A field study was carried out during rabi (winter) seasons of 2018–19 and 2019–20 at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, Tamil Nadu to study the effect of four different crop establishment methods, viz. manual transplanting; transplanting of rice seedling in puddled soil using machine; transplanting of rice seedling in non-puddled soil using machine; and direct sowing combined with four different irrigation treatments, viz. farmers practice; irrigation following the development of a hairline crack; irrigation when water level descents 5 cm; and 10 cm below soil surface on physiology of rice (Oryza sativa L.). Experiment was conducted in a strip plot design replicated thrice. The study revealed that nutrient uptake and physiological parameters were found to be maximum with seedlings of rice crop transplanted in non-puddled soil using machine combined with irrigation following the development of a hairline crack. Seedlings of rice crop transplanted in non-puddled soil using machine combined with irrigation once the water level descends to 5 cm beneath the soil surface, had a significant positive influence on rice yield during both the years. It also recorded higher photosynthetic rate and improved physiological parameters, and yield even with minimum use of water. So, it may be recommended as the best alternate method of rice cultivation compared to conventional method where the rainfall is deficit.

Background: Time of pre-emergence herbicide application is an important factor that decides the efficiency of herbicide. If the pre-emergence herbicide is not applied at appropriate time, it may cause ineffective weed control or toxicity to crops. With this background, a field experiment was conducted at TNAU, Madurai to optimize the time of pre-emergence herbicides namely pendimethalin and oxyfluorfen application for effective weed management in irrigated blackgram. Methods: The experiment was laid out in randomized block design with three replication. Treatments were application of pendimethalin at 0.75 kg ha-1 and oxyfluorfen at 0.2 kg ha-1 on 1, 2, 3, 4 days after sowing, weed free check and unweeded check. Result: Results of the study revealed that oxyfluorfen gave maximum weed control efficiency as compared to pendimethalin, but toxicity to the crop was observed when oxyfluorfen was sprayed after 2 days of sowing. Yield and economics were achieved higher with application of 0.75 kg ha-1 of pendimethalin at 2 DAS, which was on par with application of 0.2 kg ha-1 of oxyfluorfen at 1 DAS due to lesser toxicity. Application of 0.75 kg ha-1 of pendimethalin and 0.2 kg ha-1 of oxyfluorfen didn’t leave any herbicide residue after harvest. Hence, application of 0.75 kg ha-1 of pendimethalin at 2 DAS and 0.2 kg ha-1 of oxyfluorfen at 1 DAS can be recommended for effective weed management in irrigated balckgram.

Evapotranspiration is a vital process that substantially sustains the hydrothermal balance. The spatial and temporal assessment of evapotranspiration is critical for the management of water resources and drought monitoring at a regional scale. Surface Energy Balance Algorithm for Land (SEBAL) was employed to compute daily actual evapotranspiration in the lower Bhavani basin using Landsat 8 imagery, weather data and digital elevation model. The study aimed to analyze the spatial and temporal distribution of evapotranspiration. In addition, the influence of surface parameters such as surface albedo, land surface temperature, normalized difference vegetation index and net radiation flux on evapotranspiration was also investigated. The results revealed that SEBAL estimates agreed to 86.5 per cent with pan evaporation. Surface evapotranspiration showed seasonal variability with lower rates during winter and recorded maximum evapotranspiration during summer. Land use classes such as flooded vegetation and water bodies were found to have higher rates of mean daily evapotranspiration, whereas bare soil had lower evapotranspiration. Net radiation was noticed to have a significant impact on daily evapotranspiration among surface parameters. Hence, SEBAL can produce accurate evapotranspiration estimates for the study area. Moreover, vegetation cover and hydrothermal conditions significantly affect the surface parameters, which considerably affect surface evapotranspiration.

The study demonstrated the computation of evapotranspiration (ET) in cultivation of groundnut (Arachis hypogaea) through the application of crop simulation models, alongside a comparative analysis with leaf area index (LAI) from various sources. The cultivation period for groundnut was conducted during the calendar year 2023, during which 2 distinct growth patterns were noted, attributed to variations in environmental conditions. The study analyses the estimated evapotranspiration from AquaCrop model, utilizing crop coefficient (Kc) values in comparison with evapotranspiration data derived from satellite observations provided by the MOD16A2v061 product. Furthermore, LAI was measured through 3 methodologies: an empirical equation based on field data, the Li-Cor 2200 plant canopy analyzer and LAI calculations derived from cloud-free normalized difference vegetation index (NDVI). LAI obtained from Li-Cor 2200 instrument exhibited a higher degree of consistency in correlation with empirical LAI derived from ground observations. Conversely, LAI values calculated using the normalized difference vegetation index (NDVI) demonstrated a greater degree of variability, especially during times of cloud cover. The study emphasizes the relationship between LAI and ET and magnitude of LAI in amount of total evapotranspiration.

Evapotranspiration is a crucial component of the hydrological cycle and is profoundly influenced by climate change. Assessing regional evapotranspiration changes is essential for effective water resource management. The study investigated the dynamics of reference evapotranspiration in the Lower Bhavani Basin, a region with diverse landscapes increasingly vulnerable to climatic variability. Reference evapotranspiration data from the Food and Agriculture Organization using the AgERA5 dataset was analyzed to assess annual and seasonal trends from 2000 to 2022. The result showed that the mean yearly reference evapotranspiration in the basin is 1672.87 mm, with a significant decline of 3.53 mm per year. Seasonal analysis revealed a consistent decreasing trend across all seasons, with the southwest monsoon season showing the most significant reduction in evapotranspiration rates. The notable shift in the annual evapotranspiration rate was observed in 2016, highlighting the impact of climate change. Further, temperature, solar radiation and relative humidity were identified as the dominant factors influencing evapotranspiration rates in the basin. The relative moisture index indicated prevalent dry conditions, making the region susceptible to water stress. The findings provide critical insights for regional water resources management and accentuate the need for sustainable water management strategies to mitigate the impacts of climate change.

A field experimental study was conducted during summer season (2023) at Eastern farm of Tamil Nadu Agricultural University, Coimbatore to evaluate suitable irrigation method for black gram. The experiment was laid out in a strip plot design which comprise main plot treatments such as M1 – Drip Irrigation, M2 –Micro sprinkler Irrigation, M3 – Rain hose Irrigation and M4 – Conventional Irrigation and subplot consists of different depths for placement of soil moisture sensor viz., D1 – 5 cm , D2 – 10 cm and D3 – 15 cm. The growth attributes viz., plant height, number of branches per plant, number of leaves per plant were significantly higher in drip irrigation system with sensor depth of 15cm. The root length and root dry weight were significantly greater in Rain hose irrigation with sensor placed at depth of 15 cm. The yield attributes viz., number of pods per plant, number of seeds per pod, number of seeds per plant, pod weight per plant, pod length, test weight, grain yield and haulm yield were significantly higher in drip irrigation with sensor placed at depth of 15 cm. The average grain yield of drip irrigation method is 31.7 per cent higher than the grain yield of conventional irrigation method. Higher grain yield of 1159 kg ha -1 was obtained in drip system with sensor placed at the depth of 15 cm.

Back ground: More than half of the world’s population depends on rice, which is grown in transplanting conditions. Due to the global water crisis, irrigated rice systems are no longer sustainable. Therefore, cultivating aerobic rice with drip irrigation and fertigation meets the crop water and nutrient requirements, results in the optimal yield. Method: A field experiment was conducted during summer 2022 and 2023 at Research Farm of Wetland in Tamil Nadu Agricultural University, Coimbatore, to evaluate the performance of aerobic rice under drip irrigation and fertigation levels on growth and yield of Co-51 variety. The experiment was laid out in randomized complete block design with combination of thirteen treatments, replicated thrice. Results: Among different treatments, drip fertigation @ 100% PE up to 30 DAS+150% PE up to 60 DAS+ 200% PE up to 90 DAS with 125% RDF (25% through NF+75% through WSF) resulted significantly superior growth characters viz., higher plant height (92.54 and 95.95 cm), no. of tiller m-2(469.78 and 478.42), total drymatter production m-2 (988.21 and 1025.42 g m-2), no. of filled grains panicle-1 (107.5 and 114.5), total no. of grains panicle-1 (122.6 and 127.1), fertility percentage (87.7% and 90.1%) and lower no. of ill filled grains panicle-1 (15.1 and 12.6), grain yield (4316 and 4446 kg ha-1) and straw yield (5528 and 5775 kg ha-1) as compared to others, during summer 2022 and 2023, respectively.

Background: Adsorption and subsequent release of pre-emergence herbicide into the soil solution decides the herbicide availability to kill the weeds. Herbicides applied on clay or organic rich soil type, absorb more results in lowering its availability in soil solution become sub lethal to kill the weeds, whereas sandy soil adsorb less and desorb more, sometime it increases the herbicide concentration to toxic level to crop. Effective weed control could be achieved by studying the variability of soil and deciding the dose based on the sorption and desorption properties of the soil. Methods: With this information on the background a laboratory experiment was conducted at the Department of Agronomy, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, India during 2021 to study the optimum level of oxyflourfen concentration in soil solution required to kill the weeds effectively. The study on sorption and desorption was carried out with pre-emergence herbicide oxyflourfen with five different concentrations in five different soil types. Result: The highest sorption of 98.53 per cent was observed with clayey soils followed by sandy clay loam soils with high organic matter content (96.97 per cent). The lowest sorption (77.96 per cent) was recorded with sandy loam soils. The highest desorption of 57.44 per cent was recorded with sandy loam soil and the lowest desorption percentage (13.18 per cent) was obtained with sandy clay loam soil with higher organic matter. Based on the analytical results of sorption and desorption, oxyflourfen dose was optimized as 0.53 kg ha-1 for sandy clay loam soils with high organic matter, 0.34 kg ha-1 for clay soil, 0.29 kg ha-1 for sandy clay, 0.21 kg ha-1 for sandy clay loam soil and 0.12 kg ha-1 for sandy loam soils. In conclusion, the clay soil required more quantity of oxyflourfen compared to other types of soil for effective management of weeds under irrigated condition.

A field experiment was conducted at Wetland farm, Department of Agronomy, Tamil Nadu Agricultural University, Coimbatore during summer 2022 to study the effect of growth and yield parameters of greengram under different irrigation methods. The field experiment was laid out in randomized complete block design having seven treatments and replicated thrice. The treatment are T 1 : Check basin method (Line sowing), T 2 : Check basin method (Broadcasting), T 3 : Raised bed method (Line sowing), T 4 : Ridges and furrow method (Line sowing), T 5 : Drip irrigation system (Line sowing), T 6 : Drip irrigation system (Broadcasting) and T 7 : Sprinkler irrigation system (Line sowing). Experimental results showed that significantly higher plant height, number of branches plant -1 , number of pods plant -1 , pod weight plant -1 , number of seeds plant -1 , seed yield and haulm yield were recorded in drip irrigation system (Line sowing) in greengram which was on par with sprinkler irrigation system (Line sowing). Drip and sprinkler irrigation systems recorded the higher seed yield (42.1% and 36.1%, respectively) over check basin method (Broadcasting). This study revealed that the drip and sprinkler irrigation methods along with line sowing resulted better growth and yield parameters of summer greengram and enhanced its production.

Tillage is the most important age old practice, which is usefull to create favourable seed bed for sowing of seeds. It also plays a significant role in weed species persistence and its distribution in agriculture fields. Summer plough kills the weed seeds by exposing it to the sun light. Deep tillage helps for the development of enforced dormancy by burring the newly shredded seeds in the deeper layer of soil. Till now no herbicide is available to kill the weed seeds, tillage improves nitrogen mineralization thus in turn enhance the germination of weed seeds. After weed seed’s germination, controlling can be done easily with either spraying of herbicides, mechanical and manual means. Now a day’s conservation tillage or zero tillage concept is getting picking up. So it is highly important to study the effect of reduced tillage on weeds. Most of the research evidences found that under reduced tillage condition, weed seed accumulation is higher in upper layer of the soil. Annual weed population is predominant in reduced or no tilled soil. In no tillage system before planting soil was applied with non-persistent non selective herbicides to control weeds effectively.

World population is going on increasing, it may be 2.4 billion by 2050, but stabilizing the yield of crop is questionable in Indian agriculture due to improper management of agricultural land. Excess tillage accelerate the organic matter oxidation present on the top soil, soil erosion and creates subsurface hard pan. This makes the field unsuitable for cultivation of crops in future. Climate change is worsening the situation by imposing water scarcity in India. So to evade these problems, conservation agriculture is the only way. Main objectives of conservation agriculture is reducing tillage, year round cropping, crop rotation, mulching may be live or residue. Due to reduced mechanical tillage, activity of micro flora and macro flora get increases that improves biological tillage of soil, that in turn improves soil structure and enhances the plant growth. Most of the studies showed that the cost of wheat production and CO2 emission from the field is reduced when conservation agriculture was fallowed in rice-wheat cropping system. Crop rotation and also mixed cropping improves soil fertility and also it reduces soil erosion. It can be a part of climate smart agriculture. It reduces greenhouse gas emission and also it can improve carbon sequestration. Considerably it can save 20-30% of water.

Sunflower is an important crop cultivated all over world owing to its versatile nature of adaptation to different agro-climatic and soil conditions. In India sunflower gains momentum as an edible oil and ranks fourth substantially by reducing the shortage of vegetable oil. Nutritionally sunflower oil benefits human due to presence of high linoleic acid content and absence of linolenic acid content. The productivity is lower due to different factors among which nutrient management especially sulphur that plays pivot role in governing the growth, yield and quality of sunflower. Sulphur contains aminoacids viz., cystein, methionine, cystine, vitamins B, biotin and thiamine. The protolytic enzymes aids in improving the oil content, protein content and quality of seeds by sulphur supplement. Extensive investigations of research scientist on sulphur levels were critically reviewed. Application of sulphur at 40 to 60 kg ha-1 was found to increase the growth and yield attributes, yield, quality as well as higher benefit cost ratio sustaining the livelihood of sunflower growers.

Background: Blackgram [Vigna mungo (L.) Hepper] is one of the most important cultivated legume crops with high nutritive value and agricultural importance. The productivity of blackgram is not adequate to meet the domestic demand of the growing Indian population. Consequently, there is an urgent need for enhancement of productivity through proper agronomic practices. With this background, a research experiment was conducted in a farmer’s field at Pudhupalayam, Coimbatore to investigate the effect of foliar application of PPFM, plant growth regulating compounds and nutrients on growth, yield attributes, yield and economics of irrigated blackgram. Methods: A field experiment was laid out in randomized block design with three replications during 2019 (kharif and rabi) season. The treatments include 100% recommended dose of NPK along with foliar application of diammonium phosphate (DAP), brassinolide (Br), salicylic acid (SA) and pink pigmented facultative methylotrophs (PPFM) with different concentration (1%, 2%, 1 ppm, 2 ppm, 50 ppm, 100 ppm, respectively) in addition to control. PPFM and PGRs were sprayed at 30 and 45 days after the sowing of blackgram. Result: The experiment results of the two seasons study revealed that the application of 100% RDF + PPFM @ 2% recorded higher growth characters viz., plant height (cm), number of branches plant-1, leaf area index and yield attributes viz., number of pods plant-1, number of seeds pod-1, pod weight (g), pod height (cm), 100 seed weight (g) and yield viz., grain yield (kg/ha), straw yield (kg/ha) and harvest index (%). As well as the same treatment recorded higher net return and B:C ratio. Correlation and regression analysis also indicated that the yield attributes had a positive impact on the grain yield with a magnitude of 1.91 and 1.67, respectively. Therefore, application of 100% RDF+2% PPFM spray can be recommended as the best technology to improve the yield and economics of blackgram.

Maize, queen of cereals is a nutrient exhaustive crop and sensitive to sulphur deficiency. Sulphur deficiency in corn results in interveinal chlorosis, yellowing of younger leaves, reddening of stems and leaves. Sulphur is the fourth major plant nutrient next to nitrogen, phosphorus and potassium. It plays a prominent role in formation of chlorophyll, proteins, oil synthesis and biosynthesis of proteins. Sulphur has significant role in growth parameters, yield attributes and yield of maize crop. The uptake of primary nutrients and efficiency of applied fertilizers were seriously influenced by sulphur availability. Sustaining higher yield is not possible under sulphur deficiency. The investigations carried out by eminent research scientist in maize has shown positive impact and application of 45 to 60 kg ha-1 of sulphur gave maximum growth, yield attributes, nutrient uptake, yield and quality parameters. The present paper is a panoramic view of sulphur nutrition in maize from results of different researchers.

A field experiment was conducted at Tamil Nadu Agricultural University, Agricultural College and Research Institute, Madurai, Tamil Nadu, India, during summer 2019 to study about the changes in physiological parameters of rice under various establishment and water management strategies and to find out the suitable method of rice establishment and irrigation management practices for tank irrigated command areas during water scarcity situation. Field experiment comprised of four establishment methods in combination with four irrigation management strategies. Medium duration fine grain rice variety TKM 13 was used for the study. Results of the study revealed that machine transplanting under unpuddled soil combined with irrigation after formation of hairline crack recorded improved physiological parameters and yield. It was on par with machine transplanting under unpuddled soil combined with irrigation when water level reaches 5 cm below soil surface. Higher gross return, net return and B:C ratio were observed with machine transplanting under unpuddled soil combined with irrigation after formation of hairline crack. This was followed by machine transplanting under unpuddled soil combined with irrigation when water level reaches 5 cm below soil. Hence, the result of study concluded that machine transplanting under unpuddled soil combined with irrigation when water level reaches 5 cm below soil surface can be recommended as the suitable technology for the farmers of tank irrigated command area to get higher return with minimum use of resources under water scarcity situation.

Field experiments were conducted at Agricultural College and Research Institute, Tamil Nadu Agricultural University, Madurai, Tamil Nadu, India, during summer 2019 to find out energy efficient rice establishment methods under irrigation management strategy. Field experiment comprised of four establishment methods in main plot viz., conventional transplanting (M1), machine transplanting under puddled soil (M2), machine transplanting under unpuddled soil (M3) and sowing with seed drill (M4). The sub plot consisted of 4 irrigation management practices viz., farmers’ irrigation practice (continuous submergence of 5 cm throughout the crop period) (I1), Irrigation after formation of hairline crack (I2), irrigation when water level reaches 5 cm below soil surface (I3) and irrigation when water level reaches 10 cm below soil surface (I4). Medium duration fine grain rice variety TKM 13 was used for the study. Result of the study revealed that among the rice establishment methods higher energy output, net energy production, energy ratio and profitability was observed under machine transplanting under unpuddled soil. Among the irrigation management practices, irrigation after formation of hairline crack (I2) observed higher energy output and net energy production; whereas, energy ratio, energy productivity, energy intensity and B:C ratio were higher with irrigation when water level reaches 5 cm below soil surface (I3). This study concluded that machine transplanting under unpuddled soil combined with irrigation when water level reaches 5 cm below soil surface can be recommended as the suitable technology for the farmers of tank irrigated command area to get higher output energy with minimum use of input energy and also to obtain higher profit.

Maize, referred as Queen of cereals is the third most important cereal crop after rice and wheat in India. Maize serves as both human food as well as animal feed and for. Productivity of maize can be increased by proper nutrient management practices. Maize is a zinc responsive crop and found deficient in soils. Zinc as an essential micronutrient that has significant role in basic plant metabolic processes and enhances the growth, yield and quality of maize by stimulating chlorophyll production, photosynthetic activity, nutrient uptake and protein biosynthesis. The zinc application to maize crop either by seed treatment, soil application or by foliar spray by using inorganics have shown significant impact on growth, yield, nutrient uptake, quality and economics from investigations of eminent researchers with increasing trend in productivity. Application of zinc at 20-25 kg ha-1 to maize gave maximum grain yield (7500 kg ha-1) and benefit cost ratio ( 2.4 ) in maize.

To study the effect of various establishment and water managementpractices on rice, a field experiment was conducted at Periyar VaigaiCommand (PVC) during summer 2019. The experiments comprised of fourestablishment methods in main plots viz., conventional transplanting (M1),machine transplanting under puddled soil (M2), machine transplantingunder unpuddled soil (M3) and sowing with seed drill (M4); four irrigationmanagement practices in sub plots viz., farmers’ irrigation practice (I1),Irrigation after formation of hairline crack (I2), irrigation when waterlevel reaches 5 cm below soil surface (I3) and irrigation when water levelreaches 10 cm below soil surface (I4). The results of the study revealed thatmachine transplanting under unpuddled soil recorded 6.5 per cent higheryield compared to conventional manual planting. Among the irrigationmanagement strategies, irrigation after formation of hairline crack recorded8.1 per cent higher yield compared to farmer’s irrigation practice, whichwas comparable with irrigation when water level reaches 5 cm below soilsurface. Significant interaction was observed with establishment methodsand irrigation management practices. This study concluded that machinetransplanting under unpuddled soil combined with irrigation when water levelreaches 5 cm below soil surface will be the suitable management technologyto be adopted by the rice growing farmers in tank irrigated command areas.