Colorado potato beetles are currently active in South Dakota. These beetles do a lot of damage to potatoes and nightshade plants like peppers, eggplants, tomatoes, and tomatoes. Colorado potato beetles feed on the leaves and can cause severe defoliation of infested plants (Figure 1). In the absence of garden hosts, they will feed on weeds, such as buffalo-bur and ground cherry.
Colorado potato beetles overwinter as adults that emerge in the spring to feed on newly sprouted plants. In South Dakota, there can be one to two generations of Colorado potato beetles per year. They are most prevalent by midsummer, when both larvae and adults will be present. The larvae and adults eat the leaves of host plants. The later-stage larvae, on the other hand, are responsible for about 27.5 percent of plant defoliation.
Larvae of the Colorado potato beetle start out as red and will turn pink as they mature. It will always have a black head and two rows of black spots on each side of its body (Figure 2). Adult Colorado potato beetles are oval in shape and approximately 3/8 of an inch long. They have an orange head and prothorax (i. e. segment behind the head) as well as an orange underside. The prothorax will have black markings present. The elytra (hardened forewings) are cream-colored with five black stripes on each side (Figure 3).
To get rid of Colorado potato beetles, you can plant varieties that ripen early and keep your garden free of weedy hosts. As the growing season goes on, keep an eye on potatoes and other host plants for Colorado potato beetles and signs of leaf loss. Potatoes can tolerate 30% defoliation during the vegetative stage without any issue. However, when tubers begin to bulk, the plants can only tolerate 10% defoliation. Tuber bulking occurs shortly after the plants flower. If the thresholds for leaf loss have been reached and Colorado potato beetle larvae or adults are seen on plants, more management may be needed.
If there aren’t many plants to check, adults and larvae can be taken out by hand and thrown away. This process is not realistic for larger gardens, which will require alternative methods. Insecticides containing the active ingredients azadirachtin (neem) or spinosad can be used effectively. It is important to know that Colorado potato beetles are not hurt by products that have carbaryl, cypermethrin, deltamethrin, lambda-cyhalothrin, imidacloprid, permethrin, or pyrethrins in them. If using an insecticide, closely monitor populations after application. If the application doesn’t kill Colorado potato beetles, reapply using a different active ingredient. Always remember to read product labels before application and follow all label directions.
The South Dakota State University Extension is having a High Tunnel and Cut Flower Field Day for people who want to learn more about growing cut flowers outside and in tunnels for safety.
After looking at information about the use of dimethyl tetrachloroterephthalate (bought under the brand name Dacthal), the EPA has issued an emergency order to stop using this active ingredient right away.
SDSU Extension, South Dakota Specialty Producers Association (SDSPA), and Blue Sky Vegetable Co. will host a Soil Health and Cover Crop Field Day on Thursday, September 5, 2024, from 9:00-11:30 a. m.
Potatoes are a staple crop grown in home gardens and farms worldwide. Their versatility in the kitchen along with their ease of growth makes them a favorite for many gardeners. However, potato plants are susceptible to pest damage, especially on their leaves. So what happens when those leaves get eaten or damaged? Will the potatoes continue to grow and produce a harvestable crop?
How Potato Plants Grow
To understand how eating leaves affects potatoes, it helps to know how potato plants grow Potatoes produce their tubers underground, while the leaves and stems grow above ground The leaves perform photosynthesis, producing energy from sunlight to fuel growth of the entire plant. This energy gets transported down to the tubers, enabling them to bulk up.
The leaves also play a key role in pulling nutrients like nitrogen from the soil up to the rest of the plant. So while the tubers themselves are underground and protected, the leaves are vulnerable to various pests who can munch away on them.
Impact of Losing Leaves
When potato leaves get damaged, it definitely stresses the plant to some degree. The plant now has less ability to photosynthesize and take in nutrients. However, potatoes have a remarkable ability to bounce back even when leaves take a hit.
The severity of the impact depends on a few factors
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Growth stage – Young potato plants are more vulnerable to leaf damage than mature, established plants. Plants that lose a lot of leaves early on may struggle to form a decent number of tubers. More mature plants can compensate better.
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Amount of foliage lost – A few nibbles here and there on the leaves isn’t a big deal But if a pest devours large portions of the foliage, that’s more problematic. The more leaves remaining, the better the plant can recover
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Overall plant health – Vigorous, robust potato plants that receive adequate water and nutrients can rebound well after leaf damage. Weaker, stressed plants will have a tougher time.
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Presence of disease – Any diseases infecting the plant in addition to leaf loss makes recovery very difficult.
Regrowing Leaves After Damage
If potatoes lose their leaves, the plant isn’t necessarily doomed. Potato plants can initiate new growth and regrow leaves depending on growing conditions and the level of carbohydrate reserves remaining in the tubers underground.
Here are some ways the plants work to replace foliage:
- Activating dormant buds below ground to generate new shoots
- Producing new side shoots off existing stems
- Growing new smaller leaves along existing stems
So even leafless stems may surprise you by generating new greenery. Support the plant by keeping it consistently watered and fertilized. Adding a layer of mulch can help as well. But patience is required. It takes time for new foliage to regrow.
Common Pests That Eat Leaves
A wide range of pests find potato leaves irresistible. Here are some of the most likely culprits:
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Colorado Potato Beetles – This notorious pest can quickly skeletonize leaves, leaving just the veins behind. The orange and black striped beetles and their spiny yellow/red larvae often reappear year after year if not controlled.
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Aphids – Large colonies of these tiny sap-sucking insects can cause curled, wrinkled leaves. They transmit viruses too.
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Flea beetles – These small jumping beetles riddle leaves with tiny holes. Heavily damaged leaves turn brown and dry up.
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European corn borers – Caterpillars of this moth bore into stems and feed on leaves.
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Grasshoppers – These insects chew on leaves, leaving ragged edges behind.
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Caterpillars – Tomato hornworms, cabbage loopers, cutworms and armyworms all feed on potato foliage.
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Slugs and snails – Nocturnal slimy creatures scrape holes in leaves.
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Rodents – Mice, voles and rabbits nibble on potato plants.
The best defense is maintaining healthy soil, rotating crops, removing weeds/debris, and encouraging beneficial insects. Row covers and organic sprays can also deter pests when needed.
Managing Potato Plants With Leaf Damage
If your potato plants incur pest damage, here are some tips for management:
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Inspect plants thoroughly and identify the culprit if possible. Are beetles present? Are there caterpillars? Try to pinpoint the cause of damage.
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Remove any visible pests by handpicking or spraying off with water. Check under leaves too. Destroy egg masses.
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Apply organic insecticidal soap, neem oil, or BT spray to deter further damage if pests are active.
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Sprinkle diatomaceous earth around plants to discourage crawling insects. Kaolin clay sprays can deter chewing pests.
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Maintain consistent soil moisture and fertilize lightly with a balanced organic fertilizer to promote regrowth.
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Monitor closely for signs of disease like blight and treat if found.
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Add a layer of mulch around plants to conserve moisture and temperature.
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Consider using floating row covers or insect mesh to protect plants from further damage.
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Harvest potatoes early if plants decline severely. Otherwise continue caring for plants and wait for maturity.
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When planting potatoes again, use crop rotation, trap crops and other methods to deter pests.
Can You Still Get a Decent Harvest?
Losing some potato foliage doesn’t necessarily translate to a loss of your whole crop. As long as pest pressure doesn’t remain rampant, many potato varieties will go on to produce decent yields come harvest time. Potato tuber growth accelerates in the second half of the season anyway.
However, unattended pest issues that persist in devouring foliage will take a toll. Try to remain proactive with organic solutions rather than letting the pests win! With quick action to salvage and protect plants, you can still harvest armloads of potatoes for months of meals.
Key Takeaways on Potatoes and Eaten Leaves
- Potato leaves play a key photosynthesis role in plant growth, but tubers underground have energy reserves to draw from.
- Mature plants can better tolerate some leaf loss versus young plants.
- Remove pests, treat with organic deterrents, and promote plant health for recovery.
- New leaves can regrow from stems and below ground.
- Taking swift action against pests still allows for a successful harvest.
Frequency of Entities:
Something: 3
keeps: 1
eating: 2
the: 5
tops: 2
of: 4
my: 2
potato: 9
plants: 7
probably: 1
deer: 2
but: 1
luckily: 1
there: 1
is: 2
green: 1
left: 1
and: 3
they: 2
still: 1
seem: 1
to: 3
be: 2
thriving: 1
They: 1
bounce: 1
back: 1
after: 1
every: 1
critter: 1
snack: 1
sess: 1
https://permies.com/t/187858/Eating-Potato-Leaves: 1
https://www.backyardchickens.com/threads/deer-have-been-eating-my-potato-plants-down-to-stems-do-i-need-to-dig-up-all-my-potatoes-asap.1587925/: 1
https://www.chefsresource.com/will-potatoes-grow-if-leaves-are-eaten/: 1
What’s Eating My Potato Plant?
FAQ
Can potatoes grow without leaves?
Do potatoes keep growing after the leaves have died?