Partial Replacement of Inorganic Nitrogen Fertilizer by Spraying Some Vitamins, Yeast and Seaweed Extract In Ewaise Mango Orchard under Upper Egypt Conditions

摘要

During 2012 and 2013 seasons, attempts were carried out for replacing 40 to 80 % mineral N by spraying seaweed extract at 2 %, yeast at 2 % or vitamins A & D & K each at 50 ppm in Ewaise mango orchards situated at upper Egypt conditions. A remarkable promotion on the leaf area, chlorophylls a & b, total carotenoids, total chlorophylls, leaf total carbohydrates %, leaf C/N as well as nutrients namely N P K Mg, Zn, Fe and Mn in the leaves, fruit retention %, yield and fruit quality was observed with supplying the trees with the suitable N (1000 g N/ tree/ year) through 60 to 80 % mineral source in combined with spraying seaweed extract at 2 %, yeast at 2 % or vitamins A, D & K each at 50 ppm in relative to using N completely via mineral source or when mineral N was added at percentages lower than 60 %. Both total acidity % and nitrite content in the pulp were greatly reduced. Using N as mineral N at percentages lower than 60 % gave unfavourable results. For replacing 40 % of mineral N as well as improving yield and fruit quality of Ewaise mango trees grown under upper Egypt conditions, it is advised to fertilize the trees with N at 1000 g N/ tree/ year via 60 % mineral N plus spraying seaweed extract four times at 2 %.