Studies on the standardization of nursery method, seedling age and plant density for lowland rice established by the seedling broadcasting method.

摘要

A field experiment was conducted during the 1994-1995 wet and dry seasons to standardize the nursery method, seedling age and plant density for the seedling broadcast method of planting lowland rice. The yield of rice achieved by the seedling broadcast method (5.28 and 6.26 t/ha in the wet and dry seasons, respectively) was comparable with the traditional random planting method. Although the line planting method enhanced the yield to 5.80 and 6.65 t in the wet and dry seasons, respectively, the seedling throwing method was considered preferable because of the lower labour requirements (50.7% of that of line planting and 76.7% of that of random planting) and the relative ease with which the seedlings are thrown. Studies on the evaluation of component technologies to enhance the yield of seedling broadcast rice revealed that irrespective of the nursery method, the use of older seedlings (35 days old) at 30% greater plant density maximized the yield to 5.73 t during the wet season, equivalent to that of line planting (5.86 t). In the dry season, the broadcasting of 35-day-old seedlings from a semidry nursery at normal plant density itself produced a higher yield (6.67 t), which was marginally more than that of line-planted rice (6.65 t).