Author/Authors :
Shabana، Reda نويسنده Department of Agronomy, Faculty of Agriculture, Cairo University, Giza , , Abd El-Mohsen، Ashraf A نويسنده Agronomy Department, Faculty of Agriculture, Cairo University, El-Gamaa Street, P.O. Box12613 Giza , , Gouda، Hasnaa AH نويسنده National Organization for Drug Control and Research, Ministry of Health, Cairo , , S. Hafez، Hoda نويسنده National Organization for Drug Control and Research, Ministry of Health, Cairo ,
Abstract :
ABSTRACT: Growth and development of safflower are affected by different uncontrollable environmental conditions. Oil contents of safflower are largely influenced by temperature fluctuations. Temperature variations in the field can be created by sowing crops at different dates in the season. The objective of this work was to investigate the effect of different planting dates (i.e., 1st November, 15th November and 1st December), and thermal temperatures (growing degree days, GDD) on yield and quality traits of four genotypes (two local land races, i. e. G 21 and G 81 and two exotic genotypes from Cyprus i. e. G 45 and G 48) and a commercial cultivar (Giza 1). Six environments were created (three different planting dates during 2006/07 and 2007/08). The experimental design was a randomized complete blocks design with three replications. Safflower genotypes exhibited significant differences for seed, oil and protein yields, oil content, heat units accumulation and fatty acids composition. Seed yield was positively correlated (r=0.97**) with growing degree days (GDD) to maturity. The results showed that the seed, oil and protein yield, decreased significantly as the planting dates were delayed. Linear regression equation revealed that increases of one unit (15-day interval) than the optimum date decreased yield by 29.64 kg/fed. The first planting date (1 November) produced the highest seed yield (581.70 kg/fed), whereas the third planting date (1 December) produced the lowest seed yield (522.42 kg/fed). The first planting date yielded the highest average oil yield compared to the other planting dates. Although a positive linear relationship was achieved between accumulated heat units during the period of oil synthesis and until physiological maturity, the R2 value was very low. The average values of oil content were highest in seeds for genotype G 45 (34.21%). Giza 1 had on average the lowest oil content (29.55%). High linoleic acid was dominant in all the five safflower genotypes. Pronounced variation in the main unsaturated fatty acids of oil (linoleic and oleic) was obvious in different environments and was very high. The linear association between heat units and concentration of either oleic or linoleic acid was also discussed.
