Effect of pre emergence herbicides on growth and yield in transplanted rice (Oryza sativa L.) var ADT 43 in Cauvery delta zone of Tamil nadu
1*G. Bhargavi, 2A. Sundari, 3S. Kalaisudarson and 4G. Usharani
1*-3Department of Agronomy, Faculty of Agriculture, Annamalai University, Chidambaram-608002 (India) 4Department of Agricultural Microbiology, Faculty of Agriculture, Annamalai University, Chidambaram-608002 (India) *Corresponding author: bhargavi.guda9@gmail.com
ABSTRACT
It is well recognized that increase in crop yield is due to better plant growth, with less crop weed competition for nutrients, space, water and sunlight. Transplanted rice faces diverse type of weeds and it reduces the yield up to 40%. Therefore, a field experiment was conducted at experimental farm of Faculty of Agriculture, Annamalai University, Chidambaram, Tamil Nadu, India during kharif 2021-22 to study the effect of pre emergence herbicides on growth and uptake of nutrients in rice under system of rice intensification. The experiment was laid out in a randomized block design with three replications. There were eight treatments viz., T1 - Unweeded control, T2- Hand weeding twice at 20 and 40 DAT, T3- Conoweeding twice at 20 and 40 DAT, T4- Butachlor 50 EC @ 1.25 kg ai ha-1 on 3 DAT, T5- Thiobencarb 50 EC @ 1.8 kg ai ha-1 on 3 DAT, T6- Pretilachlor 50 EC @ 0.5 kg ai ha-1 on 3 DAT, T7- Oxadiazon 2G @ 0.75 kg ai ha-1 on 3 DAT and T8- Pyrazosulfuron ethyl 10 WP @ 0.5 kg ai ha-1 on 3 DAT. The experimental findings revealed that application of pre emergence herbicide pretilachlor 50 EC @ 0.5 kg ai ha-1 on 3 DAT was found to be most productive and economic among the chemical treatments than manual weeding and cono weeding, in terms of plant height (48.5, 76.8 and 83.8 cm), leaf area index (5.43), dry matter production (3834, 7420 and 12910 kg/ha), number of tillers (18.6) resulting in higher grain and straw yield (5347.6 and 6893.6 kg/ha). The application of pre emergence herbicides significantly controlled the weed growth in vegetative stage of rice effectively.