What are sentinel plots?
Sentinel plots are small plots (one-half to five acres) that are scouted often and thoroughly for soybean rust. Sentinel plots usually include an early-maturing cultivar and/or are planted two to four weeks prior to the normal soybean planting date. In Virginia, this means planting a maturity group II or III cultivar and/or planting in April or early May. For example, a maturity group III cultivar planted in April will begin flowering in mid-June, four to six weeks earlier than a maturity group IV or V planted in May. Since ASR develops more rapidly in reproductive-stage soybeans, it is more likely to be detected in reproductive stages than in the vegetative stage of the regular crop. Thus, early planting or early-maturing cultivars serve as an early-detection system. Ideally, a sentinel plot will contain two or more planting dates and/or maturity groups. Laterplanted or later-maturity groups assist in detecting a late-season invasion. The Virginia Soybean Rust and Aphid Monitoring Pro
