Author(s): R.K.GHOSH, A. KUMAR, A. GHOSH, D. MONDAL, C. KARMAKAR, BHARATH G.N., P. BANDOPADHYAY and G. SOUNDA

Abstract: For global eco-safe and sustainable food, nutritional, health and ecological security against increasing population, declining of land per capita along with escalating adverse impacts of climate change, the best management practice of available resources with more biological management is best appropriate methodology in various ecosystems. National production losses due to pests are almost around one third and out of this, the major pest weed plant alone causes around 12 % production losses. Annual planning of weed pest management (APWPM) aims to reduce the weed seed bank in crop field prior to crop planting and by reducing the weed competition in critical crop weed competition period (CCWCP) improving both soil & plant health and in the long run the productivity. Based on a sequence of field and pilot experiments were conducted during last one decade on weed seed bank status and ecosafe management of weed pest the present field experiments were conducted during 2014 – 2016 to find out the weed seed bank status in various weed management practices on rice- rapeseed- okra (aerobic) crop sequence under conventional, reduced and no till system and efficacy of bio and synthetic herbicides mixture following APWPM in SI paddy at inceptisol of India to increase the productivity. The highest density of weed seeds was found in zero tillage plots under weedy check and the lowest with zero tillage also under the eco-safe chemical control management. Among the three different tillage treatments, increase in weed seed density at the end of the crop sequence was highest in zero tillage over initial (14.85%) followed by reduced tillage (13.53%) in comparison to conventional tillage (10.99%). Among the weed management practices, eco-safe chemical control showed maximum diminution in weed seeds over weedy check (58.38%) reduction over initial) at the end of a year, which was followed by botanical control (24.07%) reduction over initial). Whereas the corresponding figures for physical control (hand weeding) was a slight increasing trend in weed seeds density (3.43%) in comparison to weedy check plots (an increase of 58.24 per cent over initial). The probable reason for higher weed seed density in zero and reduced tilled plots under weedy check situation may be due to lesser soil disturbance and other micro-environmental changes created by no tillage and crop rotations probably changes selection pressures via change in management. In both experiments of summer SI paddy twice HW recorded 69.50 -70.32 per cent WCE along with the maximum mean yield of 5.01 t ha^-1. The treatments of mixture of natural botanicals and synthetic chemical showed better weed management (WCE 51.07- 60.91%) over the mixture of only botanicals (WCE 40.57 - 49.83%) or sole application of botanicals or synthetic chemicals (WCE 26.25-49.88%). The mean grain yield data of two experiments showed similar trends, the mixture between natural botanicals and synthetic chemical recorded 7.56, 6.55, 18.69 and 46.79 per cent more yield over the mixture of only botanicals, sole application of chemical, sole application of botanicals and weedy check, respectively The reason of lowering the weed competition in paddy crop during its’ critical crop weed competition period (CCWCP) and increasing the productivity of SI paddy by using APWM may be due to reduction of weed seed bank before the rice planting and further using mixture of natural botanicals and synthetic chemicals at PE may be due to their synergistic effect further inhibition of the germinated weeds that able to create an identical apposite eco safe environment favorable for snowballing both the soil and the paddy crop health. In pilot trials of potato and mustard at 20 DAP / DAS the mixture of natural botanicals and synthetic chemicals also showed better WCE in comparison to their sole application.

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