Organic methods for managing striped cucumber beetles (Acalymma vittatum) and spotted (Diabrotica undecimpunctata) cucumber beetles were examined in the production of watermelon (Citrullus lanatus) and muskmelon (Cucumis melo) using sticky traps to monitor beetle populations. In 2002, the numbers of trapped striped and total (striped + spotted) cucumber beetles were significantly (P ≤ 0.05) reduced by the combined use of three companion plants thought to repel cucumber beetles [radish (Raphanus sativus), tansy (Tanacetum vulgare), and nasturtium (Tropaeolum spp.)] or by the combined use of three companion plants known to attract beneficial insects [buckwheat (Fagopyrum esculentum), cowpeas (Vigna unguiculata), and sweetclover (Melilotus officinalis)]. In 2003 and 2004, the single companion plant treatment consisted of the combined use of radish and buckwheat. In 2003, use of aluminum-coated plastic mulch (Al-plastic) or companion plants significantly increased muskmelon yields and vine cover, while significantly reducing numbers of trapped striped, spotted, and total cucumber beetles. The use of pyrethrin insecticide did not significantly affect muskmelon yields or vine cover. In 2004, the beneficial effects of companion plant and Al-plastic treatments on muskmelon yields and vine cover were also significant and similar to those in 2003; however, these treatments only affected early season numbers of trapped beetles. The use of rowcovers significantly increased muskmelon yields and vine cover in 2003 and 2004 and did not affect beetle populations after rowcover removal. It was concluded that use of companion plants and Al-plastic increased muskmelon yields and vine cover while reducing populations of cucumber beetles, particularly striped cucumber beetles. The use of rowcovers also increased muskmelon yields and vine cover.
Gary R. Cline, John D. Sedlacek, Steve L. Hillman, Sharon K. Parker and Anthony F. Silvernail
Ai-Yu Chang, Richard J. Gladon, Mark L. Gleason, Sharon K. Parker, Nancy H. Agnew and Dennis G. Olson
Cut Rosa ×hybrida L. `Royalty' flowers were used to determine the efficacy of electron-beam irradiation for increasing postharvest quality and decreasing petal infection by Botrytis cinerea Pers. In an experiment for determining the injury threshold, roses received electron-beam irradiation of 0, 0.5, 1, 2, and 4 kGy. Irradiation dosages ≥1 kGy caused necrosis on petal tissue and decreased postharvest life at 20 °C. In a second experiment to evaluate postharvest quality, roses were irradiated at 0, 0.25, 0.5, 0.75, and 1 kGy. Dosages of 0.25 and 0.5 kGy slowed the rate of flower bud opening for 2 days but did not decrease postharvest quality when compared with nonirradiated roses. Roses that received irradiation dosages of 0.75 and 1 kGy showed unacceptable quality. In a third experiment, roses that had or had not been inoculated with B. cinerea were irradiated at 0, 0.25, 0.5, and 0.75 kGy. Irradiation did not control B. cinerea populations, and rose quality decreased as dosage increased. In a fourth experiment to determine the effect of irradiation on B. cinerea, conidia on water-agar plates exposed to dosages ≤1, 2, and 4 kGy germinated at rates of ≈90%, 33%, and 2%, respectively, within 24 h.