Seasonal variability of tea yield as influenced by soil and water conservation measures in the Nilgiris

An experiment was conducted in the Research farm. Central Soil and Water Conservation Research and Training Institute, Research Centre, Udhagamandalam to study the effect of conservation measures on yield of green tea leaves. Contour Staggered Trenches (CST) and cover crop of beans were tried individually and in combination as conservation measures and compared with control. The increase in yield of green tea leaves over control by 25,37 and 37% in CST alone, beans alone and CST+beans, respectively was observed due to conservation measures. Four flushes occurred in the months of April, June, September and November accounting to 47.5% of the annual yield and among the dormancy months, minimum yield was observed in the month of August (4.0% of the annual yield) followed by February (6.0%). In the early season (mid April up to mid July) adequate rainfall coupled with suitable air temperature resulted in higher growth rate and yield (30% of annual yield). The mid season (July to November), contributes 41% of the average annual yield. Non uniform distribution of the rainfall, mean relative humidity below 70% and low air temperature are the major climatic variables limiting the yield of tea leaves (29% of annual yield) during the late season (December-March). In the post monsoon period, the increased in yield of green tea leaves was significant due to conservation measures (increased by 39, 34 and 38% in CST, beans and CST+bcans, respectively) compared to other seasons.