Survival and growth of peach trees and pest populations in orchard plots managed with experimental ground covers

Abstract

Field experiments conducted in North and South Carolina (USA) demonstrated that survival and growth of peach trees ( Prunus persica (L.) Batsch) as well as the severity of orchard pest populations (arthropods and nematodes) are profoundly affected by the plant species selected for orchard ground cover. Cover crops of brome ( Bromus mollis L.), hard fescue ( Festuca longifolia Thuill.) and rattail fescue ( Vulpia myuros (L.) C. Gmelin) caused high mortality in young peach trees. Bahia-grass ( Paspalum notatum var. sauri Parodi) stunted tree growth, and Korean lespedeza ( Lespedeza stipulacea Maxim.) supported unacceptably large populations of arthropod pests. Nimblewill ( Muhlenbergia schreberi J.F. Gmelin) emerged from these experiments as the most promising candidate for ground cover in commercial peach orchards. This short-statured perennial grass tolerated drought, grew well in partial shade, did not harbor two-spotted spider mites ( Tetranychus urticae Koch) or catfacing insects (Hemiptera), inhibited populations of ring nematodes ( Criconemella xenoplax (Raski) Luc and Raski), and survived winter weather with little injury. Nimblewill successfully crowded out most weed species, but it did not appear to be highly competitive with peach trees for water and nutrients even when growing directly under the tree canopy.