Abstract
Maize was grown al the Regional Agricultural Research Station, Hathazari, Bangladesh during 1988/89 and 1989/90 to study fodder yield, cob growth and grain yield together with the contribution of pre-silking stem reserves to grain. Population densities were 33300, 44400 and 66600 plants/ha. Plants were either detopped after silking and pollen shedding, keeping 0, 2 or 3 leaves above the cob, or were left entire. The results showed that the maize crop could successfully be detopped for fodder with little or no adverse effect on grain yield. Fodder yield increased with increased plant density and among the detopping treatments the highest fodder yield was obtained when the plants were detopped just above the cob. Cob growth followed a sigmoid pattern and the highest dry weight per cob was obtained from the lowest plant density and from entire plants. The number of cobs/m2 increased with increased plant density but detopping treatments did not give any significant difference in relation to densities. The number of grains/cob was highest with 33300 plants/ha but, among the detopping treatments, plants detopped just above the cob had the lowest number of grains/cob in both years. Weight of 1000-grain decreased with increasing plant density but it was increased by detopping plants just above the cob during 1988/89, although it was decreased in 1989/90. The highest apparent translocation of pre-silking reserves was obtained using densities of 44400 plants/ha but detopping treatments did not show any consistent effect, although the highest apparent translocation (20%) and harvest index (58%) were obtained from plants detopped just above the cob.