The effect of mulching and pruning on the vegetative growth and yield of the half-high blueberry

The aim of this research was to determine the influence of different mulches (peat, sawdust, plastic) and different pruning methods (moderate, severe) on the growth and yield of the half-high blueberry (Vaccinium corymbosum x Vaccinium angustifolium) ʹNorthblueʹ. The effect of a mixture of soil and peat was studied in the case of peat alone and peat and plastic mulches. The experiment was established in 1996 in South Estonia and in 2002 blueberry bushes were pruned. The results of the study showed that mulching significantly influenced nutrient content and pH. Depending on the mulch, the soil pH ranged from 4.5 to 6.1 - there was more acid soil in the peat treatment. The use of mulches had some influence on productivity of pruned half-high blueberry plants. When peat was applied a canopy of pruned plants recovered very well after one year. Within three years the plants had the same yield as un-pruned variants but four years after pruning the yield was highest in the variants where peat was applied. Plastic mulch is not suitable for blueberries: it decreases the yield and four years after pruning the normal plant growth in our study had not recovered. Severe pruning is more suitable for half-high blueberry fruiting plants in northern climate conditions.