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    Protecting Apple Fruit from Scab Risks with Latest Best Practices

    As an apple farmer, one of my biggest challenges each season is apple scab. This fungal disease leaves ugly brown lesions all over fruit, rendering an entire crop unmarketable if left unchecked. I've lost entire harvests to scab in wet years past. This season, I'm implementing new techniques to finally gain the upper hand.

    You may not think a little scab could ruin your day, but it's no joke when your livelihood is at stake. The fungus overwinters in fallen leaves, infecting new growth each spring. By summer, lesions cover branches and developing apples if conditions are right. With so much riding on this year's crop, it's time to fight back.

    What is Apple Scab? Characteristics, Bad Effects, and Symptoms on Apple

    To battle apple scab effectively, the first step is understanding its biology and life cycle. Only then can we deploy targeted monitoring and controls. In this article, I'll provide an overview of this disease's traits, Latin name, and symptoms to watch for on fruit and trees. Knowledge is power in the fight against fungal foes.

    The Venturia inaequalis Description

    Every winter, as the leaves fell to the ground and the trees went bare, I took the chance to rest and recharge for the coming year. But hidden among those fallen leaves were unseen enemies - tiny pseudothecia, fruiting bodies of the scab fungus, nestled and hibernating as they waited for spring. While the land slept under a blanket of snow, those fungal foes dreamed of the warm days to come, when they would rouse from their slumber and enact their sinister plan.

    When the first buds began to swell and the air finally grew mild, the pseudothecia's time had come. One by one they burst open, releasing puffs of brown spores to the breeze. Those infectious particles floated on the awakening winds, seeking any apple tree they could find. Any that took root meant a new crop of lesions for me to bear, and another season of scab for us all. The silent threat had struck again, and so the endless cycle continued its turn.

    Typical Symptoms

    Early scab lesions on leaves appear as small, olive-colored spots. As the season progresses, lesions enlarge with dark borders and become raised or cracked in the center. On developing fruit, lesions are russeted and corky. Heavy scab years result in leaves and apples dropping prematurely.

    Be on the lookout for that all-too-familiar scabby appearance. Small, greasy-looking spots on leaves are a telltale sign. Lesions eventually become raised and cracked as the fungus matures. Misshapen, blemished apples mean culls for fresh market. Regular scouting helps spot outbreaks before harvest is at risk.

    Damage Below the Surface

    Scab infects opening buds and new growth, disrupting photosynthesis. Lesions girdle small branches, killing them over time. Heavily infected trees put energy into fruitless defense rather than storage for winter dormancy. Weakened trees become prone to winter injury.

    The Cost of Lost Crops and Fungicides

    Yield reductions from scab translate directly to financial losses. Research shows infections decrease apple harvests 30-50% in wet years. Replanting failed acres is expensive. Culling misshapen fruit shrinks returns, and post-harvest losses occur if blemished apples reach market.

    Protecting trees from scab requires intensive spray programs. While necessary, fungicides consume much of our budget each season. And we still face risks in wet springs with no guarantee of success. The costs of control must be weighed against potential for total crop loss.

    How to Get Rid of Apple Scab: Prevention and Pest Control

    1. Targeted Fungicide Applications

    Rather than spraying on a fixed schedule, I now monitor weekly weather forecasts. As soon as rain and temperatures favor infection periods, a targeted application of mycovin or tebuconazole provides 10-14 days of protection. Less fungicide means bigger profits and less impact on pollinators.

    2. Disease-Resistant Cultivars

    After years of trial and error, I've identified scab-tolerant varieties like 'EverCrisp' and 'RubyFrost' best suited to our soil and climate. While susceptible apples still have their place, focusing new plantings on resistant types reduces overall disease pressure and risk. Speaking of which...

    3. Removing Wild Host Trees

    We all know 'Pacific Rose' and 'Gala' are prone to scab. But did you know wild crabapples are also hosts? By removing overgrown hedgerows on our property boundaries, I've cut off infection sources fueling repeated outbreaks. Out with the old, in with methods like these.

    4. Biological Controls

    When conditions are prime for scab, a foliar spray of Serenade MAX, a biofungicide containing Bacillus subtilis, helps suppress the pathogen naturally. The microbes colonize leaf surfaces, crowding out the fungus. Applied weekly, they provide an eco-friendly layer of protection.


    With diligence across scab-smart practices, I'm confident this season's crop will far surpass previous years, thanks to integrated strategies proven to outwit even the wiliest of fungal foes. Wishing you all bountiful harvests of your own.

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