Yield maximization of direct sown rice (Oryza sativa l.) under water constraint situation

Abstract

More efficient water management practices need to be adopted for better sustainable rice production grown under traditional areas due to increased water scarcity. Among the different water management practices, efficient new generation water-saving chemicals and organic products were used to conserve water under field condition.  An experiment was conducted to evaluate the yield maximization in direct sown CO51 rice (Oryza sativa L.) under water constraint situation.  The main plot treatments comprised of three levels of irrigation viz., Conventional irrigation (M₁), Tensiometer based irrigation (M₂) and Deficit irrigation (M₃), respectively and were tested with four different water conservation practices in sub-plots viz., soil application of water-saving crystals (WSC) @ 5 kg ha^-1 (S₁), foliar application of drought shield @ 3 litres ha^-1 (S₂ ), soil application of humic granules @ 2.5 kg ha^-1 (S₃) and soil application of FYM @ 12.5 t ha^-1 (S₄). Experimental results indicated that Tensiometer based irrigation with soil application humic granules @ 2.5 kg ha^-1 M₂S₃) recorded higher number of panicles m^-2  (411) and number of filled grains panicle^-1 (108.16) in direct-sown rice.  However, M₂S₃ recorded significantly maximum grain yield (6352 kg ha-1) and minimum (3940 kg ha^-1) in (M₃S₄) deficit irrigation applied with FYM @12.5 t ha^-1 in the year 2018 Sornavari season, respectively. Thus the Tensiometer based irrigation with soil application of humic granules @ 2.5 kg ha-1 can be a feasible approach for increasing grain yield and conserve water in north eastern region of Tamil Nadu, by promoting water use efficiency method in direct rice cultivation areas.