Research Article
Response of Cotton Genotypes to Time of Sowing
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M. S. Cheema
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Moazzam Jamil
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Shaukat Ali Shahid
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M. Iqbal Shahid
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Cotton (Gossypium hirsutum L.) is an important cash crop of Pakistan. It covers an area of 2927.5 thousand hectares with annual production of 10731.9 thousand bales during the year 2000 (Anonymous, 2002) Cotton is not only a source of foreign exchange but it is also a source of income to farmers and laborers because of local textile industry is based on the cotton production. Cotton seed is the major source of vegetable oil and oil seed cake for animal feed. Although Pakistan has been able to achieve breakthrough in production of cotton, yet there is vast gap between the potential and national average yield.
This yield of seed cotton is far below than the potential yield. Despite all out efforts made in this direction, yield of seed cotton is a result of many contributing factors, among these the time of sowing is important one and can only be achieved by sowing of wheat crop at its appropriate time. Late sowing beyond certain limit lowers the seed cotton yield significantly. Khan et al. (1980) concluded that sowing of cotton in early season from 15th April to 1st May gave an increased yield over that of late sowing. Pakistan Central Cotton Committee, 1985 has recommended an optimum sowing time for cotton at D.I.Khan as 3rd Week of April to end of May, in its cotton production plan for 1985-86 (Anonymous, 1985).
Itnal et al. (1993) reported that seed cotton yield was decreased by delaying sowing after July. They further observed that higher seed cotton yield due to early sowing was mainly attributed to higher number of open bolls and seed cotton weight per plant. Hosny and Shahine (1995) concluded delayed sowing increased the period from sowing to seedling emergence, 1st squre, 1st flower, 1st open boll and full harvest, while no of open bolls plant-1 and plant survival decreased however, boll wt. was unaffected by sowing date.
Sivasankaran et al. (1995) concluded that the optimum sowing dates was 15 August to get maximum seed cotton yield. Sarma et al. (1997) reported that delaying sowing decreased seed cotton yield. Supriya , MCU 5-VT and laxmi produced mean seed cotton yield of 1.45, 1.25 and 1.05 kg ha-1, respectively. Shekara et al. (1998) reported that mean seed cotton yield was 1871 kg ha-1 from the earliest sowing date, 1655 kg when sown in the first fortnight of June, and <600 kg ha-1 with later sowing dates.
Keeping in view all these, study was conducted to find out the appropriate sowing time of cotton varieties under irrigated conditions of Bahawalpur. Bolonhezi et al. (1999) reported that sowing in January and February resulted in significantly reductions in length, resistance and the micronaire index for the cotton varieties under studies, however elongation was not altered.
The study was carried out at Agronomic Research Station, Bahawalpur during the year kharif 1999 and 2000 to find out the appropriate sowing time of cotton varieties/ cultivars for maximum seed cotton yield. The experiment was laid out in split plot design with three replications and a plot size of 4.5 X 8m2 having varieties in main plots and sowing dates in sub-plots. Standard dose of NPK fertilizer (100-60-0 kg ha-1) was applied as blank application. The experiment involved the following levels of the two factors.
Factor-I
Varieties:
V1 | SLS-1 | V2 | NIAB-Karishma | V3 | FVH-53 |
V4 | BH-118 | V5 | CIM-443 | V6 | CIM-448 |
Factor-II
Sowing dates:
D1 | Ist May of year 1999 to 2000 |
D2 | 16th May of year 1999 to 2000 |
D3 | 1st June of year 1999 to 2000 |
D4 | 16th June of year 1999 to 2000 |
The Observations were recorded for yield and yield components. Data collected were analyzed statistically using least significant difference test at five percent level of probability (Steel and Torrie, 1984).
Results and Discussion
Seed cotton Yield (Kg ha-1): The analysis of variance (Table 1) showed significant differences among wheat varieties/cultivars for all the characteristics at different sowing dates. The thorough scrutiny of the data revealed a superiority of V. NIAB-Karishma over others, and among sowing dates, sowing on 16th May were the best for all growth parameters and consequently the seed cotton yield. The data (Table 1) depicts a detailed scenario of yield performance of cotton varieties at different sowing dates. The highest mean seed cotton yield of 2403 kg ha-1 was obtained when crop was sown on 16th May. Sowing before or after that date, seed cotton yield of all varieties included in the experiment decreased significantly. Therefore mid of May be considered the optimum time of cotton plantation.
Similar findings were reported by Anonymous (1985), shekara et al. (1998) and sarma et al. (1997). Results were some contradictory reported by khan et al. (1980), Hosny and Shahine (1995) and Itnal et al. (1993). As for as varieties are concerned NIAB-Karishma gave reasonably higher seed cotton yield in all the cases even from 1st may to 1st June. The interaction between cotton varieties and sowing dates was highly significant reflecting the optimum sowing time for different cotton varieties under study.
Bolls per plant: Maximum number of bolls per plant were attained on 16th May for all varieties (Table 2) included in the experiment, before or after this sowing date, growth parameter decreased significantly, reflecting optimum time for cotton plantation.
Table 1: | seed cotton yield (Kg ha-1) of different varieties (V) at different sowing dates (D) of year 1999 to 2000 |
Table 2: | Bolls per plant-1 of different cotton varieties (V) at different sowing dates (D) of year 1999 to 2000 |
Table 3: | 100 boll weight (g) of different cotton varieties (V) at different sowing dates (D) of year 1999 to 2000 |
Similar findings were reported by Itnal et al. (1993) Hosny and Shahine (1995). As for as variety was concerned SLS-1 gave maximum bolls per plant.
100 bolls weight: Maximum 100 boll weight was attained on 16th may for all the varieties included in the experiment before or after this date this growth parameter decreased significantly (Table 3). As for as varieties were concerned FVH-53 gave maximum boll weight. The interaction between sowing dates and varieties was also significant reflecting the optimum time for plantation of different cotton varieties under study.
On the basis of two years results it was concluded that sowing of cotton crop on mid May (D2) resulted in a significantly higher values as compared to rest of sowing dates. So mid of may is the appropriate sowing time of cotton plantation for all the cotton varieties under study moreover, sowing of cotton crop after mid June gave vary poor values.