The effect of different levels of seaweed extract on the growth, yield and biochemical characteristics of bitter squash (Momordica charantia L.)

The effects of foliar spraying of seaweed extract on the growth, yield and biochemical characteristics of bitter squash plant (Carla) were evaluated under field conditions. Treatments were of four levels of seaweed extract (0, 1.5, 3 and 4.5 in thousand) during three stages of foliar spraying (before flowering, flowering and fruit set time). The experiment was designed in randomized block design with three replications at the Research station of Faculty of Agriculture University of Birjand during growing season of 2016. Leaf growth indices were influenced by seaweed extract treatments, so that with increasing treatment levels, increased fresh and dry weight and leaf area. The seaweed extract improved photosynthetic pigments (chl a, chl b, total chl and carotenoid). The highest amount of chl a, b, total chl and carotenoid (4.77, 5.66, 11.03, 2.52 mg. g-1f.w) were obtained in plants treated with 4.5 in thousand seaweed extract, while the lowest values were recorded in the control. Results showed that seaweed extract improved on quantitative characteristics of bush, so that the highest bush length and number of lateral branches were obtained at the highest level of the seaweed extract, while the lowest value were recorded in the control. Application of different levels of seaweed extract has a positive effect on the yield indices (weight, length and diameter of the fruit, number of fruits and yield) and biochemical characteristics of fruit (antioxidants activity and total phenol). The highest yield (4526 kg. ha-1), total phenol (8.74 mg GAE/100g) and antioxidant activity (69.68%) were obtained in plants treated with 4.5 in thousand seaweed extract. Generally, the findings of current study revealed that the use of 4.5 in thousand seaweed extract had strong impact on qualitative characteristics of bitter squash in this study.