Plant diseases MCQ Quiz - Objective Question with Answer for Plant diseases - Download Free PDF

The correct answer is Zinc deficiency.

• Because of Zn deficiency in rice plants affected with the Khaira disease.
• Symptoms: Initially yellow color spots appear on leaves which later on turn to brown spots.
• These spots will appear on the upper side of the leaves.
• This disease will appear both in the nursery and main field. 

Important Points

• Khaira disease of Rice first appeared in India at Pantnagar, Uttarkhand, and was reported by Y. L. Nene.

Hence, Zinc deficiency leads to Khaira disease in rice which affects the plants and will also have an effect on the yield.

The correct answer is b and c. Key Points

Pteridophytes:-

• These are a group of vascular plants that reproduce via spores and do not produce seeds.
• They are commonly referred to as ferns and their relatives.
• Pteridophytes are an ancient group of plants that have been around for hundreds of millions of years and have played an important role in the evolution of Earth's ecosystems. 
• Pteridophytes have well-developed vascular tissue, which includes xylem and phloem. (Hence statement a is correct and b is incorrect)
• This vascular tissue allows for the transport of water, nutrients, and food throughout the plant.
• Mosses are not examples of pteridophytes.
• Mosses belong to a different group of non-vascular plants called Bryophytes. (Hence statement c is incorrect)
• While both pteridophytes and bryophytes are non-seed plants and share some similarities, they belong to distinct evolutionary lineages and have significant differences in their life cycles, anatomy, and reproductive strategies.
• Pteridophytes are found in a variety of habitats, including forests, wetlands, and rocky areas. They are especially abundant in moist and shaded environments.
• Pteridophytes reproduce sexually when the gametophytes (male and female) release sperm and eggs, which combine to form a zygote. This zygote then develops into a new sporophyte plant.

The correct answer is option 1.

Key Points

• Pathogens are disease-causing microorganisms that can include bacteria, viruses, fungi, and protozoa. Hence, option 1 is correct.
• They invade the body and cause infections or diseases in humans, animals, and plants.

Additional Information

• Bacteria: While some bacteria are pathogenic (disease-causing), many bacteria are harmless or beneficial (e.g., gut bacteria).
• Archaea: These are ancient microorganisms found in extreme environments; they do not cause diseases.
• Protozoa: Some protozoa (e.g., Plasmodium which causes malaria) are pathogenic, but not all protozoa cause diseases. 

The correct answer is Viral.

Key Points

• Bunchy top disease of banana is caused by the Banana Bunchy Top Virus (BBTV).
• BBTV is a single-stranded DNA virus belonging to the genus Babuvirus in the family Nanoviridae.
• This virus primarily affects banana and plantain plants, leading to significant yield losses.
• The disease is transmitted by the banana aphid (Pentalonia nigronervosa), which spreads the virus from infected to healthy plants.
• Symptoms include stunted growth, dark green streaks on the leaves, and the characteristic bunchy top appearance where leaves are bunched at the top of the plant.

Additional Information

• Transmission Mechanism:
  • The primary vector, banana aphid, acquires the virus by feeding on the phloem of infected plants.
  • The virus is then transmitted to healthy plants during subsequent feeding activities by the aphids.
• Symptoms of Bunchy Top Disease:
  • Shortened and narrower leaves with chlorotic leaf margins.
  • Overlapping of leaves giving a rosette or "bunchy top" appearance.
  • Dark green streaks on petioles and leaf midribs.
• Economic Impact:
  • Bunchy top disease can cause severe yield loss, making it one of the most devastating diseases for banana cultivation.
  • Infected plants often do not produce fruit, or the fruit produced is of poor quality.
• Management and Control:
  • Use of virus-free planting material is crucial for controlling the spread of the disease.
  • Regular monitoring and control of banana aphid populations help reduce transmission.
  • Eradication of infected plants to prevent the spread to healthy plants.

The correct answer is Iron.

Key Points

• Iron is an essential micronutrient for plants and is crucial for the synthesis of chlorophyll.
• Deficiency of iron in plants results in interveinal chlorosis, where the veins remain green while the areas between them turn yellow.
• Iron is vital for the functioning of several enzyme systems in plants, especially those involved in photosynthesis and respiration.
• Iron deficiency often occurs in alkaline soils where iron becomes unavailable to plants due to high pH levels.

Additional Information

• Chlorosis
  • Chlorosis is a condition in which leaves produce insufficient chlorophyll, leading to pale or yellow leaves.
  • It is often caused by nutrient deficiencies, particularly iron and magnesium, but can also be due to poor soil drainage, damage to roots, or high soil pH.
• Micronutrients
  • Micronutrients are essential elements required by plants in very small quantities.
  • They include iron, manganese, zinc, copper, molybdenum, boron, and chlorine.
  • Despite their small required amounts, they are critical for plant growth and development.
• Photosynthesis
  • Photosynthesis is the process by which green plants use sunlight to synthesize foods with the help of chlorophyll.
  • It involves the conversion of carbon dioxide and water into glucose and oxygen.
  • Iron plays a key role in chlorophyll synthesis and electron transport chain in photosynthesis.
• Soil pH
  • Soil pH is a measure of the acidity or alkalinity of soil.
  • The availability of nutrients to plants is greatly influenced by soil pH.
  • Iron becomes less available to plants in alkaline soils (high pH), leading to deficiencies.

The correct answer is Brinjal.

Key Points

•  The fungus Phomopsis vexans causes Phomopsis blight disease in brinjal.

Image sowing Phomopsis blight disease in Brinjal:

The correct answer is fire blight.

• The disease related to apples is known as fire blight.

Key Points

• Fire blight disease:
  • It is a common and very destructive bacterial disease that appears in apples and pears.
  • It is caused by the bacterium Erwinia amylovora.
  • The disease kills blossoms, fruit, shoots, twigs, branches, and entire apple trees. 
  • The disease appears in the spring when temperatures get above 19⁰ C.
  • Climatic conditions like rain, heavy dew and high humidity favour the infection.

Additional Information

• The red rust disease is a disease of the tea plant in which orange-brown, velvety spots develop on the leaves of infected plants. 
• The tikka disease is a disease of the groundnut plant.
• The green ear disease is a disease of the pearl millet.

• Loose smut of wheat is caused because of a fungus Ustilago tritici.
• A plant infected from it generally produces the head earlier than the healthy plants.

The correct answer is option 3 i.e., Colletotrichum falcatum.

• Red rot of sugarcane is caused by Colletotrichum falcatum.
• Colletotrichum falcatum is a fungus.
• It causes severe loss in yield and quality.
• The red rot affected field must be rotated with rice for one season and other crops for two seasons.
• The accepted name,'Red rot' was given in 1906 by Sir E. J. Butler.
• He was an imperial Mycologist in India, who was then working at Pusa, Bihar.

The correct answer is option 1, i.e Crown Gall.

• Crown gall is a disease caused by soil-inhabiting bacterium, Agrobacterium tumefaciens.
• As the disease progresses, plants lose their strength and may eventually die.
• This disease occurs on plants including grapes, raspberries, blackberries, and roses.

• Potato mosaic is NOT a seed-borne disease.
• It is a disease caused by a virus which affects the potato plant.
• Generally, mosaic viruses that infect potatoes are transmitted by aphids.
• They feed on the sap of infected plants and transmit the virus to healthy plants. 
• There are many different types of mosaic diseases that attack the potato crop.
• Most of the time, as the name suggests, the leaves show green and dark green mosaic patterns.
• The leaves may also show faint yellow patches on the leaves.
• The attacked or affected plants remain stunted and sick.
• The disease also affects tubers and their Size and numbers are reduced.
• In some other times, the leaves may show necrosis of tissues along the vein. 

The correct answer is peanuts.

Key Points

• Tikka disease is a serious disease occurring in the groundnut-growing areas in India.
• Peanut leaf spots (early leaf spots and late leaf spots) are commonly called. " Tikka" disease.
• It causes almost complete discolouration and yields a loss of 50 percent or more depending on the severity of the disease.
• Leaf spot disease is affected by epidemic weather parameters such as hot and wet conditions.
• Young spots lack a bright yellow aura, which develops around older people.

Additional Information

• Peanuts, which peanuts, Pindar, or monkey nut (UK) is also known as, and Taxonomic from the Arcis Haipogia is classified as, mainly from food seeds for a harvest of crops grown for Is. 
• The world's annual production of shell peanuts in 2016 was 44 million tonnes, led by China with 38% of the world's total.
• In India, Gujarat is the largest producer of groundnuts.
• Andhra Pradesh is the second-largest producer of groundnut.
• The Peanut Research Directorate is located in Junagadh, Gujarat.

• Karnal bunt disease is related to wheat.
• Karnal bunt (also called partial bunt) is caused by the fungus Tilletia indica which infects grains at flowering.
• It reduces grain quality through the production of masses of powdery spores that discolor the grain and grain products.
• It is recognized by a fishy smell that taints the grain.
• The name comes from the city in India, Karnal, where the disease was first identified. 

The correct answer is Only II.

Key Points

• Rust of wheat is a disease that damages the wheat grains due to infection caused by fungi. Hence II pair is correct.
• The rust of wheat is caused by the fungus Puccinia
• Puccinia is a heteroecious fungus that requires two different hosts for the completion of its life cycle.
• Puccinia is also known as Rust Fungi.
• Citrus canker is a bacterial disease that affects citrus plants and fruits. Hence I pair is Incorrect.
• Citrus canker is a bacterial disease affecting Citrus species caused by the Xanthomonas axonopodis. It affects Citrus species like lime and orange.

Additional Information

• Some Bacterial diseases of Plants are:
  • Crown Gall - Agrobacterium tunefaciens
  • Common blight of beans - Xanthomonas campestris
  • Soft rot - Erwinia carotovora
• Some fungal diseases of plants are:
  • Late blight of potato - Phytoplithora Infestans
  • Black rust of wheat - Puccinia graminis 
  • Loose smut of wheat - Ustilago nuda

Explanation:

• Red rot is the disease of sugarcane. It is one of the most severe of the known diseases of sugarcane. It was first described from Java by Went in 1893.
• Pathogen: Colletotrichum falcatum Went 
• Host: Saccharum officinarum Sugarcane
• Symptoms: 

1. Fruit - extensive mould, lesions: black or brown
2. Leaves - abnormal colours, abnormal patterns, necrotic areas
3. Stems - canker on the woody stem, dieback, discoloration of bark

Additional Information