Weed Management Practices on Growth, Yield and Economics of Kharif Grain Sorghum

In the Kharif grain sorghum growing areas of Karnataka, the sorghum production suffers greatly due to weed problem, which offers limitations to crop. It was found that weed infestation become unmanageable throughout the growing period by the traditional methods of interculturing and manual weeding due to continuous and heavy rains during entire vegetative and early reproductive stages of Kharif sorghum. Hence, integration of herbicides with some cultural operations and use of pre-emergence, post-emergence herbicides in combination with mechanical methods can prove to be more successful. A field experiment entitled “Weed management in kharif grain sorghum” was conducted during Kharif 2019 at ARS, Hagari in deep black soil with neutral reaction (pH 7.50), organic carbon (5.5 g kg-1), available nitrogen (248.00 kg ha-1), available phosphorus (36.75 kg ha-1) and available potassium (312.00 kg ha-1). An experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. There were fourteen treatments comprising of weed management practices. The dominant weeds observed in the experimental fields were among grasses Brachiaria reptans, while in broad leaved weeds, Amaranthus viridis and among sedges, Cyperus rotundus. Significantly lower population of grasses, sedges, and broad leaved weeds, weed dry weight, weed index (%) and higher weed control efficiency throughout the crop growth period was noticed in sequential pre-emergence application of atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb 2,4-D Na Salt 80 WP @ 0.75 kg a.i. ha-1 as PoE at 25 DAS except weed free treatment. Atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb 2,4-D Na Salt 80 WP @ 0.75 kg a.i. ha-1 as PoE at 25 DAS recorded significantly higher plant height, dry matter accumulation, leaf area, test weight, grain yield, straw yield, harvest index, gross return, net return and benefit cost ratio (160.8 cm, 183.4 gplant-1, 24.1 dm2 plant-1, 30.53 g, 4195 kg ha-1, 9891 kg ha-1, 29.80 %, Rs. 1,03,675ha-1, Rs. 71,636 ha-1and 3.24, respectively) except weed free and it was on par with atrazine 50 WP @ 0.50 kg a.i. ha-1 as PE fb IC at 25 DAS and HW at 25 DAS and IC at 40 DAS.

Effect of Nano Nitrogen on Growth, Yield and Nutrient Uptake of Bt Cotton

Aims: Foliar application of nano nitrogen is aimed to reduce the soil application of conventional nitrogen. Nano fertilizers enhance crop growth, yield and quality while enhancing the faster nutrient uptake and reducing costs. They provide precise nutrient management, matching crop growth stage and offer increased surface area for metabolic reactions. This boosts photosynthesis, leading to higher dry matter production and crop yield. Foliar application of nano urea (liquid) at flowering, boll initiation and boll development stages in cotton fulfills the nitrogen requirement and reflects higher crop productivity and quality. Higher productivity of crops in sustainable manner could be achieved applying appropriate combination of conventional fertilizer and nano fertilizers. Study Design: The experiment was laid out in split design with three replications.Place and Duration of Study: A field experiment was conducted in shallow black soils at Main Agricultural Research Station, Raichur, during kharif 2022.Methodology: There were fifteen treatment combinations, consisting of different doses of RDN (50 % N, 75 % N and 100 % N) with different concentrations of nano urea sprayed at 90, 100 DAS and 135 DAS for US-7067 BG-? hybrid of Bt cotton.Results: Application of 100% RDN has recorded significantly higher plant height, sympodial branches plant-1 and total dry matter accumulation (176.9 cm, 27.1 and 430.31g plant-1, respectively) followed by 75 % RDN (168 cm, 26.7 and 426.91 g plant-1, respectively) which found on par with each other. It also produced higher number of bolls plant-1 (50.3), boll weight (5.81 g) and seed cotton yield (3388 kg ha-1) followed by 75 % RDN (50.2, 5.36 g and 3376 kg ha-1, respectively) which found comparable with each other. Foliar application of nano urea @ 0.6 per cent each at 90, 100 and 135 DAS has recorded significantly higher plant height (180.8 cm), sympodial branches plant-1 (28.5), total dry matter accumulation (429.42 g plant-1), number of bolls plant-1 (52.2), boll weight (5.93 g) and seed cotton yield (3485 kg ha-1) followed by foliar spray of nano urea @ 0.4 per cent each at 90, 100 and 135 DAS (173.3 cm, 28, 428.52 g plant-1, 51.8, 5.67 g and 3465 kg ha-1, respectively) which found on par with each other. Similar trend was recorded with regard to nutrient uptake by cotton.Conclusion: Foliar application of nano urea reduced the dosage of conventional nitrogen by 25 per cent. There was linear increase in seed cotton yield (kg ha-1) with increasing levels of nitrogen levels.

Bio-Efficacy of Post Emergent Herbicides on Weeds in Direct Seeded Rice (Oryza sativa L.)

A field experiment was conducted to study the bio-efficacy of post emergent herbicides on weeds in direct seeded rice in medium black clay soil at Agricultural Research Station, Dhadesugur, University of Agricultural Sciences, Raichur, Karnataka during Kharif 2022. The experiment was laid out in Randomized complete block design with three replications. There were eight treatments consisting of five post emergent herbicides sprayed at 25 DAS, hand weeding at 20 and 40 DAS, weed free check and weedy check in direct seeded rice and the variety RNR 15048 was used in this trial. Application of cyhalofop butyl 5.1 % + penoxsulam 1.02 % OD @ 2000 ml ha-1 recorded significantly lower weed density, weed dry weight, weed index and higher weed control efficiency compared to all the other treatments. It also produced higher number of productive tillers (409.4 m-2), panicle weight (3.89 g), filled grains per panicle (243.1), lower number of unfilled grains per panicle (8.4), higher grain yield (6058 kg ha-1) and straw yield (6935 kg ha-1) in direct seeded rice. So it can be concluded that application of cyhalofop butyl 5.1 % + penoxsulam 1.02 % OD @ 2000 ml ha-1 at 25 DAS (weeds at 2-3 leaf stage) was most effective in managing the weeds with higher weed control efficiency. It also resulted in higher growth and yield components of direct seeded rice leading to higher grain yield.

Effect of Nano Fertilizers on Growth, Yield, Nutrient Uptake and Soil Microbiology of Kharif Sorghum

Aims: Foliar nutrition is aimed to eliminate the problems of fixation and immobilization of nutrients. Hence, foliar nutrition is being recognized as a significant way of fertilizing modern agriculture, especially under rainfed conditions. Nano fertilizers because of smaller size and higher surface area are efficient as compared to conventional and produce better results when used in combined form.Study Design: The experiment was laid out in Randomized complete block design with three replications.Place and Duration of Study: A field experiment was conducted in medium black soils at Agricultural Research Station, Hagari, during Kharif 2022.Methodology: There were ten treatment combinations, consisting of different doses of RDF (50 % RNP, 75 % RNP and 100 % RDF and absolute control) with different doses of nano urea and Dap sprayed at 30 and 45 DAS for CSH-16 hybrid of sorghum.Results: Application of 75% RNP as basal + nano urea & DAP spray @ 1.5 ml l-1 each at 30 and 45 DAS recorded significantly higher number of leaves, leaf area and leaf area index. It also produced higher earhead length (35.9 cm), number of grains earhead-1 (2207), grain weight (57 g plant-1) and test weight (29.3 g 1000 grains-1). Nutrient content and uptake also showed higher values for the same treatment along with the nutrient use efficiency indices. Whereas, significant reduction in soil microbes was noticed by the application of treatment.Conclusion: Combined application of conventional and nano fertilizers helped to increase growth, growth attributes like number of leaves, leaf area, leaf area index, yield attributes, nutrient content, nutrient uptake and nutrient use efficiency of sorghum.

Studies on skeletal muscle biopsies in endemic skeletal fluorosis.

Neurological manifestations of skeletal fluorosis have been attributed to compressive radiculomyelopathy. Experimental fluorosis has shown evidence of myopathic changes. Data on human muscle pathology is very scanty. This study included 22 patients with established osteofluorosis. 16 of them showed only EMG changes of neurogenic muscle disease. Histochemistry and histopathology of muscle biopsies showed features of muscle atrophy, evidenced by 'type I' atrophy and 'type I' grouping. No myopathic changes were observed. It may be concluded that the primary changes are related to the nerve, with muscle being affected secondarily. There was no evidence of any primary muscle pathology due to fluorosis.

Correlation of fragile sites and bleomycin induced chromosome break points.

Bleomycin (Blm) induced break points in human chromosome preparations were compared with the known fragile sites. A total of 136 breaks were observed from 100 well spread G-banded plates (1.3 bps/cell). These correspond to a total of 57 break prone sites. Of these 57 sites, 24 correspond to the known fragile sites, 5 to sites of protooncogenes and neoplasia, 26 sites correspond to more than one known site of fragility, protooncogene, neoplasia or reciprocal translocation sites, and 2 unknown sites. The findings suggest that fragile sites, either commonly expressed or induced, might be a predisposing factor for chromosome aberrations in human. The expression of fragile sites induced by Blm and their correlation with the known cancer chromosome break points, oncogenes and reciprocal translocation, suggest that the fragile sites are prone to mutagenic action.