Vol. 10, Special Issue 11 (2021)

Author(s):
Sagar Bidari, Aparna Aggarwal and Prashansha Singh

Abstract:
The aim of this study is to “determine the effect of numbers of seedlings and spacing on weed dynamics and vegetative growth of hybrid rice”. The research was conducted in Thakre-11, Dhading district of Nepal. For this research 30 plots of 2mX3m of individual size were made. Plot 1, 2 and 3 with 10 individual sub-plots were made. In those 10 subplots, 5 subplots were planted with single seedling with the spacing of 15X20, 20X20, 25X25, 30X20, 30X30and same with remaining double seedlings plot. After plantation numbers of leaves in several plots, plant height (cm), number of tillers per square meter, panicle length, weed population per square meter, pest and disease observation as well as root growth and development were observed in detail. Initially, data of each plot was taken and observed as mean number of leaves in each plots after 45 days of plantation. In plot number 1, the average number of leaves of single seedling of rice was 28cm whereas those of double seedlings were 56. Similarly, in plot 2 the average number of leaves with single seedling was 32 and that of plot with double seedlings were 60. Similarly, in plot number 3, single seedling had leaf number of 29.3 and that of double seedlings were 57 in average. Also, the height of plant after 28 days of transplantation was measured. The measurement of average height in plot 1 was taken as 33.8cm and 33.2cm of single and double seedling plot respectively. In plot 2 with single seedling average of 32.8 cm and double seedling with 32cm was observed. Finally, plot with single seedling with height of 35.4cm and double seedling with height of 33.2cm were observed in plot no 3. Moreover, after 45 days of transplanting, the number of tillers per square meter was recorded. In plot 1 with single seedling, average of 8.3 and double seedling with 7.2 tillers were recorded. Similarly, in plot 2 with single seedling, tiller number of 7.8 and double seedling with 7.5 tillers were observed. Lastly, in plot no. 3, single seedling had 8.4 tillers and double seedlings with 7.6 tillers were observed. Again, to determine the number of leaves in tillers after 38 days of transplantation, rice leaf was counted. After the study it was found that in plot 1, 38.8 with single seedling and 38.2 numbers of leaves in plot 2 with double seedling was observed. Also, average of 37.9 and 37.8 numbers in single and double seedlings in plot number 2 were recorded respectively. In case of plot no 3, 39 and 38.7 average leaves per tiller were found in single and double seedlings as well. Furthermore, the amount of weed infestation was recorded in all 3 plots. The average number of 37 and 23, 31 and 26 and 36 and 16 were observed in 1squuare meter of planted single and double seedling in plot number 1, 2 and 3 respectively. Moreover, pest and disease infestation in plot of single seedling were observed more prevalent compared to that of double seedlings in all plots. Finally, after 42 days of transplantation, average growth and development of roots in plot number 1 were 22cm and 24cm long. Not only that average of 23 and 25, 24 and 21 were the length of roots in plots no 2 and 3 of single seedlings and double seedlings respectively.