Effect of Sowing Date and Weed Control Methods on Direct Seeded Rice : TECTONIC STRUCTURE VS IRREGULAR DESIGN

Rice (Oryza sativa L.) is the most important crop of south east Asia popularly referred to as the rice bowl of the world. India has the largest area under rice in the world it ranks second in production falling far behind China, which has production of about 200 m tons.The reason for very low productivity in Bihar centres round the fact that rice cultivation in Bihar is mostly rain dependent. Both raising nursery and transplanting seedlings are on the mercy of monsoon, which is extremely erratic in onset, distribution, intensity and cessation. Invariably the seedlings overgrow in the nursery awaiting for rains adequate to perform puddling operations. As a result of use of overgrown seedlings, at times, the crop starts flowering soon after flowering reducing the yield tremendously. Some of the times it becomes even difficult to raise seedlings due to very delayed and erratic monsoon.A very large number of herbicides are there which have been observed to have effective control of weeds in direct seeded rice. However, selecting a particular herbicide or its combination with mechanical weed management require thorough probe.