P Anantharaju’s research while affiliated with Tamil Nadu Agricultural University and other places

Machine picking in cotton is an emerging practice in India, to solve the problems of labour shortages and production costs increasing. Cotton production has been declining in recent years; however, the high density planting system (HDPS) offers a viable method to enhance productivity by increasing plant populations per unit area, optimizing resource utilization, and facilitating machine picking. Cotton is an indeterminate plant that produce excessive vegetative growth in favorable soil fertility and moisture conditions, which posing challenges for efficient machine picking. To address this issue, the application of plant growth retardants (PGRs) is essential for controlling canopy architecture. PGRs reduce internode elongation, promote regulated branching, and increase plant compactness, making cotton plants better suited for machine picking. PGRs application also optimizes photosynthates distribution between vegetative and reproductive growth, resulting in higher yields and improved fibre quality. The integration of HDPS and PGRs applications results in an optimal plant architecture for improving machine picking efficiency. However, the success of this integration is determined by some factors, including cotton variety, environmental conditions, and geographical variations. These approaches not only address yield stagnation and labour shortages but also help to establish more effective and sustainable cotton farming practices, resulting in higher cotton productivity.

Increased plant density promotes taller growth and greater vegetative development, intensifying competition among plants for resources and consequently affecting the balance between the vegetative and reproductive stages of the cotton plant. To ensure improved square development, boll development, boll retention, and seed cotton yield under dense planting condition, this research was conducted at the Cotton Research Station, Veppanthattai. The study aimed to evaluate the effects of plant growth regulators (PGR) and foliar nutrition on the growth, yield, and fibre quality of compact cotton varieties suitable for dense populations and mechanical harvesting. The results revealed that the application of mepiquat chloride (100ppm at 45 and 60 DAS), NAA (40ppm at 60 and 90 DAS), KNO3 (2% at 60 and 90 DAS), calcium borate (0.5% at 60 and 90 DAS), and a defoliant (Thidiazuron 240 g/L and Diuron 120 g/L at 200 ml/ha at the 60% boll bursting stage) achieved optimal growth attributes. These included plant height (98.7 cm), the number of functional leaves (07), leaf area index (3.9), seed cotton yield (2351 kg/ha), stalk yield (3286 kg/ha), lint yield (933 kg/ha), and harvest index (0.69), along with improvements in fiber quality parameters. In this study, potassium facilitated the efficient translocation of photosynthates from leaves to reproductive organs, contributing to enhanced biomass accumulation and yield.

Energy efficiency is crucial for optimizing energy use, conserving resources, and assessing the input efficiency of agronomic practices. Cotton is known for its economic importance, thus many mechanized cultivation practices have been introduced. This study aimed to evaluate energy consumption and perform an economic analysis of mechanized and conventional cotton production under rainfed conditions in Tamil Nadu. The energy requirements for mechanized and conventional cotton cultivation were 17,001.1 and 15,456.0 MJ ha-1, respectively, with fertilizer application as the most energy consuming component of cotton cultivation in both the methods. Manual cotton cultivation proved to be labor-intensive, requiring 2,215.6 MJ ha-1 of labor energy, compared to just 174.2 MJ ha-1 in mechanized cultivation. Mechanization reduced labor needs by utilizing machinery such as power tillers for weeding and spindle-type cotton pickers for harvesting. In mechanized and conventional cotton cultivation, the contribution of direct, indirect, renewable, and non-renewable energy was 26.7%, 73.3%, 1.0%, 99.0%, and 24.4%, 75.6%, 14.3%, 85.7%, respectively. While the energy ratio, net energy gain, and energy productivity were higher in conventional methods, and mechanized cultivation had a higher specific energy. The total production cost for mechanized cultivation was Rs. 74,290 ha-1, which is 47.8% lower than conventional cultivation (Rs. 140,440 ha-1). Adopting mechanized practices could save Rs. 93,250 ha-1 in labor costs compared to conventional methods. Although the gross income from the Suraksha variety was 10.7% higher with conventional methods, the net income and benefit-cost ratio were greater with mechanized cultivation due to its lower total production costs. The study suggests that efforts to enhance cotton production's energy efficiency should focus on efficient fertilizer use, labor management, and reducing diesel fuel consumption by improving machinery performance.

Energy efficiency plays a pivotal role in optimizing input use and improving the sustainability of agricultural practices, especially in energy-intensive crops like cotton. Due to its high economic importance, cotton cultivation has been in the need of the hour in developing mechanized cultivation practices aimed at improving production efficiency. This study evaluated energy consumption and performed an economic analysis of mechanized versus conventional cotton production under rainfed vertisols in Tamil Nadu. Among the various inputs, fertilizer application consumed the most energy in both systems, followed by labor energy differences between the 2 methods. Mechanized cultivation drastically reduced labor energy requirements (174.2 MJ/ha) compared to manual methods (2215.6 MJ/ha), highlighting the potential for labor savings. Mechanized cultivation also showed more efficient use of non-renewable energy sources, whereas conventional methods relied more on renewable energy inputs, highlighting the trade-offs between the 2 systems. Mechanized cultivation significantly reduced production costs (Rs. 74290/ha) compared to conventional methods (Rs. 140440/ha), largely due to a 47.8 % reduction in labor costs, demonstrating its economic viability. This study suggests that improving the energy efficiency of mechanized cotton production should prioritize efficient fertilizer use and reducing diesel fuel consumption through enhanced machinery performance.

Mepiquat chloride is widely used as a growth regulator in cotton fields to increase crop yield. The present study investigated the effects of growth regulator (mepiquat chloride) and row spacings on compact cotton's growth and yield attributes. An experiment was conducted during summer and winter seasons of 2023-2024 at Cotton Research Station, Veppanthattai and the field trial was designed as a split-split plot with three main plots (Varieties - CO 17, VPT 2, Suraksha), four sub-plots (crop geometry - 90 x 15 cm, 70 x 15 cm, 90 x 10 cm, 70 × 10 cm), and two sub-sub plots (growth regulators - mepiquat chloride @150 ppm, mepiquat chloride + cyclanilide @400 ppm), each replicated three times. Results concluded that the Suraksha variety showed superior performance with greater plant height, higher biomass, more sympodial branches, higher bolls/m2 and higher seed cotton yield than CO 17 and VPT 2. Wider spacing of 90 cm resulted in greater plant height, more sympodial branches and more bolls/m2 to a significantly rise in dry matter production due to the higher number of plants per unit area. Combining mepiquat chloride with cyclanilide at 400 ppm during square initiation and boll development stages significantly increased sympodial branches and bolls/m2, improving seed cotton yield.In contrast, applying mepiquat chloride alone led to more significant biomass accumulation, increased plant height and longer internodal distances. It was suggested that the Suraksha variety be sown at a spacing of 90 x 15 cm and treated with a combination of mepiquat chloride and cyclanilide. This resulted in a plant architecture well-suited for mechanical harvesting.

Background With increasing labor challenges, achieving complete mechanization in cotton cultivation has become an urgent necessity in India. For mechanized cotton cultivation, it is necessary to have appropriate variety with designed canopy architecture. The required canopy architecture with higher seed cotton yield may be attained through optimizing crop geometry and spraying of plant growth regulators like mepiquat chloride. Also, application of mepiquat chloride alters canopy architecture in cotton by creating a more compact canopy suited for mechanization. In this study, we have optimized the different crop geometries and also studied the growth and yield potential of different desi varieties viz., CO 17, VPT 2 and Suraksha with respect to plant growth regulators. This study mainly deals with growth, physiology, dry matter production and yield of each compact cultivars by application of plant growth regulators grown under diverse spatial patterns. Results Among the three varieties tested, Suraksha variety significantly recorded optimum plant height, accumulated more dry matter in fruiting bodies, produced more sympodial branches and boll numbers per plant, and higher seed cotton yield compared to CO 17 and VPT 2 varieties. Increased plant densities significantly increased the dry matter production because of higher plant population per unit area. However, wider spacing of 90 cm significantly recorded greater plant height, more sympodial branches and boll numbers per plant, and seed cotton yield compared to narrow spacing of 70 cm. The combined application of mepiquat chloride with cyclanilide @ 400 ppm at square initiation and boll development stages had significantly increased the sympodial branches and number of bolls per plant, accumulated more biomass content in fruiting bodies and increased seed cotton yield, whereas application of mepiquat chloride alone accumulated more biomass content in vegetative parts and recorded greater plant height, and internodal distance. Conclusion Suraksha variety sown under spacing 90 x 15 cm and treated with mepiquat chloride with cyclanilide @ 400 ppm at square initiation and boll development stages resulted in higher number of bolls per plant, boll weight and seed cotton yield under mechanized cultivation. This combination also produced a desired plant architecture suitable for mechanical harvesting.

Background Cotton is mostly grown under rainfed condition by small and marginal farmers and provides economic livelihood. The assessment of adaptability of a suitable genotype is important and therefore, multilocation evaluation of genotypes was conducted at eight agro-ecologically diverse environments under rainfed ecosystems in India. The data was analyzed for key biometrical traits using pooled ANOVA, LSD test, correlation matrices and regression analysis over two years (2019-20). Additionally, we employed genotype plus genotype by environment interaction (GGE) biplot analysis to identify winning genotypes across different environments. Results The results showed that genotype, environment and their interaction (GEI) significantly (p < 0.01) influenced SCY and GOT%. The GEI showed a high significant impact on SCY (40.46%) and GOT% (48.86%) among genotypes. Correlation analysis revealed positive associations between SCY and major yielding traits such as boll weight, ginning outturn and lint yield. Regression analysis demonstrated that a combination of these traits contributed to high stable yield over the years across the rainfed conditions. The total variation in SCY was 96.61%, composed of PC1 and PC2 values at 92.06% and 4.55%, respectively. GGE biplot analysis identified the genotypes viz., NDLH2057-1, TVH007, and NH615 exhibited high yield potential and ginning outturn and high stability across multilocations. The average environment axis (AEA) of the biplot identified most representative location for the yield and GOT%, respectively. Conclusion The findings identified the use of optimal genotypes for cultivation and use of such genotypes for trait introgression in future breeding and crop improvement, which may facilitate genetic gain of yielding traits and ginning outturn in rainfed environments.