SOD COMPETITION IN PEACH PRODUCTION .2. ESTABLISHMENT BENEATH MATURE TREES

Planting sod beneath peach trees (Prunus persica) to control excessive vegetative growth was evaluated from 1987 to 1993 in three field stud ies. Peach trees were established and maintained in 2.5-m-wide vegetat ion-free strips for 3 years, and then sod was planted beneath the tree s and maintained for 5 to 7 years. Reducing the vegetation-free area b eneath established peach trees to a 30- or 60-cm-wide herbicide strip with three grass species (Festuca arundinacae, Festuca rubra, Poa triv ialis), reduced total pruning weight/tree in 5 of 16 study-years and w eight of canopy suckers in 6 of 7 study-years, while increasing light penetration into the canopy. Fruit yield was reduced by planting sod b eneath peach trees in 5 of 18 study-years; however, yield efficiency o f total fruit and large fruit (kg yield/cm(2) trunk area) were not red uced in one study and in only 1 year in the other two studies. Plantin g sod beneath peach trees increased available soil water content in al l years, and yield efficiency based on evapotranspiration (kg yield/cm soil water use plus precipitation) was the same or greater for trees with sod compared to the 2.5-m-wide herbicide strip. Planting sod bene ath peach trees has the potential to increase light penetration into t he canopy and may be appropriate for high-density peach production sys tems where small, efficient trees are needed.