Early blight in zucchini

Zucchini

by admin
March 25, 2024

Early blight in zucchini

The scientific name : Alternaria solani
The causative fungus : Alternaria cucumerina
Symptoms of early blight in zucchini:
Yellowish-brown spots with a yellow or green halo form on the leaves.
It attacks the oldest parts of plants first, before spreading to newer leaves.
If you leave these spots, they will eventually expand and merge. They become necrotic and cause the leaves to curl and die.
These affected areas may fall off and leave holes in the leaves, or the entire leaf may die and fall off (in extreme cases the entire plant may be peeled).
The flowers also often drop and cankers may appear on older stems.
Affected fruits may develop sunken spots, become covered with mold, and fall.

A picture showing you what the injury looks like (yellowish spots with a yellow or green halo)
An image shows you holes in the paper.

A picture showing you the symptoms on the leg.

A picture showing you the symptoms of the disease on the fruit.
Causes of early blight in zucchini:
This disease is spread by water, and the spores need moisture to germinate
Weeds.
Do not prune and remove the affected parts.
It is transmitted through seeds.
Failure to adhere to agricultural distances.
Heavy rain, wet soil, high humidity and warm weather.
Suitable conditions for the spread of early blight in zucchini:
This disease prefers hot, humid areas with abundant rainfall, and usually appears in mid-summer.
The presence of crop residues and harmful weeds and not getting rid of them (the development of fungal infection can be exacerbated by an increase in the number of germs on other hosts, such as weeds).
The severity and spread of infection increases in fully mature plants.
Early blight development cycle in zucchini:
Early blight fungus Imperfecta reproduces asexually by means of conidia
The fungus's life cycle begins with conidial spores found in infected crop residues from the Cucurbitaceae family.
Mushroom spores are spread by wind and insects. They enter through small wounds, gaps, or direct penetration.
Infection usually begins on older leaves close to the ground.
The fungus takes a long time to grow and the infection eventually appears. More spores are created and secondary infections spread in the field via conidia to infect other plants or other parts of the same plant. In the same growing season, all parts of the plant can be infected.
Losses of early blight spread in zucchini
The fungus can also cause lesions to appear on fruits, leading to poor quality fruit and a decrease in the quality of the crop.
Plant leaves fall, which affects the development of the fruit.

A picture showing the symptoms of a severe infection
Control strategy
Preventive measures to prevent early blight in zucchini
Avoid watering plants from above, water only the base of the plants.
Always remove weeds, as they can also be home to fungi
Prune affected leaves
Be sure to clean the field in the fall, this disease can overwinter in the soil or on plant residues.
Clean any tools you used to remove damaged foliage
Never fertilize infected plants
Chemical and organic control recommendations against early blight in zucchini
Organic control: Treating seeds before planting: Killing germs on the seeds by treating them with hot water (127 degrees Fahrenheit for 25 minutes).
Rotate your crops every 2-3 years
Chemical control: Spraying with copper-based fungicides is a good option. Apply every 7-10 days.
Biofungicides containing Bacillus subtilis can also be effective.
References
Jamiołkowska, A., & Sawicki, K. (2011). Biodiversity of fungi colonizing aboveground parts of zucchini (Cucurbita pepo L. var. giromontina). Folia Horticulturae, 23(1), 29-35
Commercial Vegetable Production in Wisconsin (A3422) from the UW Extension Learning Store. This guide offers the latest recommendations for disease, insect, and weed management in Wisconsin's most common commercial vegetable crops. Also included are lime and fertilizer recommendations as well as insect identification information and keys.
Moumni, M., Allagui, M. B., Mancini, V., Murolo, S., Tarchoun, N., & Romanazzi, G. (2020). Morphological and molecular identification of seedborne fungi in squash (Cucurbita maxima, Cucurbita moschata). Plant Disease, 104(5), 1335-1350