Sprayed Imidan last night, 1/4" of rain today

[OhioJeremy]

Sprayed the orchard last night. I knew there was a chance of rain but with my work schedule I wouldn't be able to spray for another week.
I only used a teaspoon per gallon, how effective is my work last night? Should I spray again?
my original plan was to spray last night and again Sunday the 26th and a another cover June 2nd.
My orchard has a bad Plum Curculio problem this time of year until typically 2nd or 3rd week of June.

 

[homerj]

Did you include a spreader/sticker/surfactant?

 

[OhioJeremy]

Did you include a spreader/sticker/surfactant?

Nope, Should I have? And What should I have used?

 

[aerospacefarmer]

You should be fine for a week to 10 days. After 2 inches of rain or 2 weeks is general rule unless you can see infestation

 

[Appleman]

Sprayed the orchard last night. I knew there was a chance of rain but with my work schedule I wouldn't be able to spray for another week.
I only used a teaspoon per gallon, how effective is my work last night? Should I spray again?
my original plan was to spray last night and again Sunday the 26th and a another cover June 2nd.
My orchard has a bad Plum Curculio problem this time of year until typically 2nd or 3rd week of June.

Best spray protection for Plum Curculio , tarnish plant bug, and apple sawfly is at tight cluster to pink and at 90% petal fall. PC can cause up to a 80% crop loss if not done at the critical spray time. I use 2 tablespoons per gallon of both Captan Gold WGR80 and Imidan WP70 (phosmat) or two cups of each in my 16 gallon fruit tree sprayer. Efficacy is good up to 1 inch of rain and will need additional cover sprays once reached. Plum Curculio has one generation in our area and mating cycle quickly drops off by mid-June. The insect is normally gone from the orchard by July 1st.

I received a lot of call this season from growers complaining of a poor return bloom for honeycrisp. Here is my take on it. It was a very dry season last summer so a combination of poor thinning and drought suppressed return bloom. I came to this conclusion after examining 200 honeycrisp in my orchard and discovered only 3 trees had no return bloom. All other trees are loaded with blossoms. These three trees were neither chemically or hand thinned. One of my friends who had a poor return bloom said that he did not start hand thinning until early July. This was the crux of his problem as research has proven that only early thinning helps to encourage fruit bud development for next season. Something to think about.