Research Article
Plant Population of Sunflower under Different Planting Dates
Agriculture Research Institute, Tarnab, Peshawar, Pakistan
Zar Quresh
Agriculture Research Institute, Tarnab, Peshawar, Pakistan
Sunflower is a non-traditional oilseed crop. It is a temperate crop, but is adaptable to wide range of climatic conditions. It thrives on nearly all types of soils provided they are well drained. Acidic and saline soils are not desirable, though it can tolerate a pH range from 6.5-8.0 (Hatam and Abbasi, 1994). During 1997-98 Sunflower was grown on an area of 6763 hectares in 4WFP which produced 8403 tones. In the same year total area under Sunflower cultivation in Pakistan was 98450 hectares which produced 129693 tones. (Anonymous, 1998).
Belevtsev et al. (1990) reported that the sowing dale at which soil temperature was 10.12°C gave more yield as compared to the sowing date at which the soil temperature was 14-16°C.
Shafiullah et al. (1992) reported that days to maturity decreased when the crop was sown on April 1, as compared to March 1.
Inspite of the large areas of deep soils, favorable topography, water wealth and suitable climatic conditions of Pakistan, the per acre yield of Sunflower is still very low as compared to other countries of the world. Its yield is 130D kg ha1 (Anonymous, 1998) which is very low as compared to other agriculturally advanced countries. Sunflower yields in France and USSR are 2595 and 1439 kg ha1 respectively (FAO, 1989). The present research work was designed to find out the most suitable plant population for sunflower under different planting dates.
In order to study the effect of different plant population on the yield and yield components of sunflower under different planting dates an experiment was conducted at the Agricultural Research Institute, Tarnab, Peshawar, during spring, 1998. The experiment was laid out in RCB design with split plot arrangement having four replications. Planting dates were allotted to main Welts while plant population treatments were allotted to sub plots. A treatment size of 4.5×5 m2 was used.
Sowing was accomplished on the following dates:
D1: 1-1-1998 | D2: 1-2-1998 |
D3: 1-3-1998 | D4: 1-4-1998 |
The following plant population was studied |
Sunflower hybrids ARITAR-93 was planted on proper moisture condition. Planting was done by dibbling two seeds per hill, and thinned to one plant per hill at 2 to 4 leaves stage. Standard agronomic practices were followed through out the growing period. Data were recorded on Days to 50% flowering, Days to maturity, plant height (cm), Head diameter (cm) and Achene yield (kg ha1) and analyzed statistically.
Days to 50% flowering: Mean Table 1 indicated that there was no significant effect of plant population on days to 50% flowering while dates of sowing significantly affected days to 50% flowering. Maximum days to flowering (114.2) were recorded in January 1, sowing which decreased with delay in sowing and minimum 65.00 days to flowering were observed in April sowing. Almost similar results were reported by Lupu et al. (1990) and Shafiullah et al. (1992).
Table 1: | Days to 50% Flowering of sunflower hybrid ARITAR-93 as affected by different plant population and sowing dates |
LSD value at alpha =0.05 = 0.02312 |
Days to maturity: Plant population had no significant affect on days to maturity of Sunflower while days to maturity were significantly affected by planting dates (Table 2).
Days to maturity decreased when sowing was delayed from January 1 to April 1. Maximum days to maturity (150.9) were recorded in the January planted crop while minimum (93) were recorded in the April sown crop.
Table 2: | Days to maturity of sunflower hybrid ARITAR-93 as affected by different plant population and sowing dates |
LSD value at alpha = 0.05 = 0.2585 |
This shows that lower temperature delays maturity. Days to maturity in sunflower are therefore, effected by the environmental conditions in different months of the year. Period of maturity is shortened when the temperature is higher and therefore, the requirements of degree days are met earlier than those of cooler months. It was probably also the main reason for variation in plant height on different planting dates. Thompson and Heenan (1994) also reported similar results.
Plant height (cm): Plant height increased with the increase in plant population and the maximum height of 117.8 cm was given by the plant population of 222222 plants ha1. The increase in plant height with the increase in plant population may be due to greater competition for light. Plant height was also significantly affected by Planting dates (Table 3). The maximum plant height (142.3 cm) were recorded in the January sown crop while the minimum (96.75 cm) were recorded in April sown crop. These increase and decrease in Plant height was probably because of temperature fluctuations and photoperiod. These results are in line with the findings of Swallers and Fick (1973) who reported increase in plant height with increase in plant population and Shafiullah et al. (1992) who reported decrease in plant height with delay in planting.
Table 3: | Plant Height (cm) of sunflower hybrid ARETAR-93 as affected by different plant population and sowing dates |
LSD value at alpha =- 0.05 = 7.611 LSD value at alpha = 0.05 = 1.049 |
Head diameter (Cm): Results presented in Table 4 reveal that head diameter was significantly affected by plant population and sowing dates. Maximum head diameter of 19.06 cm was recorded in the plots where minimum plant population was maintained while head diameter decreased with the increase in plant population and minimum 15.56 cm head diameter was recorded in the maximum plant population. Head diameter decreased with delay in sowing from January to April. Maximum head diameter of 18.56 cm was recorded in the January sown crop followed by 17.81 cm head diameter in the February sown crop. Similar results were also reported by Shafiullah et al. (1992).
Achene yield (kg ha1): Results presented in Table 5 revealed that achene yield was significantly affected by plant population and sowing dates. The plant population of 111111 plants/ha gave maximum achene yield of 2366 kg ha1, while the plant population of 44444 plants/ha gave minimum yield of 1823 kg ha1.
Table 4: | Head Diameter (cm) of sunflower hybrid ARITAR-93 as affected by different plant population and sowing dates |
LSD value at alpha=0.05=0.3092 LSD value at alpha=0.05=0.285 |
Table 5: | Achene yield (kg ha1) of sunflower hybrid ARITAR-93 as affected by different plant population and sowing dates |
LSD value at alpha = 0.05 = 209.45 LSD value at alpha = 0.05 = 175.22 =Abstracts, 1993-7/95 |
The highest achene yield of 2290 kg ha1 was obtained when sowing was done on 1st January, while the minimum (1988 kg ha1) was given by the April sown crop. Similar results were obtained by Gimeno et al. (1989).