Effects of hail nets on orchard light microclimate, apple tree growth, fruiting and fruit quality.

Abstract

Hail nets are necessary protection in some fruit growing regions. Several trials showed that the net color may influence tree growth and fruiting. The influence of hail nets on orchard light microclimate, growth, flowering and fruiting of apple trees was ex-amined in field experiment in the years 2004–2010. ‘Šampion’ and ‘Rubinstar’ apple trees grafted on M.9, were planted in spring 2004. After planting, half of the experimental plot was covered with three kinds of hail nets: white, gray and black. The other half was kept uncovered as the control. Tree growth, fruit bud formation, fruiting and fruit quality were recorded. Solar radiation was measured above and below the nets and within tree canopy. Black and gray nets stimulated tree growth and yield of ‘Šampion’ tree, but had no posi-tive influence on ‘Rubinstar’ trees. Covering the trees with gray and black nets caused poor red blush development and reduced soluble solids content in apples of both cultivars. Fruit firmness was unaffected by netting.