Preplanting Bahia Grass or Wheat Compared for Controlling Mesocriconema xenoplax and Short Life in a Young Peach Orchard.

The effects of four preplant ground cover systems as alternatives to chemical control of Mesocriconema xenoplax were investigated from 1991 to 1998. Ground cover establishment was initiated in 1991 in an orchard known to be infested with M. xenoplax and having a history of peach tree short life (PTSL). Ground cover systems included (i) Pensacola bahia grass, (ii) Tifton 9 bahia grass, (iii) winter wheat (Triticum aestivum 'Stacy'), and (iv) naturally occurring weeds that were maintained over the entire orchard floor. Ground cover evaluation was initiated in 1994, when herbicide was applied to the ground cover plots and half the weed plots were fumigated with methyl bromide. Peach trees were planted into all plots in 1995. Fumigation effect on M. xenoplax population density collapsed 25 months after application. Young peach trees grew faster for the first 13 months in killed Pensacola bahia grass sod and fumigated soil, intermediate in Tifton 9 bahia grass and wheat plots, and slowest in unfumigated weed plots. By the end of the experiment, tree growth was greatest in Pensacola bahia grass killed sod and least in the unfumigated weed plots. Preplant wheat was as effective as fallow for 3 years plus a preplant methyl bromide fumigation in increasing tree survival from PTSL.