Influence of Foliar Spraying by Using Paclobutrazol and Pinching Technique on the Growth, Green Pods, Dry Seed Yields, its Components and Some Chemical Constituents of Broad Bean (Vicia faba L.) Plants

This current study was conducted at Qaha Vegetable Research Farm (Qalubia Governorate), Horticulture Research Institute, Agriculture Research Center (A. R. C.), Egypt, during the two winter seasons of 2020/2021 and 2021/2022 on broad bean (Vicia faba L.) plants Weaam cv. The aim of this work was to investigate the influence of foliar application of paclobutrazol (PBZ) at three different doses i.e. 25, 50 and 75 mg/ L at three times; at the vegetative growth, at the peak flowering and at the pod setting stages i.e. at 60, 80 and 100 days after sowing (D.A.S.), respectively as well as pinching technique treatments which were done at three times; the 1st one at plants had 60 cm, the 2nd at 80 cm and the 3rd at 100 cm from the plant height per plant by removing the tip of the main stem of broad bean plants, under the two winter seasons condition on the vegetative growth characteristics, total green pods, dry seed yields and its constituents as well as the quality of the dry seed of broad bean plants. The experimental design was arranged in a complete randomized block design with three replications.

The results indicated that, all the tested treatments significantly affected increased the vegetative growth characteristics (with the exception of the plant height in the two winter seasons, respectively), total green pods, dry seed yields, its components and chemical constituents in dry seeds as compared with the control treatment. In this case, among the different concentrations of foliar spraying paclobutrazol treatment at the rate of 50 mg/ L shows the best result as compared with the other two treatments i.e. 75 and 100 mg/ L. About the stimulatory effects of broad bean plants with pinching technique treatments either at flowering stage or at the pod setting stage, which were the best treatments and markedly improved the most of all the pervious studied characters of broad bean plants and dry seed quality as compared with the other pinching technique treatment i.e. at the vegetative growth stage and no pinching treatment.