Tuesday, September 11, 2007 - 1:15 PM
Growth regulators for enhancing seed cotton yield, yield components and fibre quality in american cotton (gossypium hirsutum l.)
Cotton is the most important fibre crop of India grown both under irrigated and rain-fed conditions and has played a vital role in the agriculture based Indian economy. India is the third largest cotton producer in the world, occupying about 9 million hectares with a production of about 24.3 million bales in 2005-06. It accounts for 25 percent of world's total cotton area and 12 percent of global cotton production. However, the productivity of 448 kg ha-1 is still far lower than the world average of 718 kg ha-1. The average yields in India are the lowest among the top 10 global cotton producers. There is a need to improve the yield and fibre quality of cotton. Various factors responsible for low productivity are non availability of quality seed of approved cultivars, unbalanced use of fertilizers, and deficiency of certain important micronutrients. Besides, shedding of reproductive parts like squares and young bolls are the common problems in cotton, which results in lower cotton yields. The use of certain growth regulators and micro-nutrients was found to be beneficial in increasing the seed yield and quality in cotton (Anon. 1995).
Apart from major nutrients, the essential micronutrients like Boron and Magnesium play a vital role in certain physiological activities such as respiration, meristematic development, chlorophyll formation, photosynthesis, oil synthesis, gossypol and phenoloic compounds developments in cotton. Foliar applications of micronutrients have been widely studied (Karev, 1980, Khuzhanazarov et al. 1983 and Eshanna et al. 2004.
Biovita is an extract from a seaweed Ascophyllum nodosum-a marine plant that has been recognized as an excellent natural fertilizer and a rich source of organic matter. The manufacturer of Biovita M/S PI Industries Ltd., Udaipur claims that the application of Biovita enables plants to receive direct benefits from the naturally balanced nutrients and plant growth substances available in this seaweed extract. It is one of the most preferred products in its class as non-polluting, non-toxic natural bio-product. It provides over 60 naturally occurring major and minor nutrients and plant development substances comprising of enzymes, proteins, cytokinins, amioacids, vitamins, gibberlins, auxins, betains etc. in organic form. It contributes to greater microbial activity when applied to soil thus increasing nutrient availability. It is an ideal organic product for better growth and productivity. Moreover, it is compatible with insecticides, fungicides, and fertilizers, which can be used in combination, without additional cost of application. It is non corrosive and can be applied with any standard equipment. It has longer shelf life under normal room storage conditions. It can be applied at all stages of the plant growth from seeding to fruiting. The repeated use of Biovita contributes towards better root system, excellent appearance of plants and greater yield potential. It enhances resistance of the plants to pests and diseases and environmental and moisture stress conditions. Keeping in view the above said properties of Biovita, attempts were made in the present investigation to study the effect of Biovita on growth, seed cotton yield, yield components, and fibre quality in American cotton (G. hirsutum L.).
MATERIALS AND METHODS
The study was conducted at Punjab Agricultural University, Regional Station, Abohar in the summers of 2005 and 2006. The local approved open pollinated cultivar LH 1556 was selected for this study. The variety LH1556 is a short duration, early maturing variety of upland cotton having a semi-sympodial growth habit, medium sized green leaves, round bolls with good fluffy opening. It has a 2.5% span length of about 27.7 mm and is suitable for spinning at 40 counts with a ginning per cent of about 34. The sowing was done on May 12 in 2005 and May 14 in 2006 in a randomized complete block design using four replications. The experiment comprised of the following ten treatments: T1: A+B+C+D+E; T2: A+C+D+E; T3: A+D+E; T4: A+E; T5 : A; T6: B+C+D+E; T7: C+D+E; T8: D+E; T9: E; T10: Control (No Biovita application, only recommended dose of fertilizers); where A denotes the granules application of Biovita @ 20 kg ha-1 at the time of sowing; B indicates the foliar application of liquid Biovita @ 500 ml ha-1 at square formation; C is the foliar application of liquid Biovita @ 625 ml/ha at flowering; D is the foliar application of liquid Biovita @ 750 ml ha-1 at boll formation; and E indicates the foliar application of liquid Biovita @ 750 ml ha-1 at boll development stage. Each treatment was accommodated in a four rows plot of 6 m. Rows were kept apart at 67.5 cm while plant to plant distance was maintained at 60 cm. All recommended crop production and protection practices were followed to raise a good healthy crop. The fertilizers @ 75 kg Nitrogen and 30 kg P2O5 were applied to the crop. Five competitive plants were taken at random from each treatment and replication for recording observations on number of bolls per plant, boll weight (g), ginning out turn (%), and seed index (g). Seed cotton yield (kg ha-1) and lint yield (kg ha-1) were recorded on plot basis. The lint samples were analyzed for fibre properties such as 2.5% span length (mm), fibre strength (g tex-1), uniformity ratio and micronaire. Means of five plants over replications were used for estimating various statistical parameters.
RESULTS AND DISCUSSION
Modifying cotton growth has become an essential component of cotton production, whether by making adjustments in fertility, water management or use of harvest aids. The key to modifying plant growth is knowing what the plant needs at each stage of development to reach the final goal of higher yield and quality. The next step is to do everything possible to provide for these needs. Applying plant growth regulators to modify early and mid-season growth is similar to other management practices. Plant growth regulators have the potential to promote crop earliness, square and boll retention, higher nutrient uptake, and keeping vegetative and reproductive growth in harmony to improve lint yield and quality (Robertson and Cothren. 1993 and Oosterhuis and Zhao 1993)
Effect on seed cotton and lint yield: In our 2005 experiment, the application of Biovita results in significantly higher seed cotton yield (2097 kg ha-1) in treatment T4, which involves granular application of Biovita @ 20 kg ha-1 at the time of sowing accompanied by foliar application of liquid Biovita @ 750 ml ha-1 at boll development stage, in comparison to control (1823 kg ha-1) where no Biovita treatment was given (Table 1). The treatment T2 (granular application of Biovita @ 20 kg ha-1 at the time of sowing and foliar application of liquid Biovita @ 625 ml ha-1 at flowering; @ 750 ml ha-1 at boll formation; and @ 750 ml ha-1 at boll development stage) also significantly enhanced the seed cotton yield (2017 kg ha-1) as compared to control (T10). Significantly higher seed cotton yield (2023 kg ha-1) as compared to control T10 (1823 kg ha-1) was also obtained in T8, where only foliar applications of liquid biovia were given @ 625 ml ha-1 at flowering; @ 750 ml ha-1 at boll formation; and @ 750 ml ha-1 at boll development stage. The lint yield (926 kg ha-1) and seed index were also higher in T8 as compared to control T10. The treatments T1 and T5 also had significantly higher seed cotton yield than the control (Table 1). Similar trend was observed for lint yield (Table 1).
In 2006 experiment also, the application of Biovita significantly increased the seed cotton yield (2691 kg ha-1) in T3 (granular application @ 20 kg ha-1 at the time of sowing followed by foliar application of liquid Biovita @ 750 ml ha-1 at boll formation and boll development stage) and T4 (2649 kg ha-1) which involved the granular application @ 20 kg ha-1 at the time of sowing followed by foliar application of liquid Biovita @ 750 ml ha-1 at boll development stage only as compared to control (2263 kg ha-1). The differences among T3 and T4 for seed cotton yield were not significant. Similar trend was observed for lint yield (Table 1).
Yield components: In 2005, number of bolls per plant were significantly higher in treatment T2 (40) as compared to control (34). The treatments T3 and T4 also had considerably higher number of bolls (38) than control. The application of Biovita did not have any significant impact on boll weight and seed index in 2005. Similarly, in 2006, number of bolls per plant and boll weight improved significantly in treatment T4 (Table 1). Number of bolls and boll weight were also high in T3. The effect of Biovita on seed index was non-significant in 2006 also.
Fibre quality: With regards to the fibre quality, the application of Biovita did not have much significant impact on ginning out turn, fibre length, fibre strength and fineness. However, it improved the uniformity ratio of the fibre from 45.5 in control to 50 in T4 and T7 (Table 2).
On the basis of mean data of two years (2005 & 2006), it was observed that the T4 treatment was most effective in increasing the seed cotton yield (2373 kg ha-1), lint yield (939 kg ha-1), boll weight (3.51 g) and number of bolls per plant (41.08) in comparison to control where no application of Biovita was given (Table 1). Mondino et al. (2004) reported that due to an increase in the boll weight and boll number per plant, the yield of Cycocel 75 treated plots increased by an average of 35% in comparison with the control in American cotton. Regarding fibre quality, application of Biovita did not have much impact on ginning out turn, fibre length, strength, and micronaire. It improved the uniformity ratio of the fibre (Table 2). Contrarily, Mondino et al. 2004 reported that Cycocel 75 improved the fibre strength significantly, although other parameters of fibre quality, such as length, uniformity, elongation, and micronaire index were not affected.
Cost-benefit ratio: Before suggesting any extra growth regulators or bio-fertlizers to the cotton growers, it is important to calculate its advantages (economic benefits) in relation to its cost. According to the manufacturer, PI Industries Ltd., the granules of Biovita costs Rs. 25 kg-1, while the liquid Biovita costs Rs. 330 litre-1. Therefore, one granular application @ 20 kg ha-1 and one foliar application @ 750 ml ha-1 at boll development stage costs Rs.748. If the costs of spraying (Rs 100 per spray ha-1) is also included, the total costs for T4 treatment is Rs. 948 ha-1. The gain in seed cotton is 330 kg ha-1. Thus, the benefit from the seed cotton yield @ Rs. 2000 qtl-1 is Rs. 6660. Therefore, the net benefit to the farmers by the use of Biovita is Rs. 5612 (Table 3).
CONCLUSIONS
The results of our study suggest that the application of granular Biovita @ 20 kg ha-1 followed by foliar application of liquid Biovita @ 750 ml ha-1 at boll development stage only are effective for enhancing seed cotton yield, boll number and boll weight. However, the application of Biovita did not have any impact on fibre quality parameters.
REFERENCES
Anonymous, 1995. Hybrid cotton production technology, National Level Training Mannual Agriculture Research Station, Dharwad, Karnatka, India pp4-47.
Eshanna, M.R., S.B. Hadpad, I.S. Katageri, B.M. Khadi 2004. Effect of growth regulators and nutrients on seed and economic traits in cotton (G. hirustum). Pp332-334 In Proc. International Symposium on Strategies for Sustainable Cotton Production – A Global Vision., held at UAS, Dharwad from November 23-25, 2004
Karev, K. 1980. Effect of cotton fertilization with boron, zinc, molybdenum, and manganese in cinnamon forest soil. Biological Abstracts 72: 65-82.
Khuzhanazarov, S.H., N. Dzhumaev and S.H. Manov 1983. Effect of copper and zinc in the composition of basal fertilizers on yield of fine fibre cotton. Field Crop Abstract 37: 780.
Mondino, M.H., O.A. Peterlin, and F. Garay 2004. Response of late planted cotton to the application of a growth regulator (Chlorocholine chloride, Cycocle 75. Experimental Agriculture, 40: 381-387.
Oosterhuis, D.M., and D. Zhao1993. Physiological effect of PGR IV on the growth anfd yield of cotton. Pp 1270 in 1993 Beltwide Cotton Conference Proceedings
Robertson, W.C., and J.T. Cothren 1993. "PGR IV effects on boll distribution, lint yield, and fiber quality." 1993 Beltwide Cotton Conference Proceedings, p. 1,287.
Table 1. Effect of Biovita on seed cotton yield and yield components in cotton during summer of 2005 and 2006.
Treatment | Seed cotton yield (kg ha-1) | Lint yield (kg ha-1) | Ginning out turn (%) | Seed index (g) | Boll weight (g) | Number of bolls per plant | ||||||||||||
2005 | 2006 | Mean | 2005 | 2006 | Mean | 2005 | 2006 | Mean | 2005 | 2006 | Mean | 2005 | 2006 | Mean | 2005 | 2006 | Mean | |
T1 | 1920 | 2454 | 2187 | 878 | 833 | 856 | 35.83 | 34.03 | 34.93 | 7.25 | 9.12 | 8.19 | 3.35 | 3.46 | 3.41 | 38.0 | 41.90 | 39.95 |
T2 | 2017 | 2503 | 2261 | 922 | 892 | 907 | 35.60 | 35.64 | 35.62 | 7.25 | 8.57 | 7.91 | 3.49 | 3.44 | 3.47 | 40.2 | 34.95 | 37.58 |
T3 | 1846 | 2691 | 2269 | 844 | 948 | 896 | 34.95 | 35.23 | 35.09 | 7.25 | 9.19 | 8.22 | 3.34 | 3.65 | 3.50 | 38.2 | 39.10 | 38.65 |
T4 | 2097 | 2648 | 2373 | 959 | 918 | 939 | 34.23 | 34.70 | 34.47 | 7.75 | 8.71 | 8.23 | 3.54 | 3.48 | 3.51 | 38.4 | 43.75 | 41.08 |
T5 | 1983 | 2471 | 2227 | 906 | 834 | 871 | 35.85 | 33.70 | 34.78 | 7.25 | 8.86 | 8.06 | 3.46 | 3.50 | 3.48 | 36.4 | 35.75 | 36.08 |
T6 | 1874 | 2378 | 2127 | 857 | 863 | 860 | 34.85 | 34.62 | 34.74 | 8.00 | 9.02 | 8.51 | 3.44 | 3.46 | 3.45 | 36.4 | 32.85 | 34.63 |
T7 | 1851 | 2314 | 2083 | 846 | 791 | 819 | 36.25 | 34.20 | 35.23 | 7.75 | 8.79 | 8.27 | 3.54 | 3.38 | 3.46 | 31.0 | 30.80 | 30.90 |
T8 | 2023 | 2322 | 2173 | 925 | 811 | 868 | 34.58 | 34.98 | 34.78 | 8.00 | 9.01 | 8.51 | 3.37 | 3.50 | 3.44 | 37.4 | 33.85 | 35.63 |
T9 | 1874 | 2061 | 1968 | 857 | 733 | 795 | 35.85 | 35.59 | 35.72 | 7.50 | 8.66 | 8.08 | 3.46 | 3.31 | 3.39 | 33.6 | 31.70 | 32.65 |
T10 | 1823 | 2263 | 2043 | 833 | 829 | 831 | 35.45 | 35.33 | 35.39 | 7.50 | 8.44 | 7.97 | 3.33 | 3.32 | 3.33 | 34.4 | 36.10 | 35.25 |
CD 5% | 96.3 | 299.6 | - | 44.0 | 127.6 | - | 0.99 | 2.19 | - | NS | NS | - | NS | 0.17 | - | 3.22 | 4.75 | - |
CV % | 3.44 | 8.68 | - | 4.05 | 10.4 | - | 1.95 | 4.34 | - | 5.92 | 4.85 | - | 5.45 | 3.40 | - | 7.85 | 9.07 | - |
Table 2. Effect of Biovita on fibre quality in cotton during summer of 2005 and 2006
Treatment | 2.5% span length (mm) | Uniformity ratio | Micro-naire | Fibre strength 3.2 mm (g/tex) | ||||||||
| 2005 | 2006 | Mean | 2005 | 2006 | Mean | 2005 | 2006 | Mean | 2005 | 2006 | Mean |
T1 | 26.8 | 29.1 | 27.9 | 48 | 47 | 47.5 | 4.2 | 4.4 | 4.3 | 22.0 | 23.7 | 22.8 |
T2 | 26.1 | 27.9 | 27.0 | 48 | 46 | 47.0 | 4.4 | 4.0 | 4.2 | 21.2 | 23.4 | 22.3 |
T3 | 27.0 | 29.3 | 28.1 | 50 | 48 | 49.0 | 4.3 | 4.1 | 4.2 | 22.0 | 22.7 | 22.3 |
T4 | 26.5 | 29.0 | 27.7 | 51 | 49 | 50.0 | 4.4 | 4.4 | 4.4 | 22.1 | 22.7 | 22.4 |
T5 | 26.7 | 28.3 | 27.5 | 49 | 48 | 48.5 | 4.4 | 4.2 | 4.3 | 22.5 | 24.1 | 23.3 |
T6 | 26.9 | 30.0 | 28.4 | 49 | 49 | 49.0 | 4.3 | 4.1 | 4.2 | 22.9 | 21.5 | 22.2 |
T7 | 27.0 | 29.2 | 28.1 | 50 | 51 | 50.5 | 4.5 | 4.1 | 4.3 | 21.0 | 22.8 | 21.9 |
T8 | 27.3 | 28.9 | 28.1 | 51 | 47 | 49.0 | 4.3 | 4.0 | 4.1 | 21.4 | 23.6 | 22.5 |
T9 | 27.0 | 28.6 | 27.8 | 51 | 48 | 49.5 | 4.4 | 4.0 | 4.2 | 22.2 | 23.9 | 23.0 |
T10 | 27.4 | 30.0 | 28.7 | 46 | 45 | 45.5 | 4.3 | 4.1 | 4.2 | 23.4 | 22.0 | 22.7 |
Table 3. Estimate of cost benefit ratio with regards to application of Biovita in cotton
Cost of granular application @ 20 kg ha-1 | Rs. 500.00 |
Cost of liquid Biovita @ 750 ml h-1 | Rs. 248.00 |
Cost of spraying/ha (including labour, diesel etc.) | Rs. 200.00 |
Total cost | Rs. 948.00 |
Increase in seed cotton yield | 333 kg |
Income from enhanced seed cotton @ Rs 2000 qtl.-1 | Rs. 6600/ |
Net benefit ha-1 | Rs. 5612 |
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