PHYTOSOCIOLOGICAL STUDY OF WEED FLORA IN LOW LAND RICE ECO-SYSTEMS IN ANNAMALAI NAGAR, TAMIL NADU, INDIA

Phytosociological study was carried out to estimate the dominant of weed flora in low land rice eco-system under varing climatic condition. The survey was conducted at Annamalai University experimental farm, Department of Agronomy, Annamalainagar during 2016 and 2017. The identified numbers were 11 and 14 during 2016 and 2017 wet season. Cyperus rotundus, Cyperus irria, Cyperus difformis, Echinocoloa colonum, Eclipta alba, Echinocoloa crusgali were the densely populated in 2016 while Cyperus rotundus, Cyperus irria, Echinocoloa colonum, Cyperus difformis, Marsilia quatrifolia,  Echinocola crusgali and Bergia capensis, were the most densed in 2017. IVI computed for individual weed species in 2016 at annamalai nagar indicated that Cyperus rotundus was the predominant weed species with highest Relative abundance (RA) of 10.54 %, Relative density (RDE) of 18.97%, Relative frequency (RF) of 16% and Important value index (IVI) of 45.50 while in 2017 also obtained the Cyperus rotundus was the predominant weed species with highest Relative abundance (RA) of 10.61 %, Relative density (RDE) of 19.64%, Relative frequency (RF) of 1615.38% and Important value index (IVI) of 45.63. All other weed species were low in IVI and also rare in their occurrence with lesser frequency

Yield assessment of rice-black gram, rice-maize and rice-groundnut sequential cropping system influenced by rice establishment methods and nutrient management practices in the dry tract of the Southern zone of Tamil Nadu, India

Integrated nutrient management (INM) practices and suitable cropping systems are an effective and promising way for enhancing crop productivity. However, the impact of proper INM practices and cultivation methods in rice cropping systems in dry tracts remains unclear. The field study evaluated the suitable cropping system under different rice establishment methods with INM practices in a sequential cropping system( rice-black gram, rice-maize, and rice-groundnut). Treatments were designed as two rice establishment methods [Direct Seeded Rice (DSR) and Transplanted Rice (TPR)] and five  INM practices [RDF-Recommended Dose of Fertilizer (120:40:40 kg NPK ha-1) alone, RDF + Poultry manure compost @ 5 t ha-1, RDF+  Coir pith compost @ 5 t ha-1, RDF+ Green manure  @ 6.25 t ha-1 and RDF-Green leaf manure @ 6.25 t ha-1].  TPR with the INM practice of RDF + poultry manure compost @ 5 t ha-1  recorded maximum productive tillers m-2 (351), number of filled grains panicle-1 (130.2), grain yield (6709 kg ha-1) and straw yield (9015 kg ha-1) of rice. Rice fallow crops (black gram, maize and groundnut) recorded 10 – 24,10-18  and 10 - 21 % higher values of yield components and yield, respectively, in DSR with INM treatment of RDF + Green manure  @ 6.25 t ha-1 . Thus, RDF plus green manure or poultry manure application is an apt INM practice for a rice-based sequential cropping system under DSR, and the rice-black gram is an economical and sustainable cropping system for dry tracts of the southern zone of Tamil Nadu. 

Effect of in situ soil moisture conservation practices on maize and its crop residue incorporation on yield and economics of succeeding transplanted rice Var. ADT 46

Crop residue incorporation is a key component of sustainable cropping systems. It reduces the adverse effects of residue burning and enhances soil fertility. Effective usage of crop residue in the field and proper management are required. With this background, a field experiment was conducted during 2020 – 21 in the maize-rice cropping sequence at Annamalai University Experimental Farm, Department of Agronomy, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Tamil Nadu to find out the residual effect of different mulching practices adopted in preceding maize crop and maize stubble incorporation on the growth, yield and economics of transplanted rice Var. ADT 46. The field experiment was conducted in Factorial Randomized Block Design with three replications. In factor I, soil moisture conservation in preceding maize crop viz., mulching of sugarcane trash, water hyacinth, hydrogel and control were allotted. In factor II, different levels of maize crop stubble incorporation on rice viz., 0, 33, 66 and 100% were provided. Water hyacinth mulched plot (M3) to the preceding crop registered significantly (þ <0.05) higher yield parameters, yield and economic returns of succeeding rice. The lower values were observed in unmulched (M1) plot. With respect to maize crop stubble incorporation on rice crop, the incorporation of 66% (SI3) of maize stubble registered higher yield parameters, yield and economic returns. In the interaction effects, mulching with water hyacinth to preceding maize + maize crop stubble incorporation at 66% in rice crop (M3SI3) recorded significantly (þ <0.05) higher yield parameters, yield and economic returns than other treatments. The lowest values were recorded with an unmulched + 100% crop residue incorporated (M1SI4) plot. Mulching the preceding maize crop with water hyacinth at a rate of 12 t ha-1 and incorporating 66% maize stubble into the transplanted rice (M3SI3) had a remarkable yield advantage and financial rewards

Tuning visible emission of core-shell nanostructure by exchange the inner and outer layer

Herein, we report that synthesis of ZnS/Bi2S3 and Bi2S3/ZnS core-shell nanostructure prepared by ‘one-pot’ chemical method. We have studied the effect of structural, morphological, optical and thermal properties by exchanging the inner and outer layer of core-shell nanoparticles. The samples were studied using various characterization techniques such as XRD, TEM, FTIR, UV–Vis, Photoluminescence and TG-DTA. The XRD and TEM results demonstrated that the synthesized core-shell nanoparticles were in cubic (ZnS)-orthorhombic (Bi2S3) mixed crystal structures with a diameter of 18.6 nm and 16.3 nm with extremely monodispersing. The obtained result provides a new and simple route for synthesis of sulfide-based core-shell nanoparticles with high crystal quality. © 2021, S.C. Virtual Company of Phisics S.R.L. All rights reserved.Sathyabama Institute of Science and Technology, ChennaiKing Saud University, KSUThe authors acknowledge the Researchers Supporting Project Number (RSP-2021/354) King Saud University, for financial supports, Riyadh, Saudi Arabia. The author Dr. G. Murugadoss thanks the Chancellor, President, and Vice Chancellor, Sathyabama Institute of Science and Technology, Chennai for the support and encouragement

Simulating Potential Impacts of Future Climate Change on Post-Rainy Season Sorghum Yields in India

Given the wide use of the multi-climate model mean (MMM) for impact assessment studies, this work examines the fidelity of Coupled Model Intercomparison Project Phase 5 (CMIP5) in simulating the features of Indian summer monsoons as well as the post-rainy seasons for assessing the possible impacts of climate change on post-rainy season sorghum crop yields across India. The MMM simulations captured the spatial patterns and annual cycles of rainfall and surface air temperatures. However, bias was observed in the precipitation amounts and daily rainfall intensity. The trends in the simulations of MMM for both precipitation and temperatures were less satisfactory than the observed climate means. The Crop Environment Resource Synthesis (CERES)-sorghum model was used to estimate the potential impacts of future climate change on post-rainy season sorghum yield values. On average, post-rainy season sorghum yields are projected to vary betwee

SEED PRIMING TECHNIQUES FOR DROUGHT TOLERANCE AND ITS EFFECT ON GROWTH OF HYBRID CASTOR

A study was conducted to estimate the effect of seed priming techniques on germination and growth performance of castor. The seeds were subjected to priming in different concentration (1, 2 and 3 %) of solution viz., ZnSo4, Kc1 , KH2PO4, CaCl2,Cowdung slurry and water along with unprimed dry seed as a control. The result revealed that percentage of seed germination, germination index, speed of germination, seed vigour index, seedling shoot and root length, seedling root volume, seedling root and shoot dry weight and relative water content of castor were significantly higher with 2 per cent ZnSo4 primed seed, Hydropriming with 2 per cent ZnSo4 is the most promising priming technique for enhancing seedling characters and drought tolerance

SEED PRIMING TECHNIQUES FOR DROUGHT TOLERANCE AND ITS EFFECT ON GROWTH OF HYBRID CASTOR

A study was conducted to estimate the effect of seed priming techniques on germination and growth performance of castor. The seeds were subjected to priming in different concentration (1, 2 and 3 %) of solution viz., ZnSo4, Kc1 , KH2PO4, CaCl2,Cowdung slurry and water along with unprimed dry seed as a control. The result revealed that percentage of seed germination, germination index, speed of germination, seed vigour index, seedling shoot and root length, seedling root volume, seedling root and shoot dry weight and relative water content of castor were significantly higher with 2 per cent ZnSo4 primed seed, Hydropriming with 2 per cent ZnSo4 is the most promising priming technique for enhancing seedling characters and drought tolerance