NITROGEN, MAGNESIUM, AND BORON APPLICATIONS AFFECT CAULIFLOWER YIELD,CURD MASS, AND HOLLOW STEM DISORDER

The effects of three rates of N, Mg, and B on cauliflower (Brassica ol eracea, Botrytis group) yield, average curd mass, and hollow stem diso rder were evaluated on sandy and day loam soils. Cultivars White Empre ss 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 resp onse 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 soi l, but increased yield and mean curd mass on sandy loam soil. The Mg e ffect 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, inc reasing B from 2.2 to 8.8 kg . ha(-1) reduced hollow stem but had no e ffect 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).