THE EFFECT OF 3 IRRIGATION PRACTICES ON PHYTOPHTHORA CROWN AND ROOT-ROT OF APPLE-TREES UNDER FIELD CONDITIONS

The effect of microjet, drip, and two durations of sprinkler irrigatio n systems on phytophthora crown and root rot of apple trees was examin ed under field conditions. This eight year study indicates that crown and root rot caused by Phytophthora cactorum was most severe where you ng MM.106 rootstock trees were watered by microjet irrigation for 2.3 h each day. There was no difference in infection by P. cactorum when t rees were irrigated either by drip or sprinkler irrigation systems. Th e MM.106 apple rootstock trees watered by drip irrigation for 2.6 h ea ch day were least affected by phytophthora crown and root rot.