Captan Could Be Scarce in 2021

From Clemson Fruit Pathologist Dr. Guido Schnabel and UGA Fruit Pathologist Dr. Phil Brannen.

Unfortunately, there appears to be a shortage of Captan products this year. For our fruit crop producers this may result in a change of strategy if and when reserves run out. Strawberry growers fortunately have the option to use Thiram for basic gray mold and anthracnose control. The two products are basically equal in efficacy but thiram has a slight edge over captan for gray mold control, but it is a bit weaker against anthracnose.

Peach growers rely on captan for cover sprays. These early to mid-season applications manage green fruit rot and possibly anthracnose. Fortunately, during bloom and preharvest we use different chemistries at our disposal listed in the spray guide. As we mention often, we prefer to hold other chemical classes, those for which Monilinia fructicola (brown rot) is most likely to develop resistance, for use in the pre-harvest sprays. During captan shortage, we recommend application of two applications of a QoI/SDHI (FRAC 7+11) product, such as Luna Sensation, Merivon, Pristine or Quadris Top (FRAC 3+11), for cover sprays as needed this year. Along with any remaining captan products, we hope that this will help us to limp along till next year, while still providing excellent control of cover spray pathogens. Sulfur alone in cover sprays, though sufficient for scab control, is not efficacious for green fruit rot or other diseases; if using a QoI/SDHI (7+11) product, these will control scab as well as green fruit rot, so sulfur would not be necessary for these applications. As always, please contact your local extension agent should you have questions.

Field Update 11/18

Coastal

Zack Snipes

We have had a good bit of rain and some cooler temperatures this past week.  I have noticed damage to strawberries in fields with no fencing that will cause significant yield loss this spring. I have also noticed areas in fields where deer are going under fencing. Be sure to scout your fields and take note of where deer might be entering in your field and make necessary adjustments.  In one particular case the outside fence was slightly higher in one area which allowed the deer to walk under.  I found one field where the fence was not plugged back in after workers exited.  Be sure your fencing is on all the time.

Deer found the high spot in the fence and are beginning to travel under.

 

 

Pee Dee

Tony Melton

Sweet potato tops are dead but we are still harvesting for processing.  Greens were damaged a small amount from the cold last week.  We saw a little worse damage in upper Chesterfield and in Lancaster County than in other areas.

Upstate

Andy Rollins

Close inspection of young peach trees in this case revealed two problems.  Greater peach tree borer GPTB and scale.  If growers are seeing this jelly at the base of there trees they need to inspect further many times it is GPTB but not always.  This problem can be treated with mating disruption using PTB duel.  Young trees need to be trunk  treated with chlorpyrifos “Lorsban”.  Scale problem is the white looking dots along the trunk.  Dormant oil applications should help with reducing this problem but shouldn’t be overlooked.  Keep inspecting closely.

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Jelly coming from the base of peach trees could indicate Greater peach tree borer (GPTB) presence.  Note the scale (white dots) on the trunk.

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Peach orchard in Upstate SC