IMPROVEMENT OF GROWTH AND PRODUCTIVITY OF MANGO TREES USING SOME GROWTH STIMULANTS UNDER NEW RECLAIMED SOIL CONDITIONS

Abstract

A study was carried out during three successive years (2018, 2019 and 2020) on fifteen years old mango trees (Mangifera indica L.) Fagri Kalan cv., budded on seedling rootstock planted at 4 x 4 m in sandy soil under drip irrigation system. The experiment was conducted at a private mango orchard in new reclamation land located at “Mahfouz Moghazi farm“, Abo Ghaleb Road, Giza Governorate, Egypt Alexandria Desert Road the 68 km Cairo, Egypt. The study involved two independent experiments. The first experiment: Involved of two levels of Potassium humate (KH.) (50 and 100 g/tree/year) and two levels of Magnetite (Mag.) (250 and 500 g/tree /year) and control treatment as soil application and three levels of Cobalt sulfate (Co) (0 – 15 – 30 ppm) as foliar spray. Potassium humate (KH.) and Magnetite (Mag.) were added once in the winter (Mid-January) around the trees in drilling under the drippers and were covered after each implementation in the three seasons. Regarding Cobalt sulfate (Co) treatments, selected trees were sprayed twice (the first at the end of February at the beginning of the appearance of new leaves and the second after month later) by aqueous solution of Cobalt sulfate (Co) until the point of runoff with the various Cobalt sulfate. The control was even sprayed with tap water until the point of runoff. This experiment had fifteen treatments in Split – plot design and three replicate for each treatment was represented by two trees. This investigation aimed to study the effect of Potassium humate (KH.) and Magnetite (Mag.) levels as soil application and Cobalt sulfate (Co) levels as foliar spray on the vegetative growth, yield, fruit quality, leaf mineral content and Cobalt content in