Evaluation of appropriateness of current weed management techniques practiced in rice cultivation in Akuressa and Athuraliya D.S. divisions

Abstract

The present study was carried out to evaluate the appropriateness of different weed management methods prac-ticed in rice cultivation in the Matara district. This study comprised of a survey conducted in rice fields cultivated with variety At 362 in Akuressa and Athuraliya D.S. divisions during 2016/ 2017 Maha season. The survey was carried out using a pretested questionnaire with the participation of randomly selected 100 farmers (69 from Akuressa and 31 from Athuraliya D.S. divisions). Primary data were gathered through several focused group discussions with Agricultural Instructors and using a structured questionnaire. Based on the data gathered a field experiment was conducted in the farmers fields to study the impact of various weed management methods practiced by farmers on weed density and growth and yield parameters of rice. Based on the data obtained on different weed control techniques farmer fields were divided into 4 categories such as single herbicide, herbicide mixtures, non-chemical (manual and/or mechanical) and both chemical with mechanical weeding. Growth and yield parameters of paddy and weed growth parameters were obtained at different stages of the rice growth. ‘t’ test and Kruskal-Wallis were used to analyze the results. Descriptive and inferential statistics were employed to draw conclusions. The highest percentage of farmers used mixed herbicides (44%), while single herbicides, non-chemical and both chemicals with mechanical weeding were used by 20%, 16% and 20%, respectively. The weed count was negligible at 10 days after the application of weed management techniques indicating that the use of herbicide mixtures was ineffective. Method of weed control did not significantly alter the growth and yield parameters of rice except the use of herbicide cum mechanical weeder which showed positive effects on growth and yield of rice. The weed seed bank analysis showed higher sedges and broad-leaved weed populations in chemical applied fields while higher grass weed populations in non-chemical applied fields. Launching farmer awareness programmes at the field level are found to be more important for a better understanding of the rational use of herbicides in rice cultivation.