SEEDLING GROWTH AND CHEMICAL-COMPOSITION OF 2 PISTACHIO CULTIVARS AS AFFECTED BY BORON AND NITROGEN APPLICATION

The combined effects of four nitrogen (N) levels (0, 50, 100, and 150 mu g/g soil) and six boron (B) rates (0, 20, 40, 60, 80, and 100 mu g/ g soil) on the growth and chemical composition of Kale-ghoochi, a cult ivar of pistachio (Pistacia vera L.) semi-tolerant to B toxicity, and Badami, a cultivar very sensitive to B toxicity, were studied in a cal careous soil under greenhouse conditions. The application of 20 mu g/g B has beneficial effects on leaf growth of the Kale-ghoochi cultivar. The toxic effect of B application greater than 40 mu g/g on pistachio growth was alleviated by application of 50 and 100 mu g N/g for Kale- ghoochi and Badami cultivars, respectively. The rate of B accumulation in pistachio shoots was reduced about 39% by N additions of 50 to 150 mu g/g for Badami, and 24, 52, and 69% with N rates of 50, 100, and 1 50 mu g/g for Kale-ghoochi, respectively. Therefore, when pistachio is grown in B-enriched soils and/or is irrigated with water of relativel y high B content, it is recommended that the plants be supplied with a dequate N.