Two field experiments ( 2013- 2014) were conducted in Zaian region , Dakhlia governorate to study the effect of fertilizing integrated system (100 % organic, 50 % organic + 50 % mineral , 100 % mineral and local treatment ) on yield , N, K, Na and nitrate content of cantaloupe plant .
The obtained results can be summarized in :
Fully mineral fertilization treatment achieve the highest fresh weight of leaves and 100 % organic give the lowest value . Using 100% organic fertilizer caused a reduction in fruit number amounted by 49.29 % compared with 50 % organic + 50 % mineral fertilization treatment. Relative yield of 100 % organic fertilization treatments amounted by 74.28 % compared with 100 % mineral fertilization treatment
In spite of a very little differences were found in rounded index of fruits as a result of applying the studied treatments 100 % organic fertilization treatments recorded the highest rounded index value ,0.996 . Fleshy part percentage and dry weight percentage of fleshy part of fruit negatively affected by mineral fertilization. 100% organic fertilization recorded85.94 % and 7.8 % for the same order of the same traits.
The highest values of N leave contents ( 2.050 % and 2.017 % ) were obtained with treatments which receive higher amounts of mineral fertilizers and the lowest values ( 1.915 % and 1.985 % ) were obtained with treatments which receive higher amounts of organic fertilizers. The treatments of 100 % organic fertilization and 50 % organic + 50 % mineral fertilization showed a sever reduction in N content of Cantaloupe stems.
cantaloupe stems have the highest concentration of potassium than that of the other parts, where fleshy part of fruit took the second order in this respect and leaves comes as a latest one . Full organic fertilizer treatments got the highest potassium concentration means of leaves. fleshy part of fruit contain a higher sodium content than that of leaves and stems , approximately 1.66 : 1.75 fold than that of leaves and 2.11: 2.54 fold than that of stems .
Cantaloupe stems contain the highest level free nitrate – N compared to leaves and fleshy part of fruits, where nitrate –n content of cantaloupe fruit fleshy part approximately amounted by one fifth of leaves free nitrate-N and one tenth of the stem free nitrate N. The calculated free nitrate content ( fresh weight basis ) of local, 100 % mineral , 50 % organic + 50 % mineral and 100 % organic fertilization treatment 117.95, 91.95, 88.75 and 94.30 ppm , respectively.
The threshold amount of fleshy part eatable of cantaloupe fruit according to the most acceptable daily intake of nitrate for adult normal person is 2.75 Kg and 2.20 Kg of organic produced cantaloupe and local produced cantaloupe under the conditions of this study .