~ 3349 ~ Journal of Pharmacognosy and Phytochemistry 2020; 9(4): 3349-3355 E-ISSN: 2278-4136 P-ISSN: 2349-8234 www.phytojournal.com JPP 2020; 9(4): 3349-3355 Received: 08-05-2020 Accepted: 10-06-2020 Kaviti Vijayalakshmi Ph.D., Scholar, Department of Agronomy, S.V. Agriculture College, Tirupati, Andhra Pradesh, India APK Reddy Dean of Agriculture, ANGRAU, Guntur, Andhra Pradesh, India AV Ramana Associate Dean, Agriculture College, Naira, ANGRAU, Andhra Pradesh, India P Sudhakar Registrar, ANGRAU, Guntur, Andhra Pradesh, India TNVKV Prasad Principal Scientist, Department of SSAC, IFT, S.V. Agriculture College, Tirupati, Andhra Pradesh, India B Ravindra Reddy Associate Professor, Department of Statistics & Mathematics, S.V. Agriculture College, Tirupati, Andhra Pradesh, India Corresponding Author: Kaviti Vijayalakshmi Ph.D., Scholar, Department of Agronomy, S.V. Agriculture College, Tirupati, Andhra Pradesh, India Uptake of Zn and Fe by direct seeded rice as influenced by weed control methods, major and micronutrients Kaviti Vijayalakshmi, APK Reddy, AV Ramana, P Sudhakar, TNVKV Prasad and B Ravindra Reddy Abstract A field experiment on dry direct sown rice was conducted for two consecutive kharif seasons during 2018 and 2019 at Agricultural College Farm, Naira, Srikakulam of North-Coastal zone of A.P. Significant differences were noticed in growth, yield and uptake of Zn and Fe by grain and straw due to weed control methods, nutrient management practices and application of micronutrients. Significant reduction in the total weed density and increased the crop growth parameters viz., plant height and SPAD meter readings and yield parameters viz., productive tillers m -2 , grain and straw yield and uptake of Zn and Fe by grain and straw at harvest due to sequential application of pyrazosulfuron ethyl fb.florpyrauxifen-benzyl which was however, found parity with bispyribac sodium fb. 2,4-D amine salt + fenoxyprop-ethyl with safener. Weedy check registered the lowest values for all these parameters. Among nutrient management practices, application of 100% RDF produced taller plants, higher SPAD meter values and more number of productive tillers m -2 , higher grain and straw yields. With regard to application of micronutrients, basal application of ZnSO4 @ 50 kg ha -1 exhibited significantly superior performance over other two treatments in this regard. Significantly higher uptake values for Zn by grain and straw were noticed with basal application of ZnSO4 @ 50 kg ha -1 whereas, foliar application of ZnSO4 @ 0.2% and FeSO4 @ 0.5% each at 20 and 40 DAS registered significantly higher uptake of Fe by grain and straw. Keywords: Uptake of Zn and Fe experiment on dry direct sown rice fb.florpyrauxifen-benzyl DAS registered significantly higher Introduction Advancement of research in herbicide technology opened a new vista that has led to identification of several low dose high efficiency broad spectrum herbicides which paved the way for the farmers to shift from conventional transplanting to direct seeded rice (DSR) culture. Therefore, considering the emergence of diverse weed types in kharif season, the purpose cannot be solved by one-time application of herbicide alone. Therefore, there is every need to apply more than one herbicide in combination or in sequence, which can offer greater promise in managing complex and diverse weed flora in DSR (Raj et al., 2013) [15] . Among different nutrients, nitrogen being the most important, the efficacy of which depends amongst others, the crop-weed dynamics in the growing ecosystem. Deficiency of even a single essential micronutrient may disturb the plant developmental cascades and cause substantial reduction in crop yield (Tripathi et al, 2015) [23] . In direct seeding, availability of several nutrients including N, P, K and micronutrients such as Zn and Fe are reported to be a constraint in realization of production potential of rice. Micronutrients, particularly zinc and iron have attained a great significance in today’s intensive and exploitive agricul ture which is aiming at higher crop productivity. Materials and methods A field experiment was conducted during kharif, 2018 and 2019 at Agricultural College Farm, Naira, Srikakulam, Andhra Pradesh. The experiment was laid out in split-split plot design with three replications. The weed management subjected to main plots, nutrient management in sub plots while, application of micronutrients to sub-sub plots. Experiment was comprised of four weed control methods, viz., W1: Unweeded check, W2: Hand weeding twice at 20 and 40 DAS, W3: Pyrazosulfuron ethyl @ 20 g a.i ha -1 at 8-12 DAS fb.florpyrauxifen-benzyl @ 31.25 g a.i ha -1 at 25 DAS and W4: Bispyribac sodium @ 150 g a.i ha -1 at 20 DAS fb. 2,4-D amine salt @ 600 g a.i ha -1 + fenoxyprop-ethyl with safener @ 150 g a.i ha -1 at 40-45 DAS, four nutrient management practices, viz., N1: Foliar application of 19-19-19 @ 1% at 20 DAS and 2% at 40