Kashif Razzaq

FOLIAR APPLICATION OF ZINC INFLUENCES THE LEAF MINERAL STATUS, VEGETATIVE AND REPRODUCTIVE GROWTH, YIELD AND FRUIT QUALITY OF ‘KINNOW’ MANDARIN

Deficiency of zinc (Zn) is widespread in many citrus orchards of Pakistan, consequently hampering fruit yield. Effects of foliar applications of zinc sulfate on tree nutrition, growth, productivity and fruit quality were studied on ‘Kinnow’ mandarin. Leaf nitrogen (N), calcium (Ca), and manganese (Mn) were highest for trees sprayed with 0.2% zinc sulfate, while phosphorus (P) and iron (Fe) were highest with 0.6% zinc sulfate and potassium (K) and Zn were highest with 0.8% Zn sulfate applications. Trees sprayed with 0.6% zinc sulfate exhibited highest increase in height, crown width and stem girth, fruit diameter, fruit weight, ascorbic acid contents, and total phenolics compared to all other treatments. Pre-harvest fruit drop was lowest and total number and weight of fruit per tree was highest at harvest with 0.4% zinc sulfate application. In conclusion, foliar application of zinc sulfate up to 0.6% improved tree mineral nutrients, growth, and productivity with better fruit quality in ‘Kinnow’ mandarin.

FOLIAR APPLICATION OF BORON INFLUENCES THE LEAF MINERAL STATUS, VEGETATIVE AND REPRODUCTIVE GROWTH, YIELD AND FRUIT QUALITY OF ‘KINNOW’ MANDARIN (CITRUS RETICULATA BLANCO.)

The effects of foliar application of boron (B) in the form of boric acid on vegetative and reproductive growth, yield and fruit quality of ‘Kinnow’ mandarin (Citrus reticulate Blanco.) were investigated. Kinnow mandarin was sprayed with different concentrations of boric acid viz. (0.1%, 0.2%, 0.3% and 0.4%) at fruit set stage. Leaf nitrogen (N), phosphorus (P), potassium (K), B, and zinc (Zn) along with flush length, tree height, tree spread and tree trunk diameter increased, while leaf length and leaf age showed non-significant results after foliar B application. Yield of the ‘Kinnow’ mandarin was significantly affected by foliar application of B and a significant increase in fruit weight at harvest was also observed. Soluble solid concentration (SSC): titratable acidity (TA) ratio, ascorbic acid, total sugars, total phenolic content (TPC) and total antioxidants significantly affected, while pH of juice, SSC, TA, reducing sugars and non-reducing sugars showed non- significant results.

Locality and Orchard Management Influence Fruit Quality of Low Temperature Stored Mangoes

To investigate the impact of locality and orchard management on fruit quality, ‘Samar Bahisht Chaunsa’ fruit harvested from two commercial orchards were stored at 11°C and 80%–85% RH for 4 weeks. Physical fruit quality, fruit rot, and disorders were not influenced by locality. However, at the ripe stage, fruit harvested from orchard-1 exhibited reduced respiration rate (5.84 mmole kg−1 h−1), higher peel color (3.35), pulp color (7.33), aroma (6.66), taste (7.33), flavor (7.33), SSC:TA ratio (139.1), reducing (4.06%), non-reducing (10.38%), and total sugar (14.99%) contents. In conclusion, quality of mango fruit following cold storage is significantly influenced by locality and orchard management.