A Greenhouse Study on Growth, Yield and Anatomical Parameters of Three Pea Cultivars: under Different Irrigation Levels and Growth Regulators

Abstract

This experiment was carried out during the fall season 2009-2010 in the vegetable greenhouse, Horticulture Department, Dohuk University. Three pea cultivars namely Local crinkle, Local Smooth and Canadian were subjected to three irrigation levels where plant irrigated whenever 25, 50 or 75% of pot available water capacity were depleted, besides plants were sprayed with either 100mgl -1 gibberellic acid (GA3), 100mgl -1 indole-3-butyric acid (IBA), 2.5gl -1 micronutrient and distilled water as a check treatment. The objective was to evaluate the cultivar performance under adequate and inadequate irrigation during flowering, pod swelling and seed filling stages to find out which is the best, particularly under moderate and severe drought, besides that we intended to evaluate the possibility extent of boosting drought resistance of these cultivars by the aid of GA3, IBA and micronutrients. The obtained results exhibited that irrigating pea plants whenever 25% 0f pot available water capacity was depleted appeared to be the paramount irrigation treatment followed by that of 50% depletion and irrigation level of 75% are not advisable. 25% irrigation level manifested the highest leaf number per plant (26.33), plant height (141.15 cm), root dry weight (0.16g), flower number per plant (6.48), individual pod fresh weight (3.56g), seed number per pod (3.47), green pod yield per plant (14.53g), weight 100 seeds (23.02g), seed fresh weight per pod (1.44g), pericarp fresh weight (2.05g), aperture length of upper leaf stomata (4.38µm), stomata length of leaf lower surface (6.23 µm), stomata aperture length of leaf lower surface (4.75 µm), smallest vessel width (3.72 µm), protein content of dry seed (25.3%), GA3 (346.63 mgkg -1 dry seeds), and IAA (4109.72 mgkg -1 dry seeds). The best plant response was confined to these sprayed with micronutrient, then IBA and the lowest was GA3-treated pea. Pea sprayed by 2gl -1