In this work a field study was conducted to evaluate the effect of coloured plastic mulch on growth and yield of chilli from October 2005 to April 2006. The plastic mulches were transparent, blue, and black and bare soil was the control. Different mulches generated higher soil temperature and soil moisture under mulch over the control. Transparent and blue plastic mulches encouraged weed population which were suppressed under black plastic. Plant height, number of primary branches, stem base diameter, number of leaves and yield were better for the plants on plastic. At the mature green stage, fruits had the highest vitamin-C content on the black plastic. Mulching produced the fruits with the highest chlorophyll-a, chlorophyll-b and total chlorophyll contents and also increased the number of fruits per plant and yield. However, mulching did not affect the length and diameter of the fruits and number of seeds per fruit. Plants on black plastic mulch had the maximum number of fruits and highest yield. Thus, mulching appears to be a viable tool to increase the chilli production under tropical conditions.

Aromatic rices (Oryza sativa L.) normally produce enormous spikelets of low grain weight resulting low yield. Grain weight and grain density are the vital indicators of grain filling and mainly dependent on genetic make-up. Detail study of grain density and yield components of aromatic rice is a crucial need for yield improvement. An experiment was conducted with 40 rice genotypes to assess the grain density of aromatic rices and to observe the relationships of different grain categories with yield characters. The percentage of high density grains, good grains, average grains, poor grains, partially filled grains, spikelet sterility, and thousand grain weight were found to vary in a great extent. Maximum 50 % high density grain was harvested in BR39 and a minimum 1 % in Khazar. Thousand grain weight ranged from 10 g to 30 g. The proportion of high density grains was positively correlated with thousand grain weight (r =0.57) and grain yield (r =0.57). The negative relations were found between spikelet sterility and grain yield (r = -0.47) and also between number of grains and thousand grain weight (r = -0.74). The grain yield showed the highest positive direct relation (0.23) with thousand grain weight, followed by high density grains (0.20).

Los arroces aromáticos (Oryza sativa L.) normalmente producen espiguillas enormes con bajo peso de los granos, que resultan en un bajo rendimiento. El peso de los granos y la densidad de los granos son indicadores vitales del llenado de los granos, y dependen principalmente de la constitución genética. El estudio detallado de la densidad del grano y los componentes del rendimiento del arroz aromático es crucial para mejorar el rendimiento. Se realizó un experimento con 40 genotipos de arroz para evaluar la densidad del grano en arroces aromáticos y para observar las relaciones de diversas categorías de granos con los caracteres del rendimiento. Se encontró que el porcentaje de granos de alta densidad, granos buenos, granos promedio, granos malos, granos parcialmente llenos, la esterilidad de espiguilla y el peso de mil granos variaron en gran medida. Un máximo de 50 % de granos de densidad alta se cosechó en BR39, y una mínima de 1 % en Khazar. El peso de mil granos varió de 10 g a 30 g. La proporción de granos de alta densidad se correlacionó positivamente con peso de mil granos (r =0.57) y con rendimiento del grano (r =0.57). Se encontraron relaciones negativas entre esterilidad de la espiguilla y rendimiento del grano (r = -0.47) y también entre número de granos y peso de mil granos (r = -0.74). El rendimiento del grano mostró la más alta relación directa y positiva (0.23) con el peso de mil granos, seguido de los granos de alta densidad (0.20).