Cultivation of Sweet Potatoes: Learn these control and preventative techniques if you want to shield sweet potatoes from pests and illnesses

Cultivation of Sweet Potatoes: Welcome to our in-depth guide on handling and preventing illnesses and pests that harm sweet potatoes. It’s important to be aware of possible ailments as a sweet potato fan or gardener hoping to grow these nutrient-dense tubers. This blog will discuss common pests and illnesses that affect sweet potatoes and provide helpful cures and preventative measures.

Everything, from spotting infestation symptoms to using natural therapies, will be covered. We’ll also talk about companion plants and cultural customs that might lessen these problems.

How to Handle Diseases and Pests on Sweet Potatoes

Farming Sweet Potatoes

Globally, sweet potatoes are extensively grown, with Asia, Africa, and the Americas having the greatest production regions. China is the world’s largest producer of sweet potatoes in terms of overall output, followed by Indonesia and India. These nations profit from climates that are adequate and ideal agricultural environments. Due to their high dietary fiber, vitamin, and mineral content, sweet potatoes are widely prized for their nutritional worth. Additionally, their glycemic index is lower than that of conventional potatoes, which makes them a better option for those who are controlling their blood sugar levels.

Pest and Disease Control

Numerous illnesses, ailments, and insect pests may have an influence on the development and output of sweet potatoes. Aphids, cluster caterpillars, flea beetles, mealybugs, weevils, and whiteflies are examples of common insect pests. It’s crucial to keep an eye on plants, remove any damaged areas, and use chemical or organic pesticides as needed to control these pests. Diseases including leaf spots, soft rot, wilt, and scab may also affect sweet potatoes. These diseases may be controlled with the use of disease-resistant cultivars, crop rotation, and proper sanitation.

In addition, diseases including cold damage, vitamin deficits, and growth cracks may affect sweet potatoes. These illnesses may be avoided by maintaining ideal growth conditions, offering balanced fertilization, and using effective cultural management practices. Growers of sweet potatoes may reduce the effects of pests, illnesses, and disorders by putting in place the proper management and control techniques, guaranteeing wholesome and fruitful harvests.

Management of the Sweet Potato Weevil

Crops of sweet potatoes are susceptible to serious damage by sweet potato weevils. The West Indian weevil (Euscepes batatae) and the Whitefringed weevil are the two most prevalent varieties of weevils. The whitish, legless larvae of the West Indian weevil may reach lengths of 10 mm. The mature weevils are less than 4 mm long, robust, reddish-brown, and have short bristles all over them.

Unlike sweet potato weevils, they feed in groups, biting into store roots to create bigger holes. When they feed, bitter chemicals are produced that make the roots unpalatable. This species is a significant pest in the Caribbean, Central America, and Papua New Guinea that affects sweet potatoes. The whitefringed weevil larvae are up to 15 mm long, C-shaped, legless grubs.

The mature weevils have stripes that go from gray to brown, a small snout, and a white band running down the side. Even though they cannot fly, they can walk great distances. The larvae burrow into the soil, where they consume the store roots and leave behind small, chewed holes. The West Indian weevil is widespread in Papua New Guinea, especially during the dry season that lasts from May to October; however, it is not yet seen in Australia. In contrast, the Whitefringed weevil lays its eggs in the summer and does the majority of its harm during the larval stages that occur in the winter and spring.

A mix of management techniques, including as routinely inspecting, eliminating, and demolishing affected plants, using certified pest-free planting material, and following appropriate sanitation procedures, are needed to control these weevils. Severe infestations could require the use of insecticides, but they should only be used sparingly and in compliance with local laws.

Management of Whiteflies

Bemisia tabaci, the silverleaf whitefly, may pose a threat to sweet potato harvests. Nymphs: At around 0.3 mm in length, the first instar nymphs are flat, greenish, and movable. As they get older, they turn opaque white, become motionless, and have tails that are pointed like soft-scale insects.

Pupae: The eyes of mature nymphs become crimson, their bodies thicken, and they grow golden.

Adults: The adults have snow-white, peaked wings that are carried in a vertical posture along their body. They are about 1 mm length.

Damage: Plant sap is consumed by both nymphs and adults, resulting in yellow or reddish stippling on leaves between the veins. Growth may be hampered by this nutrition. Moreover, several viruses may be spread by whiteflies. Sweet potatoes are a preferred host; however, this has little effect on production in most cases.

Most Common: After a mild winter, populations of silverleaf whiteflies may grow quickly, especially when temperatures are between 25°C and 28°C. Furthermore, it has been shown that whiteflies may become resistant to a variety of widely used pesticides, making control efforts difficult and perhaps having an adverse effect on nearby crops.

It is recommended to use integrated pest management techniques to control silverleaf whiteflies. These include keeping an eye on population trends, promoting natural predators and parasites, putting in place cultural controls (such getting rid of infected plant material), and thinking carefully and sparingly about using pesticides in accordance with local laws and resistance management techniques.

Treatment for Flea Beetles

Xenidia sp., often referred to as sweet potato flea beetles, have the ability to harm sweet potato harvests. While the adult beetles are 3 mm long, black, and have strong hind legs, the little, white grubs are found in dirt. Adults feed on leaves, generating holes and defoliation, while larvae feed on store roots, forming shallow channels.

These beetles are usually encountered in the spring. Integrated pest management techniques, such as targeted pesticides, cultural controls, frequent monitoring, and the encouragement of beneficial insects, should be used to address infestations. Seek advice from specialists or the local agricultural extension services on the best and most suitable course of action.

Prevention of Wireworm

Protecting sweet potato crops requires preventing wireworm infestations. The ‘click’ beetles, which are the larvae of false wireworms, have huge mandibles and a brown head. They are segmented, creamy in color, and delicate. The torpedo-shaped, gray-to-brown adult beetles may reach a length of 15 mm. To stop false wireworm damage, use biological treatments, soil preparation, crop rotation, trap crops, and routine monitoring.

Sweet potato rotation with non-host crops breaks the life cycle of wireworms and lowers their number. Monitoring fields for wireworm activity aids in the early detection of infestations and the implementation of suitable control measures. Biological controls promote the activities of natural predators such as parasitic nematodes and ground beetles.

Control of Black Rot

Ceratocystis fimbriata is the fungus that causes sweet potato black rot. Use planting-resistant cultivars, maintain proper cleanliness by eliminating and discarding diseased plant waste, and establish a crop rotation strategy as ways to manage and prevent this disease. Begin with approved seed material that is free of disease and thoroughly examine it for indications of black rot.

Make sure the soil drains properly to avoid waterlogging, which may lead to the development of diseases. Use registered fungicides to combat black rot in extreme situations; inquire with your local agricultural extension agency about suitable alternatives and application requirements.

Treating Sweet Potato Dryness

Monilochaetes infuscans is the fungus that causes scurf, a disease that affects sweet potatoes. Symptoms: Dark brown to black discolored patches on the storage roots are a hallmark of scurf. These patches grow until they finally encompass the whole root surface. It is noteworthy that the sickness has no effect on the interior tissues of the sweet potato.

Favorable Conditions: Scurf is scarce in acidic soils and more common in alkaline to neutral soils. High levels of organic matter in moist soils increase the likelihood of outbreaks.

Treatment: Scurf from infected sweet potatoes cannot be completely eradicated by certain therapies. On the other hand, their effects may be reduced with the use of management techniques such crop rotation, cleanliness, and soil pH modification. Crop rotation helps to keep pathogens from building up in the soil, while sanitation gets rid of and eliminates diseased material. In alkaline to neutral soils, adjusting the pH to slightly acidic levels (around pH 6) may lessen the severity of the condition.

Management of Root-knot Nematodes

Crops of sweet potatoes may suffer significant harm from root-knot nematodes, which are members of the Meloidogyne spp. family. Nematodes are little, worm-like animals that are seldom visible to the unaided eye. They are less than 1 mm in length. They parasitize plant roots and proliferate in the soil.

Damage: Sweet potatoes are mostly harmed by root-knot nematodes in the early stages of root formation. The juveniles create permanent feeding sites after emerging from eggs buried in the ground and into plant roots. Blisters grow on the roots as a result of enlarged cell production. In addition, the roots might develop rough edges, cracks, or other abnormalities. Wilting and upper-part yellowing are common symptoms of infected plants.

Most Common: Sandy soils are more likely to harbor root-knot nematodes. Significant egg hatching takes place in the spring, and symptoms are exacerbated in warm conditions over 25 °C.
Infested plant material, equipment, and irrigation water may all spread nematodes. Consequently, using crop rotation techniques and maintaining farm cleanliness standards are crucial management measures.

Management: Crop rotation, sanitation, soil amendments, and nematicides are all necessary for the effective control of root-knot nematodes. Sweet potato rotation with non-host crops lowers nematode populations and stops the spread of infected plant material by eliminating it. Nematicides may be administered in accordance with recommendations in extreme situations.

Control of Leaf Spots

Sweet potato plants are susceptible to Alternaria spp. leaf spots. On the leaves, little brown dots with a distinctive yellow or reddish halo appear. Eventually, the lesions fall out because their interiors are papery and dry. Leaf spots seldom result in a large loss of productivity.

Favored Conditions: During the cropping season, when there are alternating dry and wet periods, such as when overhead irrigation is employed, the disease is most severe. The fungus grows best at a temperature of around 27 °C. The fungus may grow in an environment that is conducive to its growth—crop detritus. Spores may disperse by water, rain, or wind.

Management: Use fungicides, crop rotation, irrigation management, and sanitation techniques to control sweet potato leaf spots. Removing diseased plant detritus is part of sanitation, which lessens the pathogen’s supply. By adopting drip irrigation or other focused techniques, irrigation should be avoided. In extreme circumstances, fungicides approved for the management of leaf spots may be used; however, for recommended applications and suitable alternatives, speak with your local extension services. Crop rotation lowers the number of pathogens in the soil and breaks the cycle of illness.

Treatment for Sweet Potato Stem Rot

A fungus called stem rot may harm sweet potato plants, resulting in withering, rotting, and collapse. It is brought on by fungus infections such as Fusarium spp. and Rhizopus stolonifer. Prevention and early diagnosis are essential, but treatment is not always easy. Using fungicides, crop rotation, good drainage, and cleanliness are practices that lower the danger of stem rot.

Crop rotation interrupts the transmission of illness, while sanitation eliminates and destroys contaminated plant debris. Inadequate drainage leads to waterlogging, which fosters the development of fungi. Fungicides may be used preventively in extreme situations by according to prescribed rules and recommendations.

Prevention of Aphids

Keeping sweet potato crops healthy requires preventing aphid infestations. Depending on their stage of life, aphids, such as the cotton aphid (Aphis gossypii), may have a variety of looks. They stunt and deform leaves as a result of feeding on immature shoots and sucking. Their expelled honeydew may promote the formation of sooty mold, inhibit photosynthesis, and spread the feathery mottle virus.

Aphid populations, which are most prevalent, flourish in cold, dry environments, and their mothers give birth to many live babies per day. Aphid infestations can be avoided by keeping an eye out for indications of their presence on sweet potato plants, promoting the presence of natural predators such as parasitic wasps, lacewings, and ladybugs, applying insecticidal soap, utilizing reflective mulch, and growing companion plants like marigolds or catnip that ward off aphids.

Handling Bacterial Wilt

Erwinia spp. are the culprits behind bacterial wilt, which may seriously harm sweet potato plants. Wilting and collapse are among the symptoms, and the storage roots start to rot and smell bad. Injuries brought on by insect damage during field cultivation or harvesting are the source of infection. Sanitation, verified disease-free planting material, insect control, and appropriate harvesting methods are all necessary for effective management. By taking these precautions, the risk of bacterial invasion and harm to sweet potato plants is reduced.

Preventing the Leaf Curl Virus

Maintaining healthy sweet potato crops requires limiting the spread and effects of the potyvirus feathery mottle, which causes the sweet potato leaf curl virus. The virus’s symptoms differ according on the type, age of the plant, and growth environment. Common symptoms include lengthened, thin storage roots, diminished vigor, more discoloration along veins, and uneven mottled patches on leaves, as well as severe infection.

The virus is very contagious and spreads via aphids and contaminated plant debris. Consider using certified viral-Free Planting Material, putting aphid control measures in place, routinely examining crops and pulling those that exhibit viral signs, maintaining high field cleanliness, and putting in place a crop rotation strategy to stop the spread of sweet potato leaf curl virus. By taking these precautions, you may lessen the virus’s ability to spread and affect your sweet potato harvests.

Management of Tuber Rots

Fusarium solani, the causative agent of tuber rots, is necessary to preserve the quality and commercial value of sweet potatoes. They frequently produce unevenly formed brown rings and appear as sunken, shriveled lesions on the roots. Wounds may get infected, particularly while harvesting; thus, treating materials carefully and reducing mechanical harm are essential.

Use disease-free planting material from reputable suppliers and adhere to correct harvesting, post-harvest handling, and sanitation practices to prevent tuber rots. In addition to post-harvest procedures, cleanliness, and disease-free planting material preventing the spread of the illness inside storage facilities, proper harvesting reduces wounds and mechanical damage.

In summary

Mitigating the effects of pests and diseases on sweet potato crops requires effective management and preventative measures. To maintain healthy and productive sweet potato plants, proper sanitation, crop rotation, disease-free planting material, and focused control methods are necessary.