n V.... .t... p..- fifilfififilfifilfifififififi gfigfigfifil Michigan State University This is to certify that the thesis entitled POSTHARVEST HANDLING AND STORAGE OF BARE-ROOT HERBACEOUS PERENNIALS presented by MUHAMMAD MAQBOOL has been accepted towards fulfillment of the requirements for M.S d . 1986 egree 1n Major professor Date—EEBRUARLZLJEB6 0-7639 MS U i: an Afiinmm‘n Action/Equal Opportunity Institution lVdeI.) BEIURNING MATERIALS: Place in book drop to lJBRAfiJES remove this checkout from ”— your record. FINES will __,__——.._.__A__i4_ 4 - be charged if book is returned after the date stamped below. ._- -- ”h ——- V‘s < 59"“ «m9 535’ é? POSTHARVEST HANDLING AND STORAGE OF BARE-ROOT HERBACEOUS PERENNIALS By Muhammad Haqbool A THESIS Submitted to Michigan State University in partial Fulfilment of the requirements for the degree of MASTER OF SCIENCE Department of Horticulture 1986 ABSTRACT POSTHARVEST HANDLING AND STORAGE 0F BARE-ROOT HERBACEOUS PERENNIALS By Muhammad Haqbool Experiments were conducted to determine the effects of packaging, temperature. and fungicides on the regrowth quality of stored bare-root herbaceous perennials. Various packaging materials were used to generate different degrees of moisture loss for plants stored 6 months at -2°C. Hater loss varied from essentially 0% to 601. The results revealed a significant inverse relationship between water loss and regrowth quality (r g 0.90 in all cases). Polyethylene films were most effective at retarding water loss and maintaining plant quality. No significant difference in regrowth quality for several genera was noted after 6 months at either -2°C or 0°C. in a second experiment regrowth quality was comparable, in. general. following storage at -2°C. +2°C. and +S°C. Etiolated growth was common in +2°C and +S°C. fungicides effectively limited the extent of mold development but adversely effected the regrowth of many plants. On the basis of these findings prestorage fungicide treatments are not recommended. DEDICATION To My Late Mother ACKNOWLEDGEMENTS Sincere appreciation is extended to Dr. Arthur C. Cameron, my thesis committee chairman, for his invaluable guidance. motivation and constructive criticism throughout my research and thesis preparation. I am deeply grateful to my committee members, Dr. Lowel C. Ewart and Dr. Christine T. Stephans. for their valuable inputs during the course of this work and for reviewing manuscript. I would like to express my gratitude to Ralph Heiden, Anne Richards, Cindy Klobucher. and Charles Robinson for their help in my research. Special thanks are due to Mohammad Usman for many hours of computer help in preparation of graphics and word processing. Thanks are also due to Mohammad Siddique for his help in the final preparation of draft. I am indebted to the Pakistan Agriculture Research Council for providing financial support in ‘collaboration with the food and Agriculture Organization (FAQ). I would also like to thank Walter Garden’s of Zeeland, MI. for supplying plant material for this research. Finally, deep appreciation is extended to my father, my wife. and my children for their moral support, love, and patience which has made the attainment of this goal possible. TABLE OF CONTENTS Page LIST OF TABLES ......................... v LIST OF FIGURES . . . ..................... vii CHAPTER I: PACKAGING OF HERBACEOUS PERENNIALS: THE RELATION OF WATER LOSS TO STORAGE SURVIVAL ............ 1 Introduction . . . .................. 2 Materials and Methods . . . . ............ 4 Results ....................... 6 Discussion ...................... 38 Literature Cited . . . . . . . . . . . . . . . . . . . 41 CHAPTER II: EFFECT OF STORAGE TEMPERATURES ON THE PERFORMANCE OF BARE-ROOT HERBACEOUS PERENNIALS . . . . . . . . . . . . 42 Introduction ..................... 43 Materials and Methods ....... . ........ 45 Results ....................... 47 Discussion ............. . . . . ..... 73 Literature Cited ............. g . . . . . . 76 CHAPTER III: EFFECT OF FUNGICIDES ON THE CONTROL OF MOLD DEVELOPMENT AND REGROHTH OF STORE BARE—ROOT HERBACEOUS PERENNIALS ....... . . ....... . . . . . . 78 Introduction ..................... 79 Materials and Methods ................ 80 Results . . ..................... 83 Discussion ...................... 103 Literature Cited .............. . . . . . 107 iv Table LIST OF TABLES CHAPTER I The relative rates of water loss from different packaging materials based on average percent water loss from stored herbaceous perennials during 4 and 6 months storage . . . Percent moisture loss of herbaceous perennials following 4 and 6 months storage when packed in different packaging materials . . . . . . . . ....... . . . . . . . . . Overall percent weight loss from plants during storage averaged over all package barriers and both 4 and 6 months durat i on I O O I O O O O O O O O O O O O O O O O 0 O I O O Mold rating after 4 and 6 months storage of herbaceous perennials packed in different packaging materials . . . . Three week regrowth grade after 4 and 6 months storage of herbaceous perennials packed in different packaging materials . . . . . . . . . . . . . . . . . . . . . . . Overall 3 week regrowth quality influenced by the packaging materials during storage averaged over plant material and storage duration . . . . . . . . . . . . Three week regrowth height after 4 and 6 months storage of herbaceous herbaceous perennials when stored in different packaging materials . . . . . . . . . . . . . . . . . . . Statistical analysis of moisture loss curves. Percent loss in quality for percent loss in weight calculated by multiplying by 20 . . . . . . . . . . . . . . . . . . . . CHAPTER 11 Mold rating after 4 and 6 months storage of herbaceous perennials stored at different temperatures in experiment I ( 1983-84) 0 O O O O O O O O O O O I O O O O O O O O I O 0 Three week regrowth grading and height following 6 months storage of herbaceous perennials at different temperatures in experiment I (1983-84) . . . . . . . . . . . . . Page 16 I7 23 24 27 37 4B 53 Table page 2.3. Analyses of variances for 3 week regrowth grade and height following 6 months storage at -2°C or 0°C in experiment 1 (1983-84) . . . . . . . . . . . . . . . . . 54 2.4. Mold ratings following 6 months storage of herbaceous perennials at different temperatures in experiment 2 ( 1984-85) 0 o o o o o o o o o o o o e e o o o o o o o o 0 56 2.5. Three week regrowth grade after 6 months storage of herbaceous perennials stored at different temperatures in experiment 2 (1984-85) 0 o o o o o o o o o o o e e o o 65 2.6. Three week regrowth height after 6 months storage of herbaceous perennials stored at different temperatures In exper‘n‘ent 2 (1984-85) 0 o o o o o o o o o o o o o o o 67 2.7. Percentage of stored herbaceous perennials which produced etiolated growth during storage in experiment 2 (1984-85). 72 CHAPTER III 3.1. Mold ratings following 4 and 6 months storage of herbaceous perennials treated with fungicides prior to storage in exper imnt 1 ( 1983-84) 0 O O I I O O O O O O O I O O O O 84 3.2. Three week regrowth grade following 6 months storage of herbaceous perennials treated with fungicides prior to storage in experiment 1 (1983-84) . . . . . . . . . . . . 92 3.3. Three week regrowth height following 6 months storage of herbaceous perennials treated with fungicides prior to storage in experiment 1 (1983-84) . . . . . . . . . . . . 93 3.4. Mold rating following 6 months storage of herbaceous perennials treated with expanded benomyi concentrations prior to storage in experiment 2 (1984-85) . . . . . . . . 97 3.5. Three week regrowth grade following 6 months storage of herbaceous perennials treated with expanded benomyi concentrations prior to storage in experiment 2 (1984—85). 102 vi LIST OF FIGURES Figure 1. 1. .2a. .2b. .3a. .3b. .6a. .6b. CHAPTER I Percent weight loss combined for bare-root herbaceous perennials tested following 4 and 6 months storage from five different packaging materials . . . . . . . . . . Percent weight loss of D. spectabilis; P. subulata; A. rosea; and L. polyphyllus following 4 and 6 months storage from five different packaging materials . . . Percent weight loss of C. lanceolata; G. grandiflora; and A. officinallis following 4 and 6 months storage from five different packaging materials . ...... . . . . . Mold rating on Q. spectabilis; g. lanceolata; A. rosea; and A. polyphyllus following 4 and 6 months storage when packed in five different packaging materials . . . . . . Mold rating on P. subulata; A. officinallis: and G. grandiflora following 4 and 6 months storage when packed in five different packaging materials . . . . . . . . . . . . Three week regrowth grade of Q. spectabilis: E. subulata: A. officanallis; Q. grandiflora; and g. lanceolata following 4 and 6 months storage in five different packaging materials . . . . . . . . . . . . . . . Three week regrowth height of A. officingjlis; Q. spectgpilis; g. grandiflora; Q. lanceolata; A. rosea: andg L. lezghyllus following 4 and 6 months storage in five different paCkaging materials . . . . . . . . . . . . . . Relationship of mold rating and percent weight loss on 3 week regrowth grade of E. subulata; Q. grandiflora; and Q. gectabilis . . . . . . . . . . . . . . . . . . Relationship of mold rating and percent weight loss on 3 week regrowth grade of A. officinallis; and Q. lanceolata. Relationship of mold rating and percent weight loss on 3 week regrowth height of A. gglyghyllus: and A. rosea CHAPTER II Percent increase in mold development at 0 or -2°C during storage in experiment 1 (1983-84) . . . . . vii page 11 13 15 19 21 26 29 31 33 35 50 Figure Page 2.2. Percent increase in susceptibility to mold development from 4 to 6 months storage of herbaceous perennials in experiment 1 (1983—84) 0 e o e e e o e o e o o o o o o o o 52 2.3a. Mold rating and 3 week regrowth quality of A. novoae-anglji; fl. undulata; and A. schmidtiana following 6 months storage at different temperatures in experiment 2 (1984-85). . . . S8 2.3b. Mold rating and 3 week regrowth quality of C. maximum; Q. chiloense; and Q. . exima following 6 months storage at different temperatures in experiment 2 (1984- 85) . . . . . 60 2.30. Mold rating and 3 week regrowth quality of Q. ruber; A. tuberosa; and Q. spectabilis following 6 months storage at different temperatures in experiment 2 (I984-85) . . . . . 62 2.3d. Mold rating and 3 week regrowth quality of Q. polyphyllus; following 6 months storage at different temperatures in experiment 2 (1984-85) . . . . . . . . . . . . . . . . . . 64 2.4a. Three week regrowth height of G. chiloense; A. tuberosa; Q. polyphyllus; A. novoae-anglii: Q. exima: and H. undulata following 6 months storage at different temperatures in experiment 2 (1984—85) . . . . . . . . . . . . . . . . . . 69 2.4b. Three week regrowth height of C. ruber; C. maximum: A. schmidtiana; and Q. spectabilis following 6 months storage at different temperatures in experiment 2 (1984- 85) . . . 71 CHAPTER 111 3.13. Mold rating and 3 week regrowth grade following 6 months storage of Q. grandiflora; E. subulata; and A. rosea; treated with different fungicides prior to storage in experiment 1 (1983-84) . . . . . . . . . . . . . . . . . . 86 3.1b. Mold rating and 3 week regrowth grade following 6 months storage of A. officinallis: L. 29 lyphyllus; and C. lanceolata treated with different fungicides prior to storage in experiment 1 (1983- 84). . . . . . . . . . . . 88 3.1c. Mold rating and 3 week regrowth grade following 6 months storage of Q. spectabilis treated with different fungicides prior to storage in experiment 1 (1983-84) . . . . . . . . 90 3.2. Three week regrowth height following 6 months storage of Q. lanceolata; A. officinallis; Q. grandiflora; A. rosea; Q. polyphyllus; and Q. spectabilis when treated with different fungicides prior to storage in experiment 1 (1983-84). . . . 96 viii Figure page 3.3a. Mold rating and 3 week regrowth grade following 6 months storage of Q. grandiflora: l. sempervirens; and Q. angustifolia when treated with expanded benomyi concentrations prior to storage in experiment 2 (1984—85). . 99 3.3b. Mold rating and 3 week regrowth grade following 6 months storage of T. chamaedrxs and Q. deltoides when treated with expanded benomyi concentrations prior to storage in experiment 2 (1984-851. . . . . . . . . . . . . . 101 3.4. Comparison of mold rating and 3 week regrowth grade following 6 months storage of Coreopsis spp. when treated with fungicides prior to storage in 1983-84 and 1984-85 experiments . . . . . . . . . . . . . . . . . . . . . . . . 105 ix CHAPTER I PACKAGING OF HERBACEOUS PERENNIALS: THE RELATION OF WATER LOSS TO STORAGE SURVIVAL INTRODUCTION Many field-grown herbaceous perennials are harvested bare-root in the fall and stored under refrigerated conditions for processing and shipping during the winter and spring months. Growers. retail nurserymen and mail order distributors report that a significant percent of the harvested plant material never reaches the ultimate consumer due to deterioration during storage. The specific causes of these losses have not been well characterized. It is well accepted by nurserymen that desiccation during storage can lead to a decline in plant regrowth quality. However. Mahlstede and Fletcher (1960) conducted 'an experiment with fall-dug carnations. delphiniums, strawberries and hybrid rose bushes which were packed in polyethylene and shipped. They could not correlate the moisture lost by the plants with plant survival in the field and recommended that plants could be partially dried to discourage mold development in storage. Thus, it is not clear how much moisture can be lost by the plants without a loss in regrowth quality. Moistened packing materials such as shingle tow, saw dust, peat or excelsior have been used to maintain the water content of bare-root plants in storage (Mahlstede and Kirk. 1954), but they have been shown to promote mold development when too wet (Worthington and Scott, 1957; Duffield and Eide, 1957). Polyethylene and other plastic films such as cellophane wraps, asphalt impregnated papers and waxed papers have also been used to prevent moisture loss in various horticultural crops (Hardenburg, 1949 2 3 and 1951; Hardenburg et al.. 1953; Mahlstede and Kirk, 1954). These have variable permeabilities to water vapor and other gases (Hardenburg. I951; Hardenburg et al., 1953; Mahlstede and Kirk. 1954). Worthington and Scott (1957) found that strawberry plants stored at -1.I°C for 8 - 9 months in crates with polyethylene liners were superior in appearance and had better field survival than those without liners. Worthington and Smith (1966) found that asparagus plants packed in polyethylene lost less weight and were more turgid than plants packed in burlap when stored at 0°C for 10 weeks. Uota et al. (1959) reported that growth of rose plants when packed in polyethylene liners was initially more rapid than for plants stored under drier conditions in the moss pack. Duffield and Eide (1959) recommended that forest planting stock, deciduous shrubs and small trees be stored in polyethylene bags. Certain problems have been encountered with the use of plastic films. condensation commonly forms around plastic—packed plants due to a combination of factors including high relative humidity from transpiration. heat production by the plant material and temperature fluctuations within the storage facility. Regardless of the specific cause. the presence of free water on the plants encourages the development of molds and bacteria (Tomkin, 1962; Worthington and Smith, 1966). Modified atmospheres can be generated within plastic packages depending on the permeability and surface area of the film and the respiration rate of the plant material (Prince et al.. 1984; Uota et al. 1959). It is not known to what extent atmospheres are modified 4 within packed perennials or if they are beneficial or detrimental. Another disadvantage of polyethylene liners is that they retard heat exchange. For instance, Mahlstede and Fletcher (1960) have shown that polyethylene packed perennials took 14 hours to cool to refrigerator conditions. The primary objective of these experiments was to study the impact of various packaging materials and techniques on moisture loss. mold development and regrowth quality of stored bare-root herbaceous perennials. In addition, the data was used to determine the relationship between the extent of moisture loss during storage and the subsequent regrowth quality. MATERIALS AND METHODS Alcea rosea. Asparagus officinallis. Coreopsis lanceolata, Dicentra spectapjlls, Gaillardia grandiflora, QQpinus polyphyllus and Phlox subulatg plants were harvested on November 18. 1983 from a field at Walter’s Gardens. Zeeland, MI. All senesced shoots of Alcea rosea, Aspgragus officinallis, Dicentra spectabilis. and Lupinus polyphyllus and green tops of Coreopsis lanceolata and Gaillardia grandiflora were removed to within 1-2" of the crown. Plants of Phlox subulata were not trimmed. Excess soil was removed and damaged roots were trimmed off. Plants were then precooled at 2°C for 24 hours. Plant were then weighed and packed in the following packaging materials with two replicates per treatment and five plants per replicate for each perennial: 1. 4 mil. Polyethylene. 2. 4 mil. Polyethylene with perforations. 3. Cellophane. 4. Cardboard. 5. Burlap. Overall there were 20 packs which were placed randomly in crates in a way that 2 packs fit in one crate. Immediately after packing. the crates were transfered to ~2°C storage temperature. After 4 months. plants were removed from storage. weighed and visually rated for mold development using the following scale: 5 = 76 - 1001 of the plant surface covered with molds; 4 = 51 - 75% covered with molds; 3 26 - 50% covered with molds; 2 = l - 25% covered with molds; and 1 No observable molds. One half were returned to storage and the other half were potted and grown under greenhouse conditions for a gperiod of 3 weeks. Plant regrowth potential and quality were rated weekly for all plants except A. rosea and L. polyphyllus. A subjective scale of 0 - 5 was used with 0 defined as dead and 5 as Optimum regrowth quality based on experience. The rating system took into account new shoots. density of foliage and overall vigor. The scale can be defined as follows: 5 = 1001 of regrowth potential expected after 3 weeks; 4 = 801 of regrowth potential; 3 = 601 of regrowth potential; 2 = 40% of regrowth potential; 1 = 20% of regrowth potential and 0 = No observable growth. Height was measured weekly for all plants except E. subulata. Following 6 months storage. the remaining plants were weighed. rated for mold development. potted and grown in greenhouse for the 6 evaluation of regrowth quality as described above. All plants. including A. rosea and L. polyphyllus were rated weekly for regrowth grade after 6 month storage. The rate of moisture loss through each package material was calculated on the combined basis of weight loss by all herbaceous perennials tested at 4 to 6 months. Analysis of variance was performed to determine the significant effects. RESULTS Package Effect 0n Weight Loss The relative rates of weight loss through each of the packaging material are shown in Table 1.1. The overall order of package permeability was polyethylene. perforated polyethylene. cellophane. cardboard and burlap. Cellophane was the only packaging material with a significant increase in the rates of weight loss from 4 to 6 months. It was noted that the cellophane packages deteriorated markedly after the 4 month observation. Plants stored in burlap lost water slightly but significantly faster during the first 4 months than the last 2 months. It should be noted that after 4 months. the average plant stored in burlap had lost approximately 44% of its original weight. When the data was analyzed on the basis of total weight loss. package material. storage duration. variety and the interaction of package material with storage duration were all highly significant (Table 1.2). The effect of package material and storage duration on Table 1.1. The relative rates of water 105 s from the different packaging materials based on average percent water loss from stored herbaceous perennials during 4 and 6 month storage. Name of Packaging Storage 1 Wt. Transpiration Average Trans- Material. Duration Loss Rate/Mo. piration Rate Per Month. 1. 4 mil. poly- 4 Mo. 3.15 0.79 ethylene. 6 Mo. 7.26 1.21 NS 1.00 2. 4 mil. poly— 4 Mo. 5.75 .44 ethylene with 6 Mo. 9.88 .65 NS 1.54 Perforations. 3. Cellophane. 4 Mo. 8.53 2.13 6 Mo. 27.62 4.60 " 3.37 4. Cardboard. 4 Mo. 24.79 6.20 6 Mo. 41.96 6.99 NS 6.60 5. Burlap. 4 Mo. 44.10 11.03 6 Mo. 56.60 9.43 ' 10.23 LSDg05=0.95 NS: Nonsignlficant at 1% and 51 level. H: Significant at 1% and 5% level. ': Significant at 5% level. Table 1.2. Percent moisture lossY for herbaceous perennials following 4 and 6 months storage when packed in different packaging materials Analysis of variance for percent moisture loss is also given for reference. Packaging treatments Name of Storage perennials dura- Poly Perfo Cello- Card- Burlap tion. poly phane board Alcea rosea 4 Mo. 2.74 1.62 5.33 28.53 43.98 6 Mo. 2.42 7.64 25.99 35.72 48.92 Asggragus 4 Mo. 2.55 3.35 9.75 21.44 34.53 officinalis 6 Mo. 4.22 14.56 17.21 31.08 42.76 Corgggsis 4 Mo. 3.83 4.83 7.37 14.46 34.46 lanceolata 6 Mo. 3.05 5.49 '34.26 48.46 55.71 Dicentra 4 Mo. 5.01 15.23 7.54 30.14 52.03 spectabilis 6 Mo. 14.09 11.02 33.39 36.67 63.79 Gaillardia 4 Mo. 0.79 1.58 12.38 18.90 53.92 grandiflora 6 Mo. 7.85 7.87 27.58 57.74 62.05 Lupinus 4 Mo. 4.73 3.62 6.86 29.27 49.50 polyphyllus 6 Mo. 4.69 3.70 21.37 38.05 64.72 Phlox 4 Mo. 2.40 10.00 10.49 30.79 40.28 subulata 6 Mo. 14.48 18.88 33.52 45.98 58.22 y :Moisture loss in grams. ANALYSIS OF VARIANCE Source Of Mean Square F. Value Prob. Packaging materials. 4 9999.00 157.90 .000 Storage duration. 1 4547.69 71.88 .000 P.M x 8.0. 4 349.20 5.52 .000 Varieties. 6 219.92 3.48 .004 P.M x V. 24 58.97 0.93 NS 8.0. x V. 6 82.45 1.30 NS P.M. x 5.0. x V. 24 60.36 0.95 NS Error. 70 63.27 9 weight loss is shown in Figure 1.1 for the combined data of all plants tested and on a plant by plant basis in Figures 1.2a and 1.2b. Weight loss in storage ranged from 2 — 65% depending on storage duration. packaging material. and individual plant. Overall. E. subulata. Q. grandiflora. and Q. spectabilis lost the most weight during storage while A. officinallis and A. rosea lost the least (Table 1.3). Develgpment 0f Molds In Storagg Mold ratings for the bare-root plants following 4 and 6 months storage are shown in Table 1.4. The analysis of variance indicates that all main effects and interactions were significant (Table 1.4). In general. little molds developed in any of the packaging treatments after 4 months storage (Figures 1.3a and 1.3b). Q. spectabilis was the only plant which showed a significant increase in mold development with an increase in the permeability of the packaging material after 4 months storage (Figure 1.38). Mold growth was more Severe for all plants after 6 months than 4 months storage except for A. ggsga and Q. polyphyllus packed in polyethylene or perforated polyethylene (Figure 1.3a and 1.3b). E. subulata showed only a minor amount of mold development except when stored in burlap (Figure 1.3b). For Q. spectabilis. Q. polyphyllus. and A. nggg. there was a significant increase in mold development with an increase in the permeability of the package after 6 months storage (Figure 1.3a). However. the exact opposite was found for Q. lanceolata (Figure 1.3a) 10 Figure 1.1. Percent weight loss combined for bare—root herbaceous perennials tested following 4 and 6 months storage from five different packaging materials as follows: A = 4 mil. Polyethylene; B = Perforated polyethylene; C = Cellophane; D = Cardboard; and E = Burlap. 11 ’I///////////////////////////[Iw \\\\\\\\\\\\\\\\\\\\\\\\U 'I/I/I/I/I/I/I/I/I/I/M o .k\\\\\\\\\\\ 'I/I/I/I/I/I/IA o L\\\V h—b I VII/I‘m 8 \\\‘ a. . 1 g», , 33 , '///<< «to A l8 0 J: 6 ' c5 6 o co m + S a .- °39VHOIS NI SlNV'ld TIV AB OBNIBWOO SSO'I .LHOIBM lN3383d PACKAGING MATERIALS Figure 1.2a. Percent weight loss of Q. sgectabilis; E. subulata; A. rosea; and Q. polyphyllus following 4 and 6 months storage from five different packaging materials as follows: A = 4 mil. Polyethylene; B = 4 mil. Perforated polyethylene; C = Cellophane; D = Cardboard; and E = Burlap. 13 ’l/l/I/I//////////////////////. - \\\\\\\\\\\\\\\\\\\\\\\‘ ‘ PACKAGING MATERIALS I . 3. 92' 99 3 Q. _ V. . .. é s s s 5'1 5'; 5': 6 (0) seems ONIUDO 5501 'm x (0) BMOLS owmno 5501 'm x '//////////////////////. \\\\\\\\\\\\\\\\\\\V 7////////////////////////////. ‘ \\\\\\\\\\\\\\\\\\\\\\\V , '///////////////A \\\\\\\\\\\\V ’I/I/I/I/I/A ' XV ' PACKAGING MATERIALS 3'9 ' 9'3 '0 Q. II II éééééééfio assesses (9) MOB amino 5301 m x (0) 391113015 owmno 5501 'm x PACKAGING MATERIALS PACKAGING MATERIALS I4 Figure 1.2b. Percent weight loss of Q. lanceolata; Q. grandiflora; and A. officinallis; following 4 and 6 months storage from five different packaging materials as follows: A = 4 mil. Polyethylene; B = 4 mil. Perforated polyethylene; C = Cellophane; D = Cardboard; and E = Burlap. '///////////////////////////I. ‘ \\\\\\\\\\\\\\\\\\\\\\\\V s 3 :3 We ‘3’ __ Q.” 3 '8. s 93' '0 II 2's 5': é s: s 5&1 (o) mom omano 550111: 2 _ 3, 5': s ii 5'! s é é *6 (o) BMOIS 0111800 5501 ‘m z PACKAGING MATERIALS PACKAGING MATERIALS 15 ASPARAGU 05 8 93' . '0 IE 3 s5 9'. I: § 7 (o) BMOIS 91418110 5301 m x '/l/////////////////////////. ‘ u x\\\\\\\\\\\\\\\\\\\\\‘ PACKAGING MATERIALS I6 Table 1.3. Overall percent weight loss from plants during storage averaged over all package barriers and both 4 and 6 months duration. Agme of the perennigl __1Qweight loss Dicentra spectabilis 26.89 Phlox subulagg 26.50 Gaillardia grandiflora 25.06 QQginus polyphyllus 22.65 Coreopsis lanceolata 21.19 Alcea rosea 20.29 Asgaragus officinallis 18.14 LSDg05= 5.02 17 Table 1.4. Mold ratingY after 4 and 6 month storage of herbaceous perennials packed in different packaging materials. Analysis of variance for mold rating is also given for reference. Packaging treatments Name of Storage perennials dura- Poly Perfo Cello- Card- Burlap tion. . poly phane board Alcea rosea 4 M0. 1.1 1.0 1.3 1.1 1.5 6 Mo. 1.1 1.5 2.1 2.2 3.0 Asegragus 4 M0. 1.2 1.0 1.0 1.0 1.0 officinalis 6 M0. 1.6 1.6 1.4 1.9 2.0 Coreogsis 4 M0. 1.7 2.0 1.5 1.7 1.5 lanceolata 6 Mo. 3.9 4.3 3.7 2.5 2.0 Dicentra 4 M0. 1.6 1.8 ‘1.8 2.3 2.7 spectggjlis 6 M0. 3.4 3.2 4.0 4.4 5.0 Gaillardia 4 Mo. 1.3 1.1 1.0 1.1 1. grandiflora 6 M0. 2.2 1.5 1.8 3.5 3 5 Lupinus 4 M0. 1.4 1.6 1.4 1.4 1.5 polyphyllus 6 M0. 1.3 1.8 2.2 2.5 3.9 Phlox 4 Mo. 1.0 1.1 1.0 1.0 1.5 subulata 6 Mo. 1.5 1.6 1.6 1.4 3.5 y :Mold rating: 5 = 76 - 100% of the plant surface covered with molds; 4 = 51 - 75% surface covered with molds; 3 = 26 - 501 surface covered with molds; 2 = 1 - 25% surface covered with molds; and 1 = No observable molds. ANALYSIS OF VARIANCE Sggrce DF Megn nggre F. Value Prob. Packaging materials. 4 11.20 36.26 .000 Storage duration. 1 227.43 736.66 .000 P.M. x 5.0. 4 4.30 13.92 .000 Varlties. 6 34.81 112.74 .000 P.M. x V. 24 3.81 12.34 .000 5.0. x V. 6 6.05 19.61 .000 P.M. x 5.0. x V. 24 2.15 6.95 .000 Error. 630 0.31 18 Figure 1.3a. Mold rating on Q. spectabilis; C. lanceolata; A. rosea; and Q. polyphyllus following 4 and 6 month; storage when packed in five different packaging materials as follows: A = 4 mil. Polyethylene; B = 4 mil. perforated polyethylene; C = Cellophane; D = Cardboard; and E = Burlap. Mold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26-50% covered with molds; 2 = 1-251 covered with molds; and 1 = No observable molds. COREOPSIS LANCEOLATA DICENTRA SPECTABIUS 83' V. I PACKAGING MATERIALS PACKAGING MATERIALS I9 LUPIN US POLYPHYLLUS ALCEA ROSEA O 0 ‘-_‘. 3 n 38 89 < '0 r I I . n N '- PACKAGING MATERIALS PACKAGING MATERIALS 20 Figure 1.3b. Mold rating on E. subulata; A. officinallis and Q. grandiflora following 4 and 6 months storage when packed in five different packaging materials as follows: A = 4 mil. Polyethylene; B = 4 mil. Perforated polyethylene; C = Cellophane; D = Cardboard; and E = Burlap. Mold rating: 5 = 76-1001 of the plant surface covered with molds: 4 = 51-75% covered with molds; 3 = 26-50% Covered with molds; 2 = 1-251 covered with molds; and 1 = No observable molds. 21 cg ..... “‘ :1 I g g8. . g o E E o 5 in o o 3 Z i - ‘5 P 2 in < - o. 39 < V. IH in or: J) a J- ONIIVH 0'10" andfi. ifive {1809i )oard; 01615: O < a G.‘ '5 25 a :3 '- 3 .3. s m o o x 2 g 3 3 l 9: .. 0- 3 . 38 83 V. C. B B I! t in I J) ‘15 .'- 9N1]!!! 0'10“ PACKAGING MATERIALS 22 Baggage Effect On Regrowth Quality The regrowth grade of A. officinallis. Q. lanceolata. Q. spectabilis. Q. grandiflora and E. subulata as influenced by package material and storage duration is given in Table 1.5. Analysis of variance indicates that only main effects were significant. Plants packed in polyethylene. perforated polyethylene and cellophane produced plants of nearly equal regrowth quality (Table 1.6). Packaging in cardboard or burlap significantly reduced quality (Table 1.6). All perennials except Q. lanceolata showed a decline in regrowth grade following 6 months storage with an increase in package permeability (Figure 1.4). Cellophane was the only packaging material from which Q. lanceolata produced acceptable quality plants after 6 months. In general. the same trends were observed for the response of plant height with some exceptions (Table 1.7 and Figure 1.5). Both Q. polyphyllus and A. gggga statistically produced taller plants after 6 months 'storage than after 4 months when packed in polyethylene or perforated polyethylene (Figure 1.5). Relation Of Weight Loss Ang Mold Development To Regrowth Qualjty Plots of weight loss and mold rating versus regrowth grade are shown in Figure 1.6a and 1.6b. Plots of weight loss and mold rating versus regrowth height are shown in Figure 1.7 for A. ngga and Q. gglyggyllus. The results suggest a strong relationship between weight loss and regrowth grade or height for all plants except A. ngga and Q. lanceolata. Regression lines were calculated for the plots of weight loss versus regrowth grade or height for A. officinallis. Q. grandiflora. Table 1.5. packed 23 Three week regrowth gradey after 4 and 6 month storage of herbaceous perennials in different packaging materials. Analysis of variance for regrowth grade is also given for reference. Packaging treatments 4‘ Name of Storage perennials dura- Poly Perfo Cello- Card- Burlap tion. poly phane board Asearagus 4 M0. 3.4 3.9 2.9 2.9 2.5 officinallis 6 M0. 3.4 3.0 3.2 1.7 1.6 Coreoesis 4 M0. 3.1 3.3 3.4 3.1 1.6 lanceolata 6 M0. 0.6 0.7 2.2 0.2 0.1 Dicentra 4 Mo. 4.7 4.2 4.6 3.4 1.7 spectabilis 6 M0. 4.0 3.0 2.3 1.6 0.4 Gaillardia 4 M0. 4.6 4.8 4.5 3.1 0.8 grandiflora 6 M0. 3.6 3.4 2.3 0.5 0.3 Phlox 4 M0. 4.7 4.7 4.5 2.0 1.3 subulata 6 Mo. 4.8 4.5 3.5 1.5 0.7 Y :Regrowth grade: 5 = 100% of regrowth potential; 4 = 2 = 401; l = 20%: ANALYSIS OF VARIANCE and 0 = No observable growth. 80%; 3 = 60%: Source Of Mean Square F. Value Prob. Packaging materials. 4 15.97 20.50 .000 Storage duration. 1 40.17 51.60 .000 P.M. x S.D. 4 0.82 1.06 NS Varities. 3 5.71 7.33 .000 P.M. x V. 12 1.35 1.73 NS S.D. x V. 3 2.18 2.80 NS P.M. x S.D. x V. 12 0.44 0.57 NS Error. 40 0.78 24 Table 1.6. Overall 3 week regrowth qualityy influenced by the packaging materials during storage averaged over plant material and storage duration. Name of packaging material Overall regrowth quality 4 mil. Polyethylene 3.43 4 mil. polyethylene with 3.29 perforations Cellophane 3.18 Cardboard 2.06 Burlap 1.11 LSDgos = 0.63 y :Regrowth grade: 5 = 100% of regrowth potential; 4 = 80%; 3 = 60%; 2 = 40%; 1 = 201; and 0 = No observable growth. 25 Figure 1.4. Three week regrowth grade of Q. spectabilis; E. subulata; A. officigallis; Q. grandiflora; and Q. lanceolata following 4 and 6 months storage in five different packaging materials as follows: A = 4 mil. Polyethylene; B = 4 mil. Perforated polyethylene; C = Cellophane; D = Cardboard; and E = Burlap. Regrowth grade: 5 : 1001 of regrowth potential; 4 = 801; 3 = 601; 2 = 40%; 1 = 20%; and 0 = No observable growth. 26 PHLOX SUBULATA I///////. ‘\\\\\\\\\. . r////////////. ‘\\\\\\\\\\\\\\\\\\\\\\. ////////////////////////////A \\\\\\\\\\\\\\\\\\\\\\\\\\\\\. . 7////////////////////////////A \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\. 7////////////////////////////A q q q u J G 3 2 I 0 ~30 1.59.08. xuw) n DIC ENTRA SPECTABILIS V\. r/////////A .\\\\\\\\\\. .. nl////////////////////. \\\\\\\\\\\\\\\. 7///////////////////////////A .\\\\\\\\\\\\\\\\\\\. . ///////////////////////////. \\\\\\\\\\\\\\\\\\\\\\\\\N 7/////////////////////////////. « h. .u. 1.. 0. mg Sou: xwui n PACKAGING MATERIALS PACKAGING MATERIALS GAILLARDIA GRANDIFLORA ASPARAGUS - OFFICINALLIS \\\\\\\\\\\\\\\. ////////////////////////////A V\\\\\\\\\\\\\\\\\\\\\\. 7////////////////////////////. \\\\\\\\\\\\\\\\\\\\\\. _. ///////////////////////.////////. q 1 q 1 4 3 2 on mac 1.580%. v.33 n V\\\\\\\\\. .l///////////////. \\\\\\\\\\\\\\\\\\\\\. 7////////.////////A .\\\\\\\\\\\\\\\\\\\. A. /////////////////////////. \.\\\\\\\\\\\\\\\\\\\\\h . 9//////////////////// « u. u. u. was Exam: xuw) n. w PACKAGING MATERIALS PACKAGING MATERIALS COREOPSIS LANCEOLATA \\\\\\\\\\\\\\. I////////////////////A V\\3 1. 7///////////////////A s\\\. I///////////////////. 1 a q q a 4 3 2 I 0 memo 79—393mm xuui n PACKAGING MATERIALS 27 Table 1.7. Three week regrowth heightY after 4 and 6 month storage of herbaceous perennials when stored in different packaging materials. Analysis of variances for regrowth height is also given for reference. Packaging treatments Name of Storage perennials dura- Poly Perfo Cello— Card- Burlap tion. poly phane board Alceg rosea 4 Mo. 7.40 2.53 4.30 0.75 0.1 6 Mo. 17.60 11.75 4.50 0.1 0.1 Asegragus 4 Mo. 56.35 57.38 53.30 49.75 32.35 officinallis 6 Mo. 70.40 55.85 52.90 31.05 25.85 Coreoesis 4 Mo. 6.75 8.45 8.50 6.20 2.98 lanceolata 6 Mo. 2.90 4.25 7.35 0.85 0.1 Dicentra 4 Mo. 49.75 44.75 48.80 37.85 19.10 spectabilis 6 Mo. 60.30 53.60 45.30 35.70 10.60 Gaillardia 4 Mo. 8.00 8.10 8.48 4.60 1.45 grandiflora 6 Mo. 9.05 8.35 5.20 1.65 0.80 Luginus 4 Mo. 11.10 11.10 14.25 6.15 0.15 gglyghyllus 6 Mo. 17.55 21.40 8.70 10.50 .00 y :Height in centimeters. ANALYSIS OF VARIANCE Sggrce DF Mean Squage F. Valge Prob. Packaging materials. 4 1322.06 22.62 .000 Storage duration. 1 1.06 0.02 NS P.M. x 5.0. 4 155.96 2.67 .040 Varieties. 5 7877.25 134.77 .000 P.M. x V. 20 147.56 2.52 .003 5.0. x V. 5 34.36 0.59 NS P.M. x S.D. x V. 20 32.60 0.56 NS Error. 60 58.45 28 Figure 1.5. Three week regrowth height of A. officinallis; Q. spectagilis; Q. grandiflora; Q. lanceolata; A. rosea; and Q. polyphyllus following 4 and 6 months storage in five different packaging materials as follows: A = 4 mil. Polyethylene; B = 4 mil. Perforated polyethylenes; C = Cellophane; D = Cardboard; and E = Burlap. 29 \\\\\\\\\\\\\\\\. . ////////////////A ‘\\\\\\\\\\\\\\\\\\\\. //////////////////////. V\\\\\\\\\\\\\\\\\\\\\\\. _ 7///////////////////. .\\\\\\\\\\\\\\\\\\\\\\\\\\\. A 7/////////////////////. .... w m.” a. a w a a A28 58: 5:68am an; n olllll - . . m .\\\\\\\\\\\. w m . 7////////////z 4 6 m H mm \\\\\\\\\\\\\s . 7////////////////////A . \\\\\\\\\\\\\\\\\\\\\\\\. 7//////////////////////A .. .\\\\\\\\\\\\\\\\\\\\\\\\3 .. . . /////////////////////////A 1. \\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\. 7////////////////////////. .... a a a a a. m... ... 38 53: 1388”. cam; n PACKAGING MATERIALS PACKAGING MATERIALS A m m m. 7///////z ... W 4 I m o an .5. fl 9/////////////////A w .\\\\\\\\\\\\\\\\\\.\\\\\. c .1: 7/////////////////////////A m .\\\\\\\\\\\\\. I R 7//////////////////////////. O c \\\\\\\\\. A 7///////////////////A ...qq...1. 99.73543210 Ass 53: :Sozuaz an; n \\\\\. o ?////////////A \\\\\\\\\\\\\\\\\. C 7//////////////////////////. \\\\\\\\\\\\\\\\\\\\\\\\\\\. B /////////////////////////A V\\\\\\\\\\\\\\\\\\\\\\\\\\\\. A r/////////////////////////. dd dqfiddd mh87&543210 ‘ $8 58.: 2596”». you: n PACKAGING MATERIALS PACKAGING MATERIALS yo 9 PIN .\\\\\\\\\\\\\. O r//////A \\\\\\\\\\s c 7////////////////A \\\\\\\\\\\\\\\\\\\\\\\\\\\8 B //////////////. ‘\\\\\\\\\\\\\\\\\\\\\K A 7/////////////. m a. m a. d ABC—gguzaasn ALCW mm. 4. \\\\\\\\\\\\\\\\\\\\\\8 A 7////////. m ...... a .... m Azorgzioeouzfiusn PACKAGING MATERIALS PACKAGING MATERIALS 30 Figure 1.6a. Relationship of mold rating and percent weight loss on 3 week regrowth grade of E. subulata; Q. grandiflora; and Q. spectabilis. Mold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26—50z covered with molds; 2 = 1-251 covered with molds; and 1 - No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 80%; 3 = 60%; 2.: 401; 1 = 201; and 0 = No observable growth. ' swcckecceowmcm' swccknzcaowmcm SWEEKREGROWTHGRADE PHLOX SUBULATA 31 no ' o 4 no. 0 I o CHO. ‘cl 0 J-l 2-0 0 0 Id ' 5 5 1 :5 MOLD RATING GAILLARDIA CRANDIFLORA 5.. o o 4 MO. ll ’ o o no. 41 . o 3‘ C o 2-1 H o o o c i 5 1 ii MOLD RATING Q DICENTRA SPECTABILIS v o O O 4 MO. 0 IMO. I: 4- C I o 3- o a 2‘ ° 0 H 0 ° 5 s I s MOLD RATING PHLOX SUBULATA o a . O A”. 0 0 o DID. ‘1 o 3.. 2‘ o o o is c I W T t I -I 1 IO 20 JD 40 50 .0 7D PERCENT WEIGHT LOSS DURNG STORAGE (G) GAIL_LARDIA emanate/1 SWEEKREGROWTHGRAK 'k' 06‘ .e 0000. .1 O O 3‘ O O 24 1.1 o O o '1 To at 3'0 4'0 :3 oi: 10 PERCENTWEIGI-flLOSSDURINGSTORICEfi) DICENTRA SPECTABILIS JNEEKREGROWTHGRAM - . . Gm ' o no. a 4-1 O o 3- o o 2-1 . o '1 O '0 in in 3'0 4'0 0'0 0'0 70 PERCWWEIGI‘WLOSSMNGSTORAGEW) 32 Figure 1.6b. Relationship of mold rating and percent weight loss on 3 week regrowth grade of A. officinallis and Q. lanceolata. Mold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-751 covered with molds; 3 = 26-751 covered with molds; 2 = 1-251 covered with molds: 1 = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 801; 3 = 601; 2 = 401; 1 = 201; and 0 = No observable growth. _ SWEEKREGROWTHGRADE SWEEKREGROWIHGRAIE ASPARAGUS OFFICINALLIS 33 a 4 MO. 0 0 no. ‘1 31 1 2c: '0 ‘1 ' i 3 3 :1 MOLD RATING , coeeoesnsfiuuceoum ' a 4 MO. 0 0 no. ‘- O 3. O 2. I I-1 . O SKEKREGROWTHGRACE SWEEKREGROWI'MGRAII ASPARAGUS OFFICINALLIS ' 0 one. o 0110. O" . 00 SJ 0 o ' e a 2d ' o 1... o ' I I I I I II ID 20 so 40 50 ‘0 70 PERCENT WEIGHT LOSS DURING STORAGE (G) COREOPPSIS LANCEOLATA o ”In. o “D. ‘- .0 3‘ O O 24 ° 0 'd .. o T r fit Y .' %l D IO N a n a O0 70 PERCENT WEIGHT LOSS DURING STORAGE (G) 34 Figure 1.7. Relationship of mold rating and percent weight loss on 3 week regrowth height of Q. golyghyllus and A. rosea. Mold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26—50% covered with molds; 2 = 1-251 covered with molds; and 1 = No observable molds. 3 WEEK REGROWT H HEIGHT 3 WEEK REGROWT H HEIGHT 25 LUPIN US POLYPHYLLUS 20': I5- IO- 0 o 4M0. o 0M0. LQPINUS EQJPHIQQUS s ween neceowrw HEIGHT (cu) 251 20-1 is-fi 10- com. com. A A .55 3 week asceowm wacwr (cu) U fi I r 1 1 IO 20 30 40 50 U 70 PERCENT WEIGHT LOSS DURING STORAGE (G) A AA O I 1'0 23 3'0 4'0 :3 an 70 mean mom LOSS ounmc STORAGE (c) 36 Q. lanceolata. Q. spectabilis. Q. polyphyllus. E. subulata and A. rosea. For the purpose of this regression. 2 points from 6 months of Q. lanceolata in polyethylene and perforated polyethylene were ommitted. Highly significant inverse linear relationships were found in all cases (Table 1.8). All r values were A 0.90. Statistically. E. subulata tolerated up to 6 1 weight loss prior to a decline in regrowth quality. All other plants began to lose regrowth quality immediately with a loss in weight loss and at similar rates based on the slopes of the regression. According to the X intercepts. complete death of the plants occurred over a range of 40 - 78% weight loss. Q. lanceolata showed the same trends only after the 2 points were omitted. No clear relationship between mold rating and regrowth grade or height was observed for most varieties although the regrowth quality of A. officinallis and Q. spectabilis tended to decline with increased presence of molds (Figure 1.6a; 1.6b; and 1.7). It was found that when plants were covered more than 50% with molds. the regrowth quality was generally. very poor. Q. spectapilis was the most tolerant of the plants tested to the presence of mold growth. 37 Table 1.8. Statistical analysis of moisture loss curves. Percent loss in quality per percent loss in weight calculated by multiplying slope by 20 (Since regrowth grade on a 0 - 5 scale). Name of perennial slope r X-intercept 1 loss in quality/ ngeight loss Phlox subulata -0.093 -0.94 601 1.9 Dicentra sgectabilis -0.068 -0.93 701 1.4 Qaillardia grandifloga -0.070 -0.97 651 1.4 * oreogsis lanceolata -0.065 -0.96 501 1.3 +Qgpinus polyphyllus -0.047 -0.94 63% 1.1 +Alcea rosea -0.053 -0.94 401 1.1 Asgaragus officinallis -0.047 -0.90 78% 0.9 Average: -0.063 61% 1.3 The 6 month data for polyethylene and perforated polyethylene were eliminated prior to analysis. + : Analysis performed on regrowth grade versus weight loss using 6 month data only. W The most important finding of these experiments is the highly significant inverse linear relationship between regrowth quality and water loss for a range of bare-root herbaceous perennials (Figures 1.6a; 1.6b and 1.7). It is safe to assume that the great majority of weight loss was due to loss of water. There was little evidence for threshold relationship to water loss except for E. subulata. In our studies. Q. lanceolata was an exception primarily because it performed poorly in all treatments after 6 months storage. Q. lanceolata did show a similar relationship between regrowth quality and water loss for the 4 months data (Table 1.8). Heiden and Cameron (1985. unpublished data) showed that Q. lanceolata was easily injured by freeze/thaw cycles. It should be noted that all plants were inadvertently run through a freeze/thaw cycle at 6 months. Perhaps gthis accoUnts for the poor quality of Q. lanceolata. There is no apparent reason why Q. lanceolata performed better after 6 month storage when packed in cellophane. Both A. :9; a and Q. polyphyllus attained more height after 6 months than after 4 months when packed in polyethylene and perforated polyethylene and stored at -2°C (Figure 1.5). This is most probably a physiological response of the plants to storage duration. Stark and Cameron (1985. unpublished) measured a similar relationship for an increase in regrowth height of Lilium spp. with time stored at -2°C. It is evident from the Figures 1.6a and 1.6b that no prediction can be made for regrowth quality based on the presence or 38 39 absence of the molds. The entire range of regrowth grades were observed when molds covered less than 25% of stored plants. However. regrowth quality was generally reduced when molds covered more than 501 of the plant surface. Q. spectabilis was one exception which even when covered with more than 751 molds could grow to an acceptable quality. Some plants grew poorly even when molds were absent. Thus. the presence or absence of molds alone could not be used as criteria of plant regrowth quality. The regression lines calculated between moisture loss and regrowth quality (Table 1.8) showed a significant correlation with r A .90. The X-intercepts demonstrate that there is a wide range in tolerance to moisture loss prior to death 140-781; Table 1.8). The average relationship between percent loss in quality and water loss suggests that a loss of 11 moisture will drop the regrowth quality by about 1.31. (Table 1.8). The rates of transpiration for a range of bare-root perennials have been measured (Maqbool and Cameron 1983; unpublished). When calculated for 20°C and 50% relative humidity. the data indicates that most of the plants transpire at rates between 0.5 to 1.5 gms H20.hr’1.100 gms FW‘l but at rates up to 5.0 gms H20.hr‘1.100 gms FW‘l depending on time of harvest. storage duration and variety. It is obvious from these transpiration rates that plants could lose moisture during harvesting and processing when exposed to elevated temperatures and/or low relative humidity at rates which could be detrimental for their survival. Cameron (1985. unpublished) developed a mathematical model based on moisture loss. regrowth relationship and measured transpiration rates for Q. subulata. It was shown that plant 40 regrowth grade would be expected to drop to zero within 4 days at 15°C. 501 RH or 11 days at 0°C. 50% RH. The above experiments indicate that maintenance of relative humidity very near to 1001 is essential to maintain regrowth quality of herbaceous perennials. Among the packaging materials used in these experiments. 4 mil. polyethylene retained maximum moisture as compared to other materials. Similarly. regrowth quality of plants was superior when packed in 4 mil. polyethylene followed by perforated polyethylene. Furthermore. there was no evidence of any harmful effect of condensation. modified atmospheres or lack of adequate heat exchange under our conditions. These factors can be controlled to some extent by precooling (Mahlstede and Fletcher 1960; Hardenburg 1972) or package ventilation (Truter and Bester 1982). A relatively small number of perforations in the polyethylene liners will greatly enhance the exchange of oxygen and carbon dioxide with a relatively small effect on water vapor. In the current study. perforations increased the rate of water loss by approximately 50% (Table 1.1). However. this did not cause a significant decline in regrowth quality (Table 1.6). All techniques to reduce condensation or improve heat and gas exchange would be expected to increase the amount of moisture loss from the plant. The reason may be that polyethylene was not sealed but was folded on the top and thus had sufficient openings for gas exchange. On the basis of these findings. the use of unsealed or slightly perforated polyethylene is strongly recommended for the long-term storage of herbaceous perennials. LITERATURE CITED. 41 LITERATURE CITED Duffield. J. W.. R. P. Eide and W.B Greeley. 1959. Polyethylene bag packaging of conifer planting stock in the Pacific Northwest. Jour. Forestry. 57(8): 578-579. Hardenburg. R. E. 1949. Moisture losses of vegetables packaged in transparent films and their effect on shelf-life. Proc. Amer. Soc. Hort. Sci. 53: 426-430. 1951. Further studies on moisture losses of vegetables packaged in transparent films and their effect on shelf-life. Proc. Amer. Soc. Hort. Sci. 57: 277-284. 1971. Effect of in package environment on keeping quality of fruits and vegetables. HortScience. 6(3): 201. ; M. Lieberman.. and H. A. Schomer. I953. Prepackaging Carrots in different types of consumer bags. Proc. Amer. Soc. Hort. Sci. 61: 401-412. Mahlstede. J. P; and W. E. Fletcher. 1960. Storage of nursery stock. Amer. Associ. Nurserymen. Washington. D. C. pp.62. ; and L. P. Kirk. 1954. Polyethylene. A solution to nursery shipping problems. Amer. Nurserymen. 100(4): 7-8. 57-64. ‘ Prince. T. A.. and R. C. Herner. 1984. Design of modified atmosphere package for marketing of precooled Tulip bulbs. Jour. Amer. Soc. Hort. Sci. (Submitted for publication). Tomkins. R. G. 1962. The conditions produced in film packages by fresh fruits and vegetables and the effect of these conditions on storage life. Jour. Appl. Bact. 25(2): 290-307. Truter. A. 8.. and C. W. J. Bester. 1982. Packing and cooling of Strawberry runner plants. The Deciduous Fruit Grower. 32(11): 485-489. Uota. M.. J. M. Harvey.. and R. W. Lateer. 1959. Commercial packaging and storing of bare-root Rose bushes. U. S. Department of Agriculture. Marketing Research Report No.308. Washington. D. C. Worthington. J. T.. and D. H. Scott. 1957. Strawberry plant storage using polyethylene liners. Amer. Nurseryman. 105(9): 13. 56-57. .. and W. L. Smith. 1966. Effect of root trimming and storage containers on field survival and yield of Asparagus plants. Proc. Amer. Soc. Hort. Sci. 89: 346-349. CHAPTER II EFFECT OF STORAGE TEMPERATURES ON THE PERFORMANCE OF BARE-ROOT HERBACEOUS PERENNIALS 42 INTRODUCTION Long term. low temperature storage of many perishable commodities is a well known commercial horticultural practice. The main purposes of low temperature storage are to minimize the rate of respiration. metabolic activities, mold development. other physiological disorders. and to maintain the produce in an acceptable condition for as long as possible. Fall harvested bare-root herbaceous perennials are customarily maintained at low temperatures for storage throughout winter and spring months. Several of these perennials are stored as roots along with their crowns but there are many others which are stored as entire plants (Mahlstede and Fletcher. 1960). Few experiments have been conducted to determine optimum storage temperatures (Mahlstede and Fletcher. 1960). Higher ,storage temperatures accelerate the rate of chemical reactions (Nobel. 1970). desiccation (Salisbury and Ross. 1978) and etiolated. growth of plants during storage (Boontjes. 1982). whereas. freezing injuries would be expected to increase as storage temperatures are dropped below 0°C (Whiteman. 1957; Pellet. 1971; and Levitt. 1980). The optimum storage temperature represents a compromise between these two end limits. Although little is published on the optimum temperature for storage of herbaceous ornamental perennials. optimum storage temperatures for other temperate nursery crops have been shown to vary from -3°C to +4°C depending on the experiment and the plant. 43 44 Mahlstede and Fletcher (1960) cited unpublished work conducted in 1953 by Mr. George Rose of the Henry Field Seed and Nursery who stored some representative perennials at three storage environments: -2.2°C to -I.1°C; 1.1°C to 4.4°C; and 10°C to 18°C. Various trends were observed. Eggatorium coelestinum. Convallaria majalis. and Platycoden spp. were successfully stored in sealed polyethylene bags held at all of the storage temperatures tested. However. Coreogsis spp. Chrysanthemgm maximum and Stokesia sp. were difficult to handle under any of the packaging and storage conditions. Lutz and Hardenburg (1968) recommended that many kinds of herbaceous nursery stock such as Dianthus ggrygphyllus and Chrysanthemqm spp. be stored at temperatures ranging from -0.55 to 1.65°C.' Several researchers have concluded that the optimum storage temperature for strawberry is -1.l°C (Guttridge et al.. 1965; Worthington and Scott. 1970; and Anderson. 1982). A few studies have been conducted to determine optimum storage temperatures for bare—root woody plants. Mullin and Parker (1976) successfully stored White spruce and Jack pine at -4°C but not at -18°C. Seedlings of many forest species were found to store well at 2°C but storage at -5°C reduced the rate of survival after planting (Aldhous. 1964). Morby and Ryker (1979) found that certain fall lifted tree seedlings stored at 0.6°C or -2.2°C performed about the same. Swanson et al. (1983) observed more detrimental storage of Agg; ginnala. Acer saccharum and Rhus tyggina at 0°C as compared to other temperatures for long term storage. Tip dieback was apparent after 80 days at -3°C. Storage at 3°C was most effective for A. ginnala and B. tyghina. 45 The following experiments were conducted to determine the effect of storage temperatures on regrowth performance of several herbaceous perennials under conditions where desiccation was minimized. MATERIALS AND METHODS Bare-root plants of Alcea rosea. Asggragus officinallis. Coreopsis grandiflora. Dicentra spectabilis. Gaillardia grandiflora. QQpinus polyphyllus and Eth§ subulata were harvested on November 18. 1983 from a field at Walter’s Gardens. Zeeland. MI. 5011 was removed from the roots and crowns. All senesced shoots of Algga,£g§gg. Asggragus officinallis. Dicentra spectagilis and QQpinus polyphyllgg and green tops of Coreopsis grandiflora and Qgillardia grandiflora were removed to within 1-2" of the crown. Plants of £3195 subulata were not trimmed. Plants were then precooled in open crates at 2°C for 24 hours. The plants were separated according to the experimental design and were packed in polyethylene lined crates with three replicates per treatment and five plants per replicate. overall there were three bags placed in two crates for each storage temperature of 0°C and -2°C. After 4 months. plants were removed from storage. visually rated for mold development using the following scale: 5 = 76- 1001 of the plant surface covered with molds; 4 = 51- 75% covered with molds; 3 = 26- 50% covered with molds; 2 = 1-251 covered with molds; and I = No observable molds. After mold rating. plants were returned to their respective storage temperatures. After 6 months. plants were again removed from storage. similarly rated for mold development and immediately planted in 46 containers and grown under greenhouse conditions. Data was collected weekly for regrowth potential and quality. A subjective scale of 0 - 5 was used with 0 defined as dead and 5 as optimum regrowth quality based on density of the foliage. vigor and amount of new growth. The scale can be defined as follows: 5 = 1001 of regrowth potential expected during forcing; 4 = 801 of regrowth potential; 3 = 60% of regrowth potential; 2 = 401 of regrowth potential; 1 = 201 of regrowth potential and 0 = No observable growth. Height was measured weekly for all plants except 2. subulata (a creeping plant). Only the data collected at 3 weeks is presented. On November 8. 1984. plants of Artemesia schmidtiana. Asclggias tuberosa. AgQgg novoae-anglii. Centrgnthus LQQQL. Chrysanthemgm maximum. Dicentra exlmg. Q. spectapilis. Qggm chiloense. flgggg undulata and QQpinus polyphyllus were harvested and processed commercially by Walter's Gardens. The plant material was precooled for 24 hours at 2°C. Plants were .then separated according” to the experimental design and were weighed prior to packing in polyethylene-lined crates. which were placed at -10°C. -5°C. -2°C. +2°C. or +5°C storage temperatures. There were 2 replicates with 5 plants per replicate. After 6 months. plants were removed from the storage and reweighed. The presence or absence of etiolated growth was noted on a plant by plant basis and percent etiolation was calculated. Mold development and plant quality were measured as described above. Percent weight loss was calculated on the basis of initial and final fresh weights. 47 RESULTS ngeriment I MOLD RATING No significant differences in mold development were found when plants were stored either at 0°C or -2°C for 4 months in 1983-84 (Table 2.1). After 6 months storage. Q. lanceolata and Q. polyphyllus were the only two types for which significant differences in mold development were observed (Table 2.1). Q. lanceolata significantly stored better at 0°C. whereas. Q. gglyghyllus was better at -2°C after 6 months storage (Figure 2.1). These significance levels were based on mean separations using LSD values calculated from analysis of variance (Table 2.1). The percentage increase in susceptibility of mold development was calculated from 4 to 6 months storage duration combining data for .both temperatures (Figure 2.2). The extent of. mold development in descending order from Q. specthAiis; Q. lanceolata; A. nggg; Q. grandiflora; Q. gglyghyllus; A. offlcingllis; E. subulata. All increases were significant based on mean separations (Figure 2.2). Regrowth guality Despite differences in mold rating there were no significant differences in regrowth grade between 6 months storage at either 0°C or -2°C in 1983-84 (Table 2.2 and 2.3). No significant differences in regrowth height were noted except for Q. spectabilis which grew 48 Table 2.1. Hold ratingY after 4 and 6 month storage of herbaceous perennials durations stored at different temperatures in experiment 1 (1983-84). Analysis of variance for mold rating is also given for reference. Storage temperatures Name of perennial Storage Duration 0°C -2°C Alcea rosea 4 Ho. 1.27 1.40 6 Ho. 2.53 3.00 Asparagus officinallis 4 Ho. 1.20 1.07 6 Ho. 1.53 1.80 Coreopsis lanceolata 4 Ho. 1.73 2.00 6 Mo. 2.60 4.13 Dicentra spectabilis 4 Ho. 1.67 2.00 6 Ho. 3.80 3.93 Gaillardia grandiflora 4 Ho. 1.53 1.33 6 Ho. 2.40 2.07 Lupinus polyphyllus. 4 Ho. 1.80 1.53 6 Ho. 2.60 1.80 Piox subulata ‘ 4 Ho. 1.33 1.33 ‘ 6 Mo. 1.87 1.80 y :5 = 76 - 1001 of the plant surface covered with molds; 4 = 51 - 751 Surface covered with molds; 3 = 26 - 501 surface covered with molds; 2 = 1 - 251 surfaced covered with molds; and 1 = No observable molds. ANALYSIS OF VARIANCE SOURCE OF HS - F.VALUE PROB. Temperatures 1 0.952 1.35 NS Storage duration 1 115.238 162.96 .000 Temperature x 5.0 1 0.61 0.86 NS Cultivars. 6 16.610 23.49 .000 Temperature x Cuitivars 6 3.130 4.43 .000 Storage duration x Cul 6 5.538 7.83 .000 Temp x 8.0 x Cu] 6 1.287 1.82 NS Error 392 0.707 49 Figure 2.1. Percent increase in mold development at 0 or -2°C during storage in experiment 1 (1983-84). Significance levels were based on mean separations using LSD values calculated from analysis of variance in Table 2.1. Bars to the right represent superior storage at 0°C whereas bars to left represent superior storage at -2°C. Significance levels ("') are at .001 level and (') at .05 level. 50 .UQ:m>..oe 3253— . .l_ 51 Figure 2.2. Percent increase in susceptibility to mold development from 4 to 6 months storage of herbaceous perennials in experiment 1 (1983-84). Significance levels were based on mean separations using LSD values calculated from analysis of variance (Table 2.1). (**'1 significant at .001 and (*) at .05 levels. 52 th202 m C... ¢ 20¢... hzuzmodao 0.52 z. mmfimoz bzuommm Oh co cm 0* on ON 0— . . P b p — a — an; .w_.__mma50a max-£3 £4412ng m:o<¢<¢w< 4.2.50...» x033 53 Table 2.2. Three week regrowth gradingY and height2 following 6 months storage of herbaceous perennials at different temperatures in experiment 1 (1983—84). Analysis of variance are given in Table 2.4. Storage temperatures Name of perennial. Grade or Height. 0°C —2°C Alcea rosea Grade 2.07 1.13 Height 12.03 7.00 Asegragus officinallis Grade 2.87 2.80 Height 64.93 74.73 Coreopsis lanceolatus Grade 1.00 ‘ 1.00 Height 5.07 4.33 Dicentra spectabilis Grade 2.00 2.67 Height 27.33 46.40 Gaillardia grandiflora Grade 3.60 2.93 Height 9.20 8.00 Lupinus polyphyllus Grade 2.40 2.73 Height 15.20 20.30 Phlox subulata Grade 3. 73 3.80 y :Regrowth grade: 5 = 1001 of the optimum growth expected after 3 weeks; 4 = 80%; 3 = 60%; 2 = 40%; 1': 20%; and 0 = No observable growth. 2 :Height in centimeters. 54 Table 2.3. Analyses of variances for 3 week regrowth grade and height following 6 months storage at -2°C or 0°C in experiment 1 (1983-84). ANALYSIS OF VARIANCE (3 WEEK REGROHTH GRADE) SOURCE OF HS F.VALUE. PROD. Temperatures 1 0.077 0.09 NS Cultivars. 6 5.393 6.02 .000 Temp. x Cul. 6 0.457 0.51 NS Error 28 0.895 ANALYSIS OF VARIANCE (3 WEEK REGRONTH HEIGHT) SOURCE OF HS F.VALUE PROB. Temperature 1 183.602 5.15 .032 Cultivars 5 3752.973 105.27 .000 Temp. x Cul. 5 117.740 3.30 .020 Error ‘ 24 35.651 55 about 701 taller when stored at -2°C than stored at 0°C (Table 2.2). Experiment 2 Hold development over a wider range of temperatures was measured following 6 months storage in 1984-85 (Table 2.4). Very little mold development was observed on plants stored at -10°C (Table 2.4). However. most of the plants except A. schmidtiana and H. undulata were fully covered with molds following storage at -S°C. No significant differences in mold development were seen in most of the plants when stored at —2°C. +2°C and +5°C (Figures 2.33 to 2.3d). Hold development was more severe at -2°C and +5°C than at +2°C in Q. maximum and at -2°C than at +2°C or +S°C in Q. QQQQQ (Figures 2.3b; and 2.30). R_egrowth ang lty In 1984-85. none of the herbaceous plants grew after storage at -10°C (Table* 2.5; Figure 2.3a to 2.3d). A. schmidtiana; A. novae-belgii: Q. gxlmlg and fl. undulata were the only plants which grew after storage at -5°C (Table 2.5: Figure 2.3a; and 2.3b). A. schmidtiana; A. tuberosa: A. novae-belgii: Q. sgectabllis; Q. gxlmig and fl. undulata all grew equally well following storage at +S°C. +2°C or -2°C based on regrowth grade (Figures 2.3a to 2.3c). However. Q. maximum only produced acceptable quality plants after storage at +2°C (Figure 2.3b) . Q. Eggs; performed somewhat poorly following storage at +2°C or +5°C but did not survive storage at -2°C (Figure 2.3c). 56 Table 2.4. Hold ratlnng following 6 months storage of herbaceous perennials at different temperatures in experiment 2 (1984-85). Analysis of variance is given for reference. Storage temperatures Name of perennial. +5°C +2°C -2°C —5°C -10°C Artemisia schimidtiana 2.0 2.0 2.3 2.0 1.3 Asclepias tuberosa 2.7 2.4 2.9 4.9 1.0 Aster novae-belgll 4.1 3.3 3.0 3.4 1.0 Centfanthus ruber 1.8 1.7 3.8 4.9 1.0 Chrysanthemum maximum 3.5 2.4 4.0 5.0 1.0 Dicentra exima 2.2 2.4 1.6 3.6 1.1 Dicentga spectabilis 2.7 3.1 2.9 5.0 1.0 Qan chiloense 2.6 2.3 3.2 3.7 1.0 flgaQa undulata 2.8 2.7 2.0 2.2 1.0 QQpinus polyphyllaa 2.7 A 2.6 2.4 5.0 ‘ 1.0 y :5 = 76-1001 of the plant surface covered with molds; 4 = 51-751 covered with molds; 3 = 26-50% covered with molds; 2 = 1-251 covered with molds; and 1 = No observable molds. ANALYSIS OF VARIANCE SOURCE; OF HS F.VALUE PR08. Temperatures 4 22.031 90.44 .000 Cultivars 9 1.654 6.79 .000 Temperatures x Cul. 36 0.923 3.79 .000 Error 50 0.244 57 Figure 2.3a. Hold rating and 3 week regrowth quality of A. novoae-anglii; fl. undulata; and A. schmidtiana following 6 months storage at different temperatures in experiment 2 (1984-85). Hold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-751 covered with molds; 3 = 26-50% covered with molds; 2 = 1-251 covered with molds; and 0 = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 80%; 3 = 60%; 2_= 40%; l = 20%; and 0 = No observable growth. . now RAIN now RATING ASTER NOVOAE-ANGLII “5°95" 44 ‘——‘ 3" l———J ‘ 2. l -10 - s - z + 2 + 5 mm: memmnes ('C) 3 HOSTA uuouuu 4.. “5°.os'I 3. T..—d— 2. l --10 - S - 2 + 2 + s stoma mmmnes (c) . ARTEMESIA scmom 4. 31 60.05. I 2. does-2+2 +s 570m: mammass (e) 58 SEER REGROWTHGRADE SWEEK REGROWIHGRADE 3 WEEK REGROWI'H GRADE ASTER NOVOAE-ANGLII (I “5°.os'[ '—""_'l ‘d 34 2a 1.. c ~10 - 5 - 2 + 2 + 5 510m: TEMPERATURES ('c) I. HOSTA UNDULATA .. ___1"'_—’—-1 4... 60.05.[ 3.. 2.. l- [—— ° -1o*-s-2+2+s 5mm: mammaes (c; , ARTEMESIA scmuorm “ I L53.057 3.. 2.. 1.. c ~10 '- S - 2 + 2 + 5 5mm: TEMPERATURES (.C) 59 Figure 2.3b. Hold rating and 3 week regrowth quality of Q. maximum; Q. chiloense; and Q. exima following 6 months storage at different temperatures in experiment 2 (1984- 85). Hold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-751 covered with molds: 3 = 26-50% covered with molds; 2 = 1-251 covered with molds; and 1 = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 801; 3 = 60%; 2 = 401; 1 = 201; and O = No observable growth. MOLD RATING HOLD RATING MOLD RATING CHRYSANTHEMUM MAXIMUM LSDOS’ ‘1 34 2-1 i —10 - 5 - 2 + 2 + 5 STORAGE TEMPERATURES (‘c) ‘ GEUM CHILOENSE LSD -[ 4. .05 3-4 2‘1 1 -‘IO - s - 2 + 2 + s STORAGE TEMPERATURES ('G) ‘ DICENTRA EXIMA LSD -[ 4. .OS 3.. 24 _ l -lO - S - 2 + 2 + S STORAGE TEMPERATURES (’G) 60 .3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE CHRYSANTHEMUM MAXIMUM s 4.. LSD - 3. .05 2-1 1-l ° -10 - S - 2 + 2 + S STORAGE TEMPERATURES CG) 5 GEUM CHILOENSE 41 L500!)- 3. 2a 1.1 c -TO - S - 2 + 2 + s STORAGE TEMPERATURES (°G) ‘ DICENTRA EXIMA SO L a 4‘ .05 [ 3.. 2.. 1. c -10 - s - 2 + 2 + S STORAGE TEMPERATURES ('G) 61 Figure 2.3c. Hold rating and 3 week regrowth quality of Q. ruber; A. tuberosa; and Q. spectapilis following 6 months storage at different temperatures in experiment 2 (1984-85). Hold rating: 5 = 76-1001 Of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26-501 covered with molds; 2 = 1-251 covered with molds; and 1 = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 801; 3 = 60%; 2 = 40%; 1 =_201; 0 = No observable growth. MOLD RATING 2-1 MOLD RATING MOLD RATING CENTRANTHUS RUBER 5 LSD.05-[ 4. 3. 1 -10 - S - 2 + 2 + 5 STORAGE TEMPERATURES ('C) ‘ ASCLEPIAS TUBEROSA 4. LSDOS" 31 2-1 1 -10 - S - 2 + 2 + S STORAGE TEMPERATURES CG) ‘ DICENTRA SPECTABILIS LS°.OS'[ 4. 3. 2.. -10 - S - 2 + 2 + S STORAGE TEMPERATURES (G) 3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE CENTRANTHUS RUBER s 4-1 3‘ LSDOS' 2.. l. ° --10 - s - 2 + 2 + S STORAGE TEMPERATURES (G) s ASCLEPIAS TUBEROSA 4. LSDOS' 3‘ 2. 1. ° '-iO-5-2+2 +5 STORAGE TEMPERATURES (G) ‘ DICENTRA SPECTABILIS Ls".05" 4. 3. 24 H O -iO - S - 2 + 2 + 5 STORAGE TEMPERATURES CC) 63 Figure 2.3d. Hold rating and 3 week regrowth quality of Q. polyphyllus following 6 months storage ar different temperatures in experiment 2 (1984-85). Hold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-751 covered with molds; 3 = 26-501 covered with molds; 2 = 1-251 covered with molds; and 1 = NO observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 801; 3 = 601; 2 = 401; 1 = 20%; and 0 = NO observable growth. MOLD RATING LU PINUS POLYPHYLLUS .5 l U 1 N 1 ”50.05" [ -10 - S - 2 + 2 + S STORAGE TEMPERATURES CC) 64 3 WEEK REGROWTH GRADE 5 LUPINUS POLYPHYLLUS (d 1 N 1 d J 4.4 LSDDO- l O -10 - S - 2 + 2 + 5 STORAGE TEMPERATURES ('G) 65 Table 2.5. Regrowth gradeY after 6 months storage of herbaceous perennials stored at different temperatures in experiment 1 (1984-85). Analysis of variance for regrowth grade is also given for reference. Storage temperatures Name of perennial {5°C +2°C -2°C -5°C -10°C Artemisia schimidtiana 4.4 5.0 4.2 1.7 0.0 Asclegias tuberosa 1.6 1.9 1.7 0.0 0.0 Aster novae-belgli 4.9 4.6 4.5 2.5 0.0 Centranthus ruber 1.6 2.0 0.0 0.0 0.0 Chrysanthemum maximum 1.1 3.4 1.6 0.0 0.0 Qicentra exima 4.9 4.9 5.0 2.6 0.0 Dicentra spectabilis 3.1 4.2 3.9 0.0 0.0 Qan chiloense 2.2 4.0 3.4 0.0 0.0 anQa undulata 4.8 4.9 ,-4.7 1.2 , 0.0 Luginus gglyghyllus 4.2 4.2 3.9 0.0 0.0 y:5 = 1001 of regrowth potential; 4 = 801: 3 = 60%; 2 = 401; 1 = 20% 0 = No observable growth. ANALYSIS OF VARIANCE SOURCE OF HS F.VALUE. PROB. Temperature 4 60.315 210.01 .000 Cultivars 9 10.052 35.00 .000 Temp. x Cu]. 36 1.27] 4.43 .000 Error 50 0.287 66 Very poor quality and significantly reduced height was Observed in all plants which survived storage at -5°C (Table 2.6: Figure 2.4a and 2.4b). A. schimidtiana; A. tuberosa; A. novae-belgil; Q. exlmla; A. undulata and Q. chiloense grew to comparable heights following storage at +S°C. +2°C and -2°C temperatures. Q. spectabilis produced statistically equal heights following storage at +5°C and +2°C. However. a significant decrease in regrowth height followed storage at -2°C (Figure 2.4b). Q. polyphyllus produced Slightly superior height after storage at +5°C compared to +2°C or -2°C (Figure 2.43). Etiolation None Of the plants produced etiolated growth when stored at 0°C or -2°C in 1983-84 storage season. The following year. etiolated growth was only Observed from plants stored at‘+5°C and +2°C (Table 2.7). Q. undulata and A. tuberosa showed the least susceptibility to sprouting during storage followed by A. schimidtiana. Etiolated growth was 50% at +5°C as compared to 1001 at +2°C in Q. sgectabilis. All other plants showed 100% etiolation at storage temperatures of both +5°C and +2°C (Table 2.7). 67 O Table.2.6. Three week herbaceous perennials 2 (1984-85). regrowth heightY after 6 months storage Of stored at different temperatures in experiment Analysis of variance for regrowth height is also given for refrence. Name of perennial Storage temperatures +5°C +2°C -2°C -5°C -10°C Artemisia schmidtiana 10.40 12.90 8.40 3.70 0.0 Asclepias tuberosa 4.00 6.30 5.60 0.0 0.0 Aster novae-belgll 13.90 12.60 12.20 5.70 0.0 Centranthus ruber 4.00 4.20 0.0 0.0 0.0 Chrysanthemgm maximum 2.80 9.00 4.3 0.0 0.0 Dicentra eximia 14.00 16.00 15.70 9.90 0.0 Dicentra spectabilis 36.70 43.10 26.60 0.0 0.0 Geum chiloense 6.40 9.60 8.30 8.80 0.0 Hosta undQlata 13.30 13.10 15.10 5.10 0.0 Qngnus polyphyllus 18.10 13.80 14.10 0.0 0.0 y :Height in centemeters. ANALYSIS OF VARIANCE SOURCQA DF HS F.VALUE. PROB. Temperatures 4 802.464 144.23 .000 Cultivars. 9 319.455 57.42 .000 Temp. x Cul. 36 62.815 11.29 .000 Error 50 5.564 68 Figure 2.4a. Three week height of Q. chiloense; A. tuberosa; Q. pglyphyllus; A. novoae-angliae; Q. exima; and fl. undulata following 6 months storage at different temperatures in experiment 2 (1984—85). 3 WEEK REGROllml llElcuT (cu) 3 WEEK REGRowm llElcuT (en) 3 WEEK REGROWTH WT (CM) .d mm- 1. GEUM CHILOENSE d -10 -s’-2 +2 +5 STORAGE TEMPERATURES ('G) . L_._.: STORAGE TEMPERATURES CG) STORAGE TEMPERATURES CG) -2 +1 +9 QQPINUS POLYPHYLLUS ‘ 20" .. mum"I __ 10d 5. ° -10'-T- 02 +5 0‘ \O 3 WEEK REGROWTH HEIGHT (CM) 3 WEEK REGROWTH I‘EIGHT (CM) 3 WEEK REGROWTH HEIGHT (CM) 20- ASTER NOVOAE-ANGLII “—7 15-l 13035- l __—J—1 10- 5. 0‘ -1o - S - 2 ¢ 2 + S STORAGE TEMPERATURES CG) 2: OlCENTRA EXlMA TS-l —-_l:"'- I To- . ,_, 5. a -10 - - 2 + 2 + 5 STORAGE TEMPERATURES (G) 2:; WW6 IS-l — 150.05% To- 5- l—— ° -To - S - 2 . 2 0' S STORAGETEMPERATURES (’G) 70 Figure 2.4b. Three week height Of Q. ruber; Q. maximum; A. schmidtiana and Q. spectaailis following 6 months storage at different temperatures in experiment 2 (I984-85). 3 WEEK REGROWTH HEIGHT (CM) 3 WEEK REGROWTH HEIGHT (GM) CENTRANTHUS RUBER 10 5-1 5‘ L5°.OS' 4- —'—"l 2. c .-10 -5 -2 +2 +5 ,0_ QHRY§ANTH§MQM MAleQM ‘ STORAGE TEMPERATURES ('G) G '1 L50.”- 3. 4. ‘_‘ fi‘ 24 P ' -lo --5 -.2 +2 +5 STORAGE TEMPERATURES ('G) 71 3 WEEK REGROWTH HEIGHT (CM) 3 WEEK REGROWTH HEIGHT (cu) ,ARTEMESIA SCHMIDTIANA 2c Leo - [ ‘5‘ .OS 10-1 —‘ 5. fl - -10 - 5 - 2 + 2 + 5 STORAGE TEMPERATURES CG) 5c DICENTRA SPECTABILIS ‘O-l “5°.os' [ 3o. 20~ TO-i .' ' --10 -S --2 +2 +5 STORAGE TEMPERATURES CG) 72 Table 2.7. Percentage of stored herbaceous perennials which produced etiolated growth during storage in experiment 2 (1984-85). Results were not analysed statistically. Storage temperatures Name of perennial +5°C +2°C 0°C Artemisia schimidtiana 50 50 0 Ascleeias tuberosa 0 50 0 Aster novae-belgll 100 100 0 Centranthus 529;: 100 100 0 Chrysanthemgm maximum 100 100 0 Dicentga eximia 100 100 0 Dicentra spectapilis 50 100 0 Qaga chiloense 100 100 0 Hosta undulata 30 20 0 Luglnus Qalyahyllus 100 100 0 DISCUSSION There were no Significant differences in the regrowth quality of bare-root herbaceous perennials following 6 months storage at -2°C or 0°C in 1983-84 (Table 2.2). The following year. a wider range Of storage temperatures were tested to monitor Optimum temperatures for various herbaceous perennials. Our results indicate that most Of the perennials tested performed equally well following 6 months storage at -2°C. +2°C and +S°C. This is also evident from the previous work of Mr. George Rose (1953). who successfully stored E. coelestinum. C. majalia and Platycodon spp. at temperatures ranging from -2.2°c to +18°C. Our plants did very poorly following storage at -5°C. Aldhous (1964) also mentioned that survival of many forest species was generally. reduced following storage at -5°C. None of the plants survived storage at -10°C. Most likely. plants may not have sufficient root or shoot cold hardiness. Certain plants seems to have specific temperature requirements for long term storage for Optimum regrowth quality. For instance. Q. maximum only produced acceptable quality plants following storage at +2°C. whereas Q. aQaaa grew only following above freezing storage (Figures 2.3b; and 2.3c). Contrary to popular belief that higher storage temperatures enhance mold development in storage. most of the perennials stored at -2°C. +2°C and +5°C had no significant differeces in mold 73 74 development (Figure 2.33 to 2.3d). It was surprising to note that perennials stored at -5°C were fully covered with molds and those stored at -10°C were fully clean. This suggests that plants were injured at -S°C but certain molds could still grow. However. plants were severely injured at -10°C but evidently few molds can grow. When comparisons were made between mold development in storage and the regrowth quality of the plants. it is seen that presence of molds on Q. lanceolata and Q. polyphyllus in 1983-84 did not cause any negative effect on regrowth quality. In the following year. most of the plants stored at -2°C. +2°C and +5°C with fair amount Of molds performed equally well. This is in accordance with the results presented in Chapters 1 and 3. Etiolated growth was observed in 1984-85 when plants were stored at +2°C and +5°C for 6' months (Table 2.7).. However. no etiolated growth was ever observed at 0°C or lower températures in either year. Etiolated growth is considered undesirable but did not effect the regrowth quality under our conditions when grown in the greenhouse after storage. A comparison of results shows that there were significantly less molds on Q. polyphyllus at -2°C than at 0°C in I983-84 but there was no significant difference when stored at -2°C. +2°C and +5°C in 1984-85. No significant differences were seen in regrowth quality of plants in either years. Hinor differences in mold development were seen in Q. spectabilis in the 2 years. For best regrowth quality. it was evident that -2°C was more effective in 1983-84 but not in 1984-85. These variations may be due to different 75 growing seasons. different harvesting conditions. cultural practices. or some chance variation. In summary. it was observed that regrowth quality was not found to be greatly different when plants were stored either at -2°C. 0°C or +2°C although. unfortunately. 0°C was not available in 1984-85. Among these temperatures. etiolated growth was observed on plants stored at +2°C and above (Table 2.7). Conversely. some plants showed injury following storage at -2°C (Figure 2.3a to 2.3d). in addition. Heiden and Cameron (1984-85 Personnel communication) have found that certain plants like Qaaa and Coreoasis are very sensitive to freeze/thaw cycles. 0n the basis of thesefindings. we conclude that a safe storage temperatures for bare-root herbaceous perennials in general should be at or very near 0°C. LITERATURE C I TED 76 LITERATURE CITED Aldhous. J. R. 1964. Cold-storage of forest nursery plants. An account of experiments and trials; 1958-63. Forestry [Gt. Brit.]. 37(1): 47-63. Anderson. H. H. 1982. The cold-storage of strawberry runners-A review. Crop ReS(Hort. Res.). 22: 93-104. BoontJes. J. 1982. Storage temperature for planting stock and salable bulbs of lilies. Bloembollencultuur. 92(40): 1060-1061. Guttridge. C. G.. D. T. Mason. and E. G. Ing. 1965. Cold storage of strawberry runner plants at different temperatures. Expl. Hort. 12: 38-41. Levitt. J. 1980. Responses of plants to environmental stress. 2nd. Edition. Vol. 1. Chilling. freezing. and high temperature stresses. Academic press. N.Y. Lutz. J. H. and R. E. Hardenburg. 1968. The commercial storage of fruits. vegetables. and florist and nursery stocks. H. S. Department of Agriculture. Agriculture Handbook No. 66. pp.94. Mahlstede. J. P. and W. E. Fletcher. 1960. Storage of nursery stock. Amer. Associ. Nurserymen. Washington. D. C. pp. 62. Morby. F. E. and R. A. Ryker. 1979. Fall-lifted conifers successfully spring planted in Southwest Idaho. Tree Planters Notes. 30(3): 27-29. Mullin. R. E. and J. 0. Parker. 1976. Provisional guidelines for fall lifted for frozen overwinter storage of nursery stock. Forestry chronicle. 52: 22-25. Nobel. P. S. 1974. introduction to biophysical plant physiology. W. H. Freeman and Company San Francisco. Pellett. H. 1971. Comparison of cold hardiness levels of root and stem tissue. Can. Jour. Plant. Sci. 51: 193-195. Salisbury. F. 8. and C. W. Ross. 1978. Plant physiology. 2nd Edition. Wadsworth Publishing Company. Inc. Belmont. . California. 77 Swanson. 8. T.. W. P. Hacket.. C. Lane.. and D. C. Aston. 1983. Effect of temperature and duration of storage on the keeping quality of nursery stock. HortScience. Section 2. 18(4): 614. . Whiteman. T. H. 1957. Freezing points Of fruits. vegetables. and florist stocks. U. S. Department of Agriculture. Marketing Research Report NO. 196. pp.32. Worthington. J. T.. and D. H. Scott. 1970. Successful response of cold-stored strawberry plants dug in the fall. Jour. Amer. Soc. Hort. Sci. 95(3): 262-266. CHAPTER III EFFECT OF FUNGICIDES ON THE CONTROL OF HOLD DEVELOPNENT AND REGROWTH OF STORE BARE- ROOT HERBACEOUS PERENNIALS 78 INTRODUCTION The presence of molds growing on the surface Of bare-root herbaceous perennials is unacceptable to consumers primarily because of their unsightly appearance. Consumers and nurserymen believe that these molds have a pernicious influence on the quality of stored bare-root herbaceous perennials. In Chapter 1. however. it was shown that very little. if any. correlation existed between the extent of superficial mold development and regrowth quality of several herbaceous perennials. Currently. mold development is considered a serious problem on stored herbaceous perennials. Richards and Everts (1985) made a premilinary study to identify certain molds on stored bare-root herbaceous perennials and found Alternaria sp.; Botrytis sp.; Cylindrocarpan sp.; Echinodotrium sp.; Fusarium sp.; Penicillium sp.; Paplospora sp.; Plasmopara sp.; Rhizopus sp.; and Rhizoctonia sp. on .various stored perennials. Lockhart (1968) found Tyehula sp. and Sporotrichum sp. growing actively on stored strawberry runner plants at -1.1°C. Q. radicicola and Fusarium sp. were usually found at 0.5 to 1°C. Hontgomerie (1970) isolated different fungi from strawberry runner plants when stored at -1.1°C and 0 to I.6°C. Holds are common on other stored products such as woody nursery crops (Mahlstede and Fletcher. 1960). bulbs (Haude 1983; Prince et al. 1984). root crops (Lewis and Garrod 1983) and. fruit and vegetable crops (Dennis 1983; Edney 1983). Growers are interested in 79 80 control methods because of their unsightly appearance which lead to refusal shipments. This is not only causing a great amount of monetary losses to the retailers and wholesaler distributors but hurting their image in the market. There has been very limited research on chemical control of fungi for stored bare-root herbaceous perennials (Hahlstede and Fletcher. 1960). Captan as a dust successfully suppressed the molds on bare-root roses storage whereas a variable response was observed when captan was applied as dip (Hahlstede and Fletcher. 1960; Stessil. 1958; and Uota et al.. 1959). Benomyl controlled fungi in stored strawberry runner plants (Haas and Scott. 1973; and Haas. 1974). in carrots (Derbyshire and Crisp. 1978; Lockhart and Delbridge. 1974; and. Wells and Herwarth. 1973) and in potato tuber (Leech. 1971). However. benomyi resistant isolate of Penicillium spp. were found when tulip bulbs were treated (Prince et al. 1984). The .purpose of these -experiments was to determine whether selected fungicides could suppress mold development on bare-root herbaceous perennials during extended lOw temperature storage. A second objective was to determine the effect of fungicides on the regrowth quality of the bare-root plants. HATERIAQS AND HQTHODS Experiment 1 Alcea, rosea. Asgaragus officinallis. Coreogsis lanceolata. Dicentra spectaailis. Gaillardia grandiflora. Qagjgus polyphyllus. and Phlox subulata 'were harvested from a field at Walter’s Gardens. 81 Zeeland. HI. on November 18. 1983. Excess soil was removed and plants were trimmed of excess and damaged foliage and roots except E. subulata. The plants were treated as follows: 1. Rovral :(Iprodlone 50 WP: 3-(3.5-dichlorophenyl)-N- (1-methylethyl). dip 9 6 mg/l 2. Benomyl:(8enlate 50 WP: Benomyl [Hethyl-I-(butylcarbamoyl)- 2-benzimidazole-carbamate]. dip 9 12 mg/l 3. Captan :(Captan 50 WP: N-[(Trichioromethyl) thio]-4- cyclohexene-I.2-dicarboximide. talc 4. Water : dip 5. Control: dry Plants in treatments 1. 2. and 4 were soaked about 10 minutes each. spread on racks. and held overnight at 20°C to eliminate free surface moisture. Captan was dusted on plant material in bags and well shaken. All plants were precooled at 2°C for 24 hours. packed in polyethylene-lined celery crates and stored at -2°C. After 4 months. all plants were removed from storage. rated for mold develOpment using the following scale: 5 = 76 - 1002 of the plant surface covered with molds; 4 = 51 - 75% covered with molds; 3 = 26 - 50% covered with molds; 2 = I - 25% covered with molds; and 1 = No observable molds. The plants were then returned to storage for 2 additional months. After 6 months. plants were again removed from storage. rated for mold development. immediately planted in 5 inch pots and grown under greenhouse conditions for 3 weeks. Regrowth quality and height were measured weekly. A qualitative scale from 0- 5 was used for regrowth quality based on new shoots. density of foliage and overall vigor. The scale can be defined as follows: 5 = 100% of regrowth 82 potential expected; 4 = 801 of regrowth potential; 3 = 60% of regrowth potential; 2 = 401 of regrowth potential; I = 20% of regrowth potential and 0 = NO observable growth. Only data for 3 weeks regrowth quality is presented. Exgeriment 2 The following year on November 11. 1984. several plants genera including Coreoasis grandiflora. Dianthus deltoides. lQQElé sempervirens. Lavandula angustifolia. Qagtoliga incaaa. and Teucrium chamaedrys were harvested and processed by a commercial nursery (Walter's Gardens. Zeeland. Hi.). All the plants were stored with green tops except Coreoasis grandiflora. in which green top was removed. The plants were obtained within a few days after harvest and handled and monitored as described in experiment 1 except that plants were stored for 6 months without a 4 month observation and were treated only with expanded benomyi {Benlate 50 WP: Benomyl [Hethyl- 1-(butylcarbamoyl) -2-benzimidazole-carbamate]) concentrations as described below : I. Benomyl dip @ 6 mg/l 2. Benomyl dip @ 12 mg/l 3. Benomyl dip @ 24 mg/l 4. Water dip 5. Control dry Both experiments 1 and 2 were conducted using a completely randomized design with 3 replicates per treatment and 5 plants per replicate. Analysis of variance was performed to determine significant effects. 83 RESALE Experiment 1 Hold Ratigg When the plants were removed for visual observation after 4 months storage. little mold development was noted except on Q. lanceolata (Table 3.1). For this plant. mold development Observed on the controls was almost completely suppressed by rovral and benomyi treatments (Table 3.1; Figure 3.1b). Hold development on the dry control of Q. spectabilis was slightly but significantly greater than in other treatments (Table 3.1; Figure 3.2c). After 6 months storage. the only perennials which developed significant amounts Of mold development were Q. spectabilis and Q. lanceolata (Table 3.1; Figure 3.1b and 3.1c). For Q. spectabilis. all the fungicide treatments and even the water dip Significantly reduced mold growth compared with the dry control (rated as 3.4; approximately 60% covered with molds) but the fungicidal effect was relatively small (Figure 3.1c). The dry and dipped controls for Q. lanceolata were rated 3.27 and 3.13 respectively. For Q. lanceolata. all 3 fungicides almost completely suppressed mold development as Shown in Figure 3.1b. For all other perennials. the extent of mold development was limited (Table 3.1; Figure 3.13; and 3.1b). Fungicides significantly suppressed mold development compared with dry controls in every case except benomyi on E. subulata and rovral on Q. grandiflora after 6 months storage (Figure 3.1a). Benomyl was the most effective fungicide 84 Table. 3.1. Hold rating following 4 and 6 months storage of herbaceous perennials treated with fungicides prior to storage in experiment 1 (1983-84). Analysis of variance for mold growth is also given for reference. Name of Storage Treatments perennials duration Rovral Benomyl Captan Water dip Control dry Alcea rosea 4 Ho. 1.00 1.00 1.00 1.07 1.07 6 Ho. 1.30 1.0 1.27 2.00 2.00 As ra us 4 Ho. 1.00 1.00 1.00 1.00 1.00 officinallis 6 Ho. 1.47 1.27 1.20 1.67 2.00 Coreogsis 4 Ho 1.07 1.00 1.40 1.93 1.60 lanceolata 6 Ho. 1.40 1.33 1.33 3.13 3.27 Dicentra 4 HO. 1.20 1.07 1.00 1.13 1.27 spectabilis 6 Ho. 2.40 2.67 3.00 2.80 3.40 Gaillardia 4 Ho. 1.20 1.00 1.00 1.20 1.07 grandiflora 6 Ho. 1.60 1.00 1.33 1.33 2.07 Luginus 4.00 1.00 1.00 1.00 1.07 1.13 ealyghyllus 6 Ho. 1.67 1.13 1.13 2.13 1.87 Phlox 4.00 1.00 1.00 1.07 1.13 1.07 subulata 6 Ho. 1.00 1.47 1.00 1.53 1.60 y :Hold rating: 5 = 76-1002 of the plant surface covered with molds; 4 = 51-752 covered with molds; 3 = 26-50% covered with molds; 2 = 1-252 covered with molds; and 1 = NO observable molds. ANALYSIS OF VARIANCE SOURCE QE HS F. VALUE PROB. Fungicides. 4 2.707 18.61 .000 Storage duration 1 24.072 165.47 .000 Fung.x 5.0 4 1.261 8.67 .000 Cultivars 6 2.742 18.85 .000 Fung.x Cul. 24 0.288 1.98 .006 5.0 x Cul. 6 1.707 11.74 .000 Fung.x 5.0 x Cul. 24 0.116 0.80 NS Error. 140 0.145 85 Figure 3.1a. Hold rating and 3 week regrowth grade following 6 months storage of Q. grandiflora; E. subulata; and A. rosea treated with different fungicides prior to storage in experiment 1 (1983-84). Hold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26-50% covered with molds; 2 = 1-251 covered with molds; and 1 = NO observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 802; 3 = 60%; 2 = 402; 1 = 202 and 0 = No observable growth. MOLD RATING MOLD RATING GAILLAROIA GRANDIFLORA ‘1 1.50.05- I 3d 2-1 F—q' p ‘ M w coco-m. M Man can . Pl-lLOx SUBULATA 4d Sci 2. 60.05. I ‘ on ' m m w W . ALCEA ROSEA 4-1 3.: L50 II .. 1 ‘ n w m m m 86 .3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE CAI LLAROIA GRANDIFLORA ‘q 2. "l CONTROL PHLOX SUBULATA G: 3.1 2‘ I) g—mfiw— m ALCEA ROSEA ‘d 31 2. 1- 0 87 Figure 3.1b. Hold rating and 3 week regrowth grade following 6 months storage of A. officinallis; Q. aglyahyllus; and Q. lanceolata treated with different fungicides prior to storage in experiment 1 (1983-84). Hold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26-501 covered with molds; 2 = 1-251 covered with molds; and I = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 802; 3 = 602; 2 = 40%; 1 = 20%; and 0 = No observable growth. MOLD RATING MOLD RATING MOLD RATING ASPARAGUS OFFICINALUS 4-4 37 L5°.os‘ I z. __ ‘ n v m M “In; comm . LUPlNUS POCTPHYLLUS 44 L50 -I 3. .OS 33 ' r——‘ "_H n i” m m M“ Geum COREOPSIS LANCEOLATA was 88 3 WEEK REGROWTH GRADE 3WEEKREGROWTHGRADE 3 WEEK REGROWTH GRADE ASPARAGUS OFFICINALIS ‘- NS 3. 24 I. ° on no ——m—W—: CONTROL : LUPINUS POLYPHYLLUS 4. LSD.”- 3. __ 2« _, 1. °"—-u-u— so Sea-“w CONTROL : COREOPSIS LANCEOLATA “‘ I's".os' 3. 2. 0d —__J “I. 89 Figure 3.1c. Hold rating and 3 week regrowth grade following 6 months storage Of Q. spectabilis treated with different fungicides prior to storage in experiment 1 (1983-84). Hold rating: 5 = 76-1002 Of the plant surface covered with molds; 4 = 51-751 covered with molds; 3 = 26-502 covered with molds; 2 = 1-252 covered with molds; and l = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 80%; 3 = 60%: 2 = 401; 1 = 201; and 0 = No observable growth. MOLD RATING 90 DICENTRA SPECTABILIS 4d 21 Lsons- I an I. WWW?” 3 WEEK REGROWTH GRADE DICENTRA SPECTABILIS ‘d '- 91 overall except for Q. lanceolata and Q. spectabilis (Table 3.1; Figure 3.1b and 3.1c). Baggowth Quality Subjective evaluations of regrowth quality in 1983-84 following 6 months storage and 3 weeks regrowth under greenhouse conditions. are given in Table 3.2. NO significant differences were found for regrowth quality between fungicide treatments and controls for A. officinallis. Q. ggandiflora and E. subulata (Figures 3.1a; and 3.1b). Benomyl and rovral significantly improved the regrowth quality in A. gaaaa. Q. lanceolata and Q. polyphyllus (Figure 3.16; and 3.1b). Captan was only superior for regrowth quality in Q. lanceolata (Figure 3.1b). However. all 3 fungicides suppressed the regrowth quality in Q. spectapilis when compared to either control(Figure 3.1c). Water dips were not significantly different from the dry controls. Regrowth Height No significant differEnces were found for height between fungicide treatments and controls for Q. spectabilis and Q. grandiflora Table 3.3. For other herbaceous perennials. rovral and benomyi both significantly improved the height when compared to dry control except benomyi for A. officinalis (Figure 3.2). There were no significant differences between the dry and the water dipped controls. 92 Table. 3.2. Three week regrowth gradey following 6 months storage of herbaceous perennials treated with fungicides prior to storage in experiment 1 (1983-84). Analysis of variance for regrowth grade is also given for reference. Name of Traanents perennials Rovral Benomyl Captan Water dip Control dry Alcea rosea 3.40 4.00 2.50 3.13 2.33 Asgaragus 3.27 2.87 3.13 2.33 3.00 officinallis Coreogsis 3.60 3.67 2.93 1.20 1.85 lanceolata Dicentra 2.27 2.07 1.73 2.93 2.53 Spectabilis Gaillardia 3.53 3.07 4.00 3.47 3.07 grandiflora Luainus 3.13 3.27 2.47 2.07 1.87 aglxahyllus Phlox subulata 4.07 4.33 3.67 4.00 3.87 y :Regrowth grade: 5 = 100% of regrowth potential; 4 = 80%; 3 = 602; 2 = 401; 1 = 20%; and 0 = No observable growth. ANALYSIS OF VARIANCE SOURCE OF HS F.VAQQE. PROB. Fungicides. 4 2.451 4.63 .002 Cultivars 6 4.788 9.85 .000 Fung. x Cul. 24 0.935 1.92 .014 Error 70 0.486 Table. 3.3. Three week 93 regrowth heighty following 6 months srorage of herbaceous perennials treated with fungicides prior to storage in experiment 1 (1983-84). given for reference. Analysis Of variance for regrowth height is Name of Treatments perennials Rovral Benomyl Captan Water dip Control dry Alcea rosea 15.00 18.00 13.61 14.47 9.97 Asearagus 84.87 82.23 70.73 53.60 68.73 officinallis Coreopsis 16.40 17.87 14.87 7.20 9.27 lanceolata Dicentra 48.73 45.47 50.00 57.93 57.47 spectabilis Gaillardia 8.93 7.93 10.90 9.27 8.67 grandiflora Luainus 25.93 24.20 21.47 18.20 16.67 ealyahyllus y :Regrowth height in centimeters. ANALYSIS or VARIANCE SOURCE. OF Fungicide 4 Cultivars 5 Fung. x Cul. 20 Error 60 HS F.VALUE. PROB. 130.377 2.81 .030 9935.368 214.16 .000 112.632 2.43 .003 46.392 94 Experiment 2 Hold Development After 6 months storage. extensive mold development was Observed only in controls of Q. grandiflora and Q. iaaaaa . The mold ratings of controls for various perennials are shown in Table 3.4. Fungicides significantly reduced molds in all cases except Q. deltoides which had no mold growth to begin with (Figure 3.3a; and 3.3b). In Q. grandiflora. extent of mold suppression increased with the increase Of chemical concentration. However. all concentrations of benomyi essentially eliminated molds for Q. angustifolia and Q. deltoides (Figure 3.3a; and 3.3b). Regrowth Grading In all cases except Q. iaaaaa. increasing concentrations of benomyi decreased regrowth grade (Table 3.5; Figure 3.3a; and 3.3b). Treatments effect was particularly drastic for l. sempervirens and Q. angustifolia. where higher concentrations of benomyi literally killed _the plants (Figure 3.3a). Q. laaaaa did not Show any growth with any treatment. No significant difference was observed among controls (Table 3.5). 95 Figure 3.2. Three week regrowth height following 6 months storage of Q. lanceolata; A. officinallis; Q. grandiflora; A. 'rosea; Q. polyphyllus; and Q. spectabilis when treated with different fungicides prior to storage in experiment 1 (1983-84). 96 A 11. w a. N a m S Q R u. C L A w w m m. m o. e £3 58: :Eomoua Sam; A u A w T u m 0 E C N u m R. S p. a m m R D O a »m C a u. m .4. c c 2 $3 58: 5388.. SE; A. PINU P YPHY U WWW“ cl d u d d w ‘ ' 38 58: £389. 8; n q 5 n.- ASPARAGUS OFFICINALIS w m m w e o“ m ca. 58: 1588: on m... by... n.- 1 consume-Jinn _ . A .W udqqfiq «wow»... 38 58: 7.588.. é”; n IFLORA M m an. 1 5 C 38 58: 1388: E: n T5- 0‘ Table. 3.4. Hold ratingY following 6 months perennials treated with expanded benomyi storage in experiment 2 rating is given for reference 97 (1984-85). storage of herbaceous concentrations prior to Analysis of variance for mold Name of perennial Treatments . Benomyl Water Control 6 mgil 12 mgfil 24 mgll _gip. dry Coreogsis grandiflora 2.2 1.7 1.4 3.3 3.3 Qlanthus geltoides 1.0 1.0 1.0 1.1 1.1 Iberis semparvirens 1.4 1.1 1.1 1.8 1.5 Lavendula angustifolia 1.1 1.1 1.0 2.3 2.3 Qaptolina incana 1.1 1.1 1.0 2.1 3.4 Teucrium chamaedrys 1.0 1.0 1.0 1.3 1.7 y :Hold rating: 5 = 76-1001 of the plant surface covered with molds; 4 = 51-752 covered with molds; 3 = 26-50% covered with molds; 2 1-251 covered with molds; and 1 = NO observable molds. ANALYSIS OF VARIANCE SOURCE OF HS F. VAQQE Fungicides. 4 4.814 50.38 Cultivars. 5 3.351 36.07 Fung. x Cul. 20 0.550 .5.75 Error. ' 60 0.096 ' PROB. .000 .000 .000 98 Figure 3.3a. Hold rating and 3 week regrowth grade following 6 months storage of Q. grandiflora; L. sempervirens; and Q. angustifolia when treated with different benomyi concentrations prior to storage in experiment 2 (1984-85). Hold rating: 5 = 76-1002 of the plant surface covered with molds; 4 = 51-751 covered with molds; 3 = 26-50% covered with molds; 2 = 1-251 covered with molds; and 1 = NO observable molds. Regrowth grade: 5 = 100% of regrowth potential; 4 = 802; 3 = 602; 2 = 401; l = 202; and 0 = No observable growth. MOLD RATING MOLD RATING MOLD RATING 99 COREOPSIS GRANDIFLORA 4.1 LSD - .. i .1 2'1 ' an no G 12 24 CONTROL m (MG/L) _ IBERIS SEMPERVIRENS ‘d 3-1 LSDOS-I 2-1 . ‘ W ‘fl 6 12 24 COI‘TROL m (MG/L) . LAVENDULA ANGUS‘TIFOLIA 4.1 .3-4 —'—" LSD - 24 ~05 I ‘ an no G 12 24 cm KNOMYL (MG/L) 3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE 3 WEEK REGROWTH GRADE COREOPSIS GRANOIFLORA ‘4 1.50.05- 3. 2.1 1. ‘3 m—L—p L—‘Lfl" 12 24 CONTROL W (MC/L) - IBERIS SEMPERVIRENS 4-1 LSO' - __ .05 3-1 2‘ 1. °-L-%—% a IT 24 CONTROL ' ' m (MG/L) . LAVENDULA ANGUSTIFOLIA 4. 60.05- 3.1 2-4 1-1 1——: °'—Lon—'Lw‘ S T: 24 CONTROL m (MC/L) 100 Figure 3.3b. Hold rating and 3 week regrowth grade following 6 months storage of I. chamaedrys and Q. deltoides and treated with different benomyi concentrations prior to storage in experiment 2 (1984-85). Hold rating: 5 = 76-1002 Of the plant surface covered with molds; 4 = 51-75% covered with molds; 3 = 26-501 covered with molds; 2 = 1-251 covered with molds; and 0 = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 802; 3 = 602 2 = 402; 1 = 201; and 0 = No observable growth. MOLD RATING MOLD RATING 101 TEUCRlLlM CHAMAEDRYS 4.1 3. LSD I 24 ‘05 I 1—1 1 I u C 12 24 CW OENOMYL (MC/L) . DIANTHUS DELTOIOES 4-1 3. 2- "3 m ‘ on O 12 24‘ COTTROL ml. (MG/L) 3 WEEK REGROWTH GRADE‘ 3WEEKREGROWTHGRADE 4-1 TEUC RIUM CHAMAEDRYS ”—7 LSDDS' [ 3. 2.1 1.1 o'L—LF‘T T: 24 comm. m (NIL) . DIANTHUS DELTOIOES ‘4 1.50.0:- Jul 2. I. O 24 Imam. (MG/L) 102 Table. 3.5. Three week regrowth gradeY following 6 months storage of herbaceous perennials treated with expanded benomyi concentrations prior to storage in experiment 2 (1984-85). Analysis of variance for regrowth grade is given for reference. Name of perennial Treatments . Benomyl Water Control 6 agll 12 @911 24 agll dig. dry Coraggsis grandiflora 2.5 1.5 1.0 3.0 3.1 Dianthus deltoides 3.3 2.6 1.4 3.7 4.0 Iberis sempervirens 1.0 0.9 0.3 3.3 4.1 Lavendula angustifolia 3.4 0.3 0.1 2.5 2.6 Santolina incana 0.0 0.0 0.0 0.0 0.0 Teucrium chamaedrys 4.8 3.9 2.3 4.9 4.7 y :Regrowth grade: 5 = 1002 of regrowth potential; 4 = 802; 3 = 602 2 = 402; 1 = 201; and 0 = NO observable growth. ANALYSIS OF VARIANCE SOQBQE DF HS F. VALUE PROB. Fungicides. 4 19.189 32.59 .000 Cultivars. 4 14.147 24.03 .000 Fung. x Cul. 16 1.204 2.04 .021 Error. . 50 0.589 5 DISCUSSION it was found that prestorage fungicide application to bare-root herbaceous perennials almost always reduced the extent of mold development when present following 6 months storage. However. application of fungicides improved regrowth quality only for A. gaaaa. Q. lanceolata and Q. polyphyllus during the first year. In all other cases. fungicides either had no effect on or decreased the regrowth quality of the herbaceous perennials tested. In fact. elevated concentrations of benomyi severely retarded the regrowth of l. sempervirens and Q. angustifolia (Figure 3.3a). It should be noted that the most susceptible plants to fungicide application were those with green tops. These plants were not trimmed of foliage prior to storage except Q. grandiflora in experiment 2. However. Q. sgectabilis (Figure 3.1c) and Q. grandiflora. (Figure 3.3a) herbaceous perennials without green tops. also responded negatively to fungicides. From these results. it is not really possible to determine if the phytotoxic response was due to excess rates of absorption or to low levels of tolerance to the fungicides. Under our experimental conditions. storage molds were only a severe problem for Coreogsis spp.. D. sgectabllis and Q. incana. Only in the case of Q. lanceolata (Experiment 1.) did fungicides improve regrowth quality. However. in the second year. the exact opposite results were found for Q. grandiflora (Figure 3.4.) where increasing fungicide concentrations. decreased the regrowth quality. C. 103 104 Figure 3.4. Comparison of mold rating and 3 week regrowth grade following 6 months storage of Coreoasis spp. when treated with fungicides prior to storage in 1983-84 and 1984-85 experiments. Hold rating: 5 = 76-1001 of the plant surface covere with molds; 4 = 51-752 covered with molds; 3 = 26-50% covered with molds; 2 = 1-252 covered with molds; and 1 = No observable molds. Regrowth grade: 5 = 1001 of regrowth potential; 4 = 801; 3 = 602; 2 = 402; 1 = 20%; and 0 = No observable growth. 105 I) TV 333 .5023 .6528 33.: .2823 .6528 on-~.k 3:... O 3.970, 8:3 . _ E r. M L _ _ m _ A -u w m . .. ram — I000“.— Ioodmd I. W T.. . niece. .