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Abstract
Pinto bean plants (Phaseolus vulgaris L. cv. Pinto 111) in the unifoliolate leaf stage were exposed for 3 hours to 0.8 ppm SO2, 0.25 ppm 03, or a mixture of the 2 pollutants at these concentrations at 15, 24, or 32° C. Foliage exposed to O3 alone developed adaxial stipple and leaves exposed to SO2 alone developed interveinal necrosis. The mixture of O3 and SO2 induced O3-type symptoms at 32° and SO2-type symptoms at 15°. Both symptom types were present at 24°. Some abaxial glazing or silvering was also induced by the mixture, and was most common at 15° and 24°. Ozone and SO2 each induced greater foliar injury at 15° or 32°, as compared to 24°. The mixture of O3 and SO2 induced greatest macroscopic foliar injury at 15°. The degree of adaxial vs abaxial leaf surface injury varied with temperature.
Abstract
The effect of 2-chloroethanepliosphonic acid (ethrel) on the sex expression of pickling cucumbers was studied. Tests to determine concentrations, effect on sex expression, and yield potential were conducted in greenhouse and field situations.
As many as 19 successive pistillate nodes were observed for the treated monoecious cultivar ‘SC 23’. The most effective concentrations of ethrel were 120, 180 and 240 ppm for these studies. These rates in single or multiple application resulted in the greatest number of continuous female nodes with the least shortening of internodes. A much lower concentration of 24 ppm had little effect as to stunting and only limited effect on sex conversion. Significant yield increases, as measured by value per acre, were obtained for 3 monoecious cultivars, ‘Model’, ‘SC 23’ and ‘Chipper’, treated with ethrel.
Peroxidase activity in extracts from freeze-dried tissue of Fragaria × ananassa Duch. cv. Chandler was highest in tissue-cultured (TC) plants, followed by field-grown (FG) and lowest in greenhouse (GH) plants. Among tissue types, activity was highest in petioles, with leaves second highest. Fruit, root, and crown tissue all exhibited low or no activity. When subjected to isoelectric focusing (IEF), petiole tissue extracts exhibited more isozymes than extracts from other organs regardless of staining substrate. Using 4-chloro-1-naphthol and H2O2 as substrates, anionic and cationic isozymes were observed in TC petiole extract with nine isozyme bands ranging in pI from 3.9 to 9.5. In TC leaf extract an isozyme at pI 7.4 was observed that was not present in other organ extracts when H2O2 and benzidine, p-phenylenediamine or 3-amino-9-ethylcarbazole were used as substrates. Specific isozymes and number of isozymes varied according to plant organ and developmental stage. Mature leaves and over-ripe fruit appeared to exhibit more activity and a larger number of isozymes than developing tissues of those plant organs.
Abstract
‘Royal Blackeye’ southernpea [Vigna unguiculata (L.) Walp.] was released in 1985 by the Louisiana Agricultural Experiment Station. This southernpea was developed primarily for local fresh market use. The purple hulls and blackeye seed coat pattern combination is unique among released cultivars.
Abstract
Twenty-one cultivars of vegetables were treated in the greenhouse with Ethrel (2-chloroethanephosphonic acid) at concentrations of 240, 480 or 960 ppm. The stages of growth at treatment varied from 1 to 4 true leaves for the various cultivars.
The earliest observable response was stunting. With some cultivars, the stunting was permannent; but with others it appeared to be temporary. The degree and duration of stunting varied with cultivar and ethrel concentration.
Ethrel caused a strong tendency toward pistillate flowers on most of the monoecious cucurbits tested and in some cases almost complete absence of staminate flowers. The chemical greatly reduced the number of staminate flowers but had no observable effect on the number of perfect flowers of the muskmelon. The chemical also altered fruit shape of ‘Butternut’ squash.
Much fresh-cut apple research has focused on browning, yet little sensory and flavor analysis has been performed. We therefore evaluated postharvest and flavor changes in stored fresh-cut `Gala' apples prepared after harvest or after CA storage (3 months, 1.4% CO2 and 3% O2). Apples were washed, cored, sliced, dipped in browning inhibitors (BI; Na-erythorbate + CaCl2), packaged in LLDPE bags, and evaluated for descriptive flavor attributes, GC volatiles, firmness, CO2 and O2 and color after 0, 2, 7, and 14 days at 1 °C. Initial apple firmness pre-CA vs. post-CA was 38.3N and 32.7N. Bag O2 concentration dropped to 1% to 2% by day 14 and day 7 for pre- vs. post-CA, respectively. CO2 concentration in bags increased linearly through day 14 in both pre- and post-CA. All pre-CA Hunter L values were higher than post-CA for all treatments on all sampling days. Both BI treatments maintained color for 14 days, but freshly cut (FC) wedges were generally superior whereas stored untreated fresh-cut (SFC) wedges browned markedly by day 2. There was no apparent difference between BI levels in terms of browning or flavor. BI-treated wedges were rated more astringent than FC and SFC, especially after CA. With few exceptions, “fruity”, “raw/ripe apple,” and “sweet” attributes were higher in all pre- vs. post-CA treatments. This trend was conserved through 14 days of storage per treatment. “Sour” and “citrus” scores were higher after CA only in BI-treated wedges. Major compounds recovered were butanol, butyl acetate, hexanol, 2-methylbutyl acetate, amyl/isoamyl acetate, hexyl acetate, 2-hexenyl acetate, butyl 2-methylbutanoate, butyl hexanoate, hexyl butanoate, hexyl 2-methylbutanoate, hexyl hexanoate, isobutyl octanoate and α-farnesene. Flavor-related compounds varied markedly through storage and after CA. The GC volatile analysis will be presented along with any possible correlation to trained sensory evaluations.
Eight unique varietal grape juices were examined for their antioxidant characteristics and commercial potential compared to that of commercial `Niagara' and `Concord'. Grape juices were cold-pressed from mature grapes, clarified, preserved, analyzed for pH, soluble solid and titratable acidity levels, pasteurized at 73 °C for 12 seconds, and sampled for microbial testing. A preliminary panel of 41 routine evaluators assessed all juices for 18 quality characteristics against known and blind controls. Based on these results, `Reliance', `Traminette', and New York 73 juices were presented to a 107-member panel of untrained judges. Panelists rated experimental juices against commercial controls for color, appearance, aroma and flavor intensity, sweetness, tartness, overall quality, and preference. Among juices tested, `Reliance' and NY 73 offer the greatest potential as specialty grape juices. `Traminette', `Chardonel', `Chambourcin', and NY 62 may also have potential as grape juice cultivars, if processed to improve their color and clarity. Small juice lots were hand-pressed from mature grapes and examined for total anthocyanin and phenolic content, antioxidant characteristics (DPPH and FRAP) and levels of individual phenolic compounds via GC-MS. Total anthocyanin and phenolic contents of experimental juices varied from 0–1460 μg·gfw-1 and 1001–2850 μg·gfw-1, respectively, and were highest in NY 73. Estimates of antioxidant activity differed slightly among tests, but activity appeared highest in `Chambourcin' and NY 73 and lowest in `Reliance'. Levels of individual compounds varied substantially among juices.
Abstract
Rabbiteye blueberries, Vaccinium ashei (Reade), were stored in each of 3 containers and 4 time-temperature regimes: 24 hr at 1°C + 24 hr at 10° + 24 hr at 21°; 48 hr at 10° + 24 hr at 21°; 7 days at 1°; and 14 days at 1°. Berries of ‘Tifblue’ lost less weight, were firmer, had fewer “leakers” and less decay than those of ‘Woodard’ following storage under identical treatments and storage conditions. When means of both cultivars and 4 time-temperature treatments were combined, there was an effect of consumer packaging type on weight loss, but there was no effect on berry firmness or the incidence of “leakers” and decay. There was no effect of packaging type on the percentage of sugars during 1 and 2 weeks of storage at 1°.
Abstract
In vitro propagation of ‘Nemaguard’ peach rootstock [Prunus persica (L.) Batsch] was obtained on a modified Murashige and Skoog (MS) medium using shoot tips as primary explants. Shoot proliferation was induced on MS medium supplemented with 50 mg/liter L-ascorbic acid, 20 ml/liter Staba vitamin mixture, 2.0 mg/liter 6-benzylamino purine (BA), and 0.1 mg/liter naphthaleneacetic acid (NAA). Rooting was induced by subculturing plantlets on a similar medium without the Staba vitamins and without BA. When the Staba vitamin mixture was present, rooting was reduced; the inhibition resulted from the presence of riboflavin.