Influence of land preparation on weed dynamics and growth of traditional rice landraces in the diverged location of Tamil Nadu

Abstract

In recent years, traditional landraces are gaining importance due to its many health benefits. But the main drawback of the traditional rice variety is low productivity with increased water consumption. Therefore different rice establishment methods are to be evaluated. But weed infestation occurs in every establishment method. Hence the present study aimed to study the weed dynamics by evaluating the water-saving technologies compared with puddled transplanting using various landraces. The first field experiment was conducted during Samba (Aug-Sept) 2021 in the wetlands of Tamil Nadu Agricultural University, Coimbatore. The second field experiment was at the Research Station, Melalathur in Tamil Nadu during Navara (Nov-Jan) season 2021. The experiment was laid out in split plot design comprising four establishment methods as main plots viz. Aerobic rice (M1), Puddled transplanting (M2), Unpuddled transplanting (M3), Direct seeded rice (M4) with traditional landraces viz. Karuppu kavuni (V1), Mapillai samba (V2) and Seeraga samba (V3) in sub plots. In this study, weed dynamics like weed density and weed dry weight were recorded along with plant height, leaf area index and total chlorophyll content. Weed density and weed dry weight was 87.82 % and 74.63 % higher in aerobic rice cultivation than puddled transplanting method during all the observations in both experiments. On comparing the land establishment methods, Direct seeded rice performed well with 40.61% of higher plant height, 89.38 % of higher LAI, 38.48 % of increased total chlorophyll content than Aerobic rice cultivation. The landrace mapillai samba showed a significantly (p<0.05) higher plant height of 64.09±7.14 cm, Leaf area index of 2.05±0.992 and total chlorophyll content of 2.56±0.461 mg/g of fresh leaf. Hence this study provides evidence that in the initial stage of rice cultivation, direct seeded rice and the mapillai samba landrace performed well than the other establishment methods and the other two landraces.