The promotive effects of some natural extracts (algal, yeast and vermiwash) on vegetative characteristics and nutrients status of citrus lemon (Citrus aurantifolia) seedlings

Abstract

A huge amount of agricultural waste produced in agri-aquacultural farms could play a positive and important role in different aspects starting from decreasing rate of soil degradation till raising soil fertility besides maintaining activity and diversity of microorganism community in soil, thereby good and effective managing of recycling these agri-aquacultural wastes through utilizing these wastes in producing vermicompost and vermiwash may reflect in these positive impacts. Natural extracts (Algal, Yeast and Vermiwash) are considered as promising and ecofriendly foliar fertilization for vegetables and fruits. This study focused on short term evaluation and comparing three natural extracts: algal, yeast and vermiwash, as foliar fertilizers in citrus lemon (Citrus aurantifolia) seedlings. Vegetative growth parameters (leaf area, leaf fresh and dry weight) as well as leaf mineral content (N, P, K, Ca and Mg) and chlorophyll were monitored in response to different concentrations of investigated foliar fertilizers. In addition, soil microbial activity was enzymatically estimated as a reflection of positive impact of tested natural extracts. Obtained results showed that foliar spraying with algal extract at 2% and yeast extract at 1% showed increased leaf fresh and dry weight of lemon seedlings. Foliar spraying of vermiwash at 10% as well as yeast extract at 2% promoted increase in leaf area. Vermiwash was superior in enhancing mineral contents in leaves compared with algal and yeast extract. Moreover microbial activity of rhizosphere will be affected by nutritional status of plants. Algal extract as foliar fertilization could enhance soil microbial activity due to plant root exudates. Vermiwash extract as well as yeast and algal extracts (as a natural extracts) could be safely recommended (in the same order) as foliar fertilizer to improve growth of citrus lemon seedlings and increase soil microbial activity.

Keywords: Citrus seedlings, Vermiwash, natural extracts, promotion growth, nutrient status, microbial activity.