Effect of Black Polythene Mulch along with Irrigation on Pre-harvest Fruit Drop in Plum (Prunus salicina L) cv. Satluj Purple

The present investigation on “Effect of black polythene mulch along with irrigation on pre-harvest fruit drop in plum (Prunus salicina L.) cv. Satluj Purple” was carried out during 2004 and 2005 at Punjab Agricultural University, Ludhiana. The trees were irrigated at an interval of 3, 5 and 7 days starting from first week of April to the first week of May. Mulching with black polythene and transparent polythene was also done along with irrigation. Black polythene along with irrigation at 5 days interval was the most effective treatment to reduce the pre-harvest fruit drop. The fruit retention (20.74 and 19.84%), yield (14.33 and 13.55 kg/tree), fruit weight (38.52 and 39.15g), TSS (13.55 and 13.67%), TSS/acid ratio (13.29 and 13.27), nitrogen content (2.37 and 2.40%) and carbohydrate content in leaves (9.62 and 10.38%) were also the highest in this treatment. The next best treatment was black polythene mulching and irrigation at 3 days interval. Black polythene delayed fruit maturity by 1-2 days whereas transparent polythene advanced it.