Promising Impacts of Humic Acid and Some Organic Fertilizers on Yield, Fruit Quality and Leaf Mineral Content of Wonderful Pomegranate (Punica granatum L.) Trees

Abstract

HE AIMS of this research were to minimizing mineral nitrogen fertilizers and evaluate the efficiency of some organic fertilizers individually or combined with humic acid on yield, fruit quality and leaf mineral content of “Wonderful” pomegranate trees. This research was carried out through three successive seasons (2015, 2016 and 2017) in Hegazi private orchard located at 57 kilometer from Cairo on the desert road to Alexandria, Egypt on eight years old pomegranate trees “Wonderful” cv. The experiment consists of two levels of humic acid (0 and 50 g/tree/season) and five nitrogen fertilizers form [chicken manure, compost, cattle manure, mineral nitrogen as experiment control 40 kg actual N/fed and mineral nitrogen as orchard control 80kg actual N/fed] .The experiment was  designed in factorial experiment in a randomized complete block design. All organic nitrogen sources applied at a rate of 40kg actual N/fed. It could be concluded that, humic acid addition affected lack significant on yield, fruit physical and chemical properties and leaf nutrient content.Generally chicken manure and compost gave the highest values of most characters followed closely by two mineral treatments. When compared between two mineral N treatments the data revealed that 40kg N/fed /year was sufficient to give the highest values of most studied parameters and was equaled by 80kg N/fed /year. Regarding the combination between humic acid and nitrogen fertilizers the data showed that chicken manure and compost without addition of humic acid gave the highest values of yield and fruit characters followed closely by two mineral treatments Thus it could be safely recommended by fertilizing with (40kg N/fed /year) instead of (80kg N/fed /year) on the other hand, fertilizing by chicken manure or compost (40 g N/tree/year) with or without humic addition (50 g /tree/year)   improved yield ,fruit physical & chemical properties and reduce environmental pollution.