This pyracantha had a rough summer of 2016. The leaves’ veins would turn yellow on a branch, then the entire branch would die about a week later. This post details its demi-demise. First this:
Symptoms list: yellowing leaf veins, followed by branch death, on one side of the tree, and bark cracks showing pink/orange fungus-like growth at times. All during the warm summer months. Well, a little too little, a little too late, I started researching the symptoms and found this little gem:
From the University of California’s Website:
“Fusarium wilt—Fusarium oxysporum
Fusarium wilt affects relatively few woody ornamental species but can kill certain hosts, including albizia, date, palm, hebe, and pyracantha. Most forms of Fusarium oxysporum attack only herbaceous plants including aster, carnation, chrysanthemum, dahlia, and freesia. Fusarium wilt causes foliage to yellow, curve, wilt, then turn brown and die. Fusarium wilt symptoms often appear first on one side of a plant. Older leaves usually die first in infected plants, commonly followed by death of the entire plant. Plants infected when they are young often die. Cutting into infected wood may reveal that vascular tissue has turned brown, often all the way from the shoot to the soil line. Cross-sections of basal stems may reveal brown rings. Masses of spore-bearing stalks are sometimes visible on dead tissue and may look like small pink cushions.
Fusarium wilt results from infection through roots by hyphae that germinate from long-lasting survival structures in the soil. Plant with species from different genera rather than with plants previously infected there by Fusarium. Choose resistant cultivars if available. For herbaceous species, plant on raised beds. Provide proper sanitation and cultural care to reduce plant susceptibility to infection and damage. Avoid overwatering and provide good drainage. Avoid applying excessive fertilizer. Chronic branch dieback may develop in surviving trees; prune out any dead wood. Regularly inspect for possible hazards; affected trees may need to be removed. Soil solarization before planting may be effective.”
And from Gardening Zone’s website:
FUSARIUM WILT CONTROL
Fusarium wilt is a common vascular wilt fungal disease, exhibiting symptoms similar to Verticillium wilt. The pathogen that causes Fusarium wilt is Fusarium oxysporum . The species is further divided into forma specialis based on host plant. Disease fungi enter through the roots and interfere with the water conducting vessels of the plant.
HOST PLANTS: Commonly found in tomatoes, tobacco, legumes, cucurbits, sweet potatoes and banana are a few of the most susceptible plants, but it will also infect other herbaceous plants.
SYMPTOMS: As the infection spreads up into the stems and leaves it restricts water flow, causing the foliage to wilt and turn yellow. Symptoms often appear later in the growing season and are first noticed on the lower (older) leaves. As the disease progresses, the younger leaves will also be affected and the plant eventually dies. In many cases, only one branch or side of the plant show symptoms in what is referred to as the “yellow flag effect”
FAVORED ENVIRONMENT: Fusarium wilt can survive for years in the soil and is spread by water, insects and garden equipment. It develops during hot weather and is most destructive when soil temperatures approach 80 degrees F. Dry weather and low soil moisture encourage this plant disease.
FUSARIUM WILT CONTROL: Choose resistant varieties when available. Remove stricken growth and sterilize clippers (one part bleach to 4 parts water) between cuts. Control garden insects, such as cucumber beetles, which are known to spread the disease. Remove all weeds from the garden (many weed species host the disease). The biological fungicide Mycostop will control wilt caused by Fusarium. If the disease persists, it is best to remove the entire plant and solarize the soil* before planting again.
So, when the first yellow leaf of the year appeared in early June, and some Mycostop to try, it was time to get to work.
First, I mixed some with a small amount of water…
I repeated the treatment once again in late-June. By mid-July, the tree had only a few leaves showing the symptoms of Fausarium. I decided to repeat the treatment with at least another round, and likely it will be ongoing until I don’t see symptoms anymore. Here is a look as of July 15:
And on July 22 after spending the night in another bath of MicoStop; submerged to the trunk with a full packet of MicoStop in approximately 3 gallons of water:
And while I don’t have a lot of hope this will make it too much longer, the season’s berries are a treat to enjoy while they last: