Agriculture

Sugarcane Diseases and Symptoms

Sugarcane farming is an important agricultural venture in Kenya, with thousands of farmers across the country relying on it for their livelihoods. The crop is mainly grown in western Kenya, contributing significantly to the region’s economy. However, sugarcane farming in Kenya faces various challenges, including diseases that can significantly impact yields and quality.

 

Some of Kenya’s most common sugarcane diseases include smut, mosaic, and rust. These diseases can lead to reduced yields, poor quality sugarcane, and, ultimately, reduced farmer income. Therefore, disease management practices are critical for sustainable sugarcane farming in Kenya.

 

This article examines some of these diseases and how to identify and control them. You can read our sugarcane farming in Kenya guide to know more about sugarcane farming.

 

10 Sugarcane Diseases and How to Identify Them

One main disease is Pokkah Boeng disease of sugarcane. This disease is no sweet treat for farmers. This disease is caused by a virus that attacks the sugarcane plant’s leaves, causing them to curl and become brittle. As a result, the infected sugarcane plant produces fewer stalks and yields, leading to significant economic losses for farmers.

 

The disease is mainly found in Southeast Asia and some parts of Africa. Fortunately, management strategies can help control the spread of Pokkah Boeng, such as removing infected plants and using disease-resistant varieties.

 

Firstly, farmers should only use disease-free planting materials to prevent the spread of the virus. Removing any infected plants as soon as they are detected and disposing of them properly to prevent further spread is also crucial.

 

Additionally, farmers can adopt cultural practices such as crop rotation and maintaining good soil fertility to reduce the disease’s impact. They can also use insecticides to control the leafhopper vectors that transmit the virus.

 

Finally, breeding disease-resistant sugarcane varieties can also be an effective long-term solution for controlling Pokkah Boeng disease. Farmers can reduce their reliance on chemical control and improve their yields by developing resistant cultivars. Other sugarcane diseases to know about are:

 

1. Leaf Scald Disease of Sugarcane

Leaf scald disease is a bacterial disease that affects sugarcane plants, causing yellowish streaks on the leaves. The streaks later turn brown and develop into large, irregular-shaped lesions that may join to form a larger area of dead tissue.

 

The disease is caused by the bacterium Xanthomonas albilineans, which spreads through contaminated planting materials, insect vectors, and mechanical transmission.

 

Leaf scald disease can significantly reduce the sugarcane yield, especially in areas with high rainfall and humidity. In severe cases, the disease can kill the sugarcane plants, resulting in complete crop loss.

 

Effective management of leaf scald disease is critical to prevent significant economic losses for sugarcane farmers. The management strategies include disease-free planting materials, crop rotation, removal of infected plants, and use of disease-resistant varieties.

 

2. Yellow Leaf Disease in Sugarcane

Yellow leaf disease is a viral disease that affects sugarcane plants, causing yellowing and necrosis of the leaves, leading to reduced plant growth and yield. The disease is caused by the Sugarcane yellow leaf virus (SCYLV) and is spread by aphids, which transmit the virus when feeding on the sugarcane plants.

 

Yellow leaf disease is widespread in sugarcane-growing regions worldwide and significantly threatens sugarcane production. The disease can lead to significant economic losses for sugarcane farmers, as it can reduce the yield and quality of the sugarcane. The management of yellow leaf disease includes using disease-free planting materials, applying insecticides to control the aphid vectors, and using resistant sugarcane varieties.

 

3. Red Rot of Sugarcane

Red rot is a fungal disease that affects sugarcane plants, causing a reddish discoloration of the stem and internal decay of the sugarcane plant. The disease is caused by the fungus Colletotrichum falcatum, which enters the plant through wounds or natural openings such as leaf scars or bud channels.

 

Red rot disease is widespread in sugarcane-growing regions worldwide and can cause significant economic losses for sugarcane farmers. The disease can reduce the yield and quality of the sugarcane by up to 50%, and in severe cases, it can result in the death of the plant.

 

Effective management of red rot disease is essential to prevent significant economic losses for sugarcane farmers. The management strategies include disease-free planting materials, crop rotation, removal of infected plants, and use of fungicides. Proper field sanitation practices, such as removing infected plant debris and weed hosts, can also help reduce the spread of the disease.

 

In addition, breeding disease-resistant sugarcane varieties is an effective long-term solution for controlling red rot disease. Farmers can reduce their reliance on chemical control and improve their yields by developing resistant cultivars. Early detection and management of red rot disease are crucial to minimizing its impact on sugarcane production.

 

4. Ratoon Stunting Disease of Sugarcane

Ratoon stunting disease (RSD) is a bacterial disease that affects sugarcane plants, causing stunting of the plants and reducing the number and size of the sugarcane shoots. The disease is caused by the bacterium Leifsonia, which infects the sugarcane plant through wounds during harvesting or other mechanical injuries.

 

RSD is a significant threat to sugarcane production worldwide, and it can cause significant economic losses for farmers. The disease can reduce the yield and quality of sugarcane by up to 50%, and in severe cases, it can cause complete crop failure.

 

Effective management of RSD is crucial to prevent significant economic losses for sugarcane farmers. The management strategies include the use of disease-free planting materials, proper field sanitation practices, removal of infected plants, and use of resistant sugarcane varieties. Insect vectors, such as leafhoppers, can also transmit the RSD bacteria, and controlling their population through the use of insecticides can help prevent the spread of the disease.

 

It is also essential to implement cultural practices that minimize mechanical injuries during harvesting, such as using proper harvesting equipment and techniques. Early detection and management of RSD are crucial to minimizing its impact on sugarcane production. By implementing these strategies, sugarcane farmers can protect their crops from significant economic losses and improve their yields.

 

5. Brown Stripe of Sugarcane Disease

Brown stripe is a fungal disease that affects sugarcane plants, causing brown lesions on the leaves and stems of the plant. The disease is caused by the fungus Pithomyces chartarum, which infects the sugarcane plant through the stomata or natural openings.

 

Brown stripe disease significantly threatens sugarcane production, especially in regions with high humidity and warm temperatures. The disease can cause significant yield losses by reducing the growth and vigor of the sugarcane plant. In severe cases, it can also cause the death of the plant.

 

Effective management of brown stripe disease is essential to prevent significant economic losses for sugarcane farmers. The management strategies include the use of disease-free planting materials, proper field sanitation practices, removal of infected plants, and use of fungicides. Crop rotation and the use of resistant sugarcane varieties can also help reduce the severity of the disease.

 

Good cultural practices, such as proper drainage, irrigation, and fertilizer management, can also help reduce the severity of brown stripe disease. Early detection and management of the disease are crucial to minimizing its impact on sugarcane production. By implementing these strategies, sugarcane farmers can protect their crops from significant economic losses and improve their yields.

 

6. Sugarcane Mosaic Virus

Sugarcane mosaic virus (SCMV) is a plant virus that infects sugarcane plants, causing mosaic symptoms on the leaves, which appear as yellow and green patches or streaks. The virus is transmitted through sap, mechanical means, or by insect vectors, such as aphids.

 

SCMV is a significant threat to sugarcane production and can cause significant economic losses for farmers. The virus can reduce the yield and quality of sugarcane by up to 30%, and in severe cases, it can cause the death of the plant.

 

Effective management of SCMV is crucial to prevent significant economic losses for sugarcane farmers. The management strategies include using disease-free planting materials, proper field sanitation practices, removing infected plants, and using resistant sugarcane varieties. Insect control measures, such as using insecticides or biological control agents, can also help prevent the spread of the virus.

 

It is also essential to implement cultural practices that minimize mechanical injuries during harvesting, such as using proper harvesting equipment and techniques. Early detection and management of SCMV are crucial to minimizing its impact on sugarcane production. By implementing these strategies, sugarcane farmers can protect their crops from significant economic losses and improve their yields.

 

7. Gumming Disease

Gumming disease causes sugarcane to ooze gum from the stalks. The disease is caused by the bacterium Xanthomonas campestris pv. vasculorum, which infects the plant through wounds, such as those caused by insect feeding or mechanical damage during cultivation.

 

Gumming disease is a significant threat to sugarcane production and can cause significant economic losses for farmers. The disease can reduce the yield and quality of sugarcane by up to 50%, and in severe cases, it can cause complete crop failure.

 

The disease can be introduced using various management strategies such as planting disease-free varieties, proper field sanitation practices, removal of infected plants, and use of resistant sugarcane varieties. Insect control measures, such as the use of insecticides or biological control agents, can also help prevent the spread of the disease.

 

It is also essential to implement cultural practices that minimize mechanical injuries during cultivation, such as using proper equipment and techniques. Early detection and management of gumming disease are crucial to minimizing its impact on sugarcane production. By implementing these strategies, sugarcane farmers can protect their crops from significant economic losses and improve their yields.

 

8. Anthracnose Disease

Anthracnose is a fungal disease that can affect sugarcane plants. The disease is caused by the fungus Colletotrichum falcatum, and it can infect all parts of the sugarcane plant, including leaves, stalks, and buds.

 

Anthracnose causes small, circular, and water-soaked lesions on the leaves, which can grow larger and merge together, leading to leaf blight. On the stalks, the disease can cause dark, sunken lesions, which can lead to rotting and cracking of the stalks. The buds can also be infected, leading to reduced shoot growth and yield loss.

 

In addition to the visible symptoms, anthracnose can weaken sugarcane plants, making them more susceptible to other diseases and pests.

 

It is important to use disease-free planting materials to control anthracnose, avoid waterlogging, and practice good crop management practices. Fungicides can also control the disease, but they should only be used as a last resort and applied according to the manufacturer’s instructions. Proper sanitation practices, such as removing and destroying infected plant debris, can also help prevent the spread of the disease.

 

9. Smut Whip

Smut and whip diseases are two separate diseases that can infect sugarcane plants. Still, they are often grouped together because they have similar symptoms and are caused by related fungi.

 

Smut disease is caused by the fungus Sporisorium scitamineum, while whip disease is caused by the fungus Ustilago scitaminea. Both diseases can infect sugarcane plants through spores, which can be spread by wind, rain, or infected planting material.

 

Smut disease spores can infect the sugarcane plant through natural openings or wounds on the plant, such as those caused by insects or damage from farming practices. Once the spores enter the plant, they grow and multiply, leading to the characteristic black, powdery masses of spores that can be seen on the plant.

 

Whip disease spores can also enter the sugarcane plant through wounds or natural openings. Once inside the plant, the fungus grows and multiplies, causing the leaves to wilt and turn yellow or brown. The whip-like structures that give the disease its name can be seen emerging from the infected plant parts.

 

Smut whip sugarcane disease can be controlled by growing and moderately resistant varieties such as the D8484 and KEN 83-737 varieties. Other ways include:

 

Use of high-quality seed cane from a certified Nursery

Hot water treatment of setts at 50o C for 30 minutes for Nursery ‘A’

seed cane.

Sett treatment with fungicides (Carbendazim)

Roguing and burning or burying of smut whips before they open

Discourage ratooning of fields with high incidences of smut

Crop rotation

10. Pineapple Disease

This disease affects sugarcane during the first week of planting. It is caused by a fungus known as Ceratocystis. If not controlled on time, the failure rate can be as high as 95%. The fungus affects the crop through cut ends and later spreads to other parts of the plant. Infected plants turn reddish in color, while the interior of the cane becomes hollow and blackend.

 

Pineapple disease is most destructive when farmers plant their sugarcane during the dry season. There are several ways in which farmers can control the disease. The first is to use disease-resistant varieties and to plant in properly drained soils. Other management strategies include:

 

Using 3-5 eye-budded setts

Planting in soils with adequate moisture

Treating setts with fungicides such as propiconazola