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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. [ABSTRACT FROM AUTHOR]

The rhizosphere of plant possesses important microflora, which secretes wide chemical compounds including secondary metabolites necessary for plant growth and development. The microbial flora of alfalfa plant rhizosphere soil region was explored for functional activity and we found upto ten different pigmented colonies. Due to good functional diversity, this yellow pigmented colony was taken for further studies. Thus, the culture was molecularly characterized and identified for potent bioactive components responsible for antimicrobial activity. The selected culture mass was cultured and secondary metabolites were produced and extracted using ethyl acetate and subjected to GC-MS analysis. The antimicrobial study revealed selective activity against Streptococcus pneumonia, and Proteus sp with zone of inhibition to be 18 and 20 mm respectively. Molecular identification of the isolate by 16S rRNA sequencing showed the isolate as Macrococcus equipercicus with 100 % similarity. Based on GC-MS analysis report 25bioactive compounds were identified and 13-docosenamide, hexadecanoic acid esters and quercetin were found in ethyl acetate extract. Conclusion: Thus the yellow pigmented gram positive cocci M.equipercicus isolated from Medicago sativa possessed wide antibacterial activity due to presence of quercetin. Through the studies, we were able to identify potent antibacterial compound producing bacteria from M. sativa plant rhizosphere soil. [ABSTRACT FROM AUTHOR]