Usefulness of Living Mulch in Rows in a Dwarf Pear, <i>Pyrus communis</i> L., Orchard

The key problem in the cultivation of densely planted dwarf orchards is the removal of weeds—trees’ competitors for habitat resources. There is an urgent need to look for ecological methods of weed control as an alternative to herbicides that are harmful to the environment. The use of living mulch (LM) in tree rows additionally improves soil quality but usually weakens tree growth and may reduce yield. The aim of this 11-year experiment was to assess the impact of the use of two different LMs in rows (Trifolium repens—Tr and Agrostis capillaris—Ac) on the growth, yield, and fruit quality of three pear cultivars on Quince S1 rootstock compared to herbicide fallow. The presence of LM did not significantly affect tree growth. There was no significant effect of either mulch on the cumulative yield. However, for the first 4–6 years, the yield was clearly lower than in the control, which changed in the later years of the experiment. When LMs were used, pear trees showed a significantly lower tendency to alternate fruiting. The average fruit weight was significantly lower in Tr, but the other parameters of external fruit quality did not differ significantly. Furthermore, a smaller share of ultra-small fruit was found with LM compared to the control. The LM did not significantly affect such parameters as the content of soluble solids, vitamin C, Ca, Mg, and P. The use of Ac in dwarf pear orchards with sowing in tree rows is recommended in the 2nd or 3rd year after planting at the earliest