The effects of three rates of N, Mg, and B on cauliflower (Brassica oleracea, Botrytis group) yield, average curd mass, and hollow stem disorder were evaluated on sandy and clay loam soils. Cultivars White Empress and Stovepipe were tested on the sandy loam soil and `White Empress' was tested on the clay loam soil. Maximum mean curd mass and maximum yields were obtained with the highest N rates (269 and 381 kg·ha-1) applied to sandy loam and clay loam soils, respectively. Yield response to increased N rates varied with cultivar. Increasing Mg from 22.5 to 90 kg·ha-1 did not affect yield or curd mass on clay loam soil, but increased yield and mean curd mass on sandy loam soil. The Mg effect on curd mass was influenced by N and B rates. On both soil types, the higher Mg and B rates reduced the incidence of hollow stem, but the Mg effect was influenced by N applications. On clay loam soil, increasing B from 2.2 to 8.8 kg·ha-1 reduced hollow stem but had no effect on yield or curd mass. On sandy loam soil, B at 4.4 kg·ha-1 maximized yield and curd mass, but the hollow stem disorder continued to decrease as B rates were increased from 2.2 to 8.8 kg·ha-1.
K.M. Batal, D.M. Granberry and B.G. Mullinix Jr.
R.E. Worley, J.W. Daniel, J.D. Dutcher, K.A. Harrison and B.G. Mullinix
No reduction in yield and quality of pecan nuts or leaf mineral nutrient concentration occurred when 100 lb/acre of N was applied through a drip-irrigation system compared with 200 lb/acre applied either all broadcast or half broadcast and half fertigated. Yield of `Stuart', percentage kernel of `Schley', and nut size of both cultivars were increased by irrigation or irrigation and fertigation. The 100 lb/acre N-all-fertigated treatment resulted in less soil pH reduction and less loss of K, Ca, and Mg from soil underneath the tree canopy than broadcast treatments. No evidence of excessive soil pH reduction in the wetted zone of fertigated trees was noticed. Calcium and Mg were higher within than outside the wetted zone.
K.M. Batal, D.R. Decoteau, D.M. Granberry, B.G. Mullinix, D.C. Sanders, G.D. Hoyt and R.J. Dufault
Pepper and sweet corn were tested in a rotation with crimson clover and velvet bean (Mucuna pruriens) cover crops at different locations in Georgia, North Carolina, and South Carolina from 1995 to 1996. Vegetable production with minimum-till following the cover crops was compared with two different conventional methods (following rye cover or fallow). All minimum-till/cover crop treatments caused reduction of total number of pepper fruit, compared to the conventional methods. Effects on premium grade (Fancy + U.S. #1) were similar to the effects on total fruit. The highest percentage of premium grade was produced by both conventional methods in 1996. Sweet corn responded similarly to these treatments in 1995. However, in 1996, clover plots had corn yields nearly as good as the conventional plots. As in bell pepper, plots with velvet bean cover produced lower yield in 1996. Treatment effects on number of marketable corn were the same as the effects on total ears produced.