Effect of growth regulators and micronutrients spray on physico-chemical properties of litchi (Litchi chinensis)

The experiment was conducted to find out the effect of plant growth regulator and micronutrients on physico-chemical properties of litchi (Litchi chinensis Sonn.) at the Regional Horticulture Research and Training Station, Dhaulakuan, Dr. Yashwant Singh Parmar University of Horticulture and Forestry, Nauni, Solan, dring 2014–15. The experiment consisted of 19 treatments with three replications laid out in Randomized Block Design. The growth regulators and micronutrients applied were GA₃ (Tj = 25 ppm, T₂ = 50 ppm, T₃ = 75 ppm), CPPU (T₄ = 5 ppm, T₅ = 10 ppm, T₆ = 15 ppm), ZnSO₄ (T₇ = 0.25%, T₈ = 0.50%, T₉ = 0.75%), boric acid (T₁₀ = 0.25%, T₁₁ = 0.50%, T₁₂ = 0.75%), GA₃ + CPPU (T₁₃ = 25+5 ppm, T₁₄ = 50+5 ppm, T₁₅ = 75+5 ppm), Boric acid + ZnSO₄ (T₁₆ = 0.25+0.50%, T₁₇ = 0.50+0.50%, T₁₈ = 0.75+0.50%) and T₁₉ the control. The growth regulators and micronutrients significantly improved all physico-chemical properties (fruit size, fruit weight, fruit volume, fruit pulp content, pulp percentage, minimum peel percentage, pulp: peel ratio, pulp: stone ratio, peel colour and juice percentage) of fruit. Of which T₂ (GA₃ 50 ppm) increased fruit size, fruit weight and volumes, Minimum peel percentage, pulp: peel ratio and peel colour were highly affected by boric acid alone or in combination with ZnSO₄.