hort oils in the summer time? help

[macrocarpa]

This will be the 1st year that I am applying hort oils in high temps throughout the summer. Right now I have scale to spray on bradfords and holly, also some hemlocks to spray for HWA and spider mites on same property. One concern for the bradfords is that they were just topped (don't ask) and I wonder if the oil will increase the likeliness of sunscald?

I am also concerned about burning foliage and would like any advise and/or caution? I will do the applications in the morning when temps are in the low 70's, but looks like 90 degree daytime highs.

I usually mix 2% and am using:98% Parafinic Oil, 2% Emulsifier

Thanks for any advise!

 

[Eric_E]

Read the label to check for summer rates and cations. 1% should be fine as far as phytotoxicity and control are concerned. The insects/pests are more active than when doing "dormant" apps so the reduced % will work fine.

if you can keep the apps to the cooler morning temps you should me fine. I would be Leary of treating the hollies though and do not treat plant material that is showing any signs of stress.

Many years ago Diazinon and oil ( a very hot combo)was my "go to" mix for scale. Routinely sprayed in temps over 90* and only had problems with stressed plants. Of course the pests aren't much of a concern when the plants are dead.

 

[macrocarpa]

How long after application would it take to see foliar burn from hort oil?

 

[zale]

If the temps are hot enough, it can happen very quickly. Less than a week. What did you burn?

 

[macrocarpa]

Hopefully nothing. I sprayed 1% paraffin hort oil on bradfords for scale, hemlock for spider mites and adelgid, euonymus scale, and norway spruce for spider mites. Temp was between 65-75 and cloudy at the time of application, got sunny and up to low 80's at peak of day.

This is my 1st time with summer oil sprays so I'm just being cautious. I usually would backlog oil sprays for fall and spring but want to see what results I can get during the summer too.

 

[zale]

With those temps. you should be fine.

 

[Eric_E]

[ QUOTE ]
How long after application would it take to see foliar burn from hort oil?

[/ QUOTE ]

EC's in high temps can show in less than 48 hours. At 80* max it is highly unlikely to burn unless maybe a bad mix.