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

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

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

Agronomic management systems for rehabilitation and sustained crop production in coastal agro ecosystem of Tamil Nadu, India

Field experiments were conducted in the degraded coastal agro ecosystem with different land management methods and ameliorative amendments such as to boost the growth of identified MPT’s in degraded soil. The field experiment were laid out in split plot design and consisted of 16 treatment combinations with four land management treatment in the main plots (M1-pit method, M2-trench method , M3-mound method and M4-Auger hole method) and four ameliorative treatment in sub plots (S1-FYM @ 12.5 t ha-1 + Gypsum @ 200 kg ha-1+ ZnsO4 @ 25 kg ha-1 + Azospirillum @ 2kg ha-1+ Phosphobacteria @ 2 kg ha-1, S2- Pressmud @ 15 t ha-1+ Gypsum @ 200 kg ha-1+ ZnsO4 @ 25 kg ha-1+ Azospirillum @ 2kg ha-1 + Phosphobacteria @ 2 kg ha-1, S3– Composted coir pith @ 10 t ha-1 + Gypsum @ 200 kg ha-1 + ZnsO4 @ 25 kg ha-1 + Azospirillum @ 2 kg ha-1+Phosphobacteria @ 2 kg ha-1 and S4- no amendments). The treatment was replicated three times for the identified MPT’s of Pongamia pinnata Based on the results of present study it can be clearly found that trench method of planting in combination with FYM @ 12.5 t ha-1, Gypsum @ 200 kg ha-1, ZnsO4 @ 25 kg ha-1, Azospirillum @ 2 kg ha-1 and phosphobacteria @ 2 kg ha-1 recorded the highest establishment percentage height, girth, PGR and taproot length of identified MPT’s of Pongamia pinnata n the degraded coastal soil

Agronomic management systems for rehabilitation and sustained crop production in coastal agro ecosystem of Tamil Nadu, India

Field experiments were conducted in the degraded coastal agro ecosystem with different land management methods and ameliorative amendments such as to boost the growth of identified MPT’s in degraded soil. The field experiment were laid out in split plot design and consisted of 16 treatment combinations with four land management treatment in the main plots (M1-pit method, M2-trench method , M3-mound method and M4-Auger hole method) and four ameliorative treatment in sub plots (S1-FYM @ 12.5 t ha-1 + Gypsum @ 200 kg ha-1+ ZnsO4 @ 25 kg ha-1 + Azospirillum @ 2kg ha-1+ Phosphobacteria @ 2 kg ha-1, S2- Pressmud @ 15 t ha-1+ Gypsum @ 200 kg ha-1+ ZnsO4 @ 25 kg ha-1+ Azospirillum @ 2kg ha-1 + Phosphobacteria @ 2 kg ha-1, S3– Composted coir pith @ 10 t ha-1 + Gypsum @ 200 kg ha-1 + ZnsO4 @ 25 kg ha-1 + Azospirillum @ 2 kg ha-1+Phosphobacteria @ 2 kg ha-1 and S4- no amendments). The treatment was replicated three times for the identified MPT’s of Pongamia pinnata Based on the results of present study it can be clearly found that trench method of planting in combination with FYM @ 12.5 t ha-1, Gypsum @ 200 kg ha-1, ZnsO4 @ 25 kg ha-1, Azospirillum @ 2 kg ha-1 and phosphobacteria @ 2 kg ha-1 recorded the highest establishment percentage height, girth, PGR and taproot length of identified MPT’s of Pongamia pinnata n the degraded coastal soil