| PEST/DISEASE | TYPE | SYMPTOMS ON ONION | CONTROL/PREVENTION |
|---|---|---|---|
| Onion Maggot | Insect | Yellowing and wilting of leaves, stunted growth, maggots can be seen in the bulbs | Rotate onion crops, avoid planting in areas with high numbers of maggots, use floating row covers to exclude adult flies, apply insecticides |
| Onion Thrips | Insect | Silver streaks on leaves, distorted growth, onion becomes discolored and distorted | Remove any infected plants, use sticky traps to monitor for thrips, use insecticides |
| Onion Smut | Fungal | Black powdery spores on leaves, distorted bulbs, stunted growth | Remove any infected plants, avoid planting in areas with a history of smut, use fungicides |
| Botrytis Blight | Fungal | Dark spots on leaves and bulbs, white mold on leaves and bulbs, rotting of bulbs | Remove any infected plants, avoid overhead watering, ensure good air circulation, use fungicides |
| Pink Root | Fungal | Pink discoloration at the base of the bulb, stunted growth, smaller bulbs | Plant resistant varieties, avoid planting in areas with a history of pink root, use fungicides |
| Downy Mildew | Fungal | Yellow spots on leaves, purplish-black discoloration of leaves, white or gray mold on leaves and bulbs | Plant resistant varieties, avoid overhead watering, ensure good air circulation, use fungicides |
| Fusarium Basal Rot | Fungal | Wilting of leaves, yellowing of leaves, pinkish-red discoloration at the base of the bulb, rotting of the bulb | Remove any infected plants, avoid planting in areas with a history of fusarium basal rot, use fungicides |
| White Rot | Fungal | Leaves yellow and die, bulbs turn soft and mushy, white fungal growth around the base of the bulb | Remove any infected plants, avoid planting in areas with a history of white rot, use fungicides |
| Cutworms | Insect | Young plants cut off at soil level, missing leaves | Place collars around plants to protect from cutworms, apply insecticides |
| Wireworms | Insect | Stunted growth, tunneling in bulbs, yellowing and wilting of leaves | Rotate onion crops, avoid planting in areas with high numbers of wireworms, use insecticides |
Onion Maggot
Onion maggot (Delia antiqua) is a common pest that affects onion plants. Adult flies lay eggs at the base of the onion plant, which then hatch into maggots that feed on the roots and bulbs of the plant.
Symptoms of onion maggot infestation include wilting and yellowing of the onion leaves, stunted growth, and the presence of small, white maggots around the base of the plant.
Control and prevention measures for onion maggot infestations include crop rotation, using insecticides, and planting onion sets or transplants instead of direct-seeding. To prevent future infestations, it is recommended to remove and destroy any affected plants and to cover new plants with row covers until they are established.
Insecticides containing spinosad or pyrethrin can be effective in controlling onion maggot larvae. However, it is important to follow application instructions carefully and avoid using insecticides during bloom, as they can harm pollinators.
By following these prevention and control measures, onion maggot infestations can be effectively managed, resulting in healthy and thriving onion plants.
Onion Thrips
Onion thrips are tiny, slender insects that feed on onion leaves, causing damage to the plants. These pests can cause significant damage to onion crops and are a common problem for gardeners.
Symptoms: The symptoms of onion thrips infestation include silvering or bronzing of the leaves, distorted growth, and stunted plants. As the infestation progresses, the leaves may start to turn brown and die. In severe cases, the entire onion crop can be lost.
Prevention: To prevent onion thrips, it is important to keep the garden free of weeds and debris, as these can provide a habitat for the pests. Planting onions in well-drained soil with good air circulation can also help prevent infestations. Additionally, applying a layer of mulch around the base of the plants can help reduce moisture and prevent the pests from laying eggs.
Control: To control an existing onion thrips infestation, neem oil or insecticidal soap can be used. These products should be applied early in the morning or late in the evening when the bees are not active. It is also important to rotate crops each year to prevent the buildup of pests and diseases in the soil.
Overall, preventing and controlling onion thrips is essential for a healthy onion crop. With proper care and attention, gardeners can keep their onions free from these damaging pests.
Onion Smut
Onion smut is a fungal disease that affects onions, causing significant damage to the plant and reducing the yield of the crop. This disease is caused by the fungus, Urocystis cepulae, and can survive in the soil for up to six years.
Symptoms
The first symptoms of onion smut appear on the leaves, which develop yellowish-green streaks. As the disease progresses, black, powdery spores develop on the leaves and stem of the plant. These spores eventually develop into galls or tumors on the onion bulb, causing it to rot and become inedible.
Control and Prevention
Prevention is the best control for onion smut. Gardeners should ensure that they purchase onion sets from reputable suppliers, as these are less likely to be infected with the fungus. Additionally, they should avoid planting onions in soil that has previously been used to grow alliums.
Fungicides can also be used to control onion smut, but these should be applied before the disease appears. It is important to follow the instructions on the fungicide label carefully and wear appropriate protective clothing when applying it.
In summary, onion smut is a serious fungal disease that can cause significant damage to onion crops. However, with proper prevention measures and early control methods, gardeners can effectively manage this disease and ensure a healthy onion harvest.
Botrytis Blight
Botrytis Blight, also known as gray mold, is a common fungal disease that affects onions and other vegetables. This disease is caused by the fungus Botrytis cinerea and can spread quickly in wet and humid conditions.
The symptoms of Botrytis Blight include brown lesions on leaves, stems, and bulbs. These lesions can quickly turn into a fuzzy gray mold that covers the entire plant. The infected plant tissues will eventually rot and collapse, leading to reduced yield or complete crop failure.
To control or prevent Botrytis Blight, it is important to maintain good garden hygiene. This includes removing any infected plant debris and improving air circulation around the plants. Additionally, avoiding overhead watering and using drip irrigation can reduce the moisture levels that promote fungal growth.
Fungicides can also be used to control Botrytis Blight, but it is important to choose a product that specifically targets this disease. Be sure to follow the instructions carefully and apply the fungicide at the first sign of symptoms.
Overall, preventing Botrytis Blight is key to ensuring a healthy onion crop. By practicing good garden hygiene and promptly addressing any signs of disease, beginning gardeners can successfully grow onions in their home gardens.
Pink Root
Pink root is a fungal disease that affects the roots of onions, causing stunted growth and reduced yields. The fungus, Phoma terrestris, infects the roots of the onion plant, leading to the development of pinkish-red discoloration.
Symptoms of pink root include yellowing and wilting of the leaves, as well as a general decline in plant vigor. Infected roots may also become soft and mushy, making them more susceptible to other diseases.
Preventing pink root involves maintaining good soil health and avoiding planting onions in areas where the disease has been previously identified. Crop rotation can help reduce the risk of infection, as can the use of resistant onion varieties.
If pink root is identified in your garden, affected plants should be removed and destroyed. Fungicide treatments may also be effective in controlling the spread of the disease.
In summary, pink root is a fungal disease that affects the roots of onions and can lead to reduced yields. Prevention involves maintaining soil health and avoiding planting in infected areas. Infected plants should be removed and fungicide treatments may be used to control the spread of the disease.
Downy Mildew
Downy mildew is a fungal disease that affects onions and other plants in the Allium family. It is caused by the pathogen Peronospora destructor and can cause significant damage to onion crops if not managed properly.
Symptoms of downy mildew include yellowing and browning of leaves, stunted growth, and a white, powdery substance on the undersides of leaves. In severe cases, the entire plant can collapse and die.
To prevent downy mildew, it is important to practice good cultural practices such as crop rotation, proper irrigation techniques, and removal of infected plant debris. Fungicides can also be applied preventatively or at the first sign of infection.
If downy mildew is already present in your onion crop, it is important to act quickly to prevent further spread. Remove any infected plants immediately and dispose of them far away from your garden. Fungicides can also be applied to help manage the disease.
Overall, prevention is key when it comes to downy mildew. By practicing good cultural practices and taking swift action if the disease is present, you can protect your onion crop from significant damage.
Fusarium Basal Rot
Fusarium Basal Rot is a fungal disease that affects onions and other alliums. The fungus attacks the base of the onion, causing it to rot from the bottom up. The disease is most common in warm, moist conditions and can spread quickly in the soil.
Symptoms of Fusarium Basal Rot include yellowing of the leaves, wilting, and a foul odor coming from the onion. As the disease progresses, the onion will become soft and mushy, eventually collapsing.
To prevent Fusarium Basal Rot, it is important to plant onions in well-draining soil and avoid planting them in areas where other alliums have previously been grown. Crop rotation can help reduce the risk of the disease spreading. Additionally, proper spacing between plants can promote good air circulation and prevent the fungus from taking hold.
If you suspect your onions have Fusarium Basal Rot, it is best to remove them from the garden immediately and dispose of them in a sealed plastic bag. Do not compost infected onions as this can spread the disease further. Fungicides can be used to treat infected plants, but prevention is key when it comes to this destructive fungal disease.
White Rot
White Rot is a fungal disease that can severely damage onion plants. The fungus attacks the roots and bulbs of the onion plant, causing them to rot and ultimately die. This disease is highly contagious and can spread quickly, making it a serious threat to onion crops.
Symptoms of White Rot include yellowing and wilting of the leaves, followed by the death of the entire plant. The roots and bulbs will also show signs of decay, turning brown and mushy. A distinctive feature of this disease is the presence of white fluffy growth on the affected bulbs.
Prevention is key when it comes to White Rot. The fungus can survive in soil for up to 20 years, making crop rotation essential. Avoid planting onions in soil where this disease has previously been present. It's also important to maintain proper soil drainage and avoid over-watering, as this can create conditions that are favorable for the growth of the fungus.
If White Rot is detected, it's crucial to remove all infected plants and dispose of them properly. Fungicides can be used as a preventative measure, but they are not effective once the disease has taken hold.
In summary, White Rot is a serious fungal disease that can devastate onion crops. Prevention through crop rotation and proper soil management is key to avoiding this disease. Early detection and prompt removal of infected plants can help to limit its spread.
Cutworms
Cutworms are common pests that can cause severe damage to onions and other plants in the garden. These larvae of certain types of moths are known for their habit of cutting the stems of young plants at or just below the soil line, causing the plant to wilt and eventually die.
Symptoms of cutworm damage include plants that appear to have been chewed through at the base, or that suddenly wilt and die for no apparent reason. You may also see the worms themselves in the soil around affected plants.
The best way to prevent cutworm damage is to use physical barriers, such as collars made from cardboard or plastic, around the base of young plants. You can also try applying beneficial nematodes to your soil, which will attack cutworm larvae.
If you do find cutworms in your garden, handpicking them and destroying them can be an effective control method. Insecticides are also available, but should be used sparingly and according to package instructions to avoid harming beneficial insects and pollinators.
By being vigilant and taking steps to prevent and control cutworm infestations, you can help ensure a healthy and productive onion crop.
Wireworms
Wireworms are the larvae of click beetles and are a common pest in home gardens, especially in onion beds. These pests are slender, brown or yellowish-brown and have a hard, cylindrical body. Wireworms feed on the roots and bulbs of onions and other plants, causing stunted growth, yellowing of leaves, and sometimes death of the plant.
The best way to control wireworms is to prevent them from infesting your garden in the first place. One way to do this is to rotate your crops, as wireworms tend to be attracted to certain types of plants. You can also till the soil before planting and remove any weeds or plant debris that may harbor wireworms.
If you do have a wireworm infestation, there are a few methods of control that you can try. One method is to use sticky traps, which will capture adult click beetles before they can lay their eggs in the soil. You can also try applying beneficial nematodes, which are microscopic worms that will attack and kill wireworms in the soil.
Overall, preventing wireworm infestations is the best way to keep your onion plants healthy and thriving. With a little bit of vigilance and care, you can keep these pests at bay and enjoy a bountiful harvest of fresh, flavorful onions from your home garden.