EFFECT OF FOLIAR APPLICATIONS OF WUXAL FERTILIZERS ON STRAWBERRY YIELD AND FRUIT QUALITY

The aim of the study was to examine response of strawberries (Fragaria x ananassa Duch.) to foliar applications of Wuxal fertilizers. The experiment was carried out in 2003 at the Research Institute of Pomology and Floriculture in Skierniewice, Poland, on ‘Senga Sengana’ strawberries planted in a row system at 80 x 25 cm on a sandy loam soil with pH 6.1 and low organic matter (1.2%). Strawberries were foliar-supplied according to the following scheme: Wuxal Combi (30% N, 22.5% K₂O, 6% MgO, and microelements) applied at the vegetation commencement at 3 L ha-1, Wuxal Folibor (11% B) applied 7 d before flowering at 2 L ha^-1, and Wuxal Aminocal (15% CaO, 0.5% Mn, 0.5% Zn) used 3 d before flowering, at full bloom, and 2, 3 and 4 weeks after petal fall at 4 L ha^-1 spray^-1. To reduce the incidence of grey mold (Botrytis cinerea), strawberries were also sprayed during flowering with fungicide Euparen M at 1.5 (standard) or 1.1 kg ha^-1 (reduced rate). Plants untreated with Wuxal fertilizers but sprayed with Euparen M at 1.5 kg ha-1 served as a control. The results showed that foliar sprays of Wuxal fertilizers did not affect strawberry yield, weight of 100 berries, and fruit soluble solids. However, fruit sprayed with Wuxal fertilizers had increased Ca concentrations, were firmer and less sensitive to B. cinerea than those of the control plots. There were no differences in the incidence of B. cinerea between fruit sprayed with Euparen M at a standard rate and those treated at reduced one. It is concluded that sprays of Ca-containing Wuxal Aminocal can be recommended in strawberry culture, particularly in integrated fruit production, to improve fruit shelf life.