Author Archives: David Rosenberger

New Considerations for Controlling Bitter Rot on Apples

In previous commentary, fungicides recommended for control of bitter rot in the Northeast included captan, ziram, and QoI fungicides, but continued dependence on the latter is probably neither sustainable nor advisable. Read my recent article published in Scaffolds Fruit Journal for the rationale … Continue reading

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Anticipating Outcomes from a Week of Rain

Tuesday evening, May 3rd: Hudson Valley fruit growers should be thinking very carefully about their disease control strategies for the next few days. The good news is that the weather is too cool for fire blight to be a concern … Continue reading

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Credibility of Fire Blight Forecasts

Given that apples and pears are blooming again in the Hudson Valley, it’s time to think about fire blight. The primary risk from fire blight occurs during bloom, as everyone should know by now. The fire blight bacterium, Erwinia amylovora, … Continue reading

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Adding Insult to Injury: Scab Warning

In addition to cold injury from our current cold snap, a scab infection period may arrive in the Hudson Valley with the warm rains predicted for Thursday. (No the snow did NOT kill the scab spores, and yes, the spores … Continue reading

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Revisiting Scab Risks for This Week

The scab infection risk for April 1-3 in the lower Hudson Valley may be waning, although caution is still advised. As suggested in my earlier post this morning, weather predictions that vary widely for events that are three or four days … Continue reading

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Apple Scab –– Weather or Not

The first scab infection period of the year may occur later this week in the Hudson Valley, but  the probabilities of that happening depend on which weather forecast you prefer to believe.  The weather variable is the critical factor regardless … Continue reading

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Follow-up on Scab Development

Rains today (March 10th) pose no threat for apple scab in the Hudson Valley because we still do not have any green tissue on apples buds.  According to one degree-day model*, McIntosh can be expected to reach the green tip bud … Continue reading

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Scab season alert

We found the first mature apple scab ascospores this afternoon, 7 March 2016.  It appears that we may need to be ready for a really fast start to the scab season in 2016. Dan Donahue, extension educator for the Eastern … Continue reading

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RIMpro, A Useful Apple Scab Model for 2016

RIMpro contains a proprietary apple scab model that is useful for (i) identifying the start of the scab season, (ii)  quantifying risks associated with key infection periods between green tip and first cover, and (iii)  determining the end of the … Continue reading

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