Hi RI fruit growers,
So glad to see several of you at the twilight meeting last night. The next meeting will be May 21st at Bardens family Orchard in North Scituate – and I hope you will all be there.

I’m a bit worried about scab. Hopefully all of you were protected going into the wet period that started Monday, April 20. April 21 was an impressive infection period and we received over 2 inches of rain. The time period I’m worried about is Wednesday, April 22. Wednesday morning was dry and relatively warm, allowing ascospores to mature. Mature spores could have been released Wednesday afternoon and caused another infection period. After the 2+ inches of rain from the day before, how much fungicide was left on the foliage? Hopefully enough to protect from the April 22 infection period, but I’m a bit worried. The options at this point include immediately applying a fungicide with kickback or just hoping. I don’t know what to recommend. I know this isn’t too helpful, but there you go.

I do think we will have tremendous bud growth over the next few days. After this flush of growth, another fungicide should be applied before the next rain. Even if you apply a fungicide today, April 24th, you will probably need to apply a fungicide again just before it rains to protect the new foliage.

Now is the time to apply oil for European red mite control. Orchard Radar predicts we’ll have European egg hatch Monday or Tuesday. Oil applied after egg hatch is not nearly as effective as just before the eggs hatch. Wind is bound to be a problem, and hopefully temperatures will stay above freezing. This is really the best time to be applying oil.

I’ve been looking for winter moth infestations at various locations. I only see high winter moth numbers in blueberry buds along the coast. In my hunt for winter moth I have found a lot of pear thrips. Pear thrips are small, black, narrow insects that feed on apple flower buds, probably pear too! It seems as though every decade or so they cause problems in an orchard or two. A 1999 April 20 UMASS Healthy Fruit newsletter gave this description of damage:
Early-season damage centers on developing leaf tissue, and as the leaves peel back from the buds, they may appear misshapen or brown at the tips. During tight cluster, after leaf tissue begins to harden, thrips adults are able to enter the flower buds, where they begin to feed on petal tissue and the fruit calyx. This is the most commonly seen and generally most severe injury. As soon as the pink tissue starts to unfold, damage is seen as shriveling and discoloration of petal tissue, which has two effects: damaging the fruitlets directly and reducing the overall quality of the flower, so that it is no longer attractive to pollinating insects.

The message goes on to estimate a spray threshold of 3 thrips per bud. I have found more than 3 thrips per bud in one orchard and another orchard with 2 thrips per bud. I have suggested both orchards apply an insecticide at tight cluster. The good news is they are easy to control with probably any insecticide.

I don’t see any good pictures of just what the thrips look like on buds – but take a look in your own orchard. Use a handlens and look for small black, narrow insects that move quickly. I think orchards surrounded by maple trees are particularly vulnerable.

Let’s hope the season gets easier. I think we’ve had a tough start. Next message will be recorded Thursday, April 30th – I hope!