The current epidemic of Phalaris minor in the rice-wheat system in northern India threatens wheat production across a large geographic area, affecting the livelihoods of millions of people. Development of resistance against the widely used herbicide isoproturon highlighted the vulnerability of the rice-wheat cropping system and the need for an integrated weed management strategy to reduce the ecological niche in which P. minor flourishes and ensure long-term sustainability of food production. Zero tillage may contribute to P. minor management as it gives, under northern Indian conditions, a reduction in grassy weed pressure. A field experiment was conducted to develop an understanding of the mechanism by which zero tillage affects the life cycle ofP. minor. Results showed that zero tillage gives a reduction in emergence rate which cannot be solely attributed to differences in soil seed density or relative distribution of seeds through the soil profile. Variation in moisture levels and dormancy state between the two tillage systems are also likely to be involved in regulating P. minor emergence rate.
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