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- Author or Editor: T. J. Facteau x
- HortScience x
Five-year-old `Napoleon' sweet cherry (Prunus avium L.) trees were treated with single-application basal drenches of paclobutrazol (PBZ) in an attempt to regulate growth and flowering. Increasing concentrations of PBZ at 0.05 to 0.30 g·cm-1 trunk diameter reduced terminal extension the year of treatment and for at least the following 3 years. Fruit count increased on wood grown before treatment but decreased as annual growth declined following treatment. Fruit/cm growth generally increased, whereas fruit per flower bud decreased as PBZ concentration increased. No differences were found in fruit size, soluble solids concentration (SSC; 13% to 14%), or firmness of cherries harvested at brine maturity. Chemical name used: β-[(4-chlorophenyl) methyll-α- (l,l-dimethylethyl) -l-H-l,2,4-triazo1e-l-ethanol (paclobutrazol, PBZ).
Abstract
Aqueous ammonium fluoride (NH4F) sprays on ‘Early Improved Elberta’ peaches (Prunus persica (L.) Batsch) resulted in increased O2 consumption of suture tissue and inconsistent changes in O2 consumption of dorsal tissue as the spray concentration was increased. Flesh firmness on the suture side of treated fruit was less than non-sprayed fruit and decreased as either the NH4F spray concentration or number of sprays increased. The effect of the spray on the dorsal side differed from year to year. Levels of fluoride (F) in the fruit tissue were associated with F concentration and number of F sprays applied only within the same year.
Abstract
In vivo pollen tube growth of apricot (Prunus armeniaca L. cv. Tilton) was unaffected by air concentrations of pyrene or fluoranthene ranging from 0 to 4.7 μg/m3 and times of exposure from 16 to 48 hours. At similar exposure times and pollutant concentrations, pollen tube growth of ‘Van’ sweet cherry (Prunus avium L.) in ‘Napoleon’ styles was reduced as In dose (hours exposure times pollutant concentration in μg/m3) of pyrene increased.
Abstract
Aqueous sprays of NH4F applied to ‘Early Improved Elberta’ peach trees significantly increased the % of abnormal fruits. Tissue firmness was increased on the dorsal side but decreased on the suture side. Suture tissues contained more F than dorsal tissues and both had higher F levels as the F spray concn increased. The climacteric of treated fruits was initiated before the untreated fruits at every sampling date where a climacteric occurred. Both malic and citric acids were decreased in the suture tissues of F treated fruits.
Abstract
Factorial combinations of 50 and 100 ppm (2-chloroethyl)phosphonic acid (ethephon) and 1000, 2000 and 4000 ppm succinic acid-2,2-dimethyl hydrazide (daminozide) sprayed on young ‘Napoleon’ sweet cherry trees (Prunus avium L.) for 3 consecutive years showed no antagonistic or synergistic effects on either growth or flowering, Daminozide, at 2000 and 4000 ppm, reduced terminal growth but had no effect on flower initiation or flower density. Ethephon significantly reduced growth only the first year applied and appeared to increase flower initiation on wood previously untreated. Daminozide at 4000 ppm reduced fruit set on all combinations of year-wood and years but when applied at a concentration of 2000 ppm reduced set only 2 out of 5 possible year-wood, year combinations. Ethephon reduced set 3 out of the 5 year-wood combinations but the average response was not significant.
Several characteristics of amylases involved in starch degradation were studied in extracts from immature (30 days before harvest) `d'Anjou' pears (Pyrus communis L.). Enzyme activity was not detected until after at least 60 minutes of incubation in frozen or lyophilized tissues. Activity increased significantly after 90 minutes and increased linearly after 2 to 12 hours of incubation. Activity was greater, however, in frozen than in lyophilized tissues. Three buffers (acetate, tris-HCl, and imidazole-HCl) were used at a range of pH levels (4.6-8.2) to ascertain the optimum assay system. Highest specific activity was recorded with acetate buffer at pH 5.6. The Km value in this system was 1.43 × 10-3g·ml-1. Specific activity increased as Ca concentration in the reaction mixture increased from 1 to 15 mm CaCl2 but did not change as Ca concentration increased from 15 to 25 mm CaCl2. The `d'Anjou' pear amylases were purified 5.7-fold using ammonium sulfate fractionation.
Abstract
There was no reduction of surface pitting of sweet cherry (Prunus avium L.) or bruising in 7 trials over a 4-year period as a result of applications of CaCl2 from 950, 1400, or 3800 mg Ca/liter in single or multiple applications from 1 to 6 weeks before harvest. Cherry fruit firmness was increased and fruit size was decreased by increasing the amount of Ca applied in 3 out of 7 trials. The time of application, from shuck stage to 1 week before harvest, was not critical.
Gibberellic acid-treated `Napoleon' sweet cherry (Prunus avium L.) fruit were firmer but lost more weight during brining than nontreated fruit. GA treatment delayed fruit softening, thereby extending the harvest period. Mean fruit weight was increased by GA only in fruit harvested at a more mature state. GA delayed soluble solids accumulation in one of two years. In one orchard district, solution pockets were less frequent in GA -treated fruit in 1988 and in late-harvested GA -treated fruit in 1989. GA treatment did not alter the incidence of fruit with solution pockets in a second district in 1988 and increased levels of solution pockets in fruit harvested later in 1989. Incidence of fruit with solution pockets increased as maturity progressed in nontreated fruit in both years and both districts. Chemical name used: gibberellic acid (G A).