Effect of planting distance on the production of full of and long grains with addition of NPK and organic acids characters and dates on yield sunflower (Helianthus annuus L.)

A field experiment was conducted during the spring season 2021 in agriculture field in Al-Rumaitha district, which was 25 km from the center of Al-Muthanna Governorate, to study the effect of plant distance and different fertilizer combinations on the purchasing value and the size of sunflower grains (Shumoos). A factorial experiment was carried out by using the split plot Experiment, according to a randomized complete block design R.C.B.D with three replicates. The experiment included the two factors , the first factor was four plant distance : (55, 45, 35 and 25) cm, and the second was four different fertilizer combinations of N.P.K and organic acids: (100%, 1/4, 1/2 and 3/4) kg ha-1 . The grains were sown on 03-15-2021 with different distances between plant and 75 cm between one line and another. The plant wide spacing between sunflower plants significantly affected most of the yield traits; the distance of 55 cm was superior in the highest mean disc diameter, number of filled grains, weight of 1000 gm and harvest index, while the sowing distance distance of 25 cm was significantly superior in giving the highest mean of total grain yield. The addition of different fertilizer combinations affected all vegetative growth characteristics, fertilizer level exceeded F2 (120 kg N ha-1 ,75 kg P2O5 ha-1 ,120 kg K2O ha-1 +30 kg ha-1 humic and fulvic) on disc diameter, number of filled grains, weight of 1000 grains, harvest index and total grain yield. The effect of the interaction between the two factors of the study was significant on most of the studied traits. the treatment F2D4 significantlysuperiority, by giving it the highest average for each of the disc diameter, the number of filled grains, weight of 1000 grains, and the harvest index, whereas, the combination F2D1 gave the highest Mean for the total grain yield