Response of snap bean growth and seed yield to seed size, plant density and foliar application with algae extract

Two field experiments were conducted during the two growing summer seasons of 2013 and 2014, at the experimental farm of vegetables at Kaha, Qalyubia Governorate, Agriculture Research Center (ARC), Egypt, in order to investigate the effect of seed size, plant density and foliar application with some algae extracts on growth and seed yield of snap bean cv. valentino. A split-split plot design was used with three replications, where three sizes i.e., large, small and control (without grading) were randomly distributed in the main plots, two plant density rates (22 and 33 plants per m2) arranged in subplots and foliar spray with seaweed extract (algost), fresh water algae (spirulina), mixture of them and control (sprayed with distilled water) allocated in sub-subplots. Results showed a clear positively enhancement of plant vegetative growth parameters, chlorophyll, N, P, and K contents of leaves and seed yield quantity and quality positively by sowing large seeds compared with other seed sizes. Meanwhile, higher plant density (33 plants per m2) gave the highest values of plant length and seed yield per feddan, while the lower plant density (22 plants per m2) gave the highest values in other studied parameters except weight of 100 seeds where there were no significant differences between the two plant densities. All foliar applications with algae extracts significantly increased all the studied parameters compared to the control treatment. The superior application was the mixture of seaweeds and fresh water algae extracts together followed by seaweed extract alone in the two seasons, respectively.