The disease is quite common in India, and occurs on about three week old plants. Since this blight occurs earlier than the ‘late blight’ of potato (caused by Phytophthora infestans), it is called ‘early blight.’
Prevention Measures:
Field sanitation and rotation of crops can minimize the disease.
Regular spray of fungicides like Dithane Z-78 controls the disease.
Blast Disease of Rice
Pathogen Pyricularia Oryzae is the enemy number one of rice crop and occurs in India frequently.
Spindle-shaped spots, ash-coloured in centre with brown margins, appear on the leaves, culms, glumes, and the stalk (neck) of the panicle. The ears are also infected and bend downward due to rotting of the stalk.
Grey Blight of Tea (Thea Sinensis)
This is the most common blight disease of tea leaves and does considerable damage to the crop. First, small brown spots appear which later spread and cover the entire leaf blade. The old lesions turn grey and masses of conidia appear as black dots on the grey background. The infected portions turn brittle and fall off, leaving irregular cuts on the leaves.
Prevention
The blighted leaves should be collected and burnt to prevent infection next year.
Spraying of the crop should be done frequently by Bordeaux mixture.
Water-logging favours the disease and, therefore, should be avoided.
Loose Smut of Wheat
Plants, produced by internally-infected seeds, contain the hyphae in every nook and corner of their body. But marked symptoms appear only when ‘ears’ come out. Sometimes, the infected plants are stunted in Growth. The ears instead of containing grains contain black mass of spores. The sori in the early stages are covered by a thin membrane derived from host tissue but later the membrane ruptures and the spores become a loose mass; hence the name ‘loose’ smut.
Seeds for sowing should be obtained from reliable places where the disease does not occur.
If there is any doubt, the seeds may be treated by ‘hot water method’. The method was discovered by Jensen in 1889. Seeds are soaked in shallow warm water contained in pots and then spread out in the scorching sun during the day. The hyphae die due to the heat of the sun, much quicker than the embryo. The safety line is very thin and there is every chance of killing the seeds. But the risk is worth taking.
Use of resistant varieties is the best method of avoiding the disease.
Black Stem Rust of Wheat
It is a macrocyclic, heteroecious rust as it produces all the five known types of spores (basidiospores, spermatia, aeciospores, uredospores and teliospores) and needs two hosts – wheat and barberry, to complete the life cycle. Uredo-and teliospores are produced on wheat while spermatia and aeciospores are produced on barberry. Basidiospores are produced on promycelium formed by teliospores on germination.
Preventive measures
Rust-resistant varieties of wheat are available and their use is the safest and cheapest method of control.
For a heteroecious rust, like the black rust of wheat, it might be expected that eradication of one host – the economically unimportant host, barberry, may control the disease by cutting down the life cycle of the fungus.
Smut of Maize
Common smut of corn, caused by Ustilago maydis, is easily identified by tumor-like galls that form on actively growing host Tissues and contain masses of dark, sooty teliospores. Throughout most of the world, common smut is considered to be a troublesome disease of corn.
Ustilago maydis infects two hosts: maize (Zea mays) and teosinte (Zea mexicana). Like other smut diseases, common smut of corn derives its name from the sooty masses of teliospores found on infected host plants.
The most obvious symptoms are tumor-like galls that vary in size from less than 1 cm to more than 30 cm (0.4-12 inch) in diameter. All meristematic tissues are susceptible to infection. Galls are found most frequently on ears, tassels, stalks, nodal shoots, and mid-ribs of leaves.
Control Measures
Use of resistant varieties is the safest and cheapest method of control.
Soil sanitation- The soil should be sprayed with fungicides to kill the fungus present in the soil.
Late Blight of Potato
The disease is worldwide in occurrence and is also reported from all parts of India. Epiphytotics never occur in the plains, but are frequent in the hills. The non-availability of high relative humidity during the crop season (October-December) prevents the disease occurrence. The fungus, present in potato tubers, fails to survive the high summer temperature in the plains. The disease recurrence occurs through ‘seeds’ (tubers) stored in cold-storages.
The name late blight, is given to this disease because, compared to another disease-early blight (caused by Alternaria solani), it occurs late in the season. The brown spots appear on leaves only at the time of flowering; grow very fast and soon cover the entire foliage. Ultimately, the infection reaches the underground portions of the plant and infects the tubers. Independent infection of tubers also takes place by zoospores present in the soil.
Prevention measures
The seed tubers should be free from the disease. This requires strict seed tuber inspection at the cutting time. This measure will eliminate direct infection.
Storage of potato tubers in cold storage rooms reduces or even checks the progress of the rot.
Considerable success has been achieved in the perfection of resistant varieties of potato at the potato breeding station, Simla. Growing these will provide an increasing opportunity to combat the disease.
Resistance alone has not effectively checked the disease. Therefore the complete control of blight is accomplished by the application of protectant fungicides.
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Diseases of plants caused by fungi are a major problem in agriculture and Horticulture-2/”>Horticulture. They can cause significant losses in crop yields and quality, and can also make plants unsightly and unmarketable.
There are many different types of fungal diseases, but they all share some common characteristics. Fungi are organisms that live on or in other organisms, and they obtain their nutrients from the living or dead tissues of their hosts. Fungi can cause disease by attacking the roots, stems, leaves, flowers, or fruits of plants.
The symptoms of fungal diseases can vary depending on the type of fungus and the plant it is infecting. Some common symptoms include wilting, yellowing, spotting, and rotting. In severe cases, fungal diseases can kill plants.
There are a number of ways to control fungal diseases. One way is to use fungicides, which are chemicals that kill fungi. However, fungicides can be expensive and can also harm beneficial organisms, such as insects that pollinate plants. Another way to control fungal diseases is to use resistant varieties of plants. Resistant varieties have been bred to be less susceptible to certain types of fungi.
Cultural practices can also help to control fungal diseases. These practices include planting disease-free plants, rotating crops, and avoiding planting susceptible plants in areas where the disease is known to occur.
Fungicides are chemicals that are used to control fungal diseases. They can be applied as sprays, dusts, or granules. Fungicides work by killing the fungi that cause disease, or by preventing them from growing.
There are many different types of fungicides available, and they vary in their effectiveness against different types of fungi. Some fungicides are broad-spectrum, meaning they are effective against a wide range of fungi. Others are more specific, meaning they are only effective against certain types of fungi.
Fungicides can be used to control a variety of fungal diseases, including black spot, blight, canker, crown gall, Fusarium wilt, leaf spot, mildew, powdery mildew, rust, scab, smut, Verticillium wilt, and white mold.
Fungicides can be effective in controlling fungal diseases, but they should be used with care. Some fungicides can be harmful to the Environment, and they can also harm beneficial organisms, such as insects that pollinate plants. It is important to read the label carefully before using any fungicide, and to follow the directions exactly.
Resistant varieties of plants are varieties that have been bred to be less susceptible to certain types of fungi. Resistant varieties are often available for major crops, such as corn, soybeans, and wheat.
Resistant varieties can be an effective way to control fungal diseases. However, it is important to note that resistant varieties are not always 100% effective. Fungi can evolve to overcome resistance, so it is important to rotate resistant varieties with susceptible varieties.
Cultural practices can also help to control fungal diseases. These practices include planting disease-free plants, rotating crops, and avoiding planting susceptible plants in areas where the disease is known to occur.
Planting disease-free plants is one of the most important ways to prevent fungal diseases. Disease-free plants can be obtained from reputable nurseries or seed companies.
Rotating crops is another important way to prevent fungal diseases. Rotating crops means planting different crops in the same area each year. This helps to break the life cycle of fungi, and it also helps to prevent the build-up of soilborne diseases.
Avoiding planting susceptible plants in areas where the disease is known to occur is another important way to prevent fungal diseases. If you know that a particular disease is a problem in your area, you should avoid planting susceptible plants in that area.
By following these practices, you can help to prevent fungal diseases from damaging your plants.
What are the most common diseases of plants caused by fungi?
The most common diseases of plants caused by fungi are:
Fusarium wilt is a fungal disease that affects a wide range of plants, including tomatoes, potatoes, and strawberries. It is caused by the fungus Fusarium oxysporum, which can enter the plant through the roots or wounds. Fusarium wilt causes the leaves to wilt and turn yellow, and the plant eventually dies.
Powdery mildew is a fungal disease that affects a wide range of plants, including roses, grapes, and cucumbers. It is caused by the fungus Erysiphe cichoracearum, which forms a white powdery coating on the leaves and stems of the plant. Powdery mildew can weaken the plant and make it more susceptible to other diseases.
Apple scab is a fungal disease that affects apples. It is caused by the fungus Venturia inaequalis, which forms black spots on the apples. Apple scab can make the apples unsightly and inedible.
Black spot is a fungal disease that affects roses. It is caused by the fungus Diplocarpon rosae, which forms black spots on the leaves and petals of the rose. Black spot can weaken the rose and make it more susceptible to other diseases.
Leaf spot is a fungal disease that affects a wide range of plants, including tomatoes, potatoes, and peppers. It is caused by a variety of fungi, which form spots on the leaves of the plant. Leaf spot can weaken the plant and make it more susceptible to other diseases.
How can I prevent diseases of plants caused by fungi?
There are a number of things you can do to prevent diseases of plants caused by fungi, including:
Plant resistant varieties of plants.
Practice good sanitation.
Rotate crops.
Water properly.
Avoid overfertilizing.
Remove diseased plants.
Use fungicides as needed.
What are the symptoms of diseases of plants caused by fungi?
The symptoms of diseases of plants caused by fungi vary depending on the type of fungus and the plant that is affected. However, some common symptoms include:
Wilting
Yellowing of leaves
Brown or black spots on leaves
Death of plant parts
How are diseases of plants caused by fungi treated?
There are a number of ways to treat diseases of plants caused by fungi, including:
Using fungicides
Removing diseased plant parts
Practicing good sanitation
Rotating crops
Watering properly
Avoiding overfertilizing
What are the effects of diseases of plants caused by fungi?
The effects of diseases of plants caused by fungi can vary depending on the type of fungus and the plant that is affected. However, some common effects include:
Reduced crop yields
Loss of plant life
Damage to plant tissues
Increased susceptibility to other diseases
Which of the following is not a type of plant disease?
(A) Bacterial disease
(B) Viral disease
(C) Fungal disease
(D) Insect-borne disease
Which of the following is not a symptom of a plant disease?
(A) Wilting
(B) Yellowing
(C) Browning
(D) Death
Which of the following is not a type of plant pathogen?
(A) Bacteria
(B) Viruses
(C) Fungi
(D) Animals
Which of the following is not a way to control plant diseases?
(A) Using pesticides
(B) Using fungicides
(C) Using resistant varieties
(D) Using cultural practices
Which of the following is not a benefit of using resistant varieties to control plant diseases?
(A) They are more effective than pesticides.
(B) They are less harmful to the environment.
(C) They are less expensive to use.
(D) They are more sustainable in the long run.
Which of the following is not a cultural practice that can be used to control plant diseases?
(A) Rotating crops
(B) Planting resistant varieties
(C) Using clean seed
(D) Spacing plants properly
Which of the following is not a type of pesticide?
(A) Insecticide
(B) Fungicide
(C) Herbicide
(D) Rodenticide
Which of the following is not a type of fungicide?
(A) Copper sulfate
(B) Mancozeb
(C) Chlorothalonil
(D) Malathion
Which of the following is not a type of herbicide?
(A) Glyphosate
(B) Atrazine
(C) 2,4-D
(D) Malathion
Which of the following is not a type of rodenticide?
(A) Warfarin
(B) Bromethalin
(C) Strychnine
(D) Malathion
Which of the following is not a benefit of using pesticides?
(A) They can control pests quickly and effectively.
(B) They are relatively inexpensive to use.
(C) They are easy to apply.
(D) They are safe for humans and the environment.
Which of the following is not a risk of using pesticides?
(A) They can harm humans and other animals.
(B) They can contaminate water supplies.
(C) They can harm beneficial insects.
(D) They can build up in the environment.
Which of the following is not a benefit of using resistant varieties?
(A) They are more effective than pesticides.
(B) They are less harmful to the environment.
(C) They are less expensive to use.
(D) They are more sustainable in the long run.
Which of the following is not a risk of using resistant varieties?
(A) They can become susceptible to new pests.
(B) They can be more expensive than susceptible varieties.
(C) They can require more management than susceptible varieties.
(D) They can be less productive than susceptible varieties.
Which of the following is not a cultural practice?
(A) Rotating crops
(B) Planting resistant varieties
(C) Using clean seed
(D) Using pesticides
Which of the following is not a benefit of rotating crops?
(A) It helps to control pests.
(B) It helps to control diseases.
(C) It helps to control Weeds.
(D) It helps to improve Soil fertility.
Which of the following is not a benefit of planting resistant varieties?
(A) They are more effective than pesticides.
(B) They are less harmful to the environment.
(C) They are less expensive to use.
(D) They are more sustainable in the long run.
Which of the following is not a benefit of using clean seed?
(A) It helps to control pests.
(B) It helps to control diseases.
(C) It helps to control weeds.
(D) It helps to improve crop yields.
Which of the following is not a risk of using pesticides?
(A) They can harm humans and other animals.
(B) They can contaminate water supplies.
(C) They can harm beneficial insects.
(D) They can build up in the environment.
Which of the following is not a risk of using resistant varieties?
(A) They can become