A Strawberry IPM Systems Comparison Demonstration

A Strawberry IPM Systems Comparison Demonstration

Summary

Summary
The objective of this study was to develop integrated pest management (IPM) strategies for cultivated strawberries. Three different management systems are being compared: transition to organic, future IPM, and conventional IPM. In 2000, we focused on tarnished plant bug, the most serious insect pest of strawberry. Of four strawberry cultivars tested (‘Honeoye,’ ‘Earliglow,’ ‘Tribute,’ ‘Tristar’), Honeoye was the most productive and exhibited lowest incidence of damage by plant bugs. Plants in conventional plots were more productive and had lowest incidence of damage by plant bugs. Our results indicate excellent potential of using reflective mulch to increase yield and reduce damage by plant bugs.

Methods
Four strawberry cultivars, Earliglow, Honeoye and ‘Dayneutrals’ (sibling Tribute and Tristar), were planted in 1996, and parameters of yield (number and weight of fruits harvested per ha), as well as abundance of several pests (weeds, tarnished plant bugs, gray mould, slugs), were recorded between 1997 and 2000. For each cultivar, three management systems were investigated each year: Organic plots, where synthetic pesticides were never applied; future IPM plots, where the effectiveness of alternative pest control measures was tested; and conventional plots, where strawberries were cultivated as outlined in strawberry production guides. Results from 1999 in IPM plots suggested excellent potential of using reflective mulch to increase yield of strawberry plants and reduce incidence of damage by plant bugs. This approach was tested for a second year in 2000.

Results
Yields in 2000 were, on average, two times higher than in 1999, when extremely dry conditions negatively affected productivity of strawberry plants. However, yields in 2000 were still about only one-third of those obtained in 1998. Yields were higher in conventional plots, intermediate in IPM plots, and lower in organic plots. Honeoye was the most productive cultivar, followed by Earliglow and Dayneutrals. Reflective mulch enhanced yields of Honeoye and Earliglow by about 15 percent but did not impact yields of Dayneutrals.

In organic plots, weeds were extremely abundant in 2000 and interfered with the management of the strawberry plants. In the conventional and IPM plots, abundance of weeds greatly varied spatially. Of all weed species, quack grass (Agropyron repens) was the most difficult to control.

Wet conditions in 2000 contributed to high incidence of damage by slugs, with, on average, 10 percent of fruits being infested. The proportion of fruits damaged by slugs did not vary between cultivars or management systems. Incidence of gray mould was very low in 2000, with < 0.5 percent of fruits being infested. As for all other years except 1998, tarnished plant bug was the most serious pest of strawberry, with, on average, 20 percent of fruits being damaged. Incidence of damage was higher in organic plots than in conventional or IPM plots. Earliglow and Dayneutrals were more susceptible to plant bugs than Honeoye. The reflective mulch reduced the density of plant bug nymphs per flower cluster and also reduced the proportion of damaged fruits for Earliglow and Honeoye; results were not consistent for Dayneutrals. Impact
Our results indicate an excellent potential of using reflective mulch in commercial strawberry fields to simultaneously increase yield and reduce damage by tarnished plant bug, at least for some cultivars. Economic analyses evaluating costs and benefits of using reflective mulch, as well as studies investigating the mechanisms that underlie the impact of reflective mulch on yield and damage by tarnished plant bug, are still needed before reflective mulch can be implemented as a commercial strategy.

Events
A summary of this project was presented to berry growers in August 2000 as part of a field day tour of ongoing fruit research at NYSAES in Geneva, New York. Approximately 30 berry growers attended this two-hour meeting.

Reported November 2000

Collaborators: