Abstract: A field experiment was designed to assess the yield performance of four genotypes under five plant spacings (15, 22, 30, 87 and 45 cm) during 1997 and 1998 years at CCRI, Sakrand Sindh. On an average, highest seed cotton yield of 2121 kg ha–1 was obtained when the plant-to-plant distance was maintained at 22 centimeters followed by plant spacing of 15 centimeters where seed cotton yield of 2055 kg ha–1 was harvested. The lowest yield of 1720 kg ha–1 was produced from plant to plant distance of 45 centimeters. The highest yielding variety was CRIS-134 that produced 2067 kg ha–1 followed by CRIS-9 with 1944 kg ha–1 seed cotton yield.
Introduction
The potential of any variety can only be realized if it is sown at the proper spacings and optimum time. Spacings between rows and plants count a lot for proper growth, better aeration and better control of pests.
Researchers are of different opinion, some have recommended wider spacing, some have advocated for narrow spacing and some say that there is no any impact of plant spacing on yield of cotton. Bridge et al. (1973) and Hearn and Hughes (1975) concluded that the yield differences due to spacing were statistically non-significant. El-Hattab et al. (1976) obtained increased seed cotton yield with increased plant spacing from 20-30 cm. Zabab and Hafiz (1979) demonstrated that for obtaining handsome seed cotton yield cotton should be planted at 15 cm. Sinha (1974) favored wider spacing, while Brar and Singh (1978) and Virk et al. (1984) recommended closer spacing for obtaining higher yields. Hake et al. (1991) concluded that plant spacings directly influence soil moisture extraction, light interception, humidity and wind movement. These factors, in turn, influence plant height, branch development, fruit location and size, crop maturity and, narrow spacing increase light interception and plant efficiency. They recommended plant spacing 10-15 cm between plant to plant. Present studies were under taken to assess the performance of advance strains developed by CCRI, Sakrand under varying plant spacings.
Materials and Methods
An experiment was conducted to assess seed cotton yield response of three advance strains (CRIS-19, CRIS-82 and CRIS-134) and one commercial variety CRIS-9 developed by CCRI, Sakrand under five plant spacings (15, 22, 30, 37 and 45 cm) during 1997 and 1998 crop seasons. The sowing of the experiment was done in split plot design replicated four times. The plant spacings were kept as main plots while varieties were kept as sub-plots. All the required agronomical practices such as hoeing, weeding earthing-up etc were carried out when needed. Crop was protected thrice during both the years against sucking as well as bollworm complex, The seed cotton was harvested plot-wise and finally calculated as kilograms per hectare basis. Duncan's Multiple Range Test was applied to bring out the differences between the treatments.
Results and Discussion
During 1997, highest yield (2237 kg ha–1) was obtained when the distance between the plants was maintained at 22 cm followed by 15 cm where the yield of 2187 kg ha–1 was achieved. However, yield difference was non significant and was of same order according to DMR test. Significantly highest yielding variety was CRIS-134 that produced 2117 kg ha–1 seed cotton followed by CRIS-82 (2027 kg ha–1).
During 1998, almost same trend of yield performance in respect of plant spacings was observed as 22 cm plant spacing recorded highest yield of 2004 kg ha–1 followed by 15 cm spacing (1897 kg ha–1).
| Table 1: | Performance (seed cotton yield kg ha–1) of strains under varying plant spacings during 1997 cotton season at CCRI, Sakrand |
| Means followed by similar letters are not significantly different at 5% level | |
| Table 2: | Performance (seed cotton yield kg ha–1) of strains under varying plant spacings during 1998 cotton season at CCRI, Sakrand |
| Means followed by similar letters are not significantly different at 5% level | |
| Table 3: | Average performance seed cotton yield kg ha–1 of strains under varying plant spacings at CCRI, Sakrand |
| Means followed by similar letters are not significantly different at 5% level | |
However, statistically the two spacings were of the same order. This year also highest yielding variety was CRIS-134 with 1997 kg ha–1 yield followed by CRIS-9 (1917 kg ha–1).
When the data of two years were averaged (Table 1, 2, 3), 22 cm plant spacing remained on top with 2121 kg ha–1 seed cotton yield followed by 15 cm spacing (2055 kg ha–1). However, statistically both spacings were of same order according to DMR test. As regards the varietal performance, on an average, CRIS-134 remained on top by producing 2067 kg ha–1 seed cotton yield and was statistically high yielding variety as compared to other varieties. Second best was CRIS-9 with 1944 kg ha–1 seed cotton.
The findings are in conformity with the results of Brar and Singh (1978), Zabab and Hafiz (1979), Virk et al. (1984) and Hake et al. (1991) as all of them have recommended narrow spacings. However, the results to some extent contradict the results demonstrated by Sinha (1974) who favored wider spacings. The results of this study demonstrated that 15 and 22 cm plant spacings gave highest yield while wider spacing of 30, 37 and 45 cm gave low yield. Therefore the growers are advised to make the thinning in their crop Well before first irrigation and leave plant to plant distance of 15 cm up to 22 cm for getting higher yields and maintaining required/recommended plant population in the field.