EFFECT OF FOLIAR SPRAY OF UREA AND NAPHTHALENE ACETIC ACID ON YIELD AND FRUIT QUALITY OF MANGO “MANGIFERA INDICA L.”

Abstract

The present study was conducted at a private orchard in Abi El-Khssib district , Basrah Governorate during the growing season of 2003-2004 to investigate the effect of spraying urea fertilizer at the concentrations of 0 % , and 2 % , and 4 % and the growth regulator “naphthalene acetic acid ,NAA ” at the concentrations of 0 mg / l and 20 mg / l and 40 mg / l on yield and fruit quality of mango trees “Mangifera indica L.” . The results of this study were as follows : 1- Foliar spray of mango trees with urea fertilizer at the concentration of 2 % resulted in significant increases in fruit length , seed fresh weight , fruit content of total acidity and reducing sugars , fruit skin content of chlorophyll A and total chlorophyll , whereas the increases were not significant in L / D ratio , moisture content and N concentration per fruit . Spraying mango trees with the same fertilizer at the concentration of 4 % gave significant increases in the number and weight of fruits per tree and fruit content of sucrose , but the increases in yield per hectare and total sugars of fruit were insignificant . The untreated trees had significant increases in fruit diameter , volume , fresh and dry weights , flesh fresh weight,vit.C concentration and total soluble solids per fruit , fruit skin content of chlorophyll B and carotene, but the increase in the percentage of fruit juice was not significant .2- Foliar spray of mango trees with NAA at the concentration of 20 mg / l gave significant increases in fruit diameter , volume , fresh and dry weights , flesh fresh weight , fruit content of total soluble solids , sucrose and total sugars . Spraying mango trees with 40 mg / l NAA produced significant increases in the number and weight of fruits per tree , fruit length , moisture content , juice percentage , total acidity , vit. C and N concentration per fruit , fruit skin content of chlorophyll B and carotene , but the increases were not significant in yield per hectare and L / D ratio . The untreated trees had significant increases in seed fresh weight , fruit content of reducing sugars and fruit skin content of chlorophyll A and total chlorophyll . 3- The interaction between urea fertilizer and NAA growth regulator had influencail effects on mango trees . The combination treatment of 0% urea and 20 mg / l NAA gave significant increases in weight of fruits per tree and yield per hectare , fruit diameter , volume , fresh and dry weights , flesh fresh weight , fruit content of total soluble solids and sucrose , whereas the combination treatment of 0% urea and 40mg / l NAA significantly increased moisture content , juice percentage and vit. C per fruit , fruit skin content of chlorophyll B and carotene . The combination treatment of 2 % urea and 0 mg / l NAA produced significant increases in fruit content of total acidity,reducing and total sugars and fruit skin content of chlorophyll A .The combination treatment of 2 % urea and 20 mg / l NAA significantly increased fruit skin content of total chlorophyll , while the combination treatment of 2 % urea and 40 mg / l NAA recorded significant increases in fruit length and seed fresh weight but the increase in L / D ratio was not significant . The combination treatment of 4 % urea and 20 mg / l NAA produced significant increases in the concentration of N and sucrose per fruit. The combination treatment of 4% urea and 40 mg / l NAA had a significant increase in total number of fruits per tree .