Effect of time and inoculum density on the reproductive fitness of Pratylenchus coffeae and Radopholus similis populations on carrot disks

The reproductive fitness of three Pratylenchus coffeae populations (Hondura s, Ghana and Vietnam) and three Radopholus similis populations (Costa Rica, Cuba and Ghana) on carrot disks was studied as a function of time and inoc ulum densities. In the first study, the reproductive fitness of the isolate s was followed during 11 weeks for P. coffeae and during 7 weeks for R. sim ilis. All the populations increased with time. No distinction could be foun d in the maximum growth rate of the Pratylenchus populations. The R. simili s population from Cuba had a higher maximum growth rate than those from Gha na and Costs Rica. All the Radopholus populations showed a faster multiplic ation than P. coffeae. In the second study, the influence of the inoculum d ensity on the reproductive fitness was determined for the six populations. The differences in reproduction ratios confirmed the results of the first s tudy.