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 | ||
| Journal of Plant Production | ||
| Article 9, Volume 3, Issue 8, August 2012, Pages 2361-2374 PDF (441.28 K) | ||
| Document Type: Original Article | ||
| DOI: 10.21608/jpp.2012.84984 | ||
| Authors | ||
| I. M. A. Gohar; K. M. Agami; M. S. M. Aly | ||
| Sugar Crops Res. Inst., Agric. Res. Center, 12619, Giza, Egypt. | ||
| 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 2009/ 2010 and 2010/ 2011 by comparing yields in Dazomet 98% (Methyl Isothiocyanate) – fumigated and nonfumigated plots. The percentage yield decline caused by M. javanica differed among sugar beet varieties in 2009/ 2010 and 2010/ 2011. Yield decline ranged from 32.2 to 46.2 % in 2009/ 2010 and from 26.3 to 34.5 % in 2010/ 2011. Though significant levels of tolerance were measured in this study, 2 seasons of data on percentage yield decline show that tolerance is not consistently related to specific varieties in the absence of nematode resistance: susceptible varieties did not consistently express tolerance, but moderately resistant varieties did. Thus, it appears unlikely that sugar beet variety selection for tolerance to M. javanica can be utilized to minimize yield decline. Regression analysis based on the two seasons of field data revealed a relationship in which percentage yield decline caused by M. javanica increased linearly as yield potential increased. The moderately resistant sugar beet varieties, Laser, Romano and Marathon suffered the lowest percentage yield decline and supported the least reproduction in the study so they can be used in the contaminated fields with root-knot nematode through an integrated control measures to maintain good production for sugar beet in such area. Because the absolute and percentage losses to nematodes increase as yield potential increases, nematode management becomes increasingly important and beneficial in sugar beet. | ||
| Keywords | ||
| varieties; Potential yield; Percentage decline; root yield; sugar yield; root-knot; Meloidogyne javanica; relationship; sugar beet; Regression analysis; Fumigation; Dazomet 98%; eggmass; galls; Nubariya; tolerance | ||
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