BENEFITS OF MULCHING WITH DRIED WATER HYACINTH OR PADDY STRAW

Three field experiments were conducted at Regional Rainfed Lowland Rice Research Station, Gerua, Kamrup, Assam, India to study the effects of mulching on potato (Solanum tuberosum) in a rainfed rice-potato cropping system. Experiment 1 was conducted during three seasons (1999-2000, 2000-2001 and 2001-2002) to examine the effect of mulching on yield and economics of winter crops grown after rice and to identify suitable rice based cropping sequences with high productivity and profitability. Rice as preceding crop was followed by common winter crops, viz., potato, tomato, pea for green pods, lentil, gram, toria and coriander. Among the subsequent crops, potato gave the highest yield of 13.9 t ha -1 followed by tomato (12.3 t ha -1 ) under mulching with paddy straw. The rate of increase in yield due to mulching was highest for tomato (29%) followed by potato (21 %). Results of Experiment 2 conducted during two seasons revealed that mulching with dried water hyacinth improved tuber yield of potato by 3.02 t ha -1 from 11.36 t ha -1 under no mulching. The proportion of larger sized tuber yield was higher (60%) under mulching as compared to no-mulching control (51%). Results of experiment 3 (2004-005 and 2005-2006) revealed that response of potato to mulching depends on the variety used. In 2005-06, the yield levels were very low (0.5 t ha -1 under no-mulching and 2.3 t ha -1 under mulching) due to the incidence of bacterial wilt followed by late blight. Incidences of the two diseases were less severe under mulching. Results indicate that use of tolerant variety Kufri Megha and adoption of mulching may reduce wilt and blight incidence and increase tuber yield.