Impact of mineral nutrients on powdery mildew and quality attributes in umran ber (Ziziphus mauritiana)

Abstract

An experiment was conducted at the Fruit Research Farm of Punjab Agricultural University, Ludhiana, Punjab during 2019–20 to study the impact of mineral nutrients on fruit drop, powdery mildew and quality attributes of ber (Ziziphus mauritiana Lam.) cv. Umran. A 15 year’s old ber plants were sprayed with nutrients like calcium nitrate @0.25 and 0.50%; potassium sulphate @0.25 and 0.50%; boric acid @0.40 and 0.60% and liquid sulphur @0.25 and 0.50% along with control (water spray) during mid-November, mid-December and mid-January (2019–20). Fruit drop and powdery mildew incidence was recorded periodically from November-March. Ber fruits were analysed for physical and bio-chemical parameters after harvesting. Among all the foliar applications, potassium sulphate @0.50% resulted in minimum fruit drop (65.52%). Maximum fruit length (4.86 cm), fruit diameter (3.06 cm), pulp content (93.96%) and fruit colour values (59.50, -4.0 and 33.46) was also recorded in potassium sulphate applied @0.50%. Maximum TSS (15.63 0B), TSS/acid ratio (120.23), ascorbic acid content (110.25 mg/100 g), total sugars (12.70%), reducing sugars (5.75%), non-reducing sugars (6.60%) and minimum titrable acidity (0.130%) was recorded with boric acid @0.60% which was statistically at par with potassium sulphate @0.50%. However, minimum incidence of powdery mildew was observed in liquid sulphur (0.50%) followed by potassium sulphate (0.50%). From the present studies, it is concluded that 3 foliar applications of potassium sulphate @0.50% resulted in improved quality attributes, reduction in fruit drop as well as reduced incidence of powdery mildew in ber cv. Umran.