| Specialty crops contribute 40 billion (about 40%) of all annual agricultural sales in the U.S. Botrytis cinerea and Alternaria panax are common pathogens on specialty crops. Control of these foliar blights includes fungicides such as chlorothalonil, a B2 carcinogen and an industry standard. However, consumers are interested in products that are environmentally friendly and safe to humans. An in vitro bioassay was used to assess the ability of biopesticides/reduced risk fungicides to protect geraniums from B. cinerea infection. Polyoxin D zinc salt and azoxystrobin were effective in limiting germination to < 4.0 %, limiting appressorial development to < 3.0, and preventing germ tube elongation from reaching > 5.0 mum over five incubation intervals. The efficacy of biopesticides/reduced risk products for B. cinerea control was evaluated under greenhouse conditions on geranium and ginseng. Azoxystrobin and polyoxin D zinc salt significantly minimized disease severity on geraniums. Polyoxin D zinc salt, boscalid, fluazinam, and fenhexamid significantly limited number of lesions, disease progression, and disease severity on ginseng. The efficacy of biopesticides/reduced risk products was evaluated for A. panax control on a ginseng field plot. Polyoxin D zinc salt, fluazinam, and boscalid provided significant control against defoliation and disease severity. The fluazinam, boscalid, and polyoxin D zinc salt treatments provided significantly better yields of the dried, marketable product than the untreated. |
