Abstract
The objective of this study is to assess the ameliorative impact of potassium humate (KH; 0, 100, and 200 kg per feddan) as soil amendments on the growth traits, green and dry yields characteristics, leaf photosynthetic pigments, chlorophyll fluorescence, and leaf contents of nutrients of common bean (Phaseolus vulgaris L., cv. “Bronco”) plants grown under saline soil conditions. To perform the study aim, two field trials were conducted at the Experimental Farm of Faculty of Agriculture, Fayoum University during the 2016 and 2017 summer seasons. The obtained results showed that, Na+ content was significantly declined, while the all other tested parameters such as growth characteristics (i.e., shoot length, number of leaves per plant, area of leaves per plant, and shoot fresh and dry weights), yield characteristics of green pods and dry seeds (i.e., average pod weight, number of pods per plant, pods weight per plant, dry seed weight per plant and 100-seed weight), leaf photosynthetic pigments (i.e., total chlorophylls, total carotenoids) contents and leaf chlorophyll fluorescence (i.e., Fv/Fm and PI), leaf contents of N, P, K+, and Ca2+, and the ratios of K+/Na+, Ca2+/Na+ and K++Ca2+/Na+ were significantly increased by the all KH treatments compared to the controls (without KH). The two KH treatments conferred, approximately, the same results. Therefore, results of this study recommend using KH at 100 kg per feddan to optimize the common bean performance in saline soils.
Keywords: Phaseolus vulgaris, Salinity, Humic substances, Plant performance, Antioxidant defense systems, Photosynthesis, Water relations
