FIELD PERFORMANCE OF RONSTAR, RIFIT, AND AMCHLOR AS HERBICIDES FOR WEED CONTROL AND PRODUCTIVITY OF BRRI DHAN29

Abstract

An experiment was carried out at the Field Laboratory, Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Dinajpur during Boro season (December to May), 2008-09 to study the effect of weed control measures on the yield of BRRI dhan29. The experiment was laid out in the RCB design with three replications accommodating three weed control measures i.e. Ronstar 25EC, Rifit SOOEC and Amchlor 5G with different doses. The results showed that the experimental field was infested by thirty two weed species from thirteen families of which Ali ghas/ Bahuea (Cyperus difformis L.) Cyperaceae, mutha (Cyperus rotundus L.) Cyperaceae, Anguli (Digitaria sanguinalis L. scop) Gramineae, Arail (Leersia hexandra L.) Gramineae, Chanchi (Alternanthera sessils R.Br.) Amaranthaceae, Kesoti (Eclipta Prostrata L.) Compositae, were the most dominant species. The other dominant species was susnisakh (Marsilea quadrifolia L.) On the other hand, minimum infesting weed species was durba (Cynodon dactylon L.). The influence of herbicides at different doses showed significant effects on the weed density, weed dry weight and the herbicides also affect the yield and yield attributing characteristics under study. The yield attributes were significantly influenced by weed control measures. Among those the application of pre and post emergence herbicidal effect on weed population at 45 and 73 days after transplanting had the lowest (16.33 no) and the highest (250.00 no) weed density were found in control plot respectively. From the analysis of herbicidal effect among Ronstar 25EC, Rifit SOOEC and Amchlor 5G noticed that the highest yield (4.40 tha’) was found by the application of Ronstar 25EC @ 2010 mlha” and the lowest yield (2.70 tha’) obtained from the treatment of control plot. Observed that the application of Ronstar 25EC@2010 mlha’! i.e. recommended dose maximized the highest yield (4.40 tha’')and the second highest yield (4.38 tha’) were obtained from the treatment of recommended dose of Rifit 500EC @ 1005 mlha’.