Effect of rootstock on leaf nutrient concentration and productive value of ‘Mutsu’ apple trees

Various apple rootstock genotypes may affect fruit tree nutrition. The plant nutritional status has a significant impact on the growth and yield of apple trees. The experiment was conducted in 2007-2015, at the Experimental Station in Samotwór near Wrocław, south-western Poland. During the nine-year study, the impact of different rootstocks (M.26, B.7-35, B.396, ARM 18, M.9, B.491, P 16, B.146 and PB-4) on the nutritional status, growth and yield of ‘Mutsu’ apple trees was investigated. Samples of leaves were collected for the analysis of macro– and microelements in the second half of July in 2009-2011. The study showed an ambiguous influence of rootstock on leaf macro-and microelement composition. This effect differed depending on a year. The results of the average content of the analysed components showed no effect of a rootstock on P, Mg, Mn and Zn concentrations in the leaves. M.26 rootstock resulted in the lower copper level (a significant difference when compared to B.7-35, M.9, B.146 and B.491). Trees on B.491, M.26 and B.7-35 rootstocks were worse stocked in boron than apple trees on ARM-18, M.9 and B.396. In comparison with stronger growing rootstocks, trees on PB-4 were characterised by the low content of calcium. Trees on B.7-35 rootstock grew the most, while the ones grafted on PB-4 showed the weakest growth and had the smallest fruits. The highest number of root suckers was observed for trees grafted on B.7-35 and ARM 18. Until the ninth year after planting, the largest yield was obtained from trees on B.396. In the present study, this rootstock proved to be the best for the ‘Mutsu’ cultiva