Vegetable Diseases—Detect Them Early

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Vegetable diseases can be a real heartbreak. You've been working hard in your garden and you're looking forward to harvesting.

Suddenly, your vegetables are rotting in the field. Or they're moldy.

Or perhaps they're die off as seedlings, before you can even plant them in your gardens.

Yes, it can be disheartening. The good news is that most diseases don't happen all of a sudden.

If you know the signs, you can detect vegetable diseases before they become an outbreak.

Use these links to jump directly to a particular vegetable type:

Tomatoes and Potatoes | Cucumbers, Melons, Squash, Pumpkin, Zucchini
Onions | Beans | Peas | Lettuce

Tomatoes

There are several tomato diseases.

Tomato Septoria Leaf Spot is one of the worst.

Symptoms

• Tiny brown spots show up underneath the leaves first.
• The leaves slowly become yellow and drop dead as the disease makes its way up the plant.
• Early death of the vine importantly cuts tomato production.

Gray Mold

Symptoms

• It starts in a cool climate but, unlike numerous diseases, it doesn't require high humidity to prosper.
• Soil with a low pH promotes more serious gray mold infection.
• The characteristic clue of gray mold is its fuzzy, feltlike appearance.

Blossom-End Rot

Symptoms

• Horrible recessed brown patches on the underside of peppers, melons, tomatoes and cucumbers.
• A condition made by a lack of calcium in the soil.
• It usually happens after fast growth and then by a extended dry spell or extended times of heavy rain that make calcium strip from the soil.

Tomato Anthracnose

Symptoms

• Tomato Anthracnose shows up on mature fruit, creating small, round, recessed spots.
• The spots get larger, and shortly the total fruit is affected and acquires a water rot.

Late Blight

Symptoms

• It can be ravaging to fruits, stems and leaves when the climate circumstances are long times of sticky weather with cool nights and fairly warm days.
• Impacted plants appear as if they were wiped out by frost.
• Both immature and mature fruits turn corky brown on their tops and make a visual property matching that of an orange peel.
• Decayed areas stay firm but produce the fruit uneatable.

Pythium Rot (Damping-Off, Stem Rot)

Symptoms

• Diseased condition of seedlings in excessive moisture occurs at or before sprouting, causing fast descent and demise of seeds or young seedlings.
• Disease causes serious drooping and black stem, starting at ground level, resulting in dangerous stunting or death of plants on aged plants.

Suggestions

• If fertilizing, apply a slow-release organic source of nitrogen.
• Stay away from planting in badly drained regions.
• Keeping soil pH at 6.5-7.0 helps.

Fusarium Wilt

Symptoms

• Yellowing is first problem of older leaves, and then bright yellowing from top to bottom of plant, frequently impacting only one branch of plant.
• Occasionally leaves wilt and bend down.
• Plants frequently droop and die.

Suggestions

• If fertilizing, apply a slow-release organic source of nitrogen.
• Stay away from planting in poorly drained regions.
• Keeping soil pH at 6.5-7.0 helps.

Fusarium Root and Crown Rot

Symptoms

• The whole root system is affected.
• Brown discoloration is apparent at the pedestal of the stem.
• Disease advances slowly from bottom to top, often causing drooping.
• Disease is far-flung in tomato-growing areas.

Suggestion

• Keeping the soil pH at 6.5 to 7.0 helps.

Powdery Mildew

Symptoms

• A white growth sometimes with a yellow border on the surface of leaves and stems.
• Leaves finally become brown, die and drop off the plant.
• Typically seem foremost on the plant's lower leaves and gets along upward.
• Wounds do not appear on fruit, but fruit may hurt from sun scald due to defoliation in serious examples.
• Warm, wet weather favors growth of the disease.
• Spores are transported by the wind, and all plantings may be rapidly infected.

Tomatoes and Potatoes

Early Blight

Symptoms

• First atypical brown spots show up on lower leaves.
• The lower leaves drop off, revealing tomatoes to sun, getting sun scald.
• With old plants, it often makes black sunken spots by the stem end of the fruit.

Cucumbers, Melons, Squash, Pumpkin and Zucchini

Angular Leaf Spot

Symptoms

• Irregular or angular water-drenched spots form on the leaves.
• If leaves are damp, a tiny drop of bacterial exudate from on the bottom of lesions and remove the moisture to a white residue.
• The lesions afterwards become gray to brown, dry and pull away, leaving behind large atypical holes.
• The bacterium winters in diseased plant scraps and on the seed cover.
• Disease is circulated by rain and by equipment, hands and clothing.

Suggestions

• Avert doing work around cucubits when leaves are wet.
• Work soil only if it is dry.
• Do not water with overhead sprinklers.

Cucumber Bacterial Wilt

Symptoms

• Big vines slowly droop and die, young plants die quickly.
• Bacterial wilt is dispersed by cucumber beetles.

Suggestion

• Get rid of and demolish wilted plants.

Downy Mildew

Symptoms

• A period of at least 6 hours at 100% humidity on the leaf surface is needed for infection.
• Its symptoms deviate substantially, plant to plant.
• Lesions first appear on the oldest leaves and so spread to the younger leaves.

Suggestion

• Do not crowd together plants.
• Stay away from overhead watering to avoid leaf wetness.

Fusarium Wilt

Symptoms

• With young melon, cucumber and watermelon plants: damping-off, stem break down and death may happen.
• With aged plants: yellowing , stunting , drooping and death.
• The disease comes about wherever cucubits are produced.

Suggestion

• Don't permit soil to completely dry out.

Anthracnose

Symptoms

• Assaults most cucurbits in warm, wet climate.
• Tainted fruit makes ring-shaped brown to black sunless regions, up to 1 inch across.
• Spores winter in and on the seed.
• Cucumber beetles and spattering water will broadcast spores.

Scab

Symptoms

• Scab is seed born and it also endures in the soil.
• It normally develops in warm weather after the midseason, when wet weather conditions live.
• Spores can broadcast over long lengths when the air is damp.

Suggestions

• Like many diseases, it helps to plant cucurbits where others have not been planted for 2-3 years.
• Set in exposed areas where breezes and sunshine are not limited.
• Set in exposed areas will allow leaf surfaces to dry more rapidly, cutting back infection.

Alternaria Leaf Blight

Symptoms

• Shows in midseason on the oldest leaves and spreads to newer leaves.
• Expanding, circular brown spots with circles form on the upper leaf surface and are later spread over by black, moldy growth.
• Leaves dropping off may end in sunscalding of fruit.
• The fungus is seed-born and winter in harvest debris and weeds.

Suggestions

• Do not plant cucurbits where they have been produced within the last 2 to 3 years.
• Avoid sprinkler watering.

Squash Mosaic Virus

Symptoms

• Yellow and green curled leaves.
• Wartlike, distorted and spotted fruits.
• Aphids are found to spread virus to squash plants.

Onions

Neck Rot

Symptoms

• The disease attacks existing plants simply is frequently not noted until onions are in storehouse.
• Recessed, dried regions appear at the neck of the bulb and bit by bit move down continuing the total bulb.
• The symptoms commonly arise after the bulbs have been in storage for a month or more.
• The fungus perforates leaf tissue and only affects the bulb.
• When necks are lush at harvest time they allow an entering point for the fungus.
• The fungus can not attack a well-dried neck.

Suggestions

• Place plants to admit good air penetration.

Soft Rot

Symptoms

• Soft rot can cause major losses in stacked away onions.
• It is spread by spattering rain and by mechanical or insect damage.
• The bulb is infected by neck tissue of aging plants.

Suggestions

• Permit onions tops to dry before putting away.
• Avoid injuring bulbs and store onions entirely after they have been well dried out.

Downy Mildew

Symptoms

• Spots on the leaves get covered with a lavender or purplish fungus.
• Needs cool temperatures and rain or high humidity.
• With these conditions, onion leaves flex, ending in smaller yields and bulb grade.

Suggestions

• Raise onions in well-drained soil to prevent roots from becoming soggy.
• Prevent the spread of disease by washing tools and shoes after you work in the vegetable garden.
• Get rid of weeds and garden debris, which protect insects that transfer diseases.
• Investigate plants every couple days for signs of damage and do away with infected plants.

Fusarium Basal Rot

Symptoms

• Viewed as curving, discoloring of leaf tips, increasingly going downward.

Suggestion

• Don't raise grain cover crops in rotation with onions or garlic.

Beans

Pythium Root Rot

Symptoms

• Discoloring, scrawny growth, abrupt seedling wilting(damping-off) and death.
• May also kill seedlings before emersion.
• Pythium spores take place in the soil nearly everyplace beans are grown.

Gray Mold

Symptoms

• Gray mold is most usual when blooming happens on a cool time of elevated humidity.
• Crowded plants with a compact cover of leaves also promote gray mold.
• Infection starts in the flower and goes to the pod.

Suggestions

• Reduce seedlings so that the air can dry leaves.
• Don't overwater and over fertilize with nitrogen.

Bacterial Brown Spot

Symptoms

• Infection usually happens with warm temperatures, in the 80 to 90 degree F. scope, and moist weather.
• This disease turns up as yellow bits on the leaves, which afterwards become dark brown.
• Single spots are normally atypical in shape and stay moderately small, encircled by a slim yellow edge, but missing a wide yellow ring.

Suggestions

• Set disease-free seed, rotate crops, incinerate infected plant tissues, and cleanse dirty equipment.
• Avoid cultivating with plants when they are wet, as water carries the bacteria.

Common Bacterial Blight

Symptoms

• During times of warm, humid weather, bacterial blight may be particularly damaging to pods.

Suggestions

• After harvesting, clean up all crop residues (fallen beans, plant branches, etc.).
• Rotate crops.

Anthracnose

Symptoms

• Fungi exist on infected bean seed and in scraps on top of garden soil.
• Moderate and frequent rainfalls, especially if accompanied by winds, give perfect conditions for the spread of anthracnose.

Suggestions

• Put beans in a different area each year and obtain disease-free seed each year.
• It is spread rapidly and easily when plants are wet, so avoid handling or working around plants when the leaves are wet.

Fusarium Root Rot

Symptoms

• Sluggish growth and the appearance of red spots or stripes on lower stem and roots.
• The true leaves untimely yellow and fall off.
• Diseased plants frequently remain alive by making new roots near the soil surface but output is seriously reduced or did away with.

Suggestion

• Don't compact soil.

Rhizoctonia Root Rot

Symptoms

• Mainly attacks seedlings and immature plants.
• Reddish-brown spots show up on lower stems.
• Many infected plants die as seedlings.

Suggestion

• Shallow seeding depth and planting in good warm soil helps.

Peas

Pythium Root Rot

Symptoms

• Watery rot is usual.
• Plants are frequently stunted and light green for of the deficiency of root development.

Suggestion

• Plant as soon in the season as conceivable.
• Peas are a cool time of year crop, while the pythium disease is most serious at temperatures from 64 to 75 degrees F (18 to 24 degrees C), which is higher than favored for pea germination.

Fusarium Root Rot

Symptoms

• Blackening of the stem at soil level, root decline and as disease increases, general loss of energy, stunting of the plant and death of leaves.
• A severe disease of peas in all regions of the United States.

Suggestion

• Don't compact the soil.

Lettuce

Damping-Off

Symptoms

• Seed rot, abrupt wilting of seedlings, loss of energy.
• Preferred by high moisture level and poorly drained soils.
• This disease happens wherever lettuce is farmed.

Suggestions

• Stop compacting soil and set in well-drained soil.
• Flip-flopping vegetables with cover crops aids general soil fertility and diminishes soil compaction.

Pythium Wilt

Symptoms

• Dark yellow-brown roots, stunting and discoloring of outer leaves.
• Decreased root system.

Suggestion

• Give good drainage and raised beds are perfect.

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