THE UNIVERSITY OF ILLINOIS LIBRARY cop. WON CIRCUL CHECK FOR GIRCUU Effects of Prolonged Storage On Forcing Qualities of Summer-Budded Roses By F. F. WEINARD and S. W. DECKER UNIVERSITY OF ILLINOIS AGRICULTURAL EXPERIMENT STATION Bulletin 409 CONTENTS PAGE DESCRIPTION OF THE EXPERIMENT 3 DISCUSSION OF RESULTS 5 Plant Losses Increased With Longer Storage Periods 5 Flower Production Not Affected 6 Paraffining Tops Ineffective in Reducing Losses 9 SUMMARY AND CONCLUSIONS.. . 9 Urbana, Illinois December, 1934 Publications in the Bulletin series report the results of investigations made by or sponsored by the Experiment Station Effects of Prolonged Storage on Forcing Qualities of Summer-Budded Roses By F. F. WEINARD, Associate Chief in Floricultural Physiology, and S. W. DECKER, formerly Associate in Floriculture GREENHOUSE roses are ordinarily propagated by cuttings or by grafting during the winter in the greenhouse. A method which has been used recently is to summer-bud the roses in the field. In a test previously reported, 1 summer-budded roses, as compared with winter-grafted plants, gave satisfactory yields under glass. The question then arose as to how long the summer-budded plants could profitably be held in storage. For summer budding, the under-stocks are planted in the field and are budded in late summer. After the buds have united but before they have started into growth, they are lifted and stored in a cool place. From storage they are shipped to the growers, usually in January or February. In January or February, however, plants in the benches are in full production, and replanting is neither convenient nor economical. The grower, if he does not wish to plant directly in the benches, has the alternative of holding the budded plants in pots and planting them in the bench later. This means that considerable space which otherwise might be in productive use must be cleared to make room for the dormant-bud plants in 4-inch pots. If a way could be found to hold the summer-budded plants in storage successfully until late spring, they would undoubtedly find more favor with growers. It would be necessary that they be held dormant, because they are shipped with difficulty after the buds start to grow. However, even tho held dormant, there is usually some loss from dormant-bud plants which fail to start into growth, and it has been suspected that this loss would increase proportionately to a lengthened storage period. The tests described in this bulletin were made to determine the effects of prolonged storage on the forcing qualities of summer-budded stock. DESCRIPTION OF THE EXPERIMENT With the cooperation of a firm specializing in summer-budded roses, four lots of these plants were packed separately and held in 111. Agr. Exp. Sta. Bui. 358. 1930. 3 4 BULLETIN No. 409 [December, storage according to a prearranged schedule until they were wanted for planting in the greenhouse. The different shipments were received March 18, April 15, May 15, and June 15, each shipment including Matchless, Fernet, Rapture, and Rose Hill varieties. In March and April half the plants in each shipment were started into growth by packing them in moist sphagnum, and the remainder were potted in soil in 4-inch pots and covered with moist burlap. At the same time the tops were cut back to the bud, and, if the buds had already developed, as many on Fernet had, the shoots were cut back- to the first strong bud. The buds on the plants which were packed in sphagnum started to grow as promptly as those on the potted plants. The mossed plants seemed to be less vigorous, however, and showed a tendency to wilt during the heat of the day, a tendency apparently caused by tardy root development. The moss-started plants were potted in soil after the shoots had begun to grow, about two weeks after they were received. All the plants in the May and June shipments were started in soil in pots the method which gave the best results with the first two lots. On July 2 all the surviving plants from all four shipments were trans- ferred from the pots to the benches. The plants were set so that each variety occupied a 100- foot bench ; and each shipment was divided into four separate blocks. This ar- rangement was made to avoid errors which might otherwise have arisen because of differences in growing conditions in different parts of the house. Manure had been added to the brown silt loam soil in the field, in the ratio of about one part manure to four of soil. Before planting, each 100 square feet of bench soil received 15 pounds of super- phosphate, 5 pounds of dried blood and 1 pound of potassium sulfate. During the growing season a night temperature of 58 Fahrenheit was maintained in the house. In the daytime the temperature ranged from 68 to 78 F., according to the weather. During the season of record from the first of October thru May none of the buds were pinched off, because it was thought that a fairer comparison of different treat- ments could be made when the plants were allowed to flower without interference. In the following June the soil was allowed to dry out sufficiently for the plants to become dormant without dropping their leaves. After they had rested for a month they were cut back to a height of 18 inches from the ground, fertilizers were added to the soil as at the beginning of the first season, and the plants were again started into growth. 1934] FORCING QUALITY OF SUMMER-BUDDED ROSES In June, 1931-32, some summer-budded plants with the tops par- affined were received for forcing. They were planted in the bench as soon as received, June 15. These plants had been carried thru the winter in cold storage at a temperature slightly above freezing, and then held at a temperature of about 40 F. for 24 hours before ship- ping. The results obtained with this lot of plants are discussed in connection with the results of the earlier experiment. DISCUSSION OF RESULTS Plant Losses Increased With Longer Storage Periods The number of plants lost in starting was progressively greater with the lengthening of the storage period (Table 1). This result, as might be expected, was very consistent. On averaging the figures for all four varieties it was found that about 83 percent of the plants in the March shipment were started successfully. Eighty percent of the TABLE 1. LOSSES OF PLANTS IN STARTING SUMMER-BUDDED ROSES INTO GROWTH AFTER PROLONGED STORAGE, 1929-30 Variety Shipment Treat- ment Number of plants Plants lost before benching Plants lost in bench, 1929-30 Total plants lost Matchless March Moss 691 ., percl. 101 ., perct. 11 . perct. 121 <0 April Soil Moss 70J 139 661 , ,, 23/ 16 301 ,, ll 1 4\ . 24/ 18 351 ,. May Soil Soil 69 j 135 121 12/ 21 32 3J 4 3 14/ 24 36 June Soil 133 39 5 44 Fernet 691 . , 131 . 11 . 141 . . April Soil Moss 70} 139 721 ,, 7J 10 191 .* U 1 11 , 9/ 11 211 ,T May Soil Soil 69/ 139 127 13} 16 14 o} 1 10 13/ 17 24 June Soil 108 17 38 55 Rapture Moss 661 . , 81 .-, 01 . 81 .,. April Soil 76} 136 691 . ~o I*} 12 141 ll 1 0) . 17| 12 141 May Soil Soil 59J 128 138 }9 22 2J 1 3J 9 27 June Soil 135 20 13 33 Rose Hill March Moss 701 . , 431 41 . 471 ,, April Soil Moss 70/ 140 671 4~ 14J 29 401 ,, 3J 4 31 -. 17/ 32 431 , May Soil Soil 61 j 128 129 $) 35 25 3J 3 11 33/ 38 36 June Soil 132 35 6 41 Total of all vari- eties March 2741 , r 19\ i 21 -. 201 . April Soil Moss %*} 554 2741 , 15/ 17 261 ., i n} 19 281 May Soil Soil 2S8} 532 515 u} 20 23 r 16/ 22 30 June Soil 508 28 14 42 6 BULLETIN No. 409 [December, April shipment, 77 percent of the May shipment, and 72 percent of the June shipment were growing on July 1. Incidentally the tests revealed definite differences in the value of sphagnum and soil as starting media (Table 1). Altho the lots started in soil did not in every case yield a larger number of living plants than those started in sphagnum, the results were, in general, considerably better when all varieties are considered. Only about 78 percent of the March and April plants started in moss and about 86 percent of those started in soil were alive at the time of benching, July 2. The effects of prolonged storage upon plant losses were not, how- ever, confined to the starting period, but were evident after the plants were transferred to the bench, especially in weakened root systems. It was evident that prolonging the storage period was more injurious to the roots than to the buds of the budded plants. On many plants the shoot growth was noticeably stronger than the root growth, par- ticularly on the plants of the May and June shipments. Practically all the plants which were benched showed an active shoot growth, and the death of a certain number after benching was explained by the failure of the weakened root systems to function. Considering the four varieties, the losses in the benches of plants of the March and April shipments were only about 2 percent, whereas similar losses from the May and June shipments were about 7 and 14 percent respectively. The results from the individual varieties did not vary a great deal from these averages. At the end of the first season about 81 percent of the March ship- ment were in the benches in a productive condition. Of the April ship- ment, 78 percent were growing ; of the May shipment, 70 percent ; and of the June shipment, 58 percent. No plants died during the second growing season, but seven Fernet plants failed to recover after being dried off at the end of that season. A loss of 20 percent or more of the original stock is a serious matter. In addition there is a certain amount of inconvenience and loss when plants die in the bench, even tho they are replaced without cost. Flower Production Not Affected The flower-production records of the plants from the different shipments, that remained in growing condition thruout the season, are given in Table 2. The records from plants that died at different times during the season or during the rest period at the end of the first season are not included. Altho the yields from the plants in the March shipment averaged 1934] FORCING QUALITY OF SUMMER-BUDDED ROSES TABLE 2. FLOWER PRODUCTION OF SUMMER-BUDDED ROSES AFTER PROLONGED STORAGE (Exclusive of plants that died during season or subsequent rest period) Variety Year Shipment Number of plants Average number flowers per plant Average stem length (inches) Matchless 1929-30 March 113 20.04 .40 12.0 April 102 19 97 52 12 1 May 77 18.80 .47 11.5 June 74 17.65 .50 11.0 1930-31 Average March 113 19.3 24.40 .42 11.6 11.4 April 102 26.06 .46 11.6 77 24.08 .46 11.2 June 74 25.22 .59 11.0 Fernet . . . 1929-30 Average March 119 25.0 13 62 29 11.3 13 6 April 113 12.70 .30 13.3 May 95 13.15 .33 13.1 June 43 13.11 .48 13.1 1930-31 . . Average March ii9 13.2 13.56 .28 13.3 13.7 April 113 13.42 .26 13.9 May 95 13.34 .26 13.7 June 43 12.49 .58 13.0 Rapture 1929-30 Average iii 13.2 21.29 .41 13.6 13.8 April 114 21.60 .46 13.6 May 101 20.50 .45 13.3 June 90 18.29 .48 12.8 1930-31 Average iii 20.5 24.38 .47 13.4 13.7 April 114 22.93 .41 13.4 May 101 24.39 .45 13.9 June 90 24.59 .54 13.3 Rose Hill 1929-30 Average 94 24.0 16.82 .46 13.6 13.1 April 78 15.74 .48 12.9 May 84 15.50 .47 12.7 June 80 15.86 .51 12.2 1930-31 Average March 94 16.0 23.14 .53 12.7 12.3 April 78 23.05 .68 12.4 May 84 24.25 .59 12.9 June 80 24.95 .64 12.9 Total of all varieties. . . 1929-30 Average March 438 23.8 17.92 12.6 13.1 April 407 17.59 13.0 May. . . 357 17.00 12.6 287 16.67 12.3 1930-31 March 438 21.18 12.8 April 407 20.99 12.8 357 21.35 12.9 June 287 23.04 12.5 highest, there were no appreciable differences among the yields of the plants from the March, April, and May shipments during either season of record. With the exception of the yields from the June shipped plants of Matchless and Rapture varieties, which, during the first season, were noticeably lower than the yields from the earlier ship- ments, there were no differences large enough to be considered sig- nificant in showing a detrimental effect from long storage. The aver- age yield from the June shipped plants of all four varieties was 1.2 BULLETIN No. 409 [December, flowers below that of the March shipped plants in 1929-30, but about 1.9 flowers per plant higher in 1930-31. In fact, excepting Fernet, which averaged the same during the two years, the yields per plant during the second year were appreciably larger than during the first. There were no important differences in stem length in the various treatments in either season. The proportions of the season's cut taken each month from the different lots of plants of each variety were similar in the one year in which such records were taken (Table 3). Thirty percent of the Fernet cut was produced during December, January, and February. TABLE 3. FLOWER PRODUCTION OF SUMMER-BUDDED ROSES, BY MONTHS, 1929-30 Variety Shipment Percentages of total yields Oct. Nov. Dec. Jan. Feb. Mar. Apr. May Matchless March 13.9 15.7 15.2 13.8 14.6 16.1 13.7 13.0 10.3 13.8 16.7 17.0 16.2 16.8 16.7 13.5 13.5 12.9 14.5 13.6 15.0 15.0 14.3 13.8 14.5 11.8 9.3 10.1 11.8 10.8 9.8 10.3 11.2 12.3 10.6 12.7 11.2 12.8 13.3 12.3 13.0 9.5 10.0 11.1 11.1 11.8 10.1 11.0 12.1 11.3 9.5 10.7 10.7 8.9 9.9 12.4 12.3 9.8 10.1 11.4 7.6 9.2 7.1 5.2 7.6 7.2 7.6 7.8 5.9 7.1 9.2 9.9 8.8 7.5 8.9 6.3 5.2 5.9 5.2 5.7 10.2 8.8 11.4 8.9 9.9 7.1 5.8 6.7 7.7 6.7 7.3 6.8 6.9 7.5 7.1 7.7 6.6 7.7 7.3 7.4 9.9 10.0 9.2 9.5 9.7 9.0 9.4 8.4 9.2 9.0 7.8 8.5 7.6 7.2 7.8 7.0 7.6 6.3 4.6 6.5 8.4 8.9 7.9 7.6 8.2 10.7 10.1 11.3 10.4 10.6 12.4 14.2 14.3 12.5 13.4 12.1 11.7 11.8 10.5 11.7 11.0 13.8 11.8 13.6 12.5 11.5 12.4 12.3 11.7 12.0 15.6 15.2 15.2 16.8 15.7 12.4 15.1 13.3 16.3 14.0 14.2 14.6 15.6 16.8 15.1 17.8 18.9 18.8 17.9 18.3 15.0 15.9 15.7 16.9 15.9 22.3 23.8 22.4 23.6 23.0 17.7 16.2 18.6 20.4 17.9 21.8 22.0 22.2 22.5 22.1 23.2 22.3 25.5 24.9 23.8 21.2 21.1 22.2 22.8 21.2 Fernet June Average .... March Rapture April June Average .... March Rose Hill Total of all varieties. . . Average of all lo June Average .... March May June Average .... March June u Twenty-five percent of the total Matchless cut, 22 percent of the Rapture cut, and 21 percent of the Rose Hill cut were produced in the same period. In general, it was evident from these experiments with summer- budded roses that even the late-started plants, when once they were established in the bench, gave practically normal yields normally dis- tributed over the season in comparison with plants started in March. 1934] FORCING QUALITY OF SUMMER-BUDDED ROSES The chief result of the prolonged storage period, as already shown, was the loss of plants due to the weakening of the understocks. Paraffining Tops Ineffective in Reducing Losses Paraffining the tops of summer-budded roses in storage had no significant effect in these experiments (Table 4). In this test with a comparatively few plants, the losses varied considerably with the TABLE 4. LOSSES OF PARAFFINED AND UNTREATED SUMMER-BUDDED PLANTS STARTED FROM STORAGE IN JUNE, 1931-32 SEASON Variety Treatment Number of plants Plants failing to start Total plants lost Briarcliff Paraffin 40 Percl. 2 Percl. 7 Untreated 9 22 Matchless Paraffin . . . 40 7 30 Untreated 10 10 50 Fernet Paraffin 40 20 85 Untreated 10 20 80 Rapture Paraffin . . . 41 5 46 Untreated 10 30 Total of all varieties 161 9 42 Untreated 39 8 46 variety. Briarcliff was least affected; whereas the loss of Fernet, as in the earlier experiment, was relatively heavy. The average loss in the four varieties used was about 43 percent. This is practically the same figure as that obtained with June shipped stock in the two previous seasons. The paraffined plants gave, in general, no better results than the untreated plants. SUMMARY AND CONCLUSIONS Serious and increasingly heavy losses of summer-budded plants are likely to be encountered as planting is postponed and the period of storage lengthened beyond the usual time (January or February) for planting stock of this kind. The losses of plants in the present experi- ments ranged from approximately 20 percent for plants taken from storage in March to approximately 40 percent for plants removed from storage in June. Paraffining the tops had little or no effect in pre- venting the loss of late-planted stock. Normal yields may be expected from plants which become estab- lished in the bench, even tho started relatively late. Thus the success 10 BULLETIN No. 409 of a planting of summer-budded roses can be judged in the main by the way the plants start into growth. Some variation in results may be expected according to the skill and attention of the grower, but it is clear that the earlier the planting is made, the better. 5.05012-346724