Effect of some Treatments on Vegetative Growth, Yield and Fruit Quality of Gold Nugget Mandarin Trees

Abstract

This investigation was conducted during two successive seasons (2019/2020; 2020/2021) on almost 12-year old identical Gold Nugget mandarintrees Citrus reticulata Blanco (Wilking mandarin x Kincy mandarin), grafted on Volkamer Lemon (Citrus volkameriana) (VOL) rootstock cultivated in a private orchard located in Al Qalyubia Governorate, Egypt. The trees were grown at a distance of 2 × 6 m in silt soil under the Immersion irrigation system. To study the effect of hand thinning, chemical thinning using NAA at 400ppm, Potassium nitrate (5gm/L),Spirulina platensis ( algae extract) (2cm/L) and Potassium sulfate (1.25g/L) +Zinc sulfate (2.5g/L) +Salicylic acid (0.11g/L) on vegetative growth, fruit quality and yield of Gold Nuggetmandarin trees. The experiment was designed as a randomized complete block design with five replications. Results illustrate that most of the experimental treatments significantly increased tree canopy volume both hand or chemical thinning was the highest value and Chemical thinning treatment significantly increased leaf area. Potassium nitrate foliar spray significantly increased shoot thickness, number of leaves/ shoot. Spirulina platensis treatment enhancing of the spring growth cycle, number of flowers, fruit-set, number of fruits/tree, tree yield efficiency as the number of fruit / M3 canopy and vitamin C. as for Potassium sulfate + zinc sulfate+ Salicylic acid treatment was superior with statistic differences for tree yield as kg/tree and kg/ M3, fruit physical properties (fruit weight, fruit size, Juice volume, Juice weight and fruit Pulp Weight).