RELATIONSHIP BETWEEN YIELD POTENTIAL AND PERCENTAGE YIELD DECLINE CAUSED BY THE ROOT-KNOT NEMATODE, Meloidogyne javanica FOR SOME SUGAR BEET VARIETIES SOWN IN WEST NUBARIYA REGION

Abstract

Four experiments were carried out in West Nubariya region ; two of them were field trials and the other two were outdoor pots trials throughout seasons of 2009/ 2010 and 2010/ 2011 that to evaluate a collection of M. javanica susceptible sugar beet varietiess for differing levels of yield decline (tolerance), their tolerance to parasitism by this nematode. If nematode tolerant (low yield decline) but susceptible (high nematode reproduction) sugar beet varieties can be identified, they could be grown rather than intolerant varieties to reduce yield loss. The yield potential and percentage yield loss to M. javanica were measured in 15 sugar beet varieties in