Performance and economic analysis of Gossypium hirsutum under varying plant spacing and nutrient treatments in central plain zone, U.P.

Introduction

Cotton occupies a pre-eminent place among the world's cash crops and underpins the agricultural economies of several nations. Its cultivation extends to nearly one hundred countries, with China, India, Brazil, the United States and Pakistan currently accounting for the largest share of global output. Because it supplies the lint that feeds the world's spinning mills, cotton is often described as the mainstay of the textile industry. Cultivation of the crop is also spread across the tropics and sub-tropics of more than eighty countries. Domesticated cotton grown for commerce is broadly grouped into two categories, namely New World and Old World types, and the New World group is further subdivided on the basis of fibre attributes. Of the two Old World diploids, G. arboreum has the widest commercial cultivation and is chiefly raised in India, Pakistan and other parts of South and South-East Asia, largely on the marginal, low-productivity tracts of Bangladesh, Myanmar, China, Sri Lanka and Vietnam (Singh and Narayanan, 1991) [28] . Fabric fragments unearthed at Mohenjo-daro indicate that Indian cotton weaving is close to five millennia old. Within the country, cotton remains one of the most important commercial crops and continues to shape both industry and the wider economy. The market for cotton is essentially quality-driven; buyers assess a combined index of mean fibre length, fineness, maturity and strength, together with secondary characters such as colour and ash. Together, these parameters govern the spinning behaviour of the yarn, its dye uptake, tensile strength, fabric lustre and its ability to blend with synthetic fibres. External stresseswater shortage, unbalanced nutrition, prevailing season, timing of harvest, and pest or pathogen attack-are known to alter fineness, maturity and strength [15] . On average, American cotton has been observed to exceed desi types in seed index and kernel percentage. Several factors keep national cotton productivity subdued, but the most persistent are continuous monoculture, gradual loss of soil fertility, delayed sowing, and heavy pest and disease pressure. Prolonged cropping under long-term fertilization also alters both edaphic properties and crop response, [14] with a documented drift towards fertility exhaustion.

Combining organic manures with inorganic fertilizers, or using manures alone, generally sustains soil productivity and helps restore fertility. Because Bt cotton hybrids are being adopted across large tracts of the country, their nutrient schedules also need to be re-examined. [27] Since the commercial release of Bt cotton in India in 2002, farmer adoption has been rapid and widespread. Sound fertilizer management is one of the most direct routes to lifting cotton productivity, and meeting the crop's nutritional demands is a prerequisite for both high yields and superior fibre [9,13] . Nutrient responses, however, is conditioned by climatic and cultural variables. Among the many inputs available to the grower, fertilizers stand out for the size of the response they produce in cotton, so adequate fertilization becomes indispensable if the crop is to approach its yield potential. The exact quantity required nevertheless shifts with soil type and agro-ecology.

Clearly, yield and productivity can be raised by combining superior genotypes with sound agronomy-maintaining an ideal plant stand, applying a balanced fertilizer schedule, controlling insects at the right time, and following judicious weed and water management. Foliar delivery of micronutrients has drawn particular attention because of its efficient absorption and its effect on crop vigour [21] . It also modulates biochemical processes within the seed and lifts overall yield [4] . Squaring, flowering and boll formation are the phases at which cotton's nutrient demand peaks, and supplementing supply through foliar sprays during these windows can produce a marked yield response. [2] The higher gross and net returns and improved benefit:cost ratios recorded under such management can be traced to the yield increment achieved with elevated fertilizer levels and closer geometry. Jadhav et al. [8] reported the highest net income at 200:100:100 kg NPK/ha, followed by 150:75:75 kg NPK/ha, and comparable economic gains have been documented by other workers [24] . Against this backdrop, the present investigation was designed to identify the most appropriate combination of spacing and nutrient management for growth, yield, yield attributes, quality and economics of Hirsutum cotton in the Central Plain Zone of Uttar Pradesh.

Materials and Methods

The trial was set up with Hirsutum cotton genotype H-1300 during the kharif season of 2024 on the Agriculture Farm of Swami Vivekanand Subharti University at Meerut. Rainfall for the year totalled 650.6 mm, most of which fell between mid-June and the second week of September under the south-west monsoon; occasional off-season showers were also received during the winter months. The layout was designed to assess the influence of row geometry and nutrient scheduling on the growth pattern, yield-determining traits, yield and fibre quality of the crop. Seven treatments were compared: T 1 , an unfertilized check maintained at the conventional row × plant spacing of 67.5 × 30 cm; T 2 , the full recommended dose of fertilizer (RDF) with the same conventional spacing; T 3 , 100% RDF combined with rows drawn 25% closer than conventional; T 4 , 125% RDF at the narrowed spacing; T 5 , 125% RDF at the narrowed spacing plus soil-placed ZnSO 4 ; T 6 , 125% RDF at the narrowed spacing supplemented with a foliar spray of 2% urea and 2% DAP; and T 7 , 125% RDF at the narrowed spacing supplemented with a foliar spray of MgSO 4 and ZnSO 4 . The seven treatments were arranged in a Randomized Block Design and repeated in three blocks.

The soil of the experimental site was a sandy loam of moderate fertility with a slightly alkaline pH of 7.8. Organic carbon was low (0.48%) while available phosphorus (16 kg/ha) and available potash (183 kg/ha) fell in the medium range. Sowing was completed on 28 May 2024 and the crop was harvested in two pickings on 25 October and 10 November 2024. Under the conventional layout, rows were drawn 67.5 cm apart with a plant-to-plant distance of 30 cm within the row. Fertilizer was applied according to the assigned treatment, with half the nitrogen and the entire phosphorus and potassium supplied at sowing; the remaining nitrogen was split evenly and top-dressed at 30 and 60 days after sowing. Insecticidal sprays were made whenever pest incidence warranted them. Data were recorded on growth attributes, on yield and its components, and on fibre quality traits, and picking was carried out only after the bolls had opened fully. The recorded data were subjected to statistical analysis using procedures suited to the experimental layout [5] . Wherever the analysis of variance produced a significant 'F', treatment means were tabulated together with their standard errors, and critical differences were worked out to test the significance of the difference between any two treatments.

Values of critical difference (CD) computed at P = 0.05 were then applied to judge the significance of pairwise contrasts.

Results and Discussion

The imposed treatments produced significant differences in the number of established plants, plant height at 30, 60, 90, 120 and 150 days after sowing, in the counts of monopodial and sympodial branches per plant, and in the fresh and dry biomass of individual plants, with values rising steadily as the fertilizer dose was stepped up. Plants receiving 125% RDF combined with narrowed rows and a spray of 2% urea plus 2% DAP were consistently the tallest at every physiological stage, significantly outperforming the rest. Improvement of plant height with tighter spacing and higher nutrition has previously been documented by Kaur et al. 10 and Sharma et al. [23] The taller stature seen at closer spacing is largely a consequence of intra-row competition that suppresses vertical elongation in the more widely spaced canopies [22] . The largest counts of monopodia per plant were also produced by the T 6 treatment (125% RDF + closer rows + 2% urea and 2% DAP foliar spray), the difference being significant against every other treatment. Stepping up fertilizer levels in combination with the closer row arrangement raised the number of sympodial branches per plant, though the gain did not always cross the significance threshold. This lift in monopodial and sympodial branching is best explained by the fact that adequate nutrition stimulates cell division and expansion and thereby favours the formation of additional lateral shoots. The trend agrees with earlier reports by Ram and Giri and by Kaur et al. [18,10] Elevated fertilizer levels imposed under the closer geometry also had a marked effect on the fresh and dry biomass produced per plant. The heaviest fresh and dry weights again came from 125% RDF + closer rows + 2% urea and 2% DAP, while the MgSO 4 + ZnSO 4 foliar treatment (T 7 ) also lifted both fresh and dry weight significantly above the lower-nutrition, conventionally-spaced entries. Higher meristematic activity under improved nutrition is the most plausible driver, in line with the findings of Jadhav et al. [8] The 125% RDF + narrowed rows + 2% urea and 2% DAP foliar treatment likewise produced a significant increase in boll number per plant, boll number per square metre and average boll weight relative to the lower fertility and widerspaced treatments. The T 7 combination (125% RDF + closer spacing + MgSO 4 + ZnSO 4 ) also gave significantly higher boll counts per plant and heavier bolls than the remaining treatments. These gains in reproductive attributes are directly linked to the improvements already noted in vegetative characters-plant height, monopodial and sympodial branching, and fresh and dry weight-and mirror the observations of Jadhav et al. [8] Seed cotton yield under 125% RDF + closer spacing + 2% urea and 2% DAP foliar spray was 86.38 per cent higher than that recorded from the unfertilized check at conventional spacing. Application of 125% RDF + narrowed spacing + MgSO 4 + ZnSO 4 spray also delivered a significantly higher seed cotton yield. Lint yield rose sharply with higher fertilizer inputs relative to the unfertilized check at conventional spacing, and the peak lint yield again came from 125% RDF + closer rows + 2% urea and 2% DAP. Cotton seed yield was highest under 125% RDF + narrowed rows + MgSO 4 + ZnSO 4 , whereas the maximum stick yield was recorded under the 2% urea and 2% DAP foliar spray. The lowest values for seed cotton, lint, seed and stick yield were, unsurprisingly, obtained from the fertilizer-omitted control at conventional spacing. The yield gains delivered by elevated fertilizer inputs can be traced back to the parallel improvement in growth and yield attributes, an interpretation supported by the observations of Bhattoo et al. [3] Raskar [20] also noted that raising fertilizer application progressively from 50 to 100% RDF drove a significant increase in seed cotton yield, and Kote et al. 11 recorded significantly higher seed cotton and cotton seed yields under 100% RDF than under 75 or 50% RDF. A comparable yield advantage under wider row arrangements has been reported by Kumar et al. [12] The nutrient management regimes also produced significant shifts in fibre quality traits-ginning out-turn, span length, fibre strength, micronaire and uniformity ratio. Ginning outturn was highest, and significantly so, under 125% RDF + closer spacing + MgSO 4 + ZnSO 4 foliar spray. Span length, on the other hand, was significantly greater in the unfertilized control at conventional spacing. Both micronaire value and uniformity ratio were highest under 125% RDF + narrowed spacing + 2% urea and 2% DAP, closely followed by the unfertilized control at conventional spacing. The poorest fibre quality was recorded in the fertilizer-omitted, conventionally-spaced entry. These results align with Srinivasula et al. Rao and Janawade [26,19] likewise reported that 100% RDF gave the highest ginning out-turn and lint index, followed by 75 and 50% RDF. Nutrient management coupled with spacing exerted a significant influence on the gross return, net return and benefit:cost ratio realised from the crop. The highest gross return was earned under 125% RDF + closer rows + 2% urea and 2% DAP foliar spray, followed by the MgSO 4 + ZnSO 4 foliar treatment and by the soil-applied ZnSO 4 treatment. Net return was similarly maximised under the 2% urea and 2% DAP foliar treatment, statistically at par with soil-applied ZnSO 4 and with 125% RDF + closer rows. The greatest benefit:cost ratio was again recorded for 125% RDF + narrowed rows + 2% urea and 2% DAP, followed by MgSO 4 + ZnSO 4 and by soil-applied ZnSO 4 . Predictably, the lowest values for gross return, net return and benefit:cost ratio came from the unfertilized check at conventional spacing. The lift in monetary returns tracks directly with the seed cotton yield advantage secured by higher fertilizer inputs and tighter row geometry. Jadhav et al. [8] reported the highest net return at 200:100:100 kg NPK/ha, followed by 150:75:75 kg NPK/ha, with 100:50:50 kg NPK/ha giving the lowest. Similar economic gains under higher fertilizer schedules have been documented by several other workers [7,16,24] .

Conclusion

The findings of this trial indicate that Hirsutum cotton genotype H-1300 raised with 125% of the recommended fertilizer dose (60:30:20 kg NPK/ha) together with 25% narrower row spacing and a foliar spray of 2% urea and 2% DAP represents the most productive, remunerative and costeffective package for cotton cultivation in the Central Plain Zone of Uttar Pradesh.

Acknowledgement

AcknowledgmentsThe authors sincerely acknowledge Dr. Amit Kumar of the Department of Agriculture, Swami Vivekanand Subharti University, Meerut, for extending the facilities and guidance that made this study possible. The authors also declare that no conflict of interest exists in respect of this work.

References

1. Bhaskar KS, Gaikwad ST, Kumari PA. Response of upland cotton (Gossypium hirsutum L.) to the levels of fertilizers in shallow soils of watershed near Nagpur. Indian J Agron. 1993;38(1):89-92.
2. Bhatt JG, Nathu ARS. Simple measures of reducing losses of buds and bolls in cotton. J Cotton Res Dev. 1986;16:18-20.
3. Bhattoo MS, Mehta AK, Yadav M, Nirania KS, Sethi GS. Influence of high density plant population and fertilizer levels on seed cotton yield of American cotton. In: Proceedings; 2012. p. 39.
4. Chaudhary CS, Pawar WS, Mendhe SN, Nikkam RR, Ingole AS. Effect of land configuration and nutrient management on yield of rainfed cotton. J Soil Crops. 2001;11:125-127.
5. Cochran WG, Cox GM. Experimental designs. 1st ed. New York: John Wiley & Sons; 1950.
6. Devraj, Bhattoo MS, Duhan BS, Kumari P, Jain PP. Effect of crop geometry and fertilizer levels on seed cotton yield and nutrient uptake of Bt cotton under irrigated condition. J Cotton Res Dev. 2011;25(2):176180.
7. Gangvir MM, Nagdeve MB, Karunakar AP, Gabhane VV, Patode RS, Sakhare SB. Effect of land configuration and nutrient modules on productivity of cotton under dryland condition. In: Proceedings of the International Symposium on Global Cotton Production Technologies vis-a-vis Climate Change; 2012. p. 34.
8. Jadhav SG, Chavan DA, Gokhale DN, Dadgale PR. Response of Bt cotton to different spacing, growth regulator and nutrient management. In: Proceedings of the International Symposium on Global Cotton Production Technologies vis-a-vis Climate Change; 2012. p. 45.
9. Kalaichelvi K. Bt cotton response to plant geometry and fertilizer levels. J Cotton Res Dev. 2009;23(1):96-99.
10. Kaur P, Kaur M, Gill MS, Buttar GS. Response of Bt cotton hybrid RCH 134 to varied spacing and fertility levels under Punjab conditions. J Cotton Res Dev. 2010;24(2):189-192.
11. Kote GM, Giri AM, Kawsale SP. Nutrient concentration and uptake of different cotton (Gossypium hirsutum) genotypes as influenced by intercrops and fertilizer levels under rainfed conditions. J Cotton Res Dev. 2005;19(2):188-190.
12. Kumar J, Yadav MP, Kushwaha SP, Kumar N. Effect of different spacing and potassium levels on yield attributes, yield and economics of Gossypium hirsutum cotton. J Cotton Res Dev. 2010;24(2):208-209.
13. Kumar M, Pannu RK, Nehra DS, Dhaka AK. Effect of spacing and fertilizer on growth, yield and quality of different cotton genotypes. J Cotton Res Dev. 2011;25(2):236-239.
14. Mathur GM. Effect of long-term application of fertilizers and manures on soil properties and yield under cotton-wheat rotation in north-west Rajasthan. J Indian Soc Soil Sci. 1997;45:288-292.
15. Nanjundayya C. Technology in cotton in India. Monograph. Mumbai: Indian Central Cotton Committee; 1960. p. 45-70.
16. Pawar SU, Gitte PN, Bhosle GP, Suryawanshi SB. Effect of fertilizer levels and plant densities on yield, gross and net monetary return of Bt cotton hybrids. J Cotton Res Dev. 2010;24(2):182-185.
17. Pendharkar AB, Solunke SS, Lambade BM, Nawale SS, Dalvi ND. Response of Bt cotton hybrids to different plant spacing under rainfed conditions. J Cotton Res Dev. 2010;24(2):216-218.
18. Ram M, Giri AN. Response of newly released cotton (G. hirsutum) varieties to plant densities and fertilizer levels. J Cotton Res Dev. 2006;20:85-86.
19. Rao S, Janawade AD. Nutrient uptake and fibre quality parameters as influenced by integrated nutrient management practices in irrigated hybrid cotton. J Cotton Res Dev. 2009;23(1):237-239.
20. Raskar BS. Effect of irrigation methods, fertilizer levels and green manuring on yield and nutrient balance in summer cotton. J Cotton Res Dev. 2004;18(2):180-183.
21. Rathinavel K, Dharanelingam S, Panneer Selvam S. Effects of micronutrients on productivity and quality of cotton and cotton seed. Madras Agric J. 1999;86:313316.
22. Reddy RP, Kumar R, Dileep B. Spacing studies in genetically modified cotton. J Cotton Res Dev. 2010;24(2):219-220.
23. Sharma RK. Production potential of cotton as affected by various spacing and fertility levels. J Cotton Res Dev. 2004;18:187-188.
24. Solanki RM, Vadaria KN, Patel RK, Khanpara MD. Plant geometry and nutritional management in Bt cotton based intercropping under Saurashtra region. In: Proceedings of the International Symposium on Global Cotton Production Technologies vis-a-vis Climate Change; 2012. p. 23.
25. Solunke PS, Fatak SU. Effect of organic manures, inorganic fertilizers and plant protection on quality and economics of desi cotton. J Cotton Res Dev. 2010;24(2):174-181.
26. Srinivasula K, Hema K, Narayana E, Prasad NVVSD, Rao NHP. Agronomic evaluation of Bt hybrids (NCS 207 Bt) in Vertisols of Andhra Pradesh under rainfed conditions. J Cotton Res Dev. 2007;21:191-193.
27. Venugopal K. Changing paradigms in cotton production technology for improving productivity and fibre quality of cotton. In: International Symposium on Strategies for Sustainable Crop Production-A Global Vision; 2004 Nov 23-25; University of Agricultural Sciences, Dharwad, Karnataka, India. p. 1-6.
28. Singh P, Narayanan SS. Biometrical techniques in plant breeding. New Delhi: Kalyani Publishers; 1991.