Can knowledge in seed ecology contribute to improved weed management in direct-seeded rice?

Direct-seeded rice is an emerging production technology in Asia due to labour and water scarcity. However, weeds are an important biotic constraint in the production of direct-seeded rice. Manual weeding is becoming less common and herbicides are replacing manual weeding to manage weeds in direct-seeded systems. However, there are concerns about the evolution of herbicide resistance in weeds and shifts in weed flora. Therefore, there is an interest among scientists to evaluate cultural weed management strategies to improve weed management in direct-seeded rice systems. Weed seed banks are the main source of weed infestation in any crop. Depleting the weed seed bank should be the main aim of cultural weed management strategies. Better understanding of the factors affecting seed germination and seedling emergence could help in the development of effective cultural weed management strategies through either suppressing germination or encouraging germination when emerged seedlings can be easily killed. Weed seed germination and emergence are influenced by light exposure, seed burial depth, use of residue as mulches and flooding of soils. However, the factors affecting weed seed germination and seedling emergence are poorly understood in Asia.