The objective of our research is to find an effective control for Eutypa dieback, caused by the fungus Eutypa lata. Specific objectives were to test efficacy of the fungicides Benlate 50 WP, Rally 40 WP, and Nustar 20 DF, to determine whether multiple applications provide greater control than one application, and to test efficacy of the fungi Cladosporium herbarum, Fusarium lateritium, Aureobasidium pullulans, Trichoderma viride as biological control agents. Other objectives were to study colonization of wounds by applied fungi, to determine how the fungi inhibit infection by Eutypa, to test the combination of Benlate and Fusarium applied together, and to monitor the natural flora of pruning wounds of grapevines. We are testing the fungicides mentioned above and biological control agents in vineyards for their ability to prevent infection by Eutypa. This disease is difficult to study, because several years can elapse between the time of infection and the appearance of symptoms. By reisolating Eutypa from treated spurs after only nine months, we can assess efficacy long before symptoms appear. Our studies have shown that all four fungi can successfully colonize the wound surface when spore suspensions are applied immediately after pruning. Colonization is less successful when application of the spore suspensions is delayed for a period of one or two weeks. All four fungi are effective in reducing infection by Eutypa, but those studies must be conducted over many years to observe results over a variety of weather conditions. Studies on the natural wound colonization showed that numbers of filamentous fungi, yeasts, and bacteria are initially zero, and increase rapidly for 7-14 days after pruning, then remain constant.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF1994-11-22 16:59:542017-11-22 17:00:39Control of Eutypa Dieback of Grapes