Yield and quality of apple (Malus domestica) cv Red Delicious as affected by bio-inoculants

Abstract

Four different fertilizer regimes, viz. F₁ (75 % NPK as chemical fertilizer + 25% NPK as organic manure), F₂ (50% NPK as chemical fertilizer + 25% NPK as organic manure), F₃ (25% NPK as chemical fertilizer + 75% NPK as organic manure) and F₄ (25% NPK as chemical fertilizer + 50% NPK as organic manure) were tested on apple (Malus domestica Borkh.) along with two phosphate solublizing inoculants, viz. PSB (P₁ ) and VAM (P₂ ) and two nitrogen fixing inoculants, viz. Azotobacter (N₁ ) and Azospirillum (N₂ ). Maximum fruit yield (77.67 kg/tree) and fruit set (49.63%) were recorded in treatment F₁ P₂ N₁ whereas, highest fruit retention (29.87%) was recorded in treatment F₁ P₂ N₁ . Maximum TSS (14.27%) and total sugars (4.30%) were observed in treatment F₃ P₂ N₁ . Among all treatments, treatment F₃ P₂ N₁ showed highest increase in physical characteristics of fruits, viz. fruit weight (180.03g), fruit length (7.17 cm), fruit breadth (7.14 cm) and fruit volume (193.21 cm³). Amongst nitrogen fixing inoculants, Azotobacter was more effective and amongst phosphate solublizing inoculants, VAM proved to be more effective. With respect to different fertilizer regimes used, F₁ (75% NPK as chemical fertilizer + 25% NPK as organic manure) was more effective in enhancing yield, quality and nutrient use efficiency. However, among different treatment combinations, F₁ P₂ N₁ was most effective and desirable treatment combination for higher yield and better quality of fruit.