Effect of Plant Compost Enriched with Spirulina Platensis Algae as a Partial Replacement of Mineral N Fertilizers on Early Sweet Grapevine

Abstract

During 2014 and 2015 seasons, Early Sweet grapevines were fertilized with the recommended rate of N via 100% mineral N, 100% plant compost (p c) enriched or not with Spirulina platensis algae(S p a) as well as via 25 to 75% inorganic N plus 25 to 75% plant compost with or without Spirulina platensis algae. The merit was replacing inorganic N partially by using plant compost enriched or not with Spirulina platensis algae. Growth characteristics, leaf pigments, N, P, and K, yield, quality of the berries and juice content of nitrite were investigated. Using N as 50% inorganic N + 50% plant compost enriched with Spirulina platensis at 10 ml/ vine improved growth characteristics, yield, cluster weight and quality of the berries. There was a gradual effect on leaf pigments, N, P, K and fruit quality with reducing the percentages of inorganic N from 100 to 0.0% and increasing percentages of plant compost with or without the algae form 0.0 to 100%. Juice content of nitrite and shot berries % gradually declined with reducing inorganic N and increasing plant compost enriched or not with Spirulina platensis algae. Using plant compost enriched with Spirulina platensis was more favorable than using plant compost alone in this respect. A pronounced promotion on yield and fruit quality of Early Sweet cultivar was observed when the vines were subjected to the recommended rate of N as 50% inorganic N plus 50% plant compost enriched with Spirulina platensis algae at 10 ml/ vine.