EFFECT OF UNIHUMIC AND AMINOMORE ON COWPEA PLANTS (Vigna unguiculata L.) GROWN UNDER DROUGHT STRESS CONDITIONS

Document Type : Original Article

Authors

Agric. Bot. Dept., Fac. Agric., Zagazig Univ., Egypt

Abstract

Two pot experiments were carried out during two summer seasons of 2015 and 2016 in the screen house, Faculty of Agriculture, Zagazig University, Sharkia Governorate, Egypt to study the effect of foliar spraying with unihumic and/or aminomore on growth, certain physiological aspects, as well as yield and its components. Leaf anatomical features of Tepa cowpea cultivar grown under 20%, 40% and 60% water holding capacity (WHC) were also evaluated. The results revealed that drought stress at either 40% or 20% of WHC significantly decreased all growth characters studied [plant height (cm), leaf area (cm2), number of branches/plant and dry weight of whole plant (g)]. Photosynthetic pigments and carbohydrate fractions in the leaves, as well as yield and its components [number of pods/plant, number of seeds/pod, 100-seed weight, seed weight/plant (g) and carbohydrate fractions as well as protein in seeds] were also decreased. Spraying of unihumic and/or aminomore significantly increased all these parameters. With respect to leaf anatomical features, results indicated that drought stress at either 40% or 20% of WHC reduced lamina thickness of leaflet blade, thickness of palisade tissue, spongy tissue, upper and lower epidermis, size of midvein bundle (in length and in width), number of xylem vessels/midvein bundle and the mean diameter of vessel. However, foliar spraying with unihumic and/or aminomore enhanced leaf anatomical features, except slight reduction in thickness of lamina, palisade tissue and lower epidermis. The best result was attained when cowpea plants were grown under 60% of WHC and sprayed with the combination of both unihumic and aminomore. Foliar spraying of unihumic or aminomore alleviated the adverse effect of drought.

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