Effect of leaves defoliation and plant density on growth, yield and quality of some sunflower genotypes (helianthus annuus L., compositae)‎

الملخص EN

For maximization the productivity, quality of sunflower crop, two field experiments were conducted during two successive spring growing seasons of 2007, 2008-2008, 2009 to determine growth, yield and quality of sunflower genotypes (Helianthus annulus L.) to plant density and leaves defoliation.

Each experiment comprised of three sunflower genotypes (Mordent, Flame and Mann), four levels of plant density (22222, 26629, 44444 and 88888 plants.hector-1) and three levels of upper leaves defoliation (0, 4 and 8 leaves).

It was conducted according to Randomized Completely Block Design with split- split plot with three replications.

The results could be summarized as : Increasing plant density to 88888 plant.

Hector-1 led to significant increases in plant high, hollow percentage and oil percentage.

The plant density at 22222 plant.hector-1 cause a significant increase in stem diameter, leaf area, head diameter, number of seed per head and weight of thousand seed, while increasing plant density from 22222 to 44444 plant.hector-1 cause a significant increase in total yield, oil, protein yield in the two growing seasons of 2007, 2008-2008, 2009, respectively.

Non defoliation treatment recorded significant increases in characters plant high, stem diameter, leaf area, head diameter, number of seed per head and weight of thousand seed, total yield and oil percentage, while increasing defoliation treatment to 8 leaves cause a significant increase in protein percentage of the seeds in both seasons 2007, 2008-2008, 2009 respectively.

The Flame genotype gave a high mean for characters stem diameter, leaf area head diameter, number of seed per head and weight of thousand seed, total yield and oil yield (ton.hector-1) and oil percentage, while Manon genotype gave a high percentage of protein in the seeds in both seasons 2007,2008-2008,2009, respectively.

The interaction between plant densities with defoliation treatment was significant in some of growth, yield and quality characteristics, the plant density 22222 plant.hector-1 with the non-defoliation treatment gave a high means of the head diameter, number of seed per head and weight of thousand seed, while the plant density at 44444 plant.hector-1 with non-defoliation treatment gave a high rate of the total seed yield (ton.hector-1) in both seasons 2007, 2008-2008, 2009, respectively.

The plant density 44444 plant.

hector-1 with the Flame genotype gave a high rate of total seed yield (ton.hector-1) and oil yield for the two seasons 2007, 2008-2008, 2009 respectively.

The effect of the interaction between leaves defoliation treatments and genotype was significant on some growth characters, yield and quality.

Non defoliation treatment with Flame genotype gave the highest means for head diameter, weight of thousand seed and total seed yield in the two growing seasons.

The interaction between plant densities 44444 plant.

hector-1 with non-defoliation treatment with Flame genotype gave a high rate for head diameter, weight of thousand seed and total seed yield in the two growing seasons.