EVALUATION OF WEED MANAGEMENT PRACTICES ON WEED DYNAMICS IN DIFFERENT RICE (Oryza sativa) FARMING SYSTEMS

An experiment was undertaken in a farmer's field in Chidambaram Sathamangalam, Cuddalore district of Tamil Nadu, during Samba 2020 (August 2020 – January 2021) to determine the weed management in different rice farming systems on weed dynamics. The experiment was conducted in split plot design with four replications, two main treatments with different rice farming systems viz, M1- Monocropping and M2- Annamalai rice + fish + poultry farming system and three sub treatments with weed management practices viz., S1– unweeded control, S2 – twice hand weeding on 20 and 40 DAT, S3 – pre emergence (PE) application through tank mix of butachlor (50 % EC) @ 1.25 kg a.i. ha-1+ 2,4-DEE (38 % EC) @ 0.6 kg a.i. ha-1. The results indicated that, among the farming systems, Annamalai rice + fish + poultry farming system (M2) recorded the lowest weed population, weed DMP and highest weed control index (WCI) at 30 and 60 DAT. Whereas, rice monocropping (M1) recorded the highest weed population, weed dry matter production and the lowest weed control index (WCI) at all the stages of crop growth. In weed management practices, twice hand weeding in on 20 and 40 DAT (S2) recorded the lowest weed parameters and higher weed control index. It was followed by PE application through tank mix of butachlor (50 % EC) @ 1.25 kg a.i. ha-1+ 2,4-DEE (38 % EC) @ 0.6 kg a.i. ha-1 (S3). The highest weed population, weed dry weight and lower weed control index registered in unweeded control (S1). Among interactions, Annamalai rice + fish + poultry farming system along with twice hand weeding on 20 and 40 DAT (M2S2) recorded significantly the lowest weed population, weed dry weight with higher weed control index during Samba 2020. This was followed by Annamalai rice + fish + poultry farming system along with PE application through tank mix of butachlor (50 % EC) @ 1.25 kg a.i. ha-1+ 2,4-DEE (38 % EC) @ 0.6 kg a.i. ha-1 (M2S3). Hence it is concluded that Annamalai rice + fish + poultry farming system performs significantly better than rice mono cropping by recording lowest weed population, weed dry weight and the highest weed control efficiency.