The cucumber 'Passandra' (Cucumis sativus 'Passandra') are a genus consisting of climbing vines. They include cucumbers, gherkins (small cucumbers), and several types of melon fruits. Some of these plants are cultivated as food crops (such as honeydew and cantaloupe), while others (C. dipsaceus) grow wild. Most of the species have edible fruits, but C. myriocarpus is toxic to humans and animals.
Hardiness Zones
5 to 11
Care Guide for Cucumber 'Passandra'
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Watering Care
Moisture-loving, keep the soil moist but do not let water accumulate.
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Common Pests & Diseases About Cucumber 'Passandra'
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Common issues for Cucumber 'Passandra' based on 10 million real cases
Leaf beetles
Leaf beetles are a class of colored insects 1 to 2 cm in size. They gnaw on leaves and petals resulting in small, round holes scattered over the surface.
Solutions: For less serious cases: Remove beetles, nymphs, and eggs. Remove all life stages of the beetles and kill them by placing them in a bucket of warm, soapy water. This can be done more easily by placing the bucket under affected leaves and shaking the plant. This method is most effective in the afternoon when leaf beetles are more active. Always dispose of insects in a sealed bag or container to avoid escape and spread. To treat more serious infestations: Apply organic insecticides. Use naturally-derived insecticides before moving on to synthetic insecticides. Neem oil and pyrethrum are naturally-derived insecticides that should be applied following label instructions. Apply synthetic insecticides. Examples of insecticides effective for leaf beetles include carbaryl, permethrin, and bifenthrin. Apply insecticides according to label instructions.
Sap-sucking insects
Sap-sucking insects can create dense clusters of small yellow or white spots on the leaves.
Solutions: Sap-sucking insects can be hard to spot, as they are often small and attach to the undersides of plant leaves. If you see signs of an infestation, follow these steps to eradicate it. Hand-pick bugs and remove eggs: Inspect your plants for insects and drop any you find in a container of soapy water. Look carefully at the undersides of plant leaves and squish any egg clusters you find. Use Insecticide: Targeted spraying can take out sap-sucking insects. Small infestations can be controlled with insecticidal soap, though larger outbreaks might require a stronger spray. Introduce natural predators: Many insects, including ladybugs and praying mantises, love to feast on sap-suckers. You can purchase them at garden stores and release them near infected plants, or encourage wild ones by creating habitat space.
Leaf rot
This pathogen can cause the leaves to rot.
Solutions: Bacterial infections need to be treated quickly to prevent the spread to neighboring, healthy plants, potentially wiping out large sections of your indoor or outdoor garden. In mild cases: Use sterilized (10% bleach solution) pruning shears or scissors to remove any infected plant parts, making sure to dispose of them off site. Use a copper-based bactericide to treat the unaffected foliage, as well as the soil, and neighboring plants. Follow the manufacturer’s rate and timing directions found on the product label. In severe cases, where more than half the leaves are affected: Remove all of the infected plants from the garden, disposing of them off site. Treat the soil and neighboring plants using a copper-based bactericide. Follow the manufacturer’s rate and timing directions found on the product label.
Yellow spot
Leaf spot can show up as yellow or white spots on the leaves.
Solutions: Diseases Fungicides can prevent the transmission of spores, but they may not treat the established infection. The first step is removing and disposing of all infected plant parts. Then apply recommended chemicals. For bacterial infections, apply a spray containing copper or streptomycin. For fungal infections, consult the local cooperative extension for recommendations on which fungicides will work best. Nutrient deficiency Apply a liquid fertilizer via foliar application to fix the deficiency quickly. Follow label directions regarding dosing instructions and application notes, such as not using before the rain or when temperatures are out of the recommended range. Incorrect watering Determine the water requirements for your specific plant, and follow accordingly. Some plants like consistently moist soil, and others like the soil to dry out slightly before being watered. Pests Thoroughly apply an insecticidal soap, an organic product like neem oil, or an appropriate chemical insecticide to the plant.
Leaf beetles
Leaf beetles are a class of colored insects 1 to 2 cm in size. They gnaw on leaves and petals resulting in small, round holes scattered over the surface.
Overview
Leaf beetles range in size from 1.5 mm to 2 cm. Both adult beetles and their larvae eat the leaves of many different types of plants. There are over 35,000 different species of leaf beetles, in a variety of colors including gold, green, yellow-striped, and red striped. Some of these have been mistaken for ladybirds because of their shape and coloring. They can be oval, round, or elongated in shape. These insect pests are most active in spring and summer.
If not controlled, leaf beetles can do a lot of damage to vegetable crops and ornamental plants. They feed on the leaves, flowers, stems, roots, and fruits of different plants. They can fly, which means it's easy for them to move from one plant to another. Some species of leaf beetles only target one specific crop, while others will target many different types of plants. Although a lot of the damage that they cause is cosmetic, an infestation can weaken a plant and leave it prone to other more problematic diseases.
Symptom Analysis
The first signs of a leaf beetles infestation are small visible holes in leaves. Leaves then become discolored and dark beetle droppings can be seen. As the leaves turn yellow and brown, they will drop off the plant onto the ground. Some leaves will appear skeletonized with only the veins still remaining.
Infestation begins in spring, when the adult beetles emerge from the soil and lay their eggs on the leaves of plants. When these eggs hatch, the young nymphs start munching on the leaves as they grow up. Once leaf beetles are large and mature, they'll fall to the ground and pupate in the soil over winter before starting the cycle all over again.
Leaf beetles also eat holes in fruits and vegetables. These can be seen as small round holes that sometimes have a larger brown area surrounding them.
Solutions
For less serious cases:
Remove beetles, nymphs, and eggs. Remove all life stages of the beetles and kill them by placing them in a bucket of warm, soapy water. This can be done more easily by placing the bucket under affected leaves and shaking the plant. This method is most effective in the afternoon when leaf beetles are more active. Always dispose of insects in a sealed bag or container to avoid escape and spread.
To treat more serious infestations:
Apply organic insecticides. Use naturally-derived insecticides before moving on to synthetic insecticides. Neem oil and pyrethrum are naturally-derived insecticides that should be applied following label instructions.
Apply synthetic insecticides. Examples of insecticides effective for leaf beetles include carbaryl, permethrin, and bifenthrin. Apply insecticides according to label instructions.
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Sap-sucking insects
Sap-sucking insects can create dense clusters of small yellow or white spots on the leaves.
Symptom Analysis
Your plant has developed tiny yellowish spots scattered across the leaves that look like mold or mildew. If these marks won't wipe off, they are likely caused by sap-sucking insects like aphids, squash bugs, scale bugs, leafhoppers, whiteflies, mites, mealybugs, and more.
Each of these pests uses mouthparts to pierce leaf tissues and suck the sap. uses mouthparts to pierce leaf tissues and suck the sap. Signs of damage are difficult to spot at first, but a large infestation can quickly compromise the whole plant. You're most likely to see sap-sucking insects during the hottest months because plants make easier targets when already weakened from heat or drought.
Though sap-sucking insects are unlikely to kill your plant on their own, they can severely weaken it and make it more susceptible to disease. They may also spread viruses from one plant to another as they feed.
Solutions
Sap-sucking insects can be hard to spot, as they are often small and attach to the undersides of plant leaves. If you see signs of an infestation, follow these steps to eradicate it.
Hand-pick bugs and remove eggs: Inspect your plants for insects and drop any you find in a container of soapy water. Look carefully at the undersides of plant leaves and squish any egg clusters you find.
Use Insecticide: Targeted spraying can take out sap-sucking insects. Small infestations can be controlled with insecticidal soap, though larger outbreaks might require a stronger spray.
Introduce natural predators: Many insects, including ladybugs and praying mantises, love to feast on sap-suckers. You can purchase them at garden stores and release them near infected plants, or encourage wild ones by creating habitat space.
Prevention
Healthy plants are less likely to suffer from sap-sucker attacks. Keep them fortified with fertilizer and the right amounts of water and sunlight. Plants that receive excess nitrogen are also more susceptible to attack, so don’t overfertilize. You should also remove weeds and tall grasses surrounding your outdoor plants so as not to create habitat space for the pests.
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Leaf rot
This pathogen can cause the leaves to rot.
Overview
Leaf rot is very common among both house plants and garden plants. It affects foliage and occurs mainly when the leaves become wet due to rain or misting by the gardener. The cause is fungal disease and this is facilitated by the fungal spores adhering to wet leaves then penetrating the leaf and expanding rapidly. Damp conditions and poor air circulation will increase chances of infection taking place. Another factor are leaves that are damaged or have been penetrated by sap sucking insects that facilitate plant penetration.
Symptom Analysis
Spores are able to cling to a damp leaf and penetrate, often through an existing wound.
A small dark brown mark appears which expands rapidly as sporulation starts to take place.
Quite quickly these bull's eye like circles can link together and the whole leaf turns dark and loses texture.
Leaf drop occurs.
Disease Cause
These symptoms are caused by a bacterial infection invading the plant. Bacteria from many sources in the environment (air, water, soil, diseased plants) enter a plant through wounds, or in some cases the stomata when they are open. Once inside the leaf tissue, the bacteria feed and reproduce quickly, breaking down healthy leaves.
Bacterial infections threaten most plant species, and are more prominent in wet weather that more easily transfers the bacteria from plant to plant, or from soil to plant.
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Yellow spot
Leaf spot can show up as yellow or white spots on the leaves.
Overview
Yellow spot is a common condition that affects all types of plants -- flowering ornamentals, trees, shrubs, herbs, and vegetable plants -- worldwide. Yellow spots may appear because of dozens of potential causes and occur in various environmental and climatic conditions, but fortunately, most are easy to address. The most common causes of yellow spots include diseases, nutrient deficiency, watering problems, and pests.
In most cases, yellow spots can be treated without permanent damage to the plant. However, in some fungal disease cases, nothing can be done to treat the disease after infection, and the plant will ultimately perish from the disease.
Due to this, the most critical aspect of addressing yellow spots on plants is correctly determining the cause.
Symptom Analysis
Symptoms occur on varying parts of the plant, depending upon the cause. Smaller spots tend to be indicative of younger infections or newly developing problems.
Small yellow spots appear on leaves
Spots can occur on the lower or upper leaf surfaces, or both
Raised, rounded, or sunken spots with fringed or smooth edges
Spots may grow together, causing leaves to become totally discolored
Stunted growth
Premature leaf drop
Disease Cause
The vast majority of yellow spot diseases are caused by fungal pathogens. However, there are some situations in which bacteria, environmental conditions, or other issues may be blamed.
Diseases are typically host-specific, so they may only affect plants within the same family. That said, just about every single species of plant is vulnerable to at least one disease that causes yellow spot. The most common problems are leaf blight, leaf septoria, powdery mildew, and downy mildew, to name a few.
All plants need specific nutrients from the soil to survive. When these nutrients become depleted or unavailable for plant uptake due to particular conditions, deficiencies occur, and yellow spots are seen.
Nitrogen is an integral component of chlorophyll.
Iron is needed in the enzymes that make chlorophyll.
Yellow spots may also appear because of incorrect watering, mainly underwatering, or infestations of sap-sucking pests such as aphids.
Too little water inhibits photosynthesis. Too much water pushes oxygen out of the soil and the roots cannot take in nutrients or even water from the soil.
Insect problems can cause yellow spots directly by damaging leaf tissue when feeding, or they may introduce pathogens.
Continue reading in our app - it's better
A database of 400000+ plants and unlimited guides at your fingertips...
Scan the QR code with your phone camera to download the app
Treat and prevent plant diseases.
AI-powered plant doctor helps you diagnose plant problems in seconds.
Continue reading in our app - it's better
A database of 400000+ plants and unlimited guides at your fingertips...
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About
Care Guide
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Pests & Diseases
Cucumber 'Passandra'
Cucumis sativus 'Passandra'
Also known as: Gherkin 'Passandra'
The cucumber 'Passandra' (Cucumis sativus 'Passandra') are a genus consisting of climbing vines. They include cucumbers, gherkins (small cucumbers), and several types of melon fruits. Some of these plants are cultivated as food crops (such as honeydew and cantaloupe), while others (C. dipsaceus) grow wild. Most of the species have edible fruits, but C. myriocarpus is toxic to humans and animals.
Hardiness Zones
5 to 11
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Common Pests & Diseases About Cucumber 'Passandra'
Feedback
Common issues for Cucumber 'Passandra' based on 10 million real cases
Leaf beetles
Leaf beetles are a class of colored insects 1 to 2 cm in size. They gnaw on leaves and petals resulting in small, round holes scattered over the surface.
Solutions: For less serious cases: Remove beetles, nymphs, and eggs. Remove all life stages of the beetles and kill them by placing them in a bucket of warm, soapy water. This can be done more easily by placing the bucket under affected leaves and shaking the plant. This method is most effective in the afternoon when leaf beetles are more active. Always dispose of insects in a sealed bag or container to avoid escape and spread. To treat more serious infestations: Apply organic insecticides. Use naturally-derived insecticides before moving on to synthetic insecticides. Neem oil and pyrethrum are naturally-derived insecticides that should be applied following label instructions. Apply synthetic insecticides. Examples of insecticides effective for leaf beetles include carbaryl, permethrin, and bifenthrin. Apply insecticides according to label instructions.
Learn More About the Leaf beetles
Sap-sucking insects
Sap-sucking insects can create dense clusters of small yellow or white spots on the leaves.
Solutions: Sap-sucking insects can be hard to spot, as they are often small and attach to the undersides of plant leaves. If you see signs of an infestation, follow these steps to eradicate it. Hand-pick bugs and remove eggs: Inspect your plants for insects and drop any you find in a container of soapy water. Look carefully at the undersides of plant leaves and squish any egg clusters you find. Use Insecticide: Targeted spraying can take out sap-sucking insects. Small infestations can be controlled with insecticidal soap, though larger outbreaks might require a stronger spray. Introduce natural predators: Many insects, including ladybugs and praying mantises, love to feast on sap-suckers. You can purchase them at garden stores and release them near infected plants, or encourage wild ones by creating habitat space.
Learn More About the Sap-sucking insects
Leaf rot
This pathogen can cause the leaves to rot.
Solutions: Bacterial infections need to be treated quickly to prevent the spread to neighboring, healthy plants, potentially wiping out large sections of your indoor or outdoor garden. In mild cases: Use sterilized (10% bleach solution) pruning shears or scissors to remove any infected plant parts, making sure to dispose of them off site. Use a copper-based bactericide to treat the unaffected foliage, as well as the soil, and neighboring plants. Follow the manufacturer’s rate and timing directions found on the product label. In severe cases, where more than half the leaves are affected: Remove all of the infected plants from the garden, disposing of them off site. Treat the soil and neighboring plants using a copper-based bactericide. Follow the manufacturer’s rate and timing directions found on the product label.
Learn More About the Leaf rot
Yellow spot
Leaf spot can show up as yellow or white spots on the leaves.
Solutions: Diseases Fungicides can prevent the transmission of spores, but they may not treat the established infection. The first step is removing and disposing of all infected plant parts. Then apply recommended chemicals. For bacterial infections, apply a spray containing copper or streptomycin. For fungal infections, consult the local cooperative extension for recommendations on which fungicides will work best. Nutrient deficiency Apply a liquid fertilizer via foliar application to fix the deficiency quickly. Follow label directions regarding dosing instructions and application notes, such as not using before the rain or when temperatures are out of the recommended range. Incorrect watering Determine the water requirements for your specific plant, and follow accordingly. Some plants like consistently moist soil, and others like the soil to dry out slightly before being watered. Pests Thoroughly apply an insecticidal soap, an organic product like neem oil, or an appropriate chemical insecticide to the plant.
Learn More About the Yellow spot
Leaf beetles
Leaf beetles are a class of colored insects 1 to 2 cm in size. They gnaw on leaves and petals resulting in small, round holes scattered over the surface.
Overview
Leaf beetles range in size from 1.5 mm to 2 cm. Both adult beetles and their larvae eat the leaves of many different types of plants. There are over 35,000 different species of leaf beetles, in a variety of colors including gold, green, yellow-striped, and red striped. Some of these have been mistaken for ladybirds because of their shape and coloring. They can be oval, round, or elongated in shape. These insect pests are most active in spring and summer.
If not controlled, leaf beetles can do a lot of damage to vegetable crops and ornamental plants. They feed on the leaves, flowers, stems, roots, and fruits of different plants. They can fly, which means it's easy for them to move from one plant to another. Some species of leaf beetles only target one specific crop, while others will target many different types of plants. Although a lot of the damage that they cause is cosmetic, an infestation can weaken a plant and leave it prone to other more problematic diseases.
Symptom Analysis
The first signs of a leaf beetles infestation are small visible holes in leaves. Leaves then become discolored and dark beetle droppings can be seen. As the leaves turn yellow and brown, they will drop off the plant onto the ground. Some leaves will appear skeletonized with only the veins still remaining.
Infestation begins in spring, when the adult beetles emerge from the soil and lay their eggs on the leaves of plants. When these eggs hatch, the young nymphs start munching on the leaves as they grow up. Once leaf beetles are large and mature, they'll fall to the ground and pupate in the soil over winter before starting the cycle all over again.
Leaf beetles also eat holes in fruits and vegetables. These can be seen as small round holes that sometimes have a larger brown area surrounding them.
Solutions
For less serious cases:
Remove beetles, nymphs, and eggs. Remove all life stages of the beetles and kill them by placing them in a bucket of warm, soapy water. This can be done more easily by placing the bucket under affected leaves and shaking the plant. This method is most effective in the afternoon when leaf beetles are more active. Always dispose of insects in a sealed bag or container to avoid escape and spread.
To treat more serious infestations:
Apply organic insecticides. Use naturally-derived insecticides before moving on to synthetic insecticides. Neem oil and pyrethrum are naturally-derived insecticides that should be applied following label instructions.
Apply synthetic insecticides. Examples of insecticides effective for leaf beetles include carbaryl, permethrin, and bifenthrin. Apply insecticides according to label instructions.
Prevention
To prevent infestations of leaf beetles, follow these practices.
Regularly check for beetles. To prevent large pest infestations, be proactive about frequently checking plants for pests and removing them quickly.
Clear debris. Clear weeds and debris to remove areas where these beetles may overwinter and hide.
Attract natural predators. Birds and other insects, such as wasps and ladybugs, are effective natural predators of leaf beetles. Encourage them to visit by including a diverse array of plants to provide habitat and food. Also, avoid applying broad-spectrum herbicides that can harm and kill beneficial insects.
Plant aromatic herbs like mint, garlic, or rosemary, as these can repel leaf beetles.
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Sap-sucking insects
Sap-sucking insects can create dense clusters of small yellow or white spots on the leaves.
Symptom Analysis
Your plant has developed tiny yellowish spots scattered across the leaves that look like mold or mildew. If these marks won't wipe off, they are likely caused by sap-sucking insects like aphids, squash bugs, scale bugs, leafhoppers, whiteflies, mites, mealybugs, and more.
Each of these pests uses mouthparts to pierce leaf tissues and suck the sap. uses mouthparts to pierce leaf tissues and suck the sap. Signs of damage are difficult to spot at first, but a large infestation can quickly compromise the whole plant. You're most likely to see sap-sucking insects during the hottest months because plants make easier targets when already weakened from heat or drought.
Though sap-sucking insects are unlikely to kill your plant on their own, they can severely weaken it and make it more susceptible to disease. They may also spread viruses from one plant to another as they feed.
Solutions
Sap-sucking insects can be hard to spot, as they are often small and attach to the undersides of plant leaves. If you see signs of an infestation, follow these steps to eradicate it.
Hand-pick bugs and remove eggs: Inspect your plants for insects and drop any you find in a container of soapy water. Look carefully at the undersides of plant leaves and squish any egg clusters you find.
Use Insecticide: Targeted spraying can take out sap-sucking insects. Small infestations can be controlled with insecticidal soap, though larger outbreaks might require a stronger spray.
Introduce natural predators: Many insects, including ladybugs and praying mantises, love to feast on sap-suckers. You can purchase them at garden stores and release them near infected plants, or encourage wild ones by creating habitat space.
Prevention
Healthy plants are less likely to suffer from sap-sucker attacks. Keep them fortified with fertilizer and the right amounts of water and sunlight. Plants that receive excess nitrogen are also more susceptible to attack, so don’t overfertilize. You should also remove weeds and tall grasses surrounding your outdoor plants so as not to create habitat space for the pests.
Continue reading in our app - it's better
A database of 400000+ plants unlimited guides at your fingertips...
Leaf rot
This pathogen can cause the leaves to rot.
Overview
Leaf rot is very common among both house plants and garden plants. It affects foliage and occurs mainly when the leaves become wet due to rain or misting by the gardener. The cause is fungal disease and this is facilitated by the fungal spores adhering to wet leaves then penetrating the leaf and expanding rapidly. Damp conditions and poor air circulation will increase chances of infection taking place. Another factor are leaves that are damaged or have been penetrated by sap sucking insects that facilitate plant penetration.
Symptom Analysis
Spores are able to cling to a damp leaf and penetrate, often through an existing wound.
A small dark brown mark appears which expands rapidly as sporulation starts to take place.
Quite quickly these bull's eye like circles can link together and the whole leaf turns dark and loses texture.
Leaf drop occurs.
Disease Cause
These symptoms are caused by a bacterial infection invading the plant. Bacteria from many sources in the environment (air, water, soil, diseased plants) enter a plant through wounds, or in some cases the stomata when they are open. Once inside the leaf tissue, the bacteria feed and reproduce quickly, breaking down healthy leaves.
Bacterial infections threaten most plant species, and are more prominent in wet weather that more easily transfers the bacteria from plant to plant, or from soil to plant.
Solutions
Bacterial infections need to be treated quickly to prevent the spread to neighboring, healthy plants, potentially wiping out large sections of your indoor or outdoor garden.
In mild cases: Use sterilized (10% bleach solution) pruning shears or scissors to remove any infected plant parts, making sure to dispose of them off site. Use a copper-based bactericide to treat the unaffected foliage, as well as the soil, and neighboring plants. Follow the manufacturer’s rate and timing directions found on the product label.
In severe cases, where more than half the leaves are affected: Remove all of the infected plants from the garden, disposing of them off site. Treat the soil and neighboring plants using a copper-based bactericide. Follow the manufacturer’s rate and timing directions found on the product label.
Prevention
Clean up garden debris at the end of the season, especially if it contains any diseased plant tissue. Diseases can overwinter from season to season and infect new plants.
Avoid overhead watering to prevent transferring pathogens from one plant to another, and to keep foliage dry.
Mulch around the base of plants to prevent soil-borne bacteria from splashing up onto uninfected plants.
Sterilize cutting tools using a 10% bleach solution when gardening and moving from one plant to another.
Do not work in your garden when it is wet.
Rotate crops to prevent the buildup of bacteria in one site due to continuous cropping.
Use a copper or streptomycin-containing bactericide in early spring to prevent infection. Read label directions carefully as they are not suitable for all plants.
Ensure plants are well spaced and thin leaves on densely leaved plants so that air circulation is maximised.
Continue reading in our app - it's better
A database of 400000+ plants unlimited guides at your fingertips...
Yellow spot
Leaf spot can show up as yellow or white spots on the leaves.
Overview
Yellow spot is a common condition that affects all types of plants -- flowering ornamentals, trees, shrubs, herbs, and vegetable plants -- worldwide. Yellow spots may appear because of dozens of potential causes and occur in various environmental and climatic conditions, but fortunately, most are easy to address. The most common causes of yellow spots include diseases, nutrient deficiency, watering problems, and pests.
In most cases, yellow spots can be treated without permanent damage to the plant. However, in some fungal disease cases, nothing can be done to treat the disease after infection, and the plant will ultimately perish from the disease.
Due to this, the most critical aspect of addressing yellow spots on plants is correctly determining the cause.
Symptom Analysis
Symptoms occur on varying parts of the plant, depending upon the cause. Smaller spots tend to be indicative of younger infections or newly developing problems.
Small yellow spots appear on leaves
Spots can occur on the lower or upper leaf surfaces, or both
Raised, rounded, or sunken spots with fringed or smooth edges
Spots may grow together, causing leaves to become totally discolored
Stunted growth
Premature leaf drop
Disease Cause
The vast majority of yellow spot diseases are caused by fungal pathogens. However, there are some situations in which bacteria, environmental conditions, or other issues may be blamed.
Diseases are typically host-specific, so they may only affect plants within the same family. That said, just about every single species of plant is vulnerable to at least one disease that causes yellow spot. The most common problems are leaf blight, leaf septoria, powdery mildew, and downy mildew, to name a few.
All plants need specific nutrients from the soil to survive. When these nutrients become depleted or unavailable for plant uptake due to particular conditions, deficiencies occur, and yellow spots are seen.
Nitrogen is an integral component of chlorophyll.
Iron is needed in the enzymes that make chlorophyll.
Yellow spots may also appear because of incorrect watering, mainly underwatering, or infestations of sap-sucking pests such as aphids.
Too little water inhibits photosynthesis. Too much water pushes oxygen out of the soil and the roots cannot take in nutrients or even water from the soil.
Insect problems can cause yellow spots directly by damaging leaf tissue when feeding, or they may introduce pathogens.
Solutions
Diseases
Fungicides can prevent the transmission of spores, but they may not treat the established infection. The first step is removing and disposing of all infected plant parts. Then apply recommended chemicals.
For bacterial infections, apply a spray containing copper or streptomycin.
For fungal infections, consult the local cooperative extension for recommendations on which fungicides will work best.
Nutrient deficiency
Apply a liquid fertilizer via foliar application to fix the deficiency quickly. Follow label directions regarding dosing instructions and application notes, such as not using before the rain or when temperatures are out of the recommended range.
Incorrect watering
Determine the water requirements for your specific plant, and follow accordingly. Some plants like consistently moist soil, and others like the soil to dry out slightly before being watered.
Pests
Thoroughly apply an insecticidal soap, an organic product like neem oil, or an appropriate chemical insecticide to the plant.
Prevention
Depending on the type of plant and which specific disease is causing yellow spot, problems may be avoided by taking the following preventative steps:
Plant resistant varieties
Avoid planting susceptible varieties close together - space susceptible plants further apart from one another so it’s more difficult for the fungal spores to find new plant hosts.
Water wisely - water from below rather than splashing water on foliage. This can reduce the spread of both bacterial and fungal pathogens responsible for yellow spot.
Prune - prune as a way of getting rid of affected leaves but also to control the spread of yellow spot to new plants. Pruning can also improve air circulation to limit disease spread.
Rotate crops - many diseases, including downy mildew, can live in the soil over the winter and produce problems for many years. Rotate annual crops to new locations each year so that they aren’t growing anywhere in which plants in the same family were grown within the last three to four years.
Continue reading in our app - it's better
A database of 400000+ plants unlimited guides at your fingertips...
Treat and prevent plant diseases.
AI-powered plant doctor helps you diagnose plant problems in seconds.
Download the App for Free
Your Ultimate Guide to Plants
Identify grow and nurture the better way!
17,000 local species +400,000 global species studied
Nearly 5 years of research
80+ scholars in botany and gardening
Continue reading in our app - it's better
A database of 400000+ plants unlimited guides at your fingertips...
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Marketing cookies are used by advertising companies to serve ads that are relevant to your interests.
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Source
Purpose
Lifespan
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Facebook Pixel
A conversion pixel tracking that we use for retargeting campaigns. Learn more here.
1 Year
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This cookie provides mobile analytics and attribution services that enable us to measure and analyze the effectiveness of marketing campaigns, certain events and actions within the Application. Learn more here.
1 Year
Cookie Name
_fbp
Source
Facebook Pixel
Purpose
A conversion pixel tracking that we use for retargeting campaigns. Learn more here.
Lifespan
1 Year
Cookie Name
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Source
Adjust
Purpose
This cookie provides mobile analytics and attribution services that enable us to measure and analyze the effectiveness of marketing campaigns, certain events and actions within the Application. Learn more here.