Evaluation of Natural Biostimulants for Improving Flowering and Fruiting behaviour in Sweet Orange (Citrus sinensis (L.) Osbeck) var. Nucellar.

Abstract

The present investigation was conducted during the Ambe Bahar season of 2024–25 at the Sweet Orange Research Station, Badnapur, Tq. Badnapur, Dist. Jalna, Maharashtra, to evaluate the influence of natural biostimulants on flowering and fruiting behaviour of nucellar sweet orange (Citrus sinensis (L.) Osbeck). The experiment was laid out in a Randomized Block Design (RBD) comprising seven treatments replicated thrice. The treatments consisted of brassinolide @ 10, 15 and 20 ppm and yeast extract @ 1000, 1500 and 2000 ppm, along with an untreated control. The biostimulants were applied as foliar sprays at full bloom and again 30 days after full bloom. Observations were recorded on days required for flowering, number of flowers, days required from fruit set to fruit maturity, fruit set, fruit drop and fruit retention. Significant variation was observed among the treatments for flowering and fruiting parameters. Brassinolide @ 20 ppm (T3) recorded superior performance with respect to flowering and fruiting attributes, followed by brassinolide @ 15 ppm (T2), while yeast extract @ 2000 ppm (T6) performed comparatively better among the yeast extract treatments. The application of biostimulants favourably influenced fruit set and fruit retention while reducing fruit drop compared with the untreated control. Overall, foliar application of brassinolide @ 20 ppm and yeast extract @ 2000 ppm showed a positive influence on flowering and fruiting behaviour of nucellar sweet orange under the agro-climatic conditions of the Marathwada region.