of repro- duction of nematodes vary. Some nematodes are migratory [ 38 Life histories of nematode parasites of turf: A — Dagger nematode; B — Ring nematode; C — Stubby root nematode; D — Lesion nematode; E — Cyst nematode; F — Reniform nematode; G — Root-knot nematode. and feed strictly from the outside of the plant tissues (ecto- parasites! . They deposit their eggs singly in the soil. Other nematodes, such as the lesion nematode, are migratory and feed with their bodies situated either outside the root tissues or within the roots, and deposit their eggs singly in the soil or within the root. Still other nematodes only migrate as young and become sedentary as adults. Their bodies may be located exterior to the root, partially embedded within the root, or completely embedded. These nematodes lay their eggs in egg masses in the soil. The eggs are surrounded by a gelatinous matrix. The egg mass of the root-knot nema- tode may be found within the root tissue with the adult female or protruding from the root tissue into the soil. The female cyst nematode usually does not deposit her eggs outside the body wall, but retains them within her body. When the female dies, the body wall forms a leathery cyst that protects the eggs from adverse environmental condi- tions until they hatch. The location of the nematode, and its eggs, or young (i.e., within the root, or outside the root in the soil) is important when considering the application of a chemical to control nematodes on established turf. Nematodes and eggs located within the root tissues are protected from ex- posure to the chemicals that are drenched or injected into the soil and unless the nematocide is a systemic one, eggs and animals located within the root tissues will escape. Nematode larvae shed their skins (molt) four times. After the last molt, the nematode is an adult. It varies in shape from the typical worm to the spherical female. The time required for nematodes to complete a life cycle, from egg to adult, varies. Under optimum conditions most plant- parasitic nematodes complete this cycle in from 3 to 6 weeks. The life cycle may be extended to several months during periods of high or low temperatures, drought, and where poor hosts exist. Parts of turf plants attacked Nematodes are known to attack and damage most of the parts of turf plants. Some nematodes destroy the seed, others attack the stems and leaves. The most frequently- attacked portions of turf plants are the roots. There are no aboveground symptoms which are completely diagnostic [39] Leaf galls on Poa annua incited by Angnina sp. The root-knot nematode (Meloidogyne naasi) on Seaside bent grass. Lower — microphoto of root-knot female after the root tissues have been cut away from her body but with the head still located in the vascular region of the root. for nematode damage to turf roots. Nematode-diseased plants may appear stunted, chlorotic (yellowed), and gen- erally unthrifty. They also may wilt prematurely during the warmer periods of the day due to the lack of an ade- quate root system to supply the plant with water. The symp- toms on the roots vary, depending upon the nematode species. The most easily recognized nematode symptom on roots are the galls caused by the root-knot nematode. These swellings or galls are visible to the naked eye. The root-knot nematode is of great economic importance in California to vegetable, field, and deciduous crops, and is commonly found on dichondra (figure 5). In 1965, a new root-knot species, Meloidogyne naasi, was described. This nematode, found in two areas in California, is a proven pathogen of turfgrasses. Contrary to most root-knot species, M. naasi seems to prefer grasses to other hosts. The lesion nematode. Pratylenchus sp., is often found associated with turfgrasses, but we have no proof that it is pathogenic to turfgrasses in California. On other hosts the symptoms are root lesions of variable sizes and shapes. Other nematodes, such as the stubby root nematode, attack only the growing root tips and stop their elongation. These root tips may appear swollen, discolored, or both, and growth of lateral roots is pronounced on some hosts. This nematode is commonly found around turf roots, but its importance on turf species in California is questionable. Other nematodes commonly found in association with turf- grasses in California include the ring nematode (Cricone- moides sp.), the dagger nematode (Xiphinema sp.) and the pin nematode (Paratylenchus sp.). Their detrimental effects to turf have not been studied in enough detail to determine their economic importance to California turf species. Detecting plant-parasitic nematodes The only way to detect a potential nematode disease of turf roots is by proper processing of soil and root samples. A sample should consist of several soil cores, an inch or two in diameter and 6 to 8 inches in depth, taken in the area where the suspected nematode problem exists. Sub- mit the turf roots with the soil. Place all soil cores from the suspected disease area in a single plastic bag and seal to prevent drying. Take similar samples in adjacent turf areas that appear normal, so that a comparison of nematodes found in the two areas can be made. Label the bags con- taining the samples so that the identity of each individual sample can be maintained. Keep the samples cool and transport them to a diagnostic lahoralory as soon as pos- sible, preferably the same day the samples are taken. Re- member that samples should be kept, cool and not allowed to dry as most nematodes are extremely sensitive to high temperatures and drying. Your local farm advisor can give you a list of commercial laboratories in California thai provide nematode detection and identification service. These laboratories will usually provide a quantitative measure of the plant parasitic genera in each -ample submitted. I l<) I Control The potential methods for control of plant-pathogenic nematodes that may affect turfgrasses are similar to those used for the control of these pests on most other crops. Quarantine. Nematodes move very slowly in soil, pos- sibly only a foot or two per year under their own power. Man is the major disseminator of nematodes. In a turf nursery or landscaped area, nematodes are easily spread by cultivation, watering operations, and transfer of con- taminated plants within the landscape area. The first pre- caution, therefore, is to avoid introducing nematodes into areas that are free of plant-parasitic nematodes. The turf grower may employ a "self-imposed" quarantine to avoid introducing nematode-infested soil of rootings into areas free of the pest. This self-imposed quarantine by the turf grower, landscape gardener, or homeowner is the simplest and most economical means of controlling potential nema- tode problems, providing the land is free of the pest. Preplant control measures. If barren soil in which a turf nursery is to be established, or soil around a newly constructed home, is found infested with nematodes known to be pathogenic to turf, a preplant nematode control pro- gram may be used. The compounds listed in Leaflet 209 will control nematodes, and some will control other poten- tial pests, including weeds, fungi, bacteria, and insects. When considering the large investment required for estab- lishing a turfgrass nursery or turf around a home, it is apparent that the most practical approach would be to control all potential pests possible before the desired plant species are introduced, even though the initial cost may be higher. The labor costs for weeding alone, as an ex- ample, in a newly established turfgrass nursery or home lawn can easily offset the initial costs of a broad spectrum biocide such as those listed in Leaflet 209. If nematodes are the only concern of the grower, a specific nematocide may be used for a lesser cost than that of the broad spec- trum biocides. The root-knot nematode (M. incognita) on dichondra. Postplant control measures Some states make postplant recommendations for the control of various nematode diseases of turf. However, re- search data in California is not complete and no University recommendations can be made for postplant turf treatments for nematode control. If nematodes are detected in an established turf and the grower wishes to attempt a post- plant control program, small areas may be treated with registered chemicals and compared with nontreated areas for plant response and actual nematode control. The local Farm Advisor, the Extension nematology specialists, and Experiment Station nematologists can suggest compounds for control measures and provide assistance in evaluating the experimental treatments. [41] DISEASES of TURFGRASS Arthur H. McCain, Robert M. Endo, and Robert D. Raabe Most of the serious diseases of turfgrass in California result from infection by microscopic fungi. Fungi are low forms of plant life which are threadlike and are incapable of manufacturing their own food but live off dead or living plant or animal matter. Most fungi produce spores (seed- like units) or other resistant forms, e.g., sclerotia, which may be spread by wind, water, mechanically as by mowers, or infected plant material such as grass clippings. Spores, sclerotia. and threads require moisture and a favorable temperature to form new threads which grow over the surfaces of the plant or in it and cause infection. Because of this, diseases of grasses are most common dur- ing rainy seasons, or when irrigation moisture remains on the leaves for long periods. Watering during early morning is better than late evening watering; deep, infrequent watering is better than shallow frequent watering. Some diseases are favored by warm temperatures while others are destructive during the cooler months of the year. Most diseases of turf grasses are easier to prevent than to cure. To minimize the possibility of disease, plant the right kinds of grasses for the particular climatic zone; weakened, nonadapted grasses are susceptible to certain turf-attacking fungi, and to such stresses as drought and hot. dry winds. Recommended cultural practices such as mowing, ferti- lization, irrigation, aerification, etc., will help prevent dis- eases by mantaining a vigorously growing turf. A properly maintained turf generally is less severely damaged by dis- eases and is able to make a quicker recovery than one which is poorly maintained. One cultural practice that is closely tied to disease pre- vention is fertilization — specfically the amount of nitrogen applied. Too much nitrogen can result in soft, lush growth of the grass — a condition favorable to some diseases. On the other hand, turf that does not have enough nitrogen applied to it will be susceptible to certain other diseases. When disease control cannot be obtained by cultural methods, certain funpicides are effective and their use is recommended. Fungicides are usually most effective if ap- plied before the disease becomes severe. If a disease does become severe it generally requires a higher rate and more frequent fungicide applications. Ever) year new and frequently improved products are made available, Therefore specific fungicides are not men- tioned here. Recommendations for chemical control of spe- cific turfgrass diseases can be obtained from the University of California Farm Advisor in your area. Ask for Leaflet 209. Brown patch Symptoms. Areas of turf affected with brown patch consist of irregular brown areas which may range from several inches to many feet in diameter. Centers of the spots may recover, resulting in rings of diseased grass. Leaves and leaf sheaths turn olive-green, wilt, become light brown, and die. Stems, crowns, and roots also may be infected. In light attacks, roots and crowns usually are not involved and plants recover. All lawn grasses are suscep- tible. Cause. Brown patch is caused by the soil-inhabiting fungus, Rhizoctonia solani and other Rhizoctonia species. The fungi are active as fine threads (hyphae) that survive in the soil or in and on the turf. Resting structures (sclero- tia) composed of hard masses of fungus threads are resist- ant to adverse conditions and difficult to control with fungi- cides. The disease is favored by excess thatch and mat, high temperatures, (75 to 90°F) high humidity, and soft, lush growth due to excess nitrogen. Disease in the summer months is more common in warm, inland areas. A cold- weather (40 to 60°F) form of the disease occurs infre- quently. Control. Reduce shading and improve soil aeration and water drainage. Water when needed to a depth of 4 to 6 inches if possible. Check this with a soil probe since water may not be penetrating due to excess turf debris, unfavor- able soil type, or to too rapid application of water. Avoid excessive nitrogen fertilization that results in soft growth foliage. Fungicides are more effective when used in preventive applications but also will stop the disease in progress. Dollar spot Symptoms. Small, circular areas of turf about 2 inches in diameter are affected. Spots may merge to form large, irregular areas. Leaves are water-soaked at first, later turn brown and finally straw-colored. Fine, white, cobwebby fungus threads which may be seen in early morning are responsible for spread. Cause. Sclerotinia Iwmeocarpa, a fungus which survives in the soil by means of sclerotia, is the causal agent. Disease is common near or on the coast, especially on bentgrass. Moderate temperatures, (60 to 80°F) and excess mois- ture, excess mat and thatch favor dollar spot. Turf deficient in nitrogen lends to develop more dollar spot than turf adequately fertilized. [42] Brown patch. Pencil for comparison of size Dollar spot. Silver dollar for size Fusarium patch in bentgrass Melting out on Kentucky bluegrass Closeup of red thread Rust spores on grass blades Stripe smut on bluegrass Typical symptoms of fairy ring [43] Control. Keep thatch at a minimum. Water only when needed to a depth of 4 to 6 inches. Apply adequate nitro- gen. It is usually necessary to use fungicides to control this disease, especially on closely clipped grass. The fungicides are most effective if applied prior to disease development in the early spring and fall. Fusarium patch Symptoms This disease appears as roughly circular, dead patches of 1 to 2 inches, up to 12 inches in diameter. Leaves first become water-soaked, turn reddish-brown, then bleached. Minute, white or pinkish, gelatinous spore masses occasionally are seen on dead leaves. Fungus threads, also white or pinkish, may be seen in early morn- ing. The disease is common on Poa annua and bluegrass. Ryegrass, bentgrasses and fescues are also susceptible. Cause. The fungus. Fusarium nivale, probably survives the hot dry summer months as resistant hyphae. Cool, (32 to 60°F) moist conditions, such as prolonged rainy periods in winter, favor the disease, which usually appears first on shaded plants. The disease is common in northern and central Cali- fornia in winter but is rare in southern California. Control. Reduce shade, improve soil aeration and water drainage. Avoid excess nitrogen fertilization especially in the fall of the year. Mercury-containing fungicides are effective but must be applied in the fall prior to the occurrence of symptoms. Melting out (on bluegrass) Symptoms. Circular to elongate, purplish or brownish spots with straw-colored or brown centers occur on leaf blades, leaf sheaths, and stems. Leaf spots are general, indicating spread by wind-borne spores. Crown and roots frequently are attacked. Crown-infected plants are weak- ened and frequently die if irrigated during hot, dry, windy weather, resulting in a thinning-out of the turf in scattered areas. Although common Kentucky bluegrass is very suscep- tible, there are a number of improved varieties that are resistant. Cause. Melting mil i- caused by flelminthosporium i agans which probably survives in infected plants or debris as fungus threads and a- spores. It also may be seed-borne. Cool, (50 to 70°F). moist conditions favor the disease which first appears on shaded plants and is most severe on closely-clipped turf. This disease is common in the wel winter month-, especially iii coastal northern and central ( lalfoi nia. Control. Reduce -hade, improve soil aeration and water drainage. Do not mow grass lower than I ' •_• inches. Sev- eral fungicides are helpful in controlling melting out if applied when the disease firsl appears. It is important to r< 'Im< i i rown infections which are responsible for the death of plants Melting out (on other than bluegrass) Melting out of bentgrasses, fescues, ryegrass, and ber- mudas is caused by H. sorokinianum. The symptoms are similar to melting out caused by H. vagans, except leaf spots usually show brown rather than straw-colored centers, and borders of spots are purplish to dark brown. Warm temperatures (70 to 90°F), dew, and high hu- midity favor the disease which first appears on plants growing in shaded areas. It is most damaging on closely clipped turf, especially in the spring and summer in south- ern California. Plants die of crown infection, usually dur- ing hot, dry, windy weather. Control is the same as for //. vagans. Mow grass at recommended heights. Leaf blotch (bermudagrasses) Symptoms. Tiny, purplish to reddish spots occur on leaf blades and leaf sheaths. Seedlings are very suscep- tible but plants rapidly become resistant. Affected seed- lings wither, turn brown and die. Roots and crown may develop small lesions. Only bermudagrasses are susceptible. Cause. The fungus //. cynodontis is similar to H. vagans and H. sorokinianum. It probably survives in infected bermudagrass plants and debris as hyphae and as spores, though it may be seedborne. Control. Leaf blotch damages young seedlings or adult plants that have been weakened by excess thatch, deficient nitrogen, and unfavorable growing conditions. Remove thatch at regular intervals. Apply adequate nitrogen. Loose smut Symptoms. In this disease of common bermudagrass, the flower heads are replaced by masses of dark spores. Cause. The fungus, Ustilago cynodontis, remains in in- fected plants the year around. Spores infect germinating seeds and young stolons but show symptoms principally at flowering. The disease is most prevalent in warm weather and under conditions that promote flowering. Control. Keep grass growing vigorously and remove flower heads by mowing before spores are produced. Because fungus spores may cling to seeds or occur in soil, seed treatment with suitable fungicides will prevent in- fection from seed-borne or soil-borne spores. Stripe smut Symptoms. Infected plants are often pale green and stunted, and long black stripes consisting of spore pustules of the fungus occur in the leaves. Infected leaves curl, be- come shredded, and die. The disease is favored by moderate temperatures and is prevalent in the spring and fall. Infected plants may die in hot, dry weather. Although common on some blue- grass varieties, bentgrasses also are susceptible. Cause. Spores of Ustilago striiformis from the leaves frequently contaminate the seed; germinating spores may infeel seedlings and young tillers. The fungus stays in the diseased plants from year lo year. II Control. Some resistant bluegrass varieties have been developed. Seed treatment with selected fungicides will con- trol the seed-borne phase. A systemic fungicide is available. Red thread Symptoms. Turf is usually affected in patches 2 to 15 inches in diameter, but the disease may be general over large areas. Pink webs of fungal threads bind leaves to- gether and pink, gelatinous fungal crusts, ^4- to %-inch long, projecting from leaves may be seen. Plants usually are not killed. Bentgrasses. bluegrasses, fescues and ryegrasses are sus- ceptible. Cause. Red thread is caused by Corticium fiwiforme which overseasons as pink or red. gelatinous crusts of fun- gal threads. Disease occurs commonly along the coast of northern and central California; is rare in southern California. Red thread usually appears on plants deficient in nitro- gen, and during periods of prolonged cool, wet weather. Control. Apply adequate nitrogen and reduce shading. Fungicides, especially those containing cadmium, if ap- plied at the earliest stages of the disease will prevent fur- ther development. Grease spot The turf is killed in small roughly circular spots (2-6 inches) which tend to run together. Blackened leaf blades wither rapidly and turn reddish-brown. Leaf blades tend to lie flat, stick together, and appear greasy. Roots may be stunted and brown, especially the tips. All turf grasses are subject to attack by the fungi that cause grease spot. Cause. The fungi that cause grease spot are called water molds because excess free water, which is essential for their development, also may weaken the plants, favor- ing severe disease development. Several species of Pythium may be involved, especially P. aphanidermatum. The causal fungi produce thick-walled, sexual spores which survive for long periods in the soil. Because the fungus depends on excessive free moisture, grease spot usually appears in low spots that remain wet. P. aphanidermatum can spread very rapidly at high tem- peratures (80 to 95°F) and cause severe damage; other species of Pythium may cause damage during cool weather. Control. Reduce shading, improve soil aeration and water drainage. Water, when needed, to a depth of 4 to 6 inches. Several fungicides are available. Rust Symptoms. Elongate, reddish-brown to orange pustules containing spores appear on the stems, leaves, and leaf sheaths. Reddish-brown to orange spores adhere to fingers when pustules are rubbed. Some bluegrass varieties are particularly susceptible, though ryegrass is commonly in- fected. Cause. Puccinia striiformis and P. graminis overseason in infected grasses. The airborne spores may be carried long distances. Moderately warm, moist weather favors rust development. Condensed moisture, even of dew, for 10 to 12 hours is sufficient for spores to infect plants. Control. Keep plants growing rapidly by fertilization and irrigation. Most of the infected portions of leaves are removed by mowing and the spores trapped inside the mowed leaves die out rapidly. Fungicides containing oxycarboxin are particularly effective in controlling rust. Fairy ring Symptoms. A dark green band of turf develops in a circle or semicircle; mushrooms may or may not be present. Frequently, just behind the dark green band is an area of sparse, brown, dying grass, caused by lack of water penetra- tion. Weed invasion is common. All turf grasses can be affected by fairy ring, but the effects may be less on grass species with long stolons. Cause. Several species of mushrooms cause fairy rings. In northern and central California the predominant fungus is Marasmius oreades: in southern California species of Lepiota. Fairy ring develops most frequently in soil high in un- dcromposed thatch, the fungi living primarily on the thatch. Control. Apply adequate nitrogen. Remove thatch peri- odically. Aerate soil to improve water penetration, and apply water heavily in holes every day for 3-10 days. It is possible to eliminate the fairy ring fungus from soil by removing turf and fumigating with volatile fumigants. However this is an expensive and involved process and should be done only by licensed specialists. The use of surfactants (wetting agents) may help water penetrate through the area affected by fairy rings. Seed rot, damping off and root rot Symptoms. Seeds may rot in the soil or the young grass seedlings may be killed (damp-off) before or after emergence. Seed rot is not mushy but rather dry. In damp- ing-off seedlings at first are water-soaked, then blacken, shrivel, and turn brown. Frequently, affected seedlings are not killed but are yellow and stunted, with markedly re- duced root systems. All types of grasses are subject to seed rot and damping off. Cause. Seed rot, damping off, and root rot are caused by several species of Pythium and/or by Rhizoctonia solani, Fusarium culmorum, and Helminthosporium spe- cies. Seed rot and damping off are favored by excessive mois- ture, excessive nitrogen, sowing too deeply, and sowing seeds of low viability and above the recommended rates, especially during periods unfavorable for seed germination and growth. Control. Improve soil aeration and water drainage. Do not overwater. Sow only fresh, healthy seed at recom- mended rates and seasons. Treat seed with one of several fungicides. Have a qualified expert fumigate soil with a volatile fumigant before planting. Soil fumigation also kills weed seeds, insects, and nematodes. [45] RODENT DAMAGE in TURFGRASS Maynard W. Cummings The damage to turf caused by rodents is perhaps the easiest to identify. The pest animal is usually seen if the observer is patient, but if not the earth mounds or burrows, and cut-off vegetation are unmistakably the work of a size- able pest. Rodents may migrate into turf from surrounding areas or, in the case of new plantings, the changed vegetation may provide improvements which favor an increase of rodent populations already there. Some rodent species are mobile enough to cause turfgrass damage while not actually living on the area. In such situations, it may be necessary to apply control measures to surrounding areas, or to pro- tect new plantings by fences or other barriers. Rodent damage occurs any time of the year, although plant growth stages and rodent breeding and activity cycles affect extent and nature of damage. California ground squirrels undergo periodic winter and summer dormancy, but a percentage of the ground squirrel population is active the year around. The other rodents mentioned in this guide are also active during all months of the year. Turf areas should be frequently inspected for early signs of rodent activity. NOTE: A description of recommended poisons and gasses to be used for rodent control, as well as methods of application will be found in Leaflet 209. Typical mound built by pocket gopher or mole — both pests of turf. &mm w ' - M. \ pocket gopher. (It is extremely rare 10 sec one completely out ol the ground like this one.) I 46 1 PEST AND DESCRIPTION LIFE HISTORY AND HABITS DAMAGE CAUSED DETECTION AND CONTROL Ground Squirrels ( genus Sper- mophilus): Several species, commonest being the large "digger" squirrels nine to eleven inches long, tail six to eight inches. Gray and brown mottled color, long bushy tail. Internal cheek pouches opening just inside the lips, for carrying food. Meadow Mice (genus Micro- tus) : Large-bodied, four to six inches, short-tailed 1% to 2% inches, dark-colored "field mice." Soft body fur, sparse hairs on tail. Pocket Gopher (genus Thomo- mys) : Six to eight inches long, tail, three to four inches. Blunt head; small eyes and ears; ex- ternal fur-lined cheek pouches for carrying cut food: long, slender claws on front feet; large incisor teeth not covered by lips. Moles (genus Scapanus) : Seven to nine inches long, tail one to two inches. Long slen- der snout, no external eyes or ears; no cheek pouches; small numerous teeth, do not pro- trude; soft, velvety fur; short, heavy claws on shovel-like front feet. Ground-dwelling but good climb- ers; may take nuts and fruit but main food is seeds, sprouting grains and green vegetation. Vora- cious feeders taking two to three ounces green feed daily. Dig ex- tensive burrows which remain open even when animals are hi- bernating or estivating. These in- activity periods vary with temper- ature and elevation. Form large colonies, prefer open, grassy, or rocky areas. Breed in late winter and spring, one large (6-12) litter per year. Dig burrows one to two inches in diameter which open straight down, cut runways in vegetation between burrows. Prefer dense vegetation. High reproductive po- tential; populations cycle radi- cally from few to 1,000/acre. May breed several times yearly. Cut green vegetation just above or just below ground surface. Girdle roots and stems of woody vegetation. Mainly solitary, does not hiber- nate, digs extensive tunnels four to twelve inches below ground pushing dirt to surface in round or fan-shaped mounds; one litter of two to six young per year ex- cept two or even three litters in year 'round warm, irrigated con- ditions. Prefer legumes and other fleshy stemmed, thick-rooted plants, roots and bark of trees. Cut and eat surface vegetation within a body length of feeding holes but most feeding is under- ground. Not rodents; soil insects and their larvae, and earthworms are main food items but some seeds, roots, and bulbs are eaten. Prefer moist locations or irrigated areas. Dig deep burrows but also force way through surface soil making ridges above ground. Mound of exca- vated soil is volcano shape with loose central core. One litter of one to four per year. Almost con- stant feeders, may eat body weight of insects daily. Store and eat large quantities of seeds, grasses and grain. Dig and eat sprouting grasses. Important reservoir of rodent-borne diseases. Burrows a problem in lawns and ditch banks. Destroy root crowns and lower stems of clovers, other forage grasses, especially damaging to tubers. Girdle orchard trees, grape vines, other large vegetation. Dam- age extensive when local popula- tions increase drastically through breeding or migration. Riddle turf areas with holes and runways. Cut and destroy roots, root crowns, and stems of plants. Gnaw and girdle tree roots. Burrows di- vert irrigation water, may create erosion problem. Mounds disfigure lawns, smother grass, and damage mowers, furnish seed bed for un- desirable plants. Mounds and ridges disfigure lawns and turf areas. Tunnelling cuts roots and dries out sod areas, in- terferes with watering. Some vege- table matter taken as food, other plants dislodged by digging. Day feeders so animals are seen. Numerous open burrows three to five inches in diameter. Vegeta- tion cut down and ground bare around burrows. Poison baits: Most common con- trol. Best baits determined by testing. Anticoagulants: Used where haz- ard precludes use of poisons, (campgrounds, parks, etc.). Bait and labor costs high. Fumigation: Effective when soil is moist, not porous. Trapping: Slow for large numbers but effective and safe. Use modi- fied bait station — box traps. Holes and runways in vegetation. Plant girdling at ground level. Mice seen in daytime when nu- merous, especially under heavy cover. Poison baits sometimes helpful. Clean cultivation: Important pop- ulation check where practical. Orchards, roadsides and ditch bank cover removal reduces breed- ing reservoirs, reduces migration to other areas. Mounds of fresh earth are unmis- takable. Probing near mounds will locate burrows. Trapping: Insert two special traps, "Macabee," "California," etc., in excavated burrow, one facing each direction, cover open- ing, check traps daily. Poison baits: Place poisoned grain bait in burrow through probe hold. On large areas treat with mechanical gopher-bait ap- plicator. Fumigation: Poorest control method; extensive burrow system makes fumigation difficult. Loose, cone-shaped mounds and upthrust ridges in ground surface. Trapping: Best control; use spe- cial mole trap "Out-O-Sight" or "Reddick" in surface runways. Soil Insecticides: Removal of food supply is effective control on large turf areas unless earthworms are otherwise desirable. Use recom- mended insecticidal rates. Fumigation gives only limited suc- cess due to extensive burrow sys- tems. Poison baits: Insect-eating habit makes baiting difficult. Most com- mercial mole baits are of limited effectiveness. [47 GLOSSARY of TERMS USED A. — Acre (43,560 square feet) a.i. — active ingredient — weed killing component in an herbicide formulation. a.e. — the active ingredient in a herbicide formulation ex- pressed as the acid equivalent. annual — A plant that completes its life cycle from seed in one year. biennial — A plant that completes its life cycle in two \ears. The first vear it produces leaves and stores food: the second vear it produces flowers and seeds. broadcast application — An application over an entire area. broadleaf weeds — Popular term for plants in the di- cotyledon group (dandelion, knotweed, plantain, etc.) compatible — Two or more chemicals or products are said to be compatible when they can be mixed without affect- ing each other's performance. contact herbicide — A herbicide that kills only the plant tissue contacted with little to no translocation. contact insecticide — A pesticide that kills its intended victim when it touches it or is touched by it. culm — The erect stem of grasses. dicotyledonae — A botanical subclass in which dicotyle- don (broadleaf) plants are grouped. emulsion — A suspension of one liquid in another, dis- tinguished from a solution in which the two liquids combine completely and become one. flower stalk — Stalk of a plant bearing a flower. foliage-applied herbicide — An herbicide the primary action of which is on or through the foliage. formulation — A manufactured blend of herbicide and other ingredients available as a liquid, wettable powder, or granule for weed control. fumigation — The use of chemicals put into the soil as gasses or in a form that will turn into gas to destroy unwanted plants (weeds), insects, nematodes, or disease- causing elements. gal. — Gallon or gallons. herbicide— A chemical used for killing or inhibiting the growth of plants. internode The part of a stem between two successive nodes. midrib The middle or main rib of a leaf. monocotyledonae imonocot) — A botanical subclass in which monocotyledons (narrowleaf) plants are grouped. narrowleaf weeds Popular term for plants in the mono- cotyledon group l all grasses, nutsedge) . node A joint, as in a stem; the point where buds and leaves species on the area sprayed. <>/-. Ounces. panicle \ man) branched flower head, with flowers at the iiid of each branch, such a- in man] grasses I annual Mim perennial — A plant that lives for more than two years. postemergence — After germination and emergence from the soil. preemergence — Prior to germination and emergence from the soil. preplanting — Anytime before the ornamental or crop is planted. prostrate — A general term for plants tending to lie flat on the ground. psi — Pressure; measured as pounds per square inch. qt. — Quart. rhizome — A below ground stem with nodes and inter- nodes, usually producing roots and stems or leaves from the nodes. rootstock — Often used interchangeably with rhizome. rosette — A cluster of closely crowded leaves arising from a very short stem near the surface of the ground. seedling — An infant plant grown from seed. selective — A type of weed control that will kill some plant species when applied to a mixed population without seri- ous injury to other species. Excessive herbicide applica- tion rates may reduce or eliminate the desired selectivity. shoot — A young above-ground branch or growth. sod — Large sections of turf — usually used in conjunction with production of turf for vegetative propagation. soil-applied herbicide; — Chemicals that are taken up by- plants principally from the soil. soil I umigant — A material used to eradicate all vegeta- tion, usually a vapor or gas that diffuses through the soil and has a relatively short life in the soil. spike — An inflorescence (flower head) with spikelets (flowers) attached directly to an unbranched stem. spikelets — A small group of grass flowe spike. spot spraying — Application of an herbicide concentration to individual weeds applying no more spray than is re- quired to just wet the foliage. sq. ft. — Square feet. stolon — A stem that grows horizontally along the ground, usually rooting at the nodes. A new plant may be formed from each section of stolon that roots. summer annual — A plant in which the seed germinates in the spring, grows to maturity during the summer, de- velops seeds and dies during the winter. surfactant— A material that improves the emulsifying, dispersing, spreading, wetting, and other surface-modi- fying properties of herbicide formations. Has action similar to that of a detergent. systemic — When applied to a chemical this means it is absorbed into and distributed throughout the plant. In- sects sucking the plant's juices are subjected to the in- secticide. taproot A stout, vertical root giving off small laterals. thatch An accumulation of undecomposed or partially decomposed stems and leaves at the soil surface. r 48i translocation — Movement of materials (herbicide) within the plant from the point of entry to other areas of the plant (such as from leaves to the roots). tsp. — Teaspoon. vascular system — The conducting or transport avenues in plant tissue such as the leaf veins. vein — A conducting or transport unit of the vascular sys- tem of plants (leaf veins). viable — Alive, capable of germinating and growing — gen- erally applied to seed. weed control — The process of limiting weed infestations so that crops can be grown profitably, or other opera- tions can be conducted efficiently. weed eradication — The complete elimination of all live plants, plant parts, and seeds from an area. wetting agent — A compound which when added to a spray solution causes it to contact plant surfaces more thoroughly (see surf acant) . winter annual — A plant in which seed germinates in the fall or winter, lives through the winter in the vegetative stage (often as low rosettes), flower and seed in the spring and summer, and die by winter. 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