| Florida potato (Solanum tuberosum) production has a great impact in the winter-spring potato market in the United States. Among the most important plant-parasitic nematodes affecting potato quality and yield in northeast Florida are Paratrichodorus minor and Belonolaimus longicaudatus. Yield losses are caused by B. longicaudatus, whereas P. minor is important as a vector of the tobacco rattle virus (TRV), resulting in the disease known as corky ringspot (CRS). The resurgence of P. minor after soil fumigation was investigated. Resurgence of P. minor populations after soil fumigation was not associated with B. longicaudatus numbers. Relative abundance of B. longicaudatus and P. minor population densities in soil at 0-20 and 20-40 cm deep was determined. Numbers of B. longicaudatus and P. minor increased on summer cover crops of sorghum-sudangrass, but the increases varied with season.A sample size of 20 potato tubers was found to be adequate for estimating infection levels of CRS in tubers. Accuracy and precision of estimates of incidence and severity were dependent on the true mean incidence and severity of CRS-affected potato tubers in plots. There were significant associations between P. minor numbers and incidence or severity of CRS-affected potato tubers in plots.Nematode-transmitted TRV was detected in bait plants by enzyme-linked immunosorbent assay. The virus also was detected by reverse transcription from a segment of the RNA-1 followed by cDNA amplification by polymerase chain reaction. The 463-bp fragment was cloned, sequenced, and compared to sequences from a genebank database. A non-radioactive biotin-labeled probe was developed to detect TRV by tuber-tissue blotting. |
