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- Author or Editor: Jacques Brodeur x
- HortScience x
In recent years, the tomato russet mite (TRM) [Aculops lycopersici (Acarina: Eriophyidae)] has become one of the more important pests of greenhouse tomatoes in northeastern North America. As a first step toward developing a biological control strategy for the TRM, our objective has been to test the potential of already commercialized mite predators. In laboratory experiments, voracity of Chrysopa carnea (Neuroptera: Chrysopidae), Phytoseiulus persimilis (Acarina: Phytoseiidae), and Amblyseius cucumeris (Acarina: Phytoseiidae) was determined for egg, immature, and adult stages of the TRM. The first two predator species did not prey on TRM, whereas A. cucumeris fed on each of the life stages of the eriophyid mite. Further experiments showed that A. cucumeris was able to develop and reproduce when feeding on TRM. Implication of these results for controlling TRM in greenhouses is discussed with respect to predator specificity and prey suitability.
Overseeding of tall fescue and perennial ryegrass into pre-existing stands of kentucky bluegrass is viewed as a strategy to enhance the quality and durability of turfgrass lawns. In a 3-year study, the authors investigated the winter survival and establishment of tall fescue (‘Bonsai 2000’), with or without Neotyphodium coenophialum, and perennial ryegrass (‘Palmer III’), with or without N. lolii, in the province of Quebec, Canada (≈lat., 54ºN), a region characterized by rigorous winter conditions. Grass species were overseeded in June 2003 at two different rates (90 and 180 kg·ha−1), in experimental plots from two bioclimatological conditions: Quebec City and Boucherville. Turfgrass establishment and endophyte infection were evaluated during the following two spring and fall periods. Both tall fescue and perennial ryegrass had the capacity to establish and survive winter conditions, but performed best when snow cover was thick and present throughout the winter. The proportion of overseeded plants in the turfgrass stand rarely reached 30% over the years. Although the proportion of tall fescue and perennial ryegrass plants was much reduced in the spring, some tillers survived and were able, later in the season, to compete with kentucky bluegrass as tall fescue and perennial ryegrass populations returned to initial establishment populations each summer in mixed stands. Overwinter endophyte survival was species specific, with N. lolii being able to survive the cold winter but not N. coenophialum, which had a low percent of infection. For the perennial ryegrass–N. lolii association, competition with kentucky bluegrass is a primary factor limiting the increase over time in the proportion of endophyte-infected plants in a turfgrass mixture. Seeding rates did not influence the establishment of either grass species.