EFFECT OF POTASSIUM HUMATE APPLICATIONS ON FRUIT YIELD AND THEIR QUALITY OF Carica papaya PLANT GROWN UNDER ORGANIC CULTURE CONDITIONS

Abstract

In order to study the effect of potassium humate on yield and some fruit properties of seedling papaya plant, an experiment was conducted at an organic private orchard located in El Mamoura at Alexandria Governorate, Egypt during 2013/2014 and 2014/2015 seasons .The experiment included four complete treatments (Soil application of 5 or 10 ml potassium humate every two months to each plant from first of March to end of August), (Soil application of 2.5 or 5 ml potassium humate every month to each plant from first of March to end of August), and control (without application of potassium humate). The yield per plant per period from September to next May (kg) and some fruit characteristics, such as fruit weight (g), length (cm), width (cm), flesh thickness (cm), total soluble solids ( % ), total sugar ( % ), total acidity (%) and content of β carotenes (mg / 100 g of fresh) were recorded Results indicated that Soil application of (10 ml potassium humate every two months) and Soil application of (5 ml potassium humate every month) of both seasons gave the highest yield (kg) and the differences were being significant among them and the three other treatments. Also Soil application of (10 ml potassium humate every two months) gave the highest fruit weight, length and width and significantly increased compared with the other investigated treatments in most cases, in addition the differences between flesh thickness values were not big enough to be significant between treatments in most cases. According to chemical fruit properties, the highest TSS values were obtained under Soil application of (10 ml potassium humate every two months) and significantly increased compared with the other treatments, also Soil application of (10 ml potassium humate every two months) gave the highest total sugar and significantly increased compared with the other treatments except the difference between Soil application of (10 ml potassium humate every two months) and Soil application of (5 ml potassium humate every month), was slightly not significant. A according to total carotenes, (control) gave the lowest values and significantly decreased compared with the other treatments Conclusively, the obtained results give basis to conclude that, soil applying seedling papaya plant with potassium humate had a positive effect on yield and fruit quality. The most beneficial treatment in this concern is applying with 10 ml potassium humate every two months started from beginning of March to end of August which gave a reasonable yield and high fruit weight and dimensions with high content of TSS and total sugar and could be considered as a recommended treatment under the conditions of this experiment.