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- Author or Editor: Stephen Reiners x
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Starter phosphorus (P) is often recommended for warm-season vegetables sown in cool soil, even if soil P index levels are already high. The cost and environmental risk associated with excessive P fertilization justify re-examination of the practice. The objective of the study was to confirm that performance of early plantings of snap bean (Phaseolus vulgaris L.) is improved by starter P application and to test whether solubilizing soil P with potassium bicarbonate (KHCO3) can serve as an alternative in western New York soils. Addition of starter fertilizer at either recommended (15 kg·ha−1) or supraoptimal (35 kg·ha−1) P rates did not generally improve seedling tissue P concentration, early growth (biomass at flowering), or pod yield. Starter P application increased tissue P in only two of 11 experiments, and it never increased yield. Application of 6 kg·ha−1 KHCO3 to release soil-bound phosphate was not phytotoxic to snap beans. In the two experiments in which starter P increased tissue P, KHCO3 application had a smaller effect in one and no effect in the other. KHCO3 application did not increase yield in any of the six experiments where it was tested. A direct test of the contribution of P limitation to the poorer performance of early plantings showed that neither starter P nor KHCO3 application increased yield at early planting. Seasonal differences in crop performance could not be attributed to mineralization of soil phosphate after soil warmed. Water-extractable soil P was not lower in the spring than in summer, remaining constant at all 11 bean fields that were sampled from mid-April through mid-July. In these trials, P was likely not growth-limiting in the cool soils tested. Because starter P may not be necessary in vegetable soils testing high or very high for P, vegetables would also not likely benefit from bicarbonate application under high P conditions.
The motherstalk method of `Jersey Centennial' asparagus production was examined in two greenhouse studies. This technique allowed for one, two, or three spears to develop a mature fern while permitting harvest of later-developing spears. Cumulative yield was highest 10 weeks after planting with one and two motherstalks, and crown dry weights in these treatments were similar to those of the nonharvested treatment. In a second experiment, spear yield and crown dry weight were determined when the motherstalk was initiated at 0, 2.5, and 5 weeks after planting. Yields were highest when the motherstalk was established at week 0 or 2.5 compared to week 5. Crown dry weights of early motherstalk treatments were similar to those of the nonharvested treatment at the end of the 10-week harvest period. Our results indicate that the motherstalk system may allow for extended asparagus harvest in temperate areas.
Summer squash (Cucurbita pepo L.) cultivars were compared for ability to set parthenocarpic fruit. Some cultivars set no parthenocarpic fruit and others varied in the amount of fruit set when not pollinated. The degree of parthenocarpy varied with season, but the relative ranking of cultivars for parthenocarpy was generally similar. Cultivars with the best parthenocarpic fruit set were of the dark green, zucchini type, but some cultivars of other fruit types also set parthenocarpic fruit. A summer squash cultivar was developed that combines a high rate of natural parthenocarpy with multiple disease resistance. Yield of summer squash plants grown under row covers that excluded pollinating insects was as much as 83% of that of insect-pollinated plants in the open.
Field studies were conducted in 1996 on two pumpkin (Cucurbita pepo L.) cultivars, `Howden' (vining-type growth habit) and `Wizard' (semi-bush growth habit), at two locations to determine the effect of plant population and row width on marketable yield. Increasing plant populations from 2990 to 8960 plants per hectare resulted in significantly greater fruit number and yield at both locations and for both varieties. Average fruit size declined at the highest populations. Increasing row width from 1.8 to 3.6 m resulted in a slight but significant decrease in number of fruit per hectare with no effect on other yield parameters. At one location, the effect of row width on yield and number of fruit per hectare depended on the population. At low populations, row width did not influence yield or fruit number; at high populations, wide rows produced lower yield and fewer fruit than narrow rows. The results demonstrate that growers may increase pumpkin yield by increasing plant populations but should use narrower row widths and wider in-row spacing. Growers who choose higher populations should ensure that all inputs are optimized to reduce potential plant-to-plant competition and use regionally adapted cultivars.
Field studies were conducted at two locations in 1995 to determine the effect of spacing, nitrogen application, and variety on pumpkin (Cucurbita pepo L.) marketable yield. Pumpkin yield was unaffected by three rates of applied N (67, 112, or 157 kg N·ha-1). Marketable fruit number per hectare increased with both 'Howden' and 'Wizard' pumpkins as in-row plant spacing decreased from 1.2 to 0.3 m. Average fruit size significantly decreased at the closer spacing, but the decline in mass was much greater in nonirrigated as compared to irrigated plots. This resulted in a significantly greater yield in the irrigated plots at the closer spacing, while there was no significant increase in yield without irrigation. The results demonstrate that growers may increase the number of fruit per unit area with closer spacing but optimal soil moisture may be a prerequisite for the increase.
Three tomato varieties were evaluated for early and total yield using row covers. Tomatoes were planted three weeks earlier than the normal planting date and row cover treatments included; 1) slitted, clear polyethylene 2) floating, spunbonded, polypropylene and 3) bare, no row cover. `Pilgrim', `Celebrity' and' Mountain Pride' were selected as early, mid-season and late varieties, respectively. Row covers were removed after three weeks at which time a second planting was made, representing the normal planting time. Slitted, clear, polyethylene row covers significantly increased early yields in all varieties as compared to the bare treatment. In addition, clear row covers resulted in higher early yields in `Pilgrim' and `Mountain Pride' than floating row covers. Despite row covers over `Celebrity' and `Mountain Pride', early yields were still not as great as the `Pilgrim' cultivar without any row cover.
Tomatoes, cultivar `Mountain Pride', were evaluated for productivity, post-harvest qualities, and pest populations in three different production systems. These included a conventional, high chemical input system with prophylactic applications of pesticides and fertilizers; a reduced chemical input system that used pesticides only as needed; and a transitional organic system that followed the guidelines of the Organic Farmers Association of New Jersey. No significant differences were observed in either the high input or low input system despite a reduction in synthetic pesticide and fertilizer use. Organically produced tomatoes yielded significantly less than the other production systems in terms of total yields. Average fruit size was increased, however, along with the percentage of tomatoes with diameters larger than 7.7 cm. Differences in pest populations were noted between the plots.