Evaluation of short duration a non Bt cotton variety (Co-17) under HDPS with different sowing dates during kharif season

Introduction

Cotton (Gossypium spp.) popularly called "White Gold" and "King of Fibre Crops" is the most important renewable natural fibre crop of global importance enjoying a premier position among all the commercial crops. It is one of the most important crops in the world because of its economic, industrial and social significance. It is major cash crop for millions of farmers, especially in countries like India, China, USA and Pakistan to generate employment in farming, ginning, spinning, weaving, dyeing, garment manufacturing and transportation and earns foreign exchange with large export markets for raw cotton, yarn, textiles, and garments. Cotton is also back bone of the textile industry. The lint of cotton, its strength and absorbency make it best for making clothes, homewares and industrial products like tarpaulins, tents, hotel sheets, army uniforms and astronauts' clothing. Cotton is also used in medical field as for making of bandages, swabs, cotton buds and x-rays etc. By crushing the cotton seeds cholesterol free oil can be extracted and left over cakes can be fed to animals and can be applied to soil as concentrated manure (Wegier et al. 2016) [11] . In the last year (2024-25) globally cotton was cultivated in the 31.04 m ha accounting to 25.86 m tonnes with productivity 833 kg ha -1 whereas India stood first in area of cotton cultivation with 11.4 m ha and second in cotton production after china with 5 m tonnes. (Anonymous, 2025) [1,2] . There are 3 zones were classified for cotton cultivation in India viz., Northern zone comprises Punjab, Haryana and Rajasthan, Central zone comprises of Maharashtra, Madya Pradesh and Gujarat and Southern zones Comprises of Telangana, Andhra Pradesh, Karnataka and Tamil Nadu. Highest acreage was noticed in Gujarat (22.79 lakh hectares) followed by Maharashtra (42.86 lakh hectares) and Telangana (24.51 lakh hectares) (Anonymous, 2025) [3] . Nearly 10 million of small holders of rural India rely on cotton farming for their livelihoods (Najork et al., 2021) [8] . To attenuate severe pest incidence in cotton Bt cotton was introduced for offering benefaction to specific pests. By 2012, above 93% of Indian cotton farmers had adopted Bt cotton cultivation and reduced pesticide use and increasing yields (Venugopalan & Reddy, 2017) [10] . However, it remained as argument whether these yield increases are mainly due to the Bt trait itself or to increased fertilizer usage (Kranthi and Stone, 2020) [6] . In recent times, Bt cotton yields have stagnated and pests incidence was increased and this led to rising pesticide costs for farmers. With these insights, slowly farmers started cultivating non Bt cotton varieties under HDPS method of cultivation.

Materials and Methods

A field trial was carried out during Kharif 2021 and 2022 in randomized block design with four replications under rainfed condition at Regional Agricultural research Station, Palem, Nagarkurnool district, Telangana with an average altitude of 478 m above the mean sea level. The soil of experimental site was sandy clay loam with pH 6.7, electrical conductivity 0.34 dSm -1 , low organic carbon (0.52%), low available nitrogen (201.3 kg ha -1 ) and medium phosphorus (16.7 kg ha -1 ) and high in potassium (309.4 kg ha -1 ). The average annual precipitation of 650-700 mm. The monsoon arrived during second week of June and cotton crop was sown manually by dibbling method as per the treatments (sowing dates). Non Bt cotton variety CO17 (Non Bt early duration variety) was used for conduct of the field trial and sowing was done at 80 cm x 20 cm spacing with plant population of 62,500 ha -1 . The recommended dose of fertilizers for cotton variety was 90, 45, 45 kg per ha -1 (100 kg SSP or 40 kg DAP as basal, 40 kg urea + 15 kg MOP at 25-30 DAS, 40 kg urea + 15 kg MOP at 55-60 DAS) followed. Growth regulator Mepiquat chloride was sprayed at 45 and 60 days after sowing with 1.5 ml l -1 and 2.0 ml l -1 respectively. The experiment comprised of six sowing dates as treatments viz., T 1 -20 th May, T 2 -5 th June, T 3 -20 th June, T 4 -5 th July, T 5 -20 th July and T 6 -5 th August. The net plot size was 12.8 m x 5.2 m. The recommended cultural practices and plant protection measures were taken. Observations on plant height (cm), days to 50% flowering, Number of monopodial branches, Number of sympodial branches, number of bolls per plant, boll weight, days to maturity and seed cotton yield per hectare were recorded.

Results and Discussion

The data in Table 1 and 2 were presented to support the discussion of following parameters.

The data pertaining to mean plant height (cm) was significantly influenced by the sowing dates during kharif 2021 and 2022. In 2021, significantly highest plant height was recorded by 20 th May sown crop with 130.4 cm over the other sowing dates. Whereas in the year 2022 plant height recorded by 20 th May sowing (136.6 cm) was found on par with 5 th June sowing (126.0 cm). In the both the years plant height recorded less in the delayed sowings. These results are in conformity with Khashkheli et al., (2024) [5] .

Day to 50 per cent flowering

5 th August sown cotton crop has taken significantly more number of days in 2021 (61.8) and 2022 (67.6) over the other sowing dates in the either of the years. Delayed sowings have taken more days to 50% flowering due to insufficient vegetative growth of delayed sowing lead to delayed flowering.

Number of monopodial branches

There is no influence of sowing dates during Kharif season on the number monopodial branches in 2021 and 2022 years. These results are in conformity with Buttar et al., (2010) [4] .

Number of sympodial branches

In kharif 2021, 20 th June sown crop recorded significantly more sympodial branches (17.8) and was onpar with 20 th May sown crop (16.6). remaining sowing dates had contributed less sympodial branches. Whereas, In Kharif 2022 significantly highest sympodial branches were noticed in 20 th sowing cotton (19.2) and it was on par with 5 th June sowing (17.8) 20 th June sowing (16.8). The variation in the results might due to more vegetative growth of initial sowing dates led to have more number of sympodial branches than the delayed sowings. Similar findings are seen by the Nagabushanam et al., (2021) [7] .

Number of bolls plant -1

In the first year of study 20 th June sown crop recorded significantly more number of bolls plant -1 (26.4) than the other sowing dates. In the later year significantly highest sympodial branches were noticed in 20 th sowing cotton (19.3) and it was on par with 5 th June sowing (19.2) 20 th June sowing (18.6). The reason for more number of bolls to the initial sowing treatments is might be due to more vegetative growth of initial sowing dates led to have more number of sympodial branches and influenced to have more number of bolls than the delayed sowings. These findings are in coordinate with the Buttar et al., (2010) [4] , Nagabushanam et al., (2021) [7] .

May 20 th sown crop recorded boll weight (g) 4.81 g and June 5 th sown cotton crop recorded 4.73. These are significantly superior over other sowing dates in the first year study. Whereas, In Kharif 2022, boll weight obtained with 20 th May (6.84), 5 th June (6.58), 20 th June (6.50) and 5 th July (6.57) are significantly are found onpar.

In kharif 2021 seed cotton yield was observed 1594 kg ha -1 for 20 th May sown cotton crop and this was significantly higher over other sowing dates. Whereas in the year 2022 the seed cotton yield obtained by, 5 th June (1218.5 kg ha -1 ), 20 th June (1274.0 kg ha -1 ) were found onpar with 20 th May (1283.5 kg ha -1 ) and delayed sowings have shown inferior yield. The higher seed cotton yield was evidently due to cumulative effect of more number of bolls per plant and boll weight for the kharif initial sowings than the delayed. These results are in conformity with the Khashkheli et al., (2024) [5] , Tlatlaa et al., (2023) [9] , Nagabushanam et al., (2021) [7] .

Conclusion

From the findings of two years it can be concluded that, May 20 th was found best time sowing Non Bt cotton variety ensure that there must be one post sowing irrigation be provided with sprinklers if rainfall is not initiated by that time. Delayed sowings led to less vegetatiove and reproductive growth as consequence less seed cotton yield in such conditions.

References

1. Anonymousa. International Cotton Advisory Committee (ICAC) meeting held in Mumbai during 2-5 Dec 2023.
2. Anonymousb. Meeting of the Committee on Cotton Production and Consumption (COCPC) held on 24 Mar 2025.
3. Anonymousc. The Cotton Corporation of India Limited. Current cotton scenario, 30 Apr 2021. https://cotcorp.org.in/current_cotton.aspx
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