Pest Management and Fungal Diseases Quiz

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Questions and Answers

Which method is NOT effective in reducing egg-laying adults?

Submerging eggs in water

Employing kerosene light traps (correct)

Utilizing natural predators

Using mercury light traps

Which statement about IR1314 is accurate?

It is classified as a tolerant variety. (correct)

It can be grown in tungro-infested areas.

It is specifically recommended for dry conditions.

It is a commercially available resistant variety.

Which organism is responsible for killing the eggs of certain pests?

Green muscardine

Telenomus triptus (correct)

Frogs

Carabid beetles

What is one of the biological control methods mentioned for pest management?

Feeding on eggs and nymphs by beetles Signup and view all the answers

Which of the following characteristics is true for light traps using mercury bulbs?

They attract a wide range of pest species. Signup and view all the answers

What is the primary symptom of Sheath Blight on leaf sheaths?

Oval gray spots with black brown margins Signup and view all the answers

During which growth stage is Brown Spot most susceptible on seedlings?

Seed germination Signup and view all the answers

What causes the leaf withering seen in Brown Spot infections on leaves?

Fused circular spots on leaves Signup and view all the answers

What is a key visual symptom of Stem Rot on leaf sheaths?

Black irregular lesions near the water line Signup and view all the answers

Where is Sheath Rot primarily found?

At the uppermost leaf sheath enclosing the emerging panicle Signup and view all the answers

What stage of growth is the Sheath Blight most likely to affect?

Heading to maturity Signup and view all the answers

What type of discoloration occurs on grains infected with Brown Spot?

Black spots on glumes and discoloration Signup and view all the answers

Which fungal disease is characterized by irregular lesions with gray centers and brown margins?

Sheath Blight Signup and view all the answers

Which of the following correctly defines a pathogen in the context of plant diseases?

A living organism that causes diseases in plants Signup and view all the answers

What does the term 'epidemic' refer to in the context of plant diseases?

A rapid increase in disease occurrence in a plant population Signup and view all the answers

Which symptom is characteristic of leaf blast caused by Magnaporthe grisea?

Small to spindle-shaped spots with brown borders Signup and view all the answers

At which stage of rice growth is the panicle blast most susceptible?

Booting to heading stage Signup and view all the answers

Which of the following statements about biotic and abiotic agents is correct?

Biotic agents are generally infectious and have the ability to infect plants. Signup and view all the answers

What symptom indicates a black node in the tillering stage of rice?

Black rotten node that breaks later Signup and view all the answers

In which location on the plant are symptoms from panicle blast usually found?

On the nodes of the panicle Signup and view all the answers

Which of the following best describes the seedlings' risk concerning diseases?

Seedlings can suffer from diseases like leaf blast at specific stages. Signup and view all the answers

What is one benefit of intercropping rice with soybean?

Reduces the incidence of green leafhoppers Signup and view all the answers

Which method is suggested to reduce leafhopper populations in rice fields?

Draining water from the field Signup and view all the answers

What characteristic distinguishes the young nymphs of the seed bug?

They are green and slender Signup and view all the answers

What is the effective strategy for applying insecticides to control green leafhoppers?

Incorporate granules into the soil Signup and view all the answers

What environmental factors favor the multiplication of rice bugs?

Evenly distributed rainfall throughout the year Signup and view all the answers

Which of the following organisms is known to specifically kill the eggs of pests in rice?

Small wasps Signup and view all the answers

During which growth stages are rice plants most susceptible to damage from pests?

From flowering to milky stage Signup and view all the answers

What behavior do nymphs exhibit when they are threatened?

Drop to lower parts of the plant Signup and view all the answers

What developmental stage of the rice black bug primarily causes the most damage?

Nymphs Signup and view all the answers

During which life cycle stage do rice black bugs prefer high relative humidity for egg hatching?

Egg stage Signup and view all the answers

Which management option is not effective against rice black bugs?

Granular insecticides Signup and view all the answers

What characteristic primarily distinguishes adult rice black bugs?

Distinct yellowish spots Signup and view all the answers

Which of the following practices is recommended to reduce habitats for rice black bug egg-laying?

Cutting or burning grassy weeds Signup and view all the answers

What is a notable feature of nymphs of the rice black bug?

They have a green abdomen. Signup and view all the answers

What type of varieties can offer resistance to rice black bugs?

Awned (bearded) varieties Signup and view all the answers

Which of the following insects are known to feed on nymphs and adults of the rice black bug?

Lady beetles Signup and view all the answers

What is the best time of day to apply contact insecticides for high efficacy against larvae?

Late afternoon Signup and view all the answers

Which of the following methods is NOT a form of cultural management for grasshoppers?

Application of chemical insecticides Signup and view all the answers

Which characteristic is NOT true of the short-horned grasshopper?

Their nymphs are fully aquatic Signup and view all the answers

What is a significant consequence of grasshopper damage to emerging flowers on rice plants?

Chaffy grains Signup and view all the answers

In which region is the short-horned grasshopper particularly known to cause crop damage?

Pampanga and Mindanao Signup and view all the answers

What management practice can help reduce grasshopper populations besides flooding?

Sweeping along the bunds Signup and view all the answers

What are the primary roles of small wasps in managing pest populations?

Killing eggs of pests Signup and view all the answers

How long is the life cycle duration of a skipper adult, from egg to adult?

7-12 days Signup and view all the answers

Study Notes

Major Pest and Plant Diseases of Rice and Their Management

Plant diseases are disturbances disrupting normal structure, functions, and economic value of the plant (host)
A plant disease is diagnosed through characteristic manifestations of diseased conditions (symptoms) and visible structures (signs) produced by pathogens.
Pathogens are either living (biotic) or nonliving (abiotic) agents. Biotic agents can enter and colonize plant parts and other plants (infectious).
A serious outbreak of a disease in a large plant population over time is called an epidemic.
The triangle diagram illustrates the disease concept. It involves a susceptible host, a conducive environment, and a pathogen.

Diagnosis of Plant Diseases

Plant diseases can be identified by observing the characteristic manifestations of diseased conditions (symptoms) and the presence of visible structures (signs) produced by pathogens.
Symptoms can include discoloration, deformities, or other noticeable anomalies in the plant's structure and/or function.

Causal Agents of Plant Diseases

The causal agents of plant diseases can be living (biotic), like pathogens, or nonliving (abiotic) agents such as environmental factors like high humidity, temperature, or dryness etc.
Biotic causal agents are able to invade and colonize plant parts and other plants (infectious)

Disease Management

Utilize plant resistant varieties
Manage the environment to reduce root disease issues
Reduce plant stress to manage disease susceptiblity
Manage nitrogen fertilization appropriately
Practice proper field sanitation

Specific Diseases and Their Characteristics

Blast (Magnaporthe grisea): This fungal disease presents as spots on leaves(leaf blast), nodes(node blast), and panicles(panicle blast). Susceptible stages range from seedling to tillering to booting to heading.
Sheath blight (Thanatephorus cucumeris): This fungal disease affects leaf sheaths above the waterline, characterized by oval gray spots that enlarge with dark brown margins and gray centers
Brown spot (Cochliobolus miyabeanus): Brown spots on leaves are common on plants in shaded areas, potash deficient, or saline fields, characterized by small, circular spots that fuse causing leaves to wither. (Susceptible: tillering)

Other diseases:

Stem rot (Magnaporthe salvinii): Small, black irregular lesions on leaf sheaths near the water line; stem hollowing out, and many sclerotia are in decaying tissue. (Susceptible: late tillering to maturity).
Bacterial leaf blight (Xanthomonas oryzae): Tiny water-soaked spots on lower leaves of seedlings, enlarged spots turning yellow and dry rapidly, and seedling wilting. (Susceptible: seedling).
-Bacterial leaf streak (Xanthomonas oryzae):* Fine translucent streaks that enlarge, coalesce (merging lesions), brown affected leaves, and leaf withering, susceptible from tillering to maturity. (Susceptible stage: tillering to maturity)

Management Options

Cultural control: Includes practices like bund shaving, leveling fields, collecting insects during land preparation, maintaining standing water, choosing resistant varieties, and optimizing spacing.
Biological control: Emphasizes natural enemies of the pests, like wasps, spiders, and various insects that naturally prey on them.
Chemical control: Involves the use of insecticides, such as granular and foliar sprays during the most vulnerable crop growth stages.

Note: Data extracted from multiple image sources; the images do not always directly correspond to a single topic and may need careful piecing together.

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Description

Test your knowledge on pest management techniques and the symptoms of various fungal diseases affecting crops. This quiz covers biological control methods, specific fungi, and their impact on plants. Challenge yourself to identify key facts and characteristics related to Sheath Blight, Brown Spot, and more.