Abstract

The impacts of Pineapple mealybug wilt-associated virus-1 (PMWaV-1) and reduced irrigation on pineapple fruit yield in plant and ratoon crops were evaluated in a field experiment in Hawaii. In the plant crop, PMWaV-1 infection and reduced irrigation had no significant effects on fruit weight. In the ratoon crop, plants infected with PMWaV-1 produced smaller fruit than disease-free plants and plants that received reduced irrigation also produced smaller fruit than plants that received regular irrigation. Additive effects of PMWaV-1 infection and reduced irrigation were detected; plots of infected plants that received reduced irrigation produced the fewest fruit. Frequency distributions for fruit size in the ratoon cycle showed shifts to smaller sized fruit classes when PMWaV-1 or reduced irrigation were present. Estimated yield from combined plant and ratoon crops for infected plants was 6.7% less than disease-free plants when plants received regular irrigation. Reduced irrigation correlated with a 4.2% reduction in estimated yield of disease-free plants, and both infection and irrigation reduction together reduced yield 13.4%. These results show that PMWaV-1 and reduced irrigation can have a negative and additive impact on pineapple fruit production in the first ratoon.