Effect of Urea, Some Micronutrients and Two Growth Regulators Foliar Sprays on Vegetative Growth, Yield and Fruit Quality of Washington Navel Orange Trees
Year: 2011
Type: article
Abstract: This investigation was carried out during the two successive seasons 2008and 2009 on 25- years old Washington Navel orange trees grown in anorchard at El- Nobaria sector, El- Behera governorate to study the effect offoliar spraying with urea (0.5%), a mixture of Zn (0.4%), Mn (0.3%),Fe(o.5%) and Cu (0.3%) in sulphate salts form (23% Zn, 28% Mn, 19% Feand 30%Cu), respectively and two growth regulators, GA3 at 25 ppm andNAA at 10ppm. The trees spraying were two ones, the first before flowering(the third week of Feb.), and the second spraying applied four weeks afterfruit set to study the effect of these treatments on some vegetative growthcharacters and leaf mineral contents, Fruiting aspects (set, drop and Preharvest drop) percentage, yield per tree by number and weight, as well as theaverage weight of fruits and some fruit physical and chemical properties. Theobtained results showed that the treatments included spraying Ureaµnutrients (Zn, Mn, Fe and Cu), Urea and NAA achieved the highestvalues for average leaf area and shoot diameter. Regarding shoot length,Urea& micronutrients followed by GA3 had the highest values. Leaf analysisshowed that the highest values of leaf N content obtained by using Urea,Urea& micronutrients, GA3 and NAA, respectively. The lowered values ofleaf N content recorded when using micronutrients treatment followed bycontrol. All treatments were significantly effective in increasing fruit set andreducing fruit drop as compared with control. Application of NAA, Urea µnutrients and GA3 significantly increased fruit set percentage andreduced June and pre-harvest fruit drop, however NAA was more effective inreducing fruit drop than GA3. Spraying Washington Navel orange trees withUrea & micronutrients and NAA significantly increased the number of fruitper tree, yield per tree. However, the treatment included both of Urea µnutrients Followed by GA3 were the most effective in increasing fruitweight and pulp weight. Spraying of Urea and micronutrients slightly reducedjuice acidity and increased T.S.S., total sugars and ascorbic acid contents aswell as T.S.S./ acid ratio. In the contrary, either of GA3 or NAA caused thesame increase in ascorbic acid content in the juice.
Authors: Ensherah A. H. Tayeh, Eman A. A. El-Khalek, Zeinab A. I, M.Y. Hegab
Institutions: Agricultural Research Center, Fayoum University
Language: English
Subfield: Plant Science
Domain: Life Sciences
SDG: Zero hunger
Open Access status: diamond
Funders: Iowa State University, Zagazig University
OpenAlex ID: W3203488543