EFFECT OF NATURAL ACTIVATOR (BIOHORM) AND HUMIC ACID ON GROWTH AND QUALITY OF CYCAS PLANT

This investigation was conducted under open field conditions at the Experimental Farm of Hort. Res. Inst., ARC, Giza, Egypt during 2014 and 2015 seasons to find out the response of two-years-old cycas plant (Cycas revoluta, Thunb.) grown in 20-cm diameter plastic pots filled with about 2.5 kg of a mixture of sand, clay and peatmoss (1:1:1, v:v:v) to natural activator viz. BioHorm at 1 and 3 ml/l and commercial humic acid liquid fertilizer (high K humic acid) at the rate of 5 ml/l (as a foliar spray 6 times with one month interval) and their interactions. The results showed that all vegetative and root growth parameters, were significantly improved over control in response to either single or combined treatments applied in this study, but the best individual treatments were humic acid at 5 ml/l followed by BioHorm at 3 ml/l. The best improvement was obtained when combining BioHorm at 3m/l + humic acid at 5 ml/l which gave high means of vegetative and root growth parameters at all in the two seasons. A similar trend was also observed as well regarding the content of chlorophyll a, b, carotenoids, N, P, K, total carbohydrates % and total indoles in the leaves, but the phenols content was decreased in all treatments. Hence, it is recommended to spray the cycas plants with combination of BioHorm at 3 ml/l + 5 ml/l humic acid to score the best growth performance and highest quality.