New Research Projects
Exploring opinions about soya in the lower income groups
The final report is still awaited.
Investigate the effect of different planting dates on sunflower seed yield and oil content at Free State and North West
In South Africa, sunflower is often used as a catch crop and is planted as an alternative when rainfall onset is too late for maize or soy plantings. Therefore, the stable yields under these late planting conditions are well below the crop's yield potential. To maximize the use of natural resources, optimum planting time of a crop is very important because it ensures good seed germination and optimum root system development, which, in turn, enable the plant to absorb essential nutrients from a large volume of soil. Therefor the objectives of this study are to study the effect of different planting dates on sunflower grain yield and quality, and to demonstrate and promote the optimum planting dates at the farmers' field.
Four field trials were established at GC Potchefstroom research farm, three at Bethlehem and one at Henneman with different planting dates. Nine sunflower hybrids were planted and evaluated for seed yield and quality in a randomized complete block design with three replications.
At Potchefstroom site, highly significant effect of planting date on all studied parameters was observed while sunflower hybrids showed significant differences for all studied parameters except the seed yield. First planting date planted in the 31 October 2022 yielded the highest yield of 2.73 t /ha-1, while the lowest seed yield recorded for the fourth planting date on 12 January 2023 (1.74 t/ha-1). Second planting date recorded the highest oil content 45.88 % across hybrids while the third planting yielded the lowest oil content of 41.26%. Protein content ranged from 10.20% for the second planting to 14.60 % for the last planting. Oil yield ranged from 0.72 t/ha-1 for the fourth planting to 1.24 t/ha-1 for the second planting. Mean seed yield across hybrids and different planting dates was 2.31 t/ha-1, PAN 7080 produced the highest yield of 2.46 t/ha-1 and the lowest yield of 1.21 t/ha-1 was recorded for AGSUN 5106CLP. For oil yield, SY 3970 CL produced the highest oil yield of 1.16 t/ha-1.
At Bethlehem site planting dates and sunflower hybrids showed highly significant effects on all studied parameters except the seed yield. First planting date on 20th of November recorded the best seed and oil yield (2.64 t/ha-1 and 1.13 t/ha-1) respectively. The last planting date on January 11, 2023, yielded the lowest yield and oil yield of 1.98 t/ha-1 and 0.86 t/ha-1 respectively. The last planting produced the highest oil content 43.58 % and the lowest oil content 40.82% recorded for the second planting date. The highest protein content 15.43% was recorded for the last planting date and the lowest was recorded for the first planting 14.45 %. Tested sunflower hybrids showed significant differences for all studied parameters under different planting dates. For seed yield, PAN 7080 CLP produced the best seed yield of 2.54 t/ha-1 followed by AGSUN 5270 yielded 2.53 t/ha-1 hybrids. SY 3870 CL produced the highest oil content 51.01% and AGSUN 5106CLP produced the highest protein content 15.36%.
Due to heavy rainfall during the season only one planting date was successful At Henneman. The mean seed yield is 3.17 t/ha-1, PAN 7080 produced the highest yield (3.77 t/ha-1 followed by AGSUN 5270 produced 3.57 t/ha-1. SY 3970CL produced the highest oil content (54.71%) and the highest oil yield of 1.69 t/ha-1.
In conclusion, planting date showed a significant effect on all studied parameters. At Potchefstroom site, end of October and November plantings produced higher seed and oil yield while at Bethlehem 20th of November produced the highest seed and oil yield.