Interference Between Apple (Malus domestica) Seedlings and Four Ground Cover Species Under Greenhouse Conditions

Abstract

Seedlings from golden delicious apples (Malus domesticaBorkh. ‘Smoothee’) were grown in the greenhouse with orchardgrass (Dactylis glomerataL. # DACGL), Kentucky bluegrass (Poa pratensisL. # POAPR), red sorrel (Rumex acetosellaL. # RUMAA), and Korean lespedeza (Lespedeza stipulaceaL. # LESSL) at four densities and four fertility levels. Orchardgrass and red sorrel inhibited tree growth more than Kentucky bluegrass on a per plant basis. Korean lespedeza inhibition of apple growth was associated with the amount of root nodulation on the Korean lespedeza. Apple shoot dry weight over all fertility levels, ground cover species, and densities was predicted by a regression model based on increase with fertility and decrease with ground cover dry weight. These results indicate that the competitiveness between equal number of ground cover species is due to differences in biomass production. Addition of nitrogen to the system increased nitrogen levels in apples but did not completely overcome apple growth inhibition.