THE PERFORMANCE OF DIFFERENT ROOTSTOCKS IN PEACH REPLANTING(¹)

After eradication of a ten-year old peach orchard, the plot was divided in two parcels; the former was fumigated with methylbromide (700 kg/ha) and the latter was kept as control. Subsequently, "Redhaven" virus-free scion, grafted on seedling and peach rootstock selections (GF 305, Harrow Blood, PSA III, PSA V, PS B2), on Prune clones (S. Julian GF 655/2, INRA GF 43, Damas 1869) and hybrid (Almond x Peach) GF 677, were planted in both parcels, according to a randomized complete block.

Observations made during the five years demonstrated a different influence of fumigation on yield and vegetative growth development of the trees in relation to the rootstocks used.

The trees grafted on commercial seedling - very quite intolerant to replanting - benefited more by fumigation, although they had a lower vegetative growth than the other plants grafted on hybrid GF 677. This hybrid rootstock, which showed a high tolerance to replanting, induced a higher growth and yield per plant. The prune clone rootstocks had a positive response to replanting but induced lower yield than GF 677.

Nematodes population in the soil and on the roots was determined every year; fumigation caused a nematode depletion, but, in the following years, the reinfestation rate rose slightly, reaching the same population density found in non-fumigated soil.