i of The College of V I R S I T Y O F C'A L I F O R N I A **#«** ) POTATO VARIETIES IN KERN COUNTY CALIFORNIA Glen N. Davis F. J. Stevenson David N. Wright wmmmammmmm ^ Mm?* > EXPERIMENT STATION BULLETIN 727 WHITE ROSE is the potato variety most commonly associated with Kern County. It is well adapted to the area because it matures early, has a pleasing uniform appear- ance on the market, and in general gives fairly high yields. It is also called American Giant, Wisconsin Pride, Late Pride, Long White, Delta White, and Shafter White. AN IMPROVED POTATO would keep the good features of the White Rose but would have other desir- able characters also, including: Early maturity, the tubers reaching harvest stage 110 to 120 days from planting time. High yields comparable with or greater than those obtained from White Rose. Uniform tubers, oblong, free from side growths and growth cracks. Smooth, golden skin color. White flesh. High cooking quality (good bakers). Resistance to disease, especially common scab. VARIETAL STUDIES conducted for the past 10 years in Kern County have been directed toward testing other varieties that might meet the needs of the industry. This bulletin reports these studies. THE AUTHORS: Glen N. Davis is Associate Professor of Truck Crops and Associate Oleri- culturist in the Experiment Station. F. J. Stevenson is Principal Geneticist in the Bureau of Plant Industry, Soils, and Agricultural Engineering, United States Department of Agriculture. David N. Wright is Farm Advisor in Kern County, with the University of California Agricultural Extension Service. POTATO VARIETIES IN KERN COUNTY Glen N. Davis CALIFORNIA F. J. Stevenson David N. Wright The problem was to find varieties that growers could substitute for White Rose California ranks first in the produc- tion of early potatoes. Acreage in the state between 1946 and 1950 inclusive accounted for more than 20 per cent of the United States total. Of the California early acreage, 80 to 85 per cent is grown in Kern County, located in the southern end of the San Joaquin Valley. Kern County has developed since 1920 from raw desert land growing only 300 acres of potatoes to a highly specialized agricultural area producing annually 50,000 to 65,000 acres (table 1). Yields have increased from an average of 100 sacks per acre in 1920 to an average of approximately 250 sacks per acre in 1950. White Rose is the principal variety produced in the early potato area in Cali- fornia — called also American Giant, Wis- consin Pride, Late Pride, Long White, Delta White, and Shafter White. Other varieties grown to a minor extent include Pontiac and Triumph, both red-skinned potatoes grown for special markets. Because of its early maturity and its pleasing uniform appearance on the mar- ket, White Rose has been found to be especially well adapted to the Kern County area. Yields are in general fairly high. Although it has been satisfactory for this area, growers have stressed the need for continued effort to develop other varieties that keep the good features of the White Rose and have other desirable characters as well. In the search for an improved potato, the following factors have been consid- ered: 1) Early maturity, the tubers reaching harvest stage 110 to 120 days from plant- ing time. 2) High yields comparable with or TABLE 1— Acreage, Yield Per Acre, and Total Production of Potatoes in Kern County, 1940 to 1949, Inclusive Year Acreage Yield per acre (100-pound sacks) Total production (100-pound sacks) 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 29,625 34,320 32,961 40,226 53,978 60,765 65,406 50,791 64,782 56,239 185 161 202 215 218 185 252 256 221 245 5,404,388 5,523,300 6,664,407 8,639,633 11,789,083 11,269,607 16,510,445 13,016,019 14,351,109 13,764,052 greater than those obtained from White Rose. 3) Uniform tubers, oblong, free from side growths and growth cracks. 4) Smooth, golden skin color. 5) White flesh. 6) High cooking quality (good bakers). 7) Resistance to disease, especially com- mon scab. This bulletin presents information ob- tained in varietal studies made during the past 10 years in Kern County. Thirty-one varieties that show promise of meeting the needs of the industry were tested and are here reported on. TABLE 2— Summary of Ten Years of Potato Variety Studies in Kern County' 1 Variety Calrose Canus Cayuga Chippewa DeSoto Earlaine Earlaine — 2. . . Essex Houma Huinkul Kasota Katahdin Kennebec La Soda Menominee. Mohawk Ontario Pawnee Pontiac Potomac ...... Progress RedWarba Russet Burbank Russet Sebago . Saranac Satapa Sebago Sequoia Teton Triumph White Rose Total Number of years tested Av. yield per acre (100-lb. sacks) 243 257 375 317 227 205 220 275 350 298 480 337 354 250 350 295 412 215 375 179 223 336 164 260 256 308 347 375 389 254 303 Number of times the variety yield significantly exceeded, equaled, or was less than that of White Rose 15 40 19 * 1949 data not included because of no White Rose check. [4] The tests showed that many varieties compare favorably with White Rose White Rose has been the leading vari- ety ever since potato growing became an industry in Kern County. A big consumer demand has been built up during this time for "Shafter Long Whites" or "California Long Whites." Although this in itself justifies continuance of the vari- ety, consumers are not fully satisfied with the quality of White Rose and are voicing more objections each year. In the period of 1940 to 1950, inclu- sive, 31 different potato varieties were included in the varietal studies in Kern County. Comparison with White Rose was made on the basis of yield, date of maturity, and disease resistance. Some of the varieties were tested only once, but others were tested several times. Yield. The data in table 2 suggest that it is not difficult to find potato varieties that will consistently yield as high as White Rose or higher. This table is a summary of the varieties studied, the number of years each variety was in- cluded in the tests, the average yield of each variety for the number of years tested, and the number of times during the tests that the yield of each variety equaled that of White Rose, or the num- ber of times the yield of each was above or below that recorded for White Rose. Reference to the last three columns of the table shows that a total of 74 com- parisons with White Rose was made. Of this number, 15 were significantly higher in yield than White Rose; 40 were equal to, and 19 yielded significantly less than White Rose. In other words, in 55 times out of 74 the yields produced by other varieties were equal to or higher than those produced by White Rose. However, varietal characteristics other than yield play an important role in the selection of a variety for Kern County. Furthermore, it is evident from the data presented in tables 4 to 13 that yields vary greatly for the same variety from year to year — so much so, in fact, that any single variety should be tested for several years before any estimate of its performance is attempted. Date of maturity. Another impor- tant factor is the time of maturity of the different varieties. While most of the acreage of White Rose is harvested be- fore it is fully mature, White Rose is naturally earlier than most of the other varieties tested. This, however, should not prejudice a grower to any great ex- tent against growing one of the other varieties tested. All the varieties included in the tests were planted and harvested on the same dates as the White Rose checks, and all yield comparisons were made for the same number of days in the growing season. All varieties that gave the same yield as White Rose or higher did so in the same growing period. All varieties with the exception of Se- bago handled just as easily as White Rose and with no more skinning, bruising, or windburn. Unless allowed to grow to full maturity the variety Sebago is difficult for pickers to handle, since most of the potatoes cling tightly to the plant even after they are dug and must be pulled from the vine individually. It will be seen from table 3 in the center of this bulletin that the following classi- fications were made as to time of ma- turity: Early: Earlaine, Essex, La Soda, Red Warba, Triumph Medium early: Canus, Pawnee, White Rose Midseason: Calrose, De Soto, Earlaine 2, Houma, Kasota, Mohawk, Satapa Late: Cayuga, Chippewa, Huinkul, Ka- tahdin, Kennebec, Menominee, On- tario, Pontiac, Potomac, Progress, Russet Burbank, Russet Sebago, Sara- nac, Sebago, Sequoia, Teton [5] o "3 O to M O 2S |2 S.S c o u c 0) c o few .a Q6w ■a a & 'a 03 2 73 CQ bO § o P5o s- W bo bo W 3 3 i3h 73 ii tf JO O o ■*3 •■&S > <» aS CO CD w W2 ill JO s* boo 3.2 PQ |1 O t-i fl.l S.se ►J boOC! si J q3 bo IIS « ft =94 tf ft W 02 2 ft O M«2 ft O sit is is ■ - *1 jjj >> ©71 S3 bo 3 >> o £3 CD ft a o w w CO +> go S J W +» c8 to J3 to O ft* ©fc 43 g J2S -a a .2 I •as 03 e3 si 73 ft 53 §5 s.sp bo £ !f« ft > 2 - bo a.s :3t3 38 was a 03 TJ Ph 03 eg en eS a 03 H £ o bo o 73 o 03 Oi ft OS 2 e S 4» .2 Jh '3 bo +a o o a p tf bo .a J2 CO ta f— 1 >H bo d "C 10 n >» H d 2* 2 © 19 o 9 o •— 1 9 o o =3 o a d '•B p. 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Resistance to scab may in time become a critical con- sideration in the selection of a variety for Kern County. Most of the potato land is infested with the scab organism and some of it so heavily that it has been abandoned for potato production. The scab picture is further complicated by the fact that several varieties and seedlings resistant to scab in other parts of the United States have not maintained their resistance when grown under California conditions. Two varieties among those tested, Menominee and Ontario, have shown a very high degree of resistance when grown on some of the most severely in- fested soil in the county. Both varieties produce white tubers that must be classed as round in shape rather than as the pres- ently preferred long type. Among the va- rieties studied, only Calrose produces the same type of tuber as White Rose. Table 3 shows the different varieties resistant to various diseases as follows : Fusarium wilt: Kasota (tolerant to) Late blight: Essex, Kennebec, Sebago, Potomac, Calrose Leaf roll: Houma, Katahdin Mild mosaic: Chippewa, De Soto, Ear- laine, Houma, Katahdin, Kennebec, Mohawk, Red Warba Net necrosis: Chippewa, Katahdin, Kennebec Ring rot: Saranac, Teton Scab; Menominee, Ontario, Cayuga VerticiUium wilt: Menominee And here is a report of the experiments by years, from 1 940 to 1 950 Studies were conducted at the U. S. Cotton Field Station, Shafter, California. All the potato seed planted, with the ex- ception of White Rose, was seed grown by the U. S. Department of Agriculture in Maine. Certified White Rose seed was ob- tained each year from a local grower. In all cases the seed was relatively free from virus and other diseases. Each variety in test was replicated 5 times in a randomized plot. Each repli- cation consisted of 25 uniform-sized seed pieces planted in 25 feet of row. Planting was by hand except in 1949 and 1950, when an assisted feed planter was used. The plots were fertilized at the time of planting with ammonium sulphate ap- plied at the rate of 600 pounds per acre. They were dug with a single-row digger, and each replication was picked up and weighed separately. Insofar as possible, all cultural operations were the same as those employed in the commercial fields of the area. The variety White Rose was considered the check in all years except 1949, when it was not included in the planting. A number of the varieties studied normally require a longer growing season to reach maturity than does the variety White Rose. However, all varieties were dug at the same time as the check, so that the period elapsing from the date of planting until harvest was the same for each va- riety. A longer growing season would un- doubtedly have resulted in increased yields for those varieties classified as late- maturing. The potatoes were not sepa- rated into market grades, but total yield was taken in every case. You are referred to the table on pages 6, 7, and 8 for brief characterizations of the varieties used in the study. 1 940. In 1940 six varieties of potatoes were tested in a rondomized block. The yield data (table 4) show that only one variety, Chippewa, gave a significantly higher yield than White Rose. That of one variety, Earlaine, was significantly lower, and the remaining three varieties yielded approximately the same as White Rose. 1941. In 1941 (table 5) the same six varieties as tested in 1940 were used. However, two different seed lots of each variety were planted. Lot 1 was seed grown by the U.S.D.A. in Maine, and [9] TABLE 4— Potato Variety Yield Data, Kern County, 1940 Yield in pounds Total Mean Sacks Variety Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 (100 lbs.) White Rose 48 40 41 47 43 219 43.8 280 Chippewa Earlaine 51 33 51 35 53 38 53 19 49 31 257 156 51.4 31.2 329 200 Houma 47 52 47 50 52 248 49.6 317 Katahdin 36 40 49 41 42 208 41.6 266 Sebago 24 239 43 54 50 43 214 42.8 274 Total 261 282 260 260 1,302 Least significant difference between means =7.5 lbs. Least highly significant difference between means = 10.3 lbs. Lot 2 was seed saved from the 1941 Shafter plot — or seed one year removed from Maine-grown seed. The twelve seed lots were handled as twelve distinct units and planted in a rondomized block. In Lot 1, Chippewa, Katahdin, and Sebago yielded significantly higher than White Rose, while Katahdin and Sebago yielded significantly higher in Lot 2. Considering the total mean yield of the two lots of seed, the mean of Lot 1 was 42.9 lbs. and that of Lot 2 was 32.3 lbs. This represents a difference of 10.6 lbs. in favor of the Maine-grown seed, whereas only 4.49 lbs. difference is required for significance. Such results serve to emphasize the im- portance of high-quality seed. 1942. In 1942 seven varieties (table 6) were placed in test. No variety pro- duced a significantly higher yield than White Rose, and the yields of four vari- eties — Chippewa, Russet Burbank, Se- bago, and Triumph — were significantly lower. Two varieties, Houma and Se- quoia, equaled White Rose in production. 1 943. No yield data are presented for 1943 since the entire plot was devoted to the study of a large number of unnamed seedlings. Each seedling lot consisted of two to five hills, and yield data on such small lots were not considered reliable. 1944. In 1944, as in 1943, the major portion of the study was devoted to seed- ling or unnamed varieties. The plot did, however, include two named varieties. Calrose and Sebago, besides the White Rose check. Reference to table 7 shows that Sebago gave a significantly higher yield than the check but that the yield of Calrose was about the same. 1945. The 1945 test included twelve varieties. Of this number only one, Ka- tahdin, gave a significantly higher yield than the check variety, White Rose; and only one variety, Pawnee, gave a signifi- cantly lower yield. Each of the remaining nine varieties gave a yield statistically equal to that of White Rose (table 8) . 1946. The 1946 yield test (table 9) included thirteen varieties. In this year not a single variety gave a significantly higher yield than White Rose, and the yield of only one, Sequoia, equaled that of the check. All the rest produced yields significantly below that of White Rose. 1 947. Data for the 1947 test are pre- sented in table 10. Eight varieties were tested. The results were almost the re- verse of those obtained in 1946. All but two varieties gave yields significantly higher than did White Rose — Chippewa, Houma, Pontiac, Red Warba, and Se- bago. The yield of Sequoia equaled that of the check, and that of Russet Burbank was significantly lower than that of White Rose. 10 TABLE 5-Potato Variety Yield Data, Kern County, 1941 Variety Yield in pounds Total Mean Sacks per acre (100 lbs.) Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 r White Rose 28 29 29 32 51 169 33.8 216 Chippewa 44 46 43 49 53 235 47.0 301 1 i Earlaine 55 26 29 29 25 164 32.8 210 Houma 30 47 38 44 50 209 41.8 257 Katahdin 46 48 59 58 45 256 51.2 326 _ Sebago 59 47 42 59 46 253 50.6 324 1,286 42.9 272 White Rose ... 30 25 26 29 30 140 28.0 179 Chippewa 20 36 36 24 25 141 28.2 180 2* Earlaine 8 20 25 22 16 91 18.2 116 Houma 20 25 34 32 37 148 29.6 189 Katahdin 53 49 46 17 53 218 43.6 279 ^ Sebago 48 45 51 37 50 231 46.2 296 969 32.3 206 ■ rotal 441 443 458 432 481 2,255 Least significant difference between means = 11.0 lbs. Least highly significant difference between means =14.5 lbs. Least significant difference between means of combined seed lots 1 and 2 * Not included in summary table 2. 4.49 lbs. TABLE 6— Potato Variety Yield Data, Kern Coun fy, 1942 Variety Yield in pounds Total Mean Sacks per acre (100 lbs.) Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 White Rose Chippewa 63 49 26 26 48 61 20 63 47 62 27 49 74 23 60 36 61 26 49 47 20 52 45 54 26 46 50 15 43 38 50 26 43 49 30 281 215 253 131 235 281 108 56.2 43.0 50.6 26.2 47.0 56.2 21.6 360 275 324 168 301 360 138 Houma Russet Burbank . . . . Sebago Sequoia Triumph Total 293 345 299 288 279 1,504 Least significant difference between means = 6.26 lbs. Least highly significant difference between means =8.32 lbs. Text and tables continued ^ [in 1948. Ten varieties were tested in 1948 (table 11). Of the ten, four— Me- nominee, Pontiac, Sebago, and Sequoia — yielded significantly higher than White Rose. One, Cayuga, yielded significantly lower than the check variety. The yields of four — Chippewa, Houma, Katahdin, and Teton — equaled the yield of the White Rose check. 1949. In 1949 (table 12) nine vari- eties were included in the plot. White Rose, the variety generally used as the check, is not included in the table be- cause of an unavoidable incident in the field. There are no significant differences among the varieties tested. 1 950. Seventeen varieties were planted in 1950. The data are presented in table 13. None of the varieties tested produced a significantly higher yield than White Rose; and only one, Red Warba, yielded significantly lower than the check. The rest, or fifteen varieties, each produced a yield statistically equal to that of White Rose. TABLE 7— Potato Variety Yield Data, Kern County, 1944 Variety Yield in pounds Total Mean Sacks Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 (100 lbs.) White Rose Calrose Sebago 19 50 69 39 58 60 26 31 46 41 24 55 120 35 27 35 160 190 265 32.0 38.0 53.0 205 243 339 Total 138 157 103 97 615 Least significant difference between means = 17.2 lbs. Least highly significant difference between means = 24.9 lbs. TABLE 8— Potato Variety Yield Data, Kern County, 1945 Variety Yield in pounds Total Mean Sacks per acre (100 lbs.) Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 White Rose Chippewa Earlaine — 2 Houma Katahdin Menominee Mohawk Pawnee Pontiac 24 21 34 23 32 26 19 14 29 41 32 31 26 30 36 22 50 24 25 26 32 18 41 39 29 16 28 22 31 27 16 16 23 31 24 24 35 33 44 21 41 18 37 12 33 18 34 59 26 27 30 22 34 33 21 14 29 32 30 29 140 127 172 110 188 128 118 82 146 140 161 182 28.0 25.4 34.4 22.0 37.6 25.6 23.6 16.4 29.2 28.0 32.2 36.4 179 163 220 141 243 164 152 105 187 179 208 233 Potomac Sebago Sequoia Total 326 369 287 385 327 1,694 Least significant difference between means = 8.6 lbs. Least highly significant difference between means = 11.6 lbs. [12] TABLE 9— Potato Variety Yield Data, Kern County, 1946 Variety Yield in pounds Total Mean Sacks per acre (100 lbs.) Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 White Rose 72 78 97 87 93 427 85.4 547 Chippewa 55 53 66 66 60 300 60.0 384 Houma 79 73 81 69 73 78 68 79 76 76 377 375 75.4 75.0 483 480 Kasota Katahdin 50 61 72 72 65 320 64.0 410 Mohawk 50 67 60 71 79 327 65.4 419 Pawnee 55 47 45 48 60 255 51.0 326 Pontiac 74 58 65 65 83 345 69.0 442 Red Warba 55 57 64 61 63 300 60.0 384 Sebago 77 74 79 73 75 378 75.6 484 Sequoia 83 73 84 81 75 396 79.2 507 Teton 69 56 63 61 59 54 86 , 60 68 58 345 289 69.0 57.8 442 370 Triumph Total 848 842 896 917 931 4,434 Least significant difference between means = 8.75 lbs. Least highly significant difference between means = 11.67 lbs. TABLE 10— Potato Variety Yield Data, Kern County, 1947 Variety Yield in pounds Total Mean Sacks per acre (100 lbs.) Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 White Rose Chippewa Houma Pontiac Red Warba Russet Burbank. . . Sebago Sequoia Total 59 64 61 62 63 26 62 55 47 66 63 66 70 20 67 50 43 67 65 82 63 24 53 47 47 64 53 64 61 29 62 62 49 68 64 68 71 26 50 59 245 329 306 342 328 125 294 273 49.0 65.8 61.2 68.4 65.6 25.0 58.8 54.6 314 421 392 438 420 160 383 349 452 449 444 442 455 2,242 Least significant difference between means = 7.59 lbs. Least highly significant difference between means = 10.25 lbs. Tables concluded [13 TABLE 1 1 -Potato Variety Yield Data, Kern County, 1948 Yield in pounds Total Mean Sacks Variety Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 (100 lbs.) White Rose Cavuera 62 32 47 61 52 74 68 76 69 61 58 36 55 67 58 70 71 68 73 56 612 46 51 57 52 81 62 52 67 46 34 548 57 64 48 65 62 57 56 62 68 83 59 57 62 62 38 68 87 64 78 60 282 240 269 307 291 331 334 337 334 294 56.4 48.0 53.8 61.4 58.2 66.2 66.8 67.4 66.8 58.8 361 307 Chippewa 344 Houma 393 Katahdin 372 Menominee Pontiac 424 428 Sebago 431 Sequoia 428 Teton 376 Total 602 622 635 3,019 Least significant difference between means = 7.02 lbs. Least highly significant difference between means = 9.41 lbs. TABLE 12— Potato Variety Yield Data, Kern County, 1949 Variety Yield in pounds Total Mean Sacks Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 (100 lbs.) Cayuga 60 78 65 74 86 58 73 64 69 77 63 77 63 96 79 347 387 348 69.4 77.5 69.6 444 Houma 496 Katahdin 445 Kennebec 63 31 75 63 92 324 64.8 415 Menominee 51 77 75 92 66 361 72.2 462 Ontario 71 68 53 90 65 347 69.4 412 Pontiac 63 88 85 63 82 381 76.2 488 Sebago 70 99 64 58 77 368 73.6 471 Teton 74 53 634 81 86 83 377 75.4 487 Total 595 639 669 703 3,240 No significant differences. [ 14 TABLE 13-Potato Variety Yield Data, Kern County, 1950 Variety Yield in pounds Total Mean Sacks per acre (100 lbs.) Rep. 1 Rep. 2 Rep. 3 Rep. 4 Rep. 5 White Rose Canus 44 34 33 43 52 53 53 30 49 42 39 32 44 38 43 34 45 48 20 37 35 47 43 43 33 36 41 28 35 53 41 47 41 39 43 56 38 41 47 43 42 36 37 47 30 27 36 40 75 37 36 36 47 35 26 44 46 47 34 81 36 38 32 35 30 34 41 39 39 52 34 70 43 47 44 62 42 41 39 33 35 51 42 46 40 210 209 177 215 233 232 229 195 245 207 174 159 203 200 241 199 199 42.0 41.8 35.4 43.0 46.6 46.4 45.8 39.0 49.0 41.4 34.8 31.8 40.6 40.0 48.2 39.8 39.8 269 257 227 275 298 297 293 250 314 266 223 204 260 256 308 255 255 De Soto Essex Huinkul Katahdin Kennebec La Soda Mohawk Pontiac Progress Red Warba Russet Sebago Saranac Satapa Sebago Teton Total 708 667 711 681 760 3,527 Least significant diff < Least highly signifies jrence between means =9,25 lbs. nt difference between means = 12.2 lbs. ACKNOWLEDGMENTS The writers wish to acknowledge their indebtedness to Mr. George Harrison and Mr. Gordon Smith for their excellent co- operation in making the facilities and equipment of the U. S. Cotton Field Sta- tion, at Shafter, available for the success- ful growing of the plots, and also for their help at the time of planting and harvesting. Thanks are extended also to Mr. James Bishop for his assistance in planting, harvesting, and supervision of the plots. 7£m-ll,'51(7588)A.A. IS test tube farming pays off for you Not all of the agricultural research done by the University of California is field work. Much useful knowledge comes to light through work done under controlled laboratory conditions. This information, after thorough checking and application to field problems, becomes available to all California farmers. Distribution of this knowledge is made through: LITERATURE: Circulars, bulletins, lithoprints, and leaflets by specialists are available free. These publications cover many subjects re- lating to agriculture in the state. For a catalog of this litera- ture write to the Office of Agricultural Publications, 22 Giannini Hall, University of California, Berkeley 4. COUNTY FARM ADVISORS: Farm Advisors are agricultural specialists with a background of practical knowledge. They serve 52 counties throughout the state and their mission is to help farmers work out their problems. Get to know your Farm Advisor — take advantage of his services. MAIL INQUIRIES: If you prefer to put your questions in a letter, mail them to the Public Service Office of the College of Agriculture, Uni- (|N versity of California, either at Berkeley or at Davis. Your S^ problem will be referred to the person or department best ^ able to give you the exact information you need. THE COLLEGE OF AGRICULTURE UNIVERSITY OF CALIFORNIA