INFLUENCE OF SOURCES AND PLACEMENT OF ORGANIC FERTILIZERS ON NUTRITIONAL STATUS, YIELD AND BUNCH CHARACTERISTICS OF THOMPSON SEEDLESS GRAPEVINES

The effect of various sources of organic N fertilizers namely, filter mud  (2.5% N), Compost El-Neel (2.15% N), Chicken manure (2.0% N) and Farmyard manure (0.25% N) applied at 25% of the recommended rate of nitrogen (80 g/vine) and placements (25, 50 and 75 cm dig depth) on leaf area,  percentages of N, P and K, berry set (%), yield and quality of  Thompson seedless grapes was investigated during three consecutive seasons, 2005 , 2006 and 2007,in the grapevine field in Assuit.
Results showed that fertilization with filter mud, Compost El-Neel, Chicken manure and Farmyard manure, in the descending order was highly effective for enhancing leaf area, percentages of N, P and K in the leaves, berry set, yield as well as physical and chemical characters of the berries. Placement of organic fertilizers had obvious effect on these characters. Increasing placement depth from 25 to 50 cm around the vines resulted in stimulating leaf area, percentages of N, P and K in the leaves, yield and quality of the berries. However, placing these, organic fertilizers in digs 75 cm depth caused a slight reduction in these characters and had adverse effect on yield and quality of the berries.
Fertilizing Thompson seedless grapevines annually with Nat 80 g/ vine composed of 50% inorganic + 25% organic (0.8 kg filter mud/vine in digs 50 cm depth) + 25% Biogen (20 g/vine) is  suggested   for   obtaining   an   economical yield   and improving berries quality.