Reaction of Renovated Blueberry (Vaccinium corymbosum L.) Plants on Nitrophoska® 12-12-17 and Wigor S Fertilizers

The trial was performed under field conditions on renovated blueberry plants of Vaccinium corymbosum L. 'Bluecrop.' In the spring of 2002, after twenty years of growth, old plants were cut off at soil surface level and then the experimental plots were chosen. Dimensions of the single plots were 4 m x 2 m. There were four plants in each plot. In advance of the first fertilizer applications in 2003, the length of new shoots was measured. Each year from 2003 to 2006, Nitrophoska (R) 12-12-17 was applied individually at 500 or 650 kg.ha(-1) or simultaneously with sulfur fertilizer Wigor S 90 (90% sulfur) at 100 or 150 kg.ha(-1) doses. Plants in non-treated plots served as controls. There were four replications of each treatment. An impact of combined mineral fertilization on the total yield as well as weight of 100 berries was observed. The most effective treatment was 650 kg.ha(-1) of Nitrophoska (R) 12-12-17 and 100 kg.ha(-1) Wigor S 90 when applied simultaneously. Soil and index leaves were sampled in the spring of 2003 and analyzed for mineral content.