Avena sativa L. تأثير التغذية الورقية باالثيفون والبورون في نمو وحاصل الشوفان

Abstract

A field experiment was carried out during the two winter seasons of 2017-2018 and 2018-2019 in agricultural area, in Ramadi western Iraq on the left bank of the Euphrates River, 110 km west of Baghdad. This study aimed to evaluate four cultivars of oat (Genzania, Shafa, Carrolup and Hamel) suffering from lodging and lack of active tillers. These cultivars were given foliar application with three concentrations of ethephon (0, 500 and 1000 mg L-1 ) and three concentrations of boron (0, 50, and 100 mg L-1 ), in order to reduce lodging, promote tillering and improve some traits of growth and yield. The Randomize Complete Block Design (RCBD) was used according to the split-split plot arrangement, and three replicates.. The results showed: 1. The cultivars differed significantly in all traits studied. Genzania delay flowering and ripening and it was the most lodging, and recorded the highest number of grains head-1 , grain yield (6.512 and 5.565 t ha-1 ) and harvest index in the two seasons. Shafa was least lodging, and it was recorded the highest values of number of tillers m2 , number of heads m-2 , and biological yield (22.83 and 22.95 t ha-1 ). Carrolup had the highest chlorophyll content (56.0 and 52.6 SPAD), grain protein (11.62 and 12.19%) in the two seasons. Hamel was early in flowering and ripening and was superior in stem diameter in the two seasons. 2. Ethephon spraying with concentrations 500 and 1000 mg L-1 in both seasons led to delay flowering and ripening, increase in grain filling c period, stem diameter, number of tillers m-2 and number of heads m-2 , and decrease in plant height, flag leaf area and lodging index. There was no significant difference between the ethephon concentrations 500 and 1000 mg L-1 in the grain filling period, stem diameter, flag leaf area, and lodging index. Ethephon spraying with concentration of 500 mg L-1 led to increase grain yield by 9.15% over the control in the first season only. 3. Boron with concentration 50 and 100 mg L-1 increased plant height, chlorophyll content, and grain yield over the control by 27.81% and 33.80% respectively in the first season, and by 20.17 and 12.45% respectively in the second season. Biological yield increase over the control with 50 and 100 mg L-1 by 14.94 and 17.70% in the first season, by 12.64 and 17.31% in the second season. In addition to increase grains protein, but there is no significant difference between the two boron concentrations (50 and 100 mg L-1 ). The boron spray with 100 mg L-1 produced the highest grain yield reached 6.171 t ha-1 in the first season, while in the second season; the concentration 50 mg L-1 had the highest grain yield 5.337 t ha-1 . 4. There was significant effect of the interaction of cultivars × ethephon concentrations in the two seasons, on the number of days from planting to flowering, number of days from planting to maturity, plant height, stem diameter and number of heads m-2 . Shafa with ethephon concentration of 1000 mg L-1 produced the highest Number of heads m-2 reached 455.6 and 379.8 heads m-2 in the two seasons respectively. 5. There was a significant effect of interaction between cultivars × boron concentrations in both seasons, on the grain filling period and 1000 grains weight. Grain filling period reached the maximum (35.3 and 35.0 days) in Genzania with boron concentration of 0 mg L-1 . d 1000 grains weight reached the maximum (38.7 g) in Carrolup with boron concentration of 100 mg L-1 in the first season, and in the same cultivar with boron concentration of 50 mg L-1 in the second season (38.9 g). 6. The effect of interac