Journal of Applied Microbiology (2008) 104, 659-671

B. Guijarro, P. Melgarejo, R. Torres, N. Lamarca, J. Usall and A. De Cal (2008)
Penicillium frequentans population dynamics on peach fruits after its applications against brown rot in orchards
Journal of Applied Microbiology 104 (3), 659-671
Abstract: Aims: The study provides useful information on the temporal population dynamics of the biological control agent, Penicillium frequentans, after its applications against brown rot in orchards.
Methods and Results: Population dynamics of P. frequentans were studied on peach flower and fruit surfaces after different field treatments. Eight experiments were carried out in commercial peach orchards in Spain, over four growing seasons from 2002 to 2005. Six different formulated P. frequentans conidia were applied four to six times from blossom to harvest and P. frequentans population sizes were monitored using conidial numbers and colony forming units (CFU) per flower or fruit. A consistent population of P. frequentans, ranging from 10⁵ to 10⁶ number of conidia or 10³ to 10⁴ CFU of P. frequentans per flower or fruit, was obtained. Colonization of peach surfaces by all P. frequentans formulation are similar and it appears to follow a general pattern: (i) higher colonization of fruits at preharvest than on the flowers at bloom; (ii) high populations just after treatments, especially after preharvest treatments; and (iii) a slight decline between treatments, especially in cool and moist springs. The exponential model was the most appropriate for fitting and comparing the P. frequentans dynamic populations on peaches and nectarines over time. The linearization of the P. frequentans population curve was essential to determine dynamic population and for population levels forecast. A positive relationship between number of blossom and preharvest applications, temperature, relative humidity and dynamic of P. frequentans population applied on peaches was studied using a multiple regression model.
Conclusions: Blossom and preharvest applications were the most important spray times for obtaining the highest population of P. frequentans on peach surfaces.
Significance and Impact of the Study: The study provides useful information on dynamic P. frequentans population and its effects on the brown rot biocontrol.
(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): Paloma Melgarejo, Josep Usall, Rosario Torres

Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
application technology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Monilinia laxa	Peach/nectarine (Prunus persica)	Spain (continental)
Penicillium frequentans (antagonist)	Monilinia laxa	Peach/nectarine (Prunus persica)	Spain (continental)