Effect of Living Mulch on Chlorophyll Index, Leaf Moisture Content and Leaf Area of Sweet Cherry (Prunus avium L.)

The experiment was conducted in an organic orchard of sweet cherry (Prunus avium L.) cultivars “Valery Chkalov” and “Dilemma”/Prunus mahaleb planted in 2011 at 7 m × 5 m. The work was conducted from 2017 to 2018 in the southern steppe of Ukraine (Melitopol district, Zaporozhye region). Standard mechanical cultivation (one discing at a 15 cm depth followed by harrowing) (MC) was compared with living mulch—spontaneous vegetation cover (LM). The natural vegetation of grasses was mowed four times during the growing season, and the clippings were left on the ground for decomposition. Any other management was identical in each treatment. Synthetic fertilizers and chemical plant protection products were not used. Our studies showed that LM contributed to an increase in the chlorophyll index of cherry leafs of the cultivar “Dilemma” in 2017 and both studied cultivars in the conditions of severe drought in 2018. For cultivar “Valery Chkalov,” there was no significant difference between the MC and LM in the total moisture content, relative turgrescence, and humidity deficit. The cultivar “Dilemma” was characterized by a significantly lower total moisture content in the leaves in 2017–2018, but in 2018 the water-retaining ability of the leaves in LM was greater compared to MC. The leaf area was significantly less in LM for both studied cultivars in 2017. In 2018, significant difference in leaf area wasn’t noted.