Reaction of Ten Cultivars of Watermelon (Citrullus lanatus) to a Puerto Rican population of Meloidogyne incognita


  • A. E. Montalvo
  • J. Esnard


Ten cultivars of watermelon were evaluated for their response to a Puerto Rican population of Meloidogyne incognita under greenhouse conditions in a 2-year study (1989 and 1990). Ten-day-old seedlings were planted in steam-sterilized soil in 15-cm-d plastic pots. The nematode inoculum consisted of 10,000 eggs and (or) second-stage juveniles (J2)/plant. The cultivars were Sugar Baby, Charleston Gray, Seedless, Prince Charles, Charleston 76, Jubilee, Florida Giant, Royal Charleston, Royal Sweet, and Royal Jubilee, with tomato cv. Rutgers included as a susceptible check. A completely randomized design with 10 replications was used. Fifty-five days after soil infestation, root-gall indices, numbers of nematode eggs per root system, and J2 per 250 cm³ of soil were recorded. All cultivars were susceptible. Sugar Baby had the lowest root-gall index, egg and J2 numbers, and a reproductive factor (Rf) of 2.89. Rf differed (P = 0.05) among cultivars and ranged up to 7.36. Sugar Baby, Seedless, and Florida Giant showed the lowest susceptibility to M. incognita, whereas Charleston 76 and Charleston Gray were the most susceptible. Key words: Citrullus lanatus, fruits, host status, Meloidogyne incognita, nematode, Puerto Rico, root-knot nematode, susceptibility, vegetables, watermelon.