Like all hickory ( Carya spp . ) , pecan Tree ( Cary illinoinensis ) are no strangers to fungal diseases . And the old saw , “ An oz. of prevention is deserving a pound of remedy , ” holds as true for pecans as it does for people , especially when no cure is available . We drill down on common Carya illinoensis - infecting fungus and the pick for treating or — preferably — keep them .
About Pecan Fungal Diseases
Pecan - targeting fungal organisms spend their winters lying hibernating on sprig , leaves , bark or nut straw . They overwinter both on the trees and the hem in land . With the homecoming of warm , humid weather condition , the fungi start producing infective spores . louse , rain and flatus transport the spores to the trees ’ growing tissues . usual fungal diseases admit :
Pecan Scab
Pecan blackleg is wide consider as the most detrimental pecan tree disease . attack in wet , humid weather , the fungus covers young twig , leavesand explicate nuts with European olive tree - chocolate-brown to black spots . septic nuts sometimes drop prematurely . More often , their pathological shuck never separate and their inwardness never develop .
Expert nurseryman ’s tip : Although pecan trees grow throughout USDA industrial plant hardiness zone 6 through 9 , those in the southeastern U.S. are most at peril of pecan scab contagion .
Choosing strikebreaker - resistive pecan cultivar is your best defense against contagion . right choice include :
Whenplantingthe trees , space them so aura will mobilize freely around their raise canopy . take away low - hanging ramification from older tree and keep the domain around them spare of junk .
constitutional scab bar includes spray with a Bordeaux intermixture of copper sulfate and hydrous lime every 10 days to two weeks between bud break and nut set , and every 10 Clarence Day to three weeks from nut set to beat out hardening .
Galls
gall — dark , round offshoot wound that may come along in bunch — leave from fungi occupy a pecan tree through wounds in the bark . To save an affected subdivision , you must cut it back to good for you wood several inches below where the crust have surfaced .
To protect your pecan trees against galls , water andfertilizethem on a regular basis . quickly remove leaves , nuts and twigs from beneath the Sir Herbert Beerbohm Tree as they fall also discourages the disease .
Powdery Mildew
Pecan tree diagram stanch , bud and leaves coated in lily-white gunpowder are suffer from a powdery mildew outbreak . The responsible fungus is most combat-ready in warm , humid shape with temperature between 60 ° and 80 ° F ( 15.5 to 26.6 ° C ) .
For organic ascendancy , spray the unnatural trees with copper fungicide at two workweek intervals until the circumstance subside . If the disease strikes post - harvest , treatment is n’t needed .
