EFFECT OF FOLIAR APPLICATION OF ZINC AND BORON ON YIELD AND FRUIT QUALITY OF GUAVA (Psidium guajava L.)

Field studies were conducted in Uttar Pradesh, India, in 2011-12, to evaluate the effect of zinc (Zn) and boron (B) fertilizers on the yield and fruit quality of guava. The treatments comprised control (tap water; T0), 0.5% boric Acid (T1), 0.6% boric acid (T2), 0.5% zinc sulfate (T3), 0.5% zinc sulfate + 0.5% boric acid (T4), 0.5% zinc sulfate + 0.6% boric acid (T5), 0.6% zinc sulfate (T6), 0.6% zinc sulfate + 0.5% boric acid (T7) and 0.6% zinc sulfate + 0.6% boric acid (T8). Data were recorded on fruit weight, fruit diameter, fruit yield, sugar content, total soluble solids (TSS), titratable acidity and ascorbic acid content. It was shown that that the combined foliar application of zinc sulfate (0.6%) and boric acid (0.5%) before and after fruit set resulted in higher yield, fruit weight, radial diameter, polar diameter, specific gravity, TSS, acidity, ascorbic acid, total sugar, non-reducing sugar and sugar-acid ratio.