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Abstract
The effects of cultural practices on the yield and uniformity of 2 cabbage varieties were studied during a 3-year period. There was no advantage of using more than 60 lb. of N per acre. Most uniform plants, as measured by variance of head weights, were produced on plots transplanted at a shallow or medium depth although greater yields were usually produced on the deeply transplanted plots. Largest yields of cabbage were produced by plants designated as large at transplanting. There were no important uniformity differences between plant sizes. Spacing of plants 9 inches apart in the row instead of 12 or 15 inches resulted in larger yields. In all experiments, the hybrid variety ‘Emerald Cross’ was equal to or superior to the non-hybrid ‘Round Dutch’. These experiments suggest that the best combination of conditions for once-over harvest is use of large plants of a hybrid variety fertilized with 60 lb. of N per acre and transplanted 9 inches apart in the row at a medium depth.
Abstract
Rooted stem cuttings of Ilex crenata Thunb. ‘Helleri’ were grown in a series of experiments for 3 or 6 weeks at day/night temperatures ranging from 6°/2° to 26°/22°C. Percentage of tissue N increased over time at all temperatures but at progressively slower rates as temperature decreased. Temperatures of 18°/14° or less prevented visible shoot elongation, although plant dry weights increased at all temperatures. Percentage of dry weight K increased and P, Ca, Mg, Mn, and Zn decreased with time for plants grown at 10°/6°, 14°/10° and 18°/14°, whereas the total amounts of each nutrient per plant increased. Nutrient content increased at greater rates as temperature increased. Nitrogen accumulation data were used to develop a method of timing fertilizer application in the fall. The proposed procedure ensures adequate nutrient accumulation to support vigorous spring growth without jeopardizing proper cold acclimation in the fall
An experiment was conducted to determine the effects of banded phosphorus (P) applications at differing rates in irrigated and nonirrigated pecan (Carya illinoinensis) plots on P movement within the soil, P uptake and movement within pecan trees, and the yield and quality of nuts. On 20 Mar. 2015, P applications of 0 kg·ha−1 (0×), 19.6 kg·ha−1 (1×), 39.2 kg·ha−1 (2×), and 78.5 kg·ha−1 (4×) were administered to bands of triple superphosphate to randomly selected trees in nonirrigated and irrigated plots of a ‘Desirable’ orchard bordered by ‘Elliot’ trees. When P was applied at the 2× and 4× rates, the total soil test P decreased linearly by 35% and 54%, respectively, in nonirrigated plots and by 41% and 59%, respectively, in irrigated plots over the course of the experiment. There was no change in soil test P over time at the 0× rate for either irrigation regimen; however, at the 1× rate, soil test P decreased 44% in the irrigated plot but did not change in the nonirrigated plot. The largest linear decrease of the soil test P from the start of the experiment to the end of the experiment occurred in the top 0 to 7.6 cm. In contrast, soil test P at a depth of 15.2 to 22.9 cm decreased linearly by 23% in the nonirrigated plot, but it did not decrease over time in the irrigated plot. Increasing the P application rate increased foliar P quadratically in the nonirrigated plot, but only the 4× application rate increased foliar P compared with the 0× control. In the irrigated plot, foliar P concentrations decreased linearly from 2015 to 2017, and foliar P concentrations were not influenced by the P application rate. No differences in pecan yield or quality were observed in either irrigated or nonirrigated plots. Overall, P banding may not be the most sustainable way to increase foliar concentrations of P quickly or to maintain concentrations of the nutrient in the long term.