Effect of Ethephon and Incomplete Irrigation on some Growth and Yield Characteristics of Safflower

Abstract

Abstract The experiment was conducted to study the effect of ethephon and moisture stress in different growth stages on the yield, its components, and the water consumption efficiency of safflower (Gilla) variety. This experiment was carried out during the winter season 2021-2022, on 11/24/2021, in the Al-Bulatif area, which is 3 km from the governorate center, in the fields of a farmer in Al-Muthanna Governorate. It was implemented that using the split-section design with three replications, where the first factor included four levels (full irrigate-Drop irrigation when branching-Drop irrigation at the flower bud-Drop an irrigation when it is full), which is denoted by the symbol. I 1, I 2, I 3, I 4. The second factor: spraying with Ethephon at five levels 2000-1500-1000-500-0 mg/l, which is coded as E0, E1, E2, E3, and E4, with a plant density of 40,000 plants/ha. The results showed a significant effect of the athephon for most of the studied traits. Treatment E2 gave the highest mean for the two characteristics of plant height and number of leaves, which reached 125.40 cm and 410.60 leaves per plant, while treatment E3 showed the highest average number of branching, reaching 81.6 branches, and finally with regard to the athephon, the treatment gave E4 was the highest mean of grain yield, reaching 5.10 kg H-1. As for the effect of lack of irrigation, the significant effect was only for the characteristics of the number of leaves, the weight of 500 seeds, and the grain yield. As the I1 treatment excelled in giving the highest average grain yield of 4.49 kg H-1, while the I2 treatment presented the highest average weight of 500 seeds, which amounted to 23.19 g. As a final point I3 treatment is the highest average number of leaves, as it reached 341.00 leaves per plant. As for the bilateral overlap between the ethephon and the lack of irrigation, the overlap treatment (I3 * E2) excelled in giving the highest average height, reaching 135.6 cm, while the overlap treatment (I2 * E3) gave the highest average number of branching, reaching 97.30 branches per plant. As for the overlap treatment (I2 * E2), it gave the highest average weight of 500 seeds, reaching 25.55 gm, while the overlap treatment between (I1 * E4) gave the highest average grain yield, reaching 7.186 kg H-1.