Search Results
Abstract
Eight seed blends of gynoecious with monoecious cultivais of cucumber (Cucumis sativus L.) ranging from 87.5 to 0% gynoecious seed were evaluated in spring and fall multiple harvest trials. Yield advantages were associated with blends having a high proportion of gynoecious seed during the early part of the harvest season but advantages were less pronounced as the season progressed.
Abstract
Experiments were conducted in the spring and fall of 1967 and the spring of 1968 to determine harvest indices and to evaluate the rate of fruit development and changing grade sizes for both white- and black-spined cucumbers. White-spined ‘Southern Cross’ and black-spined ‘Piccadilly’ were used. Per-acre plant populations in the order of 100,000 in the spring and 70,000 in the fall were established using gynoecious cultivars. The first plots were harvested when only a few marketable fruits were present; subsequent plots were harvested at 2- or 3-day intervals for a total of 8 per experiment. The single deviation from this was the 7-day interval between the seventh and eighth harvests of the fall experiment.
Maximum returns per acre occurred when the proportion of fruit greater than 2 inches in diameter ranged from 14 to 31% of the total weight. It is suggested that plantings should be harvested as soon as fruits larger in diameter than 2 inches are found in the field.
In spring plantings the percentage of plants bearing fruit reached 91 whereas those in the fall trial reached 98. The average number of fruit per plant did not exceed 1.27 in any trial.
Cultigens frequently are tested for eventual monoculture production conditions in trials with different cultigens in adjacent rows. We determined the effect of using different cultigens of pickling and fresh-market cucumber (Cucumis sativus L.) in bordered (three-row) and unordered (l-row) plots. Cultigens contrasted in characteristics important in competitive effects: plant architecture (tall vs. dwarf), anthracnose resistance (susceptible vs. resistant), and sex expression (monoecious vs. gynoecious). In all four test years, there was no significant interaction of border with center row in unordered vs. bordered plots, with three exceptions: there was a significant reduction in yield of M 21 in 1982 when bordered by `Calypso' (a large-vined genotype), and a reduction in yield of `Southern Belle' in 1984 when bordered by `Calypso' or SMR 58. In most cases, there was an increase in yield if the border genotype had short vines. We concluded that. in most cases, trials can be run using unordered plots without significant effect or yield.
Abstract
Fruit of cucumbei plants (Cucumis sativus L.) of a gynoecious and 2 monoecious cultivars treated at the 2-3 leaf stage with 0 or 240 ppm (2-chloroethyl)phosphonic acid (ethephon) were harvested at 3 weekly intervals, and processed as either fresh-pack pickles or brine stock. Experienced judges detected differences in shape and degree of seed development attributable to ethephon treatment. There were no significant differences in texture, flavor, external or internal color, firmness or internal defects. Differences caused by ethephon treatment were less apparent in fruit of the gynoecious than monoecious cultivars.
Abstract
Three versions of the hybrid ‘Meridian 76’ (‘Marketmore 76’ × ‘Tablegreen 72’) differing in sex expression were used to evaluate the effect of gynoecious expression on fruit yield and earliness. The versions tested were gynoecious × gynoecious (G×G), gynoecious × monoecious (G×M), and monoecious × monoecious (M×M). In 2 years of testing, the gynoecious (G×G and G×M) hybrids had 99% to 100% pistillate flowers on the first 10 nodes of the main stem of the plant, whereas the monoecious (M×M) hybrid had 3% to 5% pistillate flowers. The monoecious hybrid had a higher percentage of U.S. Fancy and No. 1 fruits and a lower percentage of culls than the gynoecious hybrids. There were few significant differences in yield among the 3 hybrids. The gynoecious hybrids were earlier than the monoecious hybrid, but there were no important differences in the yield of marketable fruit after the first harvest in either year. The G×M hybrid had a significantly higher yield than the M×M hybrid in the first harvest for both years. The G×M hybrid tended to outyield the G×G hybrid as well, but the differences were not always significant. The gynoecious hybrids (especially the G×M hybrid) of ‘Meridian 76’ provided an advantage in early yield but not in yield summed over all harvests (6 to 8 depending on year), compared to the monoecious hybrid.
Abstract
Three rapid methods of measuring yield (small plots harvested at the green stage, and single plants harvested at the green or at the mature stage) were tested for correlation with yield from a replicated multiple-harvest yield trial to determine how well they predicted performance of 10 hybrids in 1981, and 18 lines and cultivars tested in 1982. Only 2 methods of measuring yield were evaluated in 1981, small plots harvested once-over at the green stage and the standard replicated multiple-harvest trial. In that year, the most efficient method for measuring yield, based on capacity of the method to handle lines and to predict multiple-harvest trial performance, was 2 or 3 replications of 3 m plots harvested once-over. Those methods had a calculated advantage (relative capacity × correlation coefficient) of 43% to 80% over the replicated multiple-harvest trial. The most efficient method for measuring yield, of the 4 tested in 1982, was single plots with 1, 2, or 3 replications harvested once-over at the green stage. The tests had a calculated advantage of 102 to 107% over the replicated multiple-harvest trial, respectively. It was concluded that 2 or 3 replications in the test would provide the best results by controlling environmental variability without using an excessive number of seeds per family. In addition, the best correlation with yield in the multiple-harvest test was obtained when all fruit from the plot were counted, rather than just those of marketable size (38 to 60 mm diameter).
Abstract
Sweet potato (Ipomoea batatas L.) blister is primarily a superficial disease that develops in stored roots. The cultivar ‘Nugget’ is particularly susceptible and was used to investigate the role of mineral nutrition of the growing plant on the development of the disease. Results from greenhouse and field experiments demonstrated that the disease developed in roots that received excesses of N, K, and Mg during growth and the disease was prevented by including B in the fertilizer program.
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.
Abstract
At a fertilizer rate of 80-42-80 lb of N-P-K per acre, dry matter production by pickling cucumbers through the normal fruiting period totaled 2,800 lb/A, and marketable yields (about 33% of the total dry matter) were in the order of 100,000 fruit/A (10 tons fresh weight). Total N, P, and Κ uptake was 90, 12, and 145 lb/A, respectively, and nutrient removal in the harvested fruit was estimated at 40 lb N, 6 lb P, and 55 lb Κ per acre. The maximum rate of growth and nutrient accumulation occurred about 50 days after seeding.
Abstract
Cucumbers from plants of a gynoecious cultivar treated with 0, 240, or 480 ppm 2-chloroethylphosphonic acid (Ethrel)were made into fresh-pack pickles and brine stock and evaluated by experienced judges. Fruit from Ethrel-treated plants were shorter than those from untreated plants. Otherwise there were no significant differences in appearance, flavor, texture, firmness, bloater formation, or acceptability of the processed product.