Jonathan Oliver

  • In conventional blueberry production, fungicides are frequently used to manage blueberry diseases. Unfortunately, as a result of repeated fungicide usage, the fungi targeted by these chemicals can develop resistance to specific fungicide modes of action.  This ultimately can make these fungicides less effective for disease management.  To reduce the chances of this occurring, growers are…

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  • Fungicides containing captan are an important component of spray programs for disease control on blueberry. Solo and tank mix applications of captan products have an especially significant role in the management of fungicide resistance, since captan’s mode of action is not likely to lead to the development of fungal pathogens with resistance to this material. …

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  • Fruit Splits and Yeast Rot in Blueberries

    As a follow-up on Dr. Sial’s post from last week, I have also received several calls from Extension Agents about the prevalence of soft fruit and fruit splits. Furthermore, in addition to reports of berry splits, we’ve received reports that yeast rot has been found affecting some of this fruit. Since yeast rot is an…

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  • Mummy Berry Threat is HIGH (as of 2/17/20)

    Recent warmer, damp weather has led blueberry growers in the southern region of Georgia to initiate sprays for mummy berry disease. According to the mummy berry model developed by Dr. Harald Scherm (UGA), there is a HIGH RISK for mummy berry disease initiation in southern Georgia as of February 17th, 2020.  Growers who haven’t already done so…

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  • Following recent freezes in the Georgia blueberry production region, the threat exists for subsequent damage from fungal pathogens. On tissues already damaged by freezes, two fungal pathogens of particular concern are Botrytis and Botryosphaeria.  In addition, root zone saturation from overhead freeze protection/subsequent rainfall can lead to issues with Phytophthora root rot. BotrytisThe fungus Botrytis cinerea causes…

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  • Captan Fungicide Review Process

    Captan is under a draft risk assessment in the registration review process and the deadline to submit comments was extended to March 15, 2019. You can submit your comments at this link. We appreciate your supporting comments on the benefits of captan – its role in disease management and in fungicide resistance management programs. Please forward…

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  • Mummy Berry Threat is HIGH (as of 2/12/2019)

    Recent warmer, damp weather has led blueberry growers in the southern region of Georgia to initiate sprays for mummy berry disease. According to the mummy berry model developed by Dr. Harald Scherm (UGA), there is a HIGH RISK for mummy berry disease initiation in southern Georgia as of February 12th, 2019.  Growers who haven’t already done…

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  • Mummy Berry Risk Remains Low (as of 1/15/19)

    In the southern region of Georgia, recent bouts of warmer than normal weather and earlier than normal emergence of leaves has led to the question of whether there is currently a risk of mummy berry infections developing. According to the mummy berry model developed by Dr. Harald Scherm (UGA), as of January 15th, 2019 there remains…

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  • Disease Development Following 2018 Freeze Damage

    Following the damage to blueberries in Georgia caused by recent freezes, the threat exists for subsequent damage from fungal pathogens. On tissues already damaged by the freezes, two fungal pathogens of particular concern are Botrytis and Botryosphaeria. Botrytis The fungus Botrytis cinerea causes Botrytis flower blight and fruit rot on blueberry. Cold-damaged blooms, shoots, and…

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  • Mummy Berry Threat is High

    In the southern region of the state, leaf emergence on blueberries coupled with recent rains and warmer temps leads to the question of whether mummy berry will be an issue (infections at green tip or early bloom, whichever comes first).  Mummy berry disease epidemics are set-up by the synchronized release of fungal ascospores and the…

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