Effect of cobalt and silver ions and naphthaleneacetic acid on fruit retention in mango (Mangifera indica L.)

Abstract

The effect of aqueous spray of cobalt nitrate, silver nitrate or 1-naphthaleneacetic acid (NAA) on fruit retention in mango (Mangifera indica L.) was investigated at Tando Jam, Pakistan. The chemicals were applied to immature fruits at pea size (5-6 mm) and again 2 weeks later when the fruitlets had developed to marble size (10-15 mm). Three cultivars, Sindhri, Langra (3 seasons) and Dasehari (4 seasons), were tested and it was observed that all concentrations of the chemicals significantly (P<0.05) increased fruit retention. In Sindhri, cobalt nitrate, silver nitrate and NAA treatments increased yields by 106-165%, 89-146% and 94-115%, respectively, and in Langra by 100-135%, 98-138% and 95-118%. Whole tree sprays of cv. Dasehari with Co(NO3)2 at 100 mg/L, AgNO3 at 100 mg/L, and NAA at 20 mg/L yielded 129%, 66% and 54% more fruit than the control.