Annals of Applied Biology (1999) 134, 109-116

Neus Teixido, J. Usall, N. Magan and I. Vinas (1999)
Microbial population dynamics on Golden Delicious apples from bud to harvest and effect of fungicide applications
Annals of Applied Biology 134 (1), 109-116
Abstract: The microbial population dynamics on apples cv. Golden Delicious were analysed every 15 days between bud and harvest in a fully replicated experiment in northern Spain in 1994 and 1995. The total microbial populations varied with developmental stage, and with prevailing climatic conditions. The predominant mycroflora were the filamentous fungi Cladosporium and Alternaria spp. and white and pink yeasts. Other genera isolated included mainly species of Epicoccum, Fusarium and Acremonium. However, the most important post-harvest pathogens Penicillium expansum and Botrytis cinerea were seldom isolated from ripening apples. Maximum total filamentous fungal populations occurred after fruit set and during early ripening [2 x 10⁴ cfu (colony-forming units) g^-1 approximately] while those of bacteria were maximum at bud stage (3:5 x 10⁵ and 3.0 x 10⁴ cfu g^-1 in 1994 and 1995 respectively). White yeasts were more numerous than pink yeasts. Endophytic infection of apple buds by Alternaria spp., responsible for core rot, was found in almost all bud tissue. By contrast, Cladosporium spp., were initially isolated later from 12.5-50% of tissue samples during blooming and fruit set. The impact of a four-spray fungicide regime during apple development significantly decreased the total filamentous fungal populations in both years, and that of Cladosporium spp. in 1994. However, bacterial populations were often higher on apples from fungicide-treated plots. Fungicide sprays decreased populations of Cladosporium, Alternaria and white yeasts for a maximum of up to 15-30 days after application. Fungicide application had little effect on endophytic infection of apples by Alternaria spp. between bud and harvest.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Neus Teixidó, Josep Usall, Naresh Magan

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Botrytis cinerea	Stored fruits/vegetables	Spain (continental)
	Penicillium expansum	Stored fruits/vegetables	Spain (continental)