Abstract:
Influence of crop geometry on the growth and yield of rice variety 'Jaya'.
An experiment was conducted in the Regional Agricultural Research Station, Pattambi during the second crop season of 1983 to study the influence of crop geometry on the growth and yield of rice variety 'Jaya'. The experiment was laid out in split plot with three replications. The treatments consisted of six treatment combinations of two levels of spacing between plants (20 x 15 cm, 20 x 10 cm) and three levels of spacing between alleys (80 cm, 160 cm and 240 cm apart) in the main plot and four levels of crop orientation (north-South, East-West, diagonal planting North East-South West and diagonal planting North West-South East) in the sub plot.
Observations on weather factors such as temperature, relative humidity, rainfall, sunshine hours, wind velocity and evaporation were recorded daily. Crop growth characters like height, number of tillers, leaf area index were recorded at different stages of development of the crop and yield components like number of productive tillers, length of panicle, and yield of girth and straw were noted during the harvest.
The day time variation of albedo was also measured at frequent intervals.
N-S oriented crop was significantly superior to others with regard to crop growth characters as well as yield components. Height, number of tillers, number of productive tillers, length of panicle and number of grain per panicle were influenced by the 20 x 15 cm spacing while the 20 x 10 cm spacing showed the maximum drymatter production, maximum thousand grain weight and highest value of grain and straw yields. The grain yield was not significantly influenced by the alley treatments.
It was found that proper spacing and orientation had significant effect on overall growth and yield of the crop. Highest grain yield was recorded in plots with N-S orientation and with 20 x 10 cm spacing. The best performance is attributed to more effective utilisation of solar radiation with the uniform exposure of plants to sunlight.
The albedo measurements were also higher over the closely spaced and N-S oriented plots indicating the better growth and performance of the crop.
Results of the present investigation indicate that rice in Kerala during the second crop season can be grown most successfully if planted at a spacing of 20 x 10 cm and oriented in N-S direction.
