Poor coloration of red grapes grown in warm regions is a frequent problem that decreases production efficiency. Most table grape growers use ethephon to improve color, but its influence on color development is erratic, and it may reduce berry firmness. Application of S-abscisic acid (ABA) to grapes can increase the anthocyanins in their skins, but no protocols have been established regarding its potential commercial use. Therefore, we evaluated the effects of ABA and ethephon treatments on fruit quality characteristics, including those related to firmness and color, on `Flame Seedless' grapes (Vitis vinifera L.) in several experiments over three consecutive seasons. Abscisic acid had few effects on berry weight or juice composition, but it increased berry softening and skin anthocyanin concentrations. The effect of ABA on berry firmness was similar to ethephon. With respect to skin anthocyanin concentration and fruit color characteristics, 300 mg·L–1 ABA applied at veraison was superior to the other ABA concentrations and to ethephon applied at any of the times tested. Moreover, any concentration of ABA between 75 and 300 mg·L–1 applied after veraison improved color better than ethephon applied at the same time. There was a highly significant inverse curvilinear relationship between skin anthocyanin concentration and the lightness and hue of the berries. Anthocyanin concentrations between 0.01 and 0.04 mg·cm–2 had little effect on berry lightness and hue, so researchers should consider measuring color, not just anthocyanins, when evaluating the quality of red table grapes.
M. Cecilia Peppi, Matthew W. Fidelibus, and Nick Dokoozlian
John A. Cline, Mary Bom, and Donald C. Elfving
104 ORAL SESSION 32 (Abstr. 240–247) Culture & Management/Fruit & Nuts (Temperate)
Jacques R. Fouché, Stephanie C. Roberts, Stephanie J.E. Midgley, and Willem J. Steyn
red blush, sunburn blemishes, and whitening of the peel. Fruit with sunburn or red blush are downgraded to Class 3 and will not pass for export. Although older GS orchards are being replaced with more profitable cultivars, GS will remain an important
J. L. Mason
‘Starking Red Delicious’ trees 15 years old on seedling rootstocks were fertilized with 5 levels of N as ammonium nitrate from 0.165 to 3.0 lb. per tree applied in a narrow band from 1961 to 1966 and cultivated at a shallow depth with a rotavator each year in March and May, March alone, or not at all.
Evaluation of fruit quality at harvest time showed that there was no significant effect of N level or cultivation treatments on fruit color. Pressure test was reduced by the higher N treatments but soluble solids concentration was highest at the medium N applications. Titratable acidity was reduced by the higher N treatments but cultivation treatments had no effect. Flesh color of the fruit was the most sensitive of several tests made, higher N and more cultivation causing greener flesh. In tests at the end of storage life, pressure test and titratable acidity were still reduced by the higher N treatments. There was little effect on soluble solids, per cent rots or storage scald. Again, cultivation treatments had no effect.
There was very little difference in yield among the N treatments except at the lowest levels of 0.5 and 0.165 lb. This effect was most marked with no cultivation. The N content of the leaves was increased by the N treatments from approximately 2.1% at the lowest level to approximately 2.4% at the highest level. There was no effect on terminal length or trunk circumference.
It was shown that grass sod with or without moderate cultivation could largely override the effect of a very wide range of N levels. There was a deleterious effect only at very low N levels combined with no cultivation.
Thomas M. Sjulin, J. Scott Cameron, Carl H. Shanks Jr., and Carlos E. Munoz
In January, 1990, a team of U.S. and Chilean scientists collected native and cultivated Fragaria from central and southern Chile. During the course of this expedition, 363 new accessions of Fragaria were collected. Approximately 2,500 plants of 250 clones were collected from 66 sites in 19 different areas, and 113 seedlots (estimated at over 100,000 seeds) were obtained.
Plants were collected from a wide range of habitats, and considerable variability was observed in vegetative and reproductive characteristics. Fruit were round to conical in shape, deep red to white in color, soft to moderately firm, with soluble solids ranging from 5-18%, dull to glossy skin, bland to strong flavor, low to very high aromatics, and difficult to moderately easy capping. Fruit size in situ approached 4 g, while fruit larger than 12 g were found under cultivated conditions. Strawberry aphids (Chaetosiphon fragaefolii) were found on plants in situ and under cultivation. Little or no evidence of other pests were observed on clones collected in situ.
Roberto G. Lopez and Erik S. Runkle
Prohexadione-Ca (ProCa) is a relatively new plant growth regulator (PGR) that inhibits internode length in rice, small grains, and fruit trees. However, little is known about its efficacy and potential phytotoxicity on floriculture crops and how it compares to other commercially available PGR chemicals. The effects of two foliar spray applications (2 weeks apart) of ProCa (500, 1000, or 2000 ppm), paclobutrazol (30 ppm), or a tank mix of daminozide plus chlormequat (2500 and 1000 ppm, respectively) were quantified on Dianthus barbatus L. `Interspecific Dynasty Red', Ageratina altissima R. King & H. Robinson (Eupatorium rugosum) `Chocolate', Lilium longiflorum Thunb. `Fangio', and Buddleia davidii Franch. `Mixed.' All plants were forced in a glass-glazed greenhouse with a constant temperature setpoint of 20 °C under a 16-h photoperiod. Two weeks after the second spray application of ProCa at 500, 1000, or 2000 ppm, plant height of Dianthus and Lilium was shorter than control plants by 56%, 60%, and 65% and by 6%, 26%, and 28%, respectively. However, ProCa bleached and reduced the size of Dianthus flowers. ProCa at 2000 ppm and daminozide plus chlormequat were effective at controlling the height of Eupatorium (64% and 53% reduction, respectively); however, leaves of Eupatorium were discolored and showed symptoms of phytotoxicity 1 week after the first ProCa application. Only daminozide plus chlormequat were effective on Buddleia. ProCa is an effective PGR for most of the crops we tested; however, its discoloration of red flowers and foliage may limit its application for commercial use.
entire cane, elaborate trellises that separate primocanes from floricanes and enhance light penetration into the lower canopy serve little purpose. Annual removal of all canes after fall fruiting also helps break insect and pathogen life cycles, assisting
Gerard W. Krewer, Thomas G. Beckman, Jose X. Chaparro, and Wayne B. Sherman
-pigmented flecks in the outer flesh on the sun-exposed side of the fruit, but there is little or no red in the flesh at the pit. Flesh texture is smooth and without strings but is clingy to the pit even when fully ripe. Flesh is firm with good sweetness (10% to 12
Chad E. Finn, Bernadine C. Strik, Mary E. Peterson, Brian M. Yorgey, Patrick P. Moore, Patrick A. Jones, Jungmin Lee, and Robert R. Martin
‘Kokanee’ ( Fig. 1 ) is a new primocane-fruiting red raspberry ( Rubus idaeus L.) from the U.S. Dept. of Agriculture–Agricultural Research Service (USDA–ARS) breeding program in Corvallis, OR released in cooperation with the Oregon State
Doron Holland, Kamel Hatib, Irit Bar-Ya'akov, Ehud Yonay, and Fathi Abd El Hadi
increasing. Red pomegranate cultivars are among the most commercially valuable cultivars because of their appealing red skin color and their good taste. One of the more recognized and popular pomegranate cultivars is ‘Wonderful’, with red fruit skin and dark-red