Primary spread of apple black spot is by ascospores produced from overwintering apple leaf litter To find effective degraders of litter an in vitro trial screened 59 fungal isolates for the ability to colonise sterilised senesced apple leaf discs The isolates of Aureobasidium Alternaria Chaetomium Coniothyrium Epicoccum Fusarium Phoma Trichoderma and Ulocladium spp had originated from the phylloplane or leaf litter of fruit crops The whiterot basidiomycete isolates were from fruiting bodies on native beech poplar and fruit trees The 18 isolates that colonised leaf discs most rapidly were further tested with five nutrient leaf amendments for their biodegradation activity on leaf discs After incubation at 10C for 9 weeks the most effective isolates of Trametes versicolor Phoma Epicoccum and Chaetomium spp caused 54 39 37 and 23 weight reduction respectively while the leaf amendments urea and the mixture of Mycorrcintrade; and Digestertrade; caused 29 and 20 reduction respectively These treatments were selected for evaluation in a field trial
Field trials were conducted in Hawke's Bay and Lincoln into methods of treating over-wintering apple leaves to reduce ascospore production by the apple black spot pathogen, Venturia inaequalis. The leaf treatments comprised three levels of nutrient amendments (including a water control) and five levels of saprophytic fungal isolates (including a nofungus control), in a factorial design. Leaves were left to over-winter on the orchard floor, and in spring the V. inaequalis ascospores released were trapped on glass slides and counted. Ascospore numbers were reduced (P<0.05) by the leaf amendment urea, which alone caused 73% reduction, but not by the Bio-Start™ product. The effect of fungal isolates was not significant (P=0.12), although when combined with the water treatment, the isolates, Chaetomium, Phoma and Epicoccum spp. and Trametes versicolor reduced numbers of ascospores by 33, 27, 15 and 28%, respectively, compared to the no-fungus control. When combined with urea, the Chaetomium isolate reduced ascospore numbers by 92 and 82% compared to the nil fungus/water control treatments in Hawke's Bay and Lincoln, respectively, indicating that this treatment has potential for reducing primary inoculum of apple black spot.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.