EVALUATION OF PINEAPPLE, ANANAS-COMOSUS, FOR HOST-PLANT RESISTANCE AND TOLERANCE TO ROTYLENCHULUS-RENIFORMIS AND MELOIDOGYNE-JAVANICA

Eighteen cultigens of pineapple, Ananas comosus were evaluated for res istance and tolerance to Rotylenchulus reniformis and Meloidogyne java nica. Reproductive factors (Pf/Pi) were compared between cultigens, pe rcentage crown growth was contrasted between inoculated and uninoculat ed pineapples, and nematodes supported per g of dry root were calculat ed. All cultigens were susceptible to both species of nematodes. The c ultigens were more susceptible to M. javanica than to R. reniformis in fection. Lot 520 and A. ananassoides, previously reported to be immune to nematode infection, both supported high levels of nematode reprodu ction. The Cayenne clones of A. comosus were less tolerant to M. javan ica and more tolerant to R. reniformis infection than other cultigen g roups. The tolerance found in Cayenne clones may be the result of indi rect selection in the field, yet it is not sufficient to prevent crop loss from nematode infection.