Re-establishment and resurgence of plant-parasitic nematodes in fumigated pineapple fields at different elevations and irrigation regimes in Hawaii
The relationships between Rotylenchulus reniformis population densities and pineapple growth and yield were studied in a small-plot field experiment. Increasing rates of handgun-injected 1,3-dichloropropene (1,3-D) preplant fumigant from 0 to 337 liters/ha resulted in greater nematode control, faster plant growth, and larger pineapple fruits. Rotylenchulus reniformis population densities at 2, 4, 6, and 8 months postplant were correlated with plant size and yield. The shorter the time period following planting in which R. reniformis densities remained low, the greater was the average loss in yield. A measurement of nematode-days as the area under the R. reniformis population growth curve indicated that this parameter was also correlated with plant growth and yield. Both population density and length of the control period affected the amount of crop damage.