Search Results
Abstract
Killing Sudan grass (Sorghum vulgare var. sudanense) at a 30-cm height with glyphosate and leaving the residue on the soil surface reduced the number of marketable heads, head weight, and total yield of fall transplanted ‘Market Prize’ cabbage (Brassica oleracea L., Capitata Group). The total plant weight and weight of heads where the cover crop was killed at a 15-cm height were equal to those of conventional culture. Killing the grass at different heights also affected the concentration and distribution of N, K, and Ca in leaf petioles, leaf laminae, and the core of the matured plant. There were positive correlations of head weight with N in the petioles of wrapper leaves, laminae of inner leaves, and core and with Ca in the laminae of the oldest leaves, wrapper leaves, inner head leaves, and core. Sidedressing with N increased head weight, marketable yield, and N concentration in all plant parts analyzed. The response to Ca(N03)2 was similar to that of NH4NO3. Chemical names used: N-(phosphonomethyl) glycine (glyphosate).
Abstract
Direct-seeded bush beans, sweet corn, summer squash, and transplanted tomato and cabbage were grown under varying tillage and cropping systems in 1982 and 1983. Cultural treatments were conventional tillage (CT), no-tillage without cover crop (NT–CC), and no-tillage with a cover crop (NT + CC) of hairy vetch (Vicia villosa) in 1982 and perennial ryegrass (Lolium multiflorum) in 1983. Split applications of N were 56 and 112 kg·ha−1 in CT plots and 0, 56, and 112 kg·ha−1 in NT plots. Plant stand and yields of bush beans and sweet corn were highest in CT plots in both years. Plant stand of squash was less for CT in 1982, but greater for CT than for NT + CC in 1983. Yields of squash were similar, but plant dry weight was greater in CT than in NT + CC. Plant stand of tomato and cabbage for NT + CC was similar to CT in 1982, but cabbage stand was greatest for CT in 1983. Total tomato yields were greater for NT – CC in 1982 and similar to those for CT in 1983, but yields were greatly reduced for NT + CC in 1983. Only in 1982 were cabbage heads of certain treatments marketable and they were greatest for CT. Sidedressing bush bean, sweet corn, cabbage, and summer squash plants with N in NT – CC plots increased yields linearly in 1982. Of the crops grown by NT + CC, only yields of bush beans and cabbage in 1982 and green fruit of tomato in 1982 showed a linear increase by sidedressing with N. Sidedressing with N increased N contents of all crops linearly in 1982, but not in 1983. Weed control was excellent in CT sweet corn and satisfactory in CT and NT – CC plots of the other crops. For the other crops in NT + CC plots, most of the weed and/or cover crop growth was the regrowth of vetch in 1982 and perennial ryegrass in 1983 after weed control chemicals were applied.
Abstract
Spring cabbage plants (Brassica oleracea L. Capitata group) grown by no-tillage culture yielded less than conventionally tilled plants when grown under the same N treatment and spacing. No-till yields could be compensated somewhat by increasing plant population and N, but head size was generally smaller than for conventionally tilled plants. Large head size was positively correlated with high N content of wrapper leaves in 3 of 4 years, while high Ca was associated with large plants or heads in 2 of 4 years.
Abstract
A two-year study of popcorn cultivars grown by no-tillage (NT) and conventional tillage (CT) systems indicated that popcorn can be produced successfully by NT. Plant populations, plant heights, ear lengths, and ear weights were generally greater for NT than for CT. Popping expansion of NT corn, except for ‘Snow Puff’, a white kernel cultivar, was equal to that of CT. The use of either NH4NO3 or Ca(NO3)2 at 56 kg N/ha in 1981 and 84 kg N/ha from NH4NO3 in 1982 produced the highest yields. Increasing N to 140 kg/ha decreased yields of ‘Snow Puff’ in CT. The N levels had no effect on popping quality.