discolored leaves

[jetsmell]

This is about my Crab Apple trees. They start the season full and green. After a few weeks some of the leaves brown and begin to fall. This continues throughout the season. This is the second year in a row with this dilemma.

 

[rianscott]

That is something new to look at. Instead of having them all green.

 

[Urban Forester]

Google: Apple Scab (Venturia inaequalis) A common foliar disease of suseptible Crabapple cultivars. Treatment needs to begin at 1/3 leaf expansion and continue until mid-summer.

 

[dingeryote]

Looks like scab.

You can shotgun with protectants now to reduce further spread, but will need a Systemic like Indar, Pristine, or other Strobulin for any curative action on the infected trees, and if the Strobulin resistance is an issue in your area, it's gonna be a fight.

Dunno what the restrictions on Ag pesticides are in your state for non Liscensed folks though.

Bonnide sells a homeowner formulation called "Fruit tree spray" that is essentially Captan, Carbaryl, and Malthion, all in a mix together for the one spray does all. Kinda pricy though, and to be effective you have to maintain a protective Captan coating on the trees, so you would be wasting the Carbaryl and Malthion if not needed.

Stay safe!
Dingeryote

 

[ch woodchuck]

apple scab pathogens overwinter in infected leaves on the ground.My golden delicious had a severe case last yr.Picked off all infected leaves,and any leaf litter on the ground.No problem this year.This is the same pathogen as mentioned above.

 

[dingeryote]

apple scab pathogens overwinter in infected leaves on the ground.My golden delicious had a severe case last yr.Picked off all infected leaves,and any leaf litter on the ground.No problem this year.This is the same pathogen as mentioned above.

The guys that clean till thier orchards in late fall, or at frost break have fewer problems, but still get the crud blowing in from the neighbors. It's gotta originate somewhere. Prunings left unburnt upwind can do it as well. Nasty stuff.

Dormant sprays of Lime sulphur or Sulphorix really knocks down the scab once it sets in, but the timing is everything and gawd does that stuff reek up the place.

Stay safe!
Dingeryote