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ARS Home » Southeast Area » Tifton, Georgia » Crop Protection and Management Research » Research » Publications at this Location » Publication #188891
Title: WATERMELON YIELD IS SUPPRESSED BY MELOIDOGYNE INCOGNITA

Author
item Davis, Richard

Submitted to: Society of Nematology Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2005
Publication Date: 9/1/2005
Citation: Davis, R.F. 2005. Watermelon yield is suppressed by Meloidogyne incognita [abstract]. Journal of Nematology. 37:365.

Interpretive Summary:

Technical Abstract: Watermelon (Citrullus lanatus) is an excellent host for the southern root-knot nematode (Meloidogyne incognita), which is often found in fields of watermelon in the southeastern US. Surprisingly, the effect of M. incognita on yield of watermelon has not been documented previously. The effect of M. incognita race 1 on the number of melons produced, the weight of individual melons, and the total weight of all melons was evaluated in a field trial with 24 replications of methyl bromide-fumigated and non-fumigated plots. Fumigated plots had very low nematode pressure during the study, whereas non-fumigated plots had high nematode pressure. Mature fruit were collected during two harvests, with the second harvest 8 days after the first. Thirty percent fewer fruit were collected from non-fumigated plots than from fumigated plots during the first harvest. The total weight of fruit also was reduced by 30%, but the mean weight per fruit was not affected. The number and weight of fruit from the second harvest did not differ between fumigated and non-fumigated plots. When number and weight of fruit were combined for the two harvests, the number of fruit collected was 19% lower and the weight of fruit was 23% lower in non-fumigated plots than in fumigated plots, but the mean weight per fruit was not affected. Following the second harvest, the amount of root galling on all plants was assessed on a 0-10 scale based on percentage of the root system galled, and the mean ratings were 1.0 for fumigated plots and 5.3 for non-fumigated plots. Meloidogyne incognita reduced the yield of watermelon by reducing the number of fruit produced and delaying the maturity of those fruit, but the weight of individual fruits was not reduced. This documents that M. incognita is a significant pathogen of watermelon, and that nematode management is necessary.