EFFECT OF SOME ORGANIC N FERTILIZERS ENRICHED WITH SPIRULINA PLATENSIS ALGAE AS A PARTIAL REPLACEMENT OF INORGANIC N FERTILIZER ON GRWOTH AND FRUITING OF SUPERIOR GRAPEVINES

Abstract

During 2014, 2015 and 2016 seasons, Superior grapevines were fertilized with three organic manures (poultry manure, plant compost and farmyard manure) enriched with Spirulina platensis algae as a partial replacement of 25 to 75% inorganic N. The merit was detecting the best source of organic N enriched with Spirulina platensis algae applied with inorganic N that responsible for producing higher yield with better quality berries. Replacing 50% of inorganic N by 50% organic manures enriched with Spirulina platensis algae at 20 ml/vine enhanced growth, yield and cluster weight while replacing 75% of inorganic N by 75% organic manures enriched with Spirulina platensis algae at 40 ml/vine gave favourable effects on vine nutritional status and quality of the grapes. Shot berries percentage was greatly declined by N as 25% inorganic N plus 75% organic manures enriched with Spirulina platensis algae at 40 ml/vine. The best organic manures in this respect was poultry manure, plant compost and farmyard manure, in descending order. Conclusively, for enhancing growth and yield of Superior grapevines, it is suggested to supply the vines with N (60g/vine/year) through 50% inorganic N + 50% poultry manure enriched with Spirulina platensis algae at 20 ml/vine/year. Fertilizing the vines with N as 25% inorganic N + 75% poultry manure enriched with 40 ml Spirulina platensis algae gave the best results with regard to berries quality.