Seed Treatment Methods and Mechanisms

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Questions and Answers

What is the primary purpose of seed pelleting?

To reduce seed treatment costs

To make seeds larger, heavier, and consistent in size (correct)

To protect seeds from moisture

To enhance seed germination rate

Which method is the most common form of seed treatment?

Pesticide pelleting

Seed pelleting

Seed dressing (correct)

Seed coating

What is one of the key ingredients often used in pesticide pelleting?

Water

Organic fertilizers

Chemicals in powder form (correct)

A special binder

Which seed treatment equipment is used for treating seeds in powder form?

Drum Mixer Signup and view all the answers

How does the slurry treatment process work?

Treatment materials are suspended in water and metered accurately Signup and view all the answers

Which of the following is NOT a characteristic of Direct Treaters?

They include manual mixing for treatment Signup and view all the answers

In which way can a Grain Auger contribute to seed treatment?

By applying chemicals as seeds are fed through it Signup and view all the answers

What is the primary use of a shovel in seed treatment?

To spread seeds on a clean surface Signup and view all the answers

What is represented by the symbol 'I' in the efficiency formula for test bio control agents?

Per cent inhibition of the mycelium Signup and view all the answers

Which mechanism involves the antagonist competing with pathogens for nutrients or space?

Competition Signup and view all the answers

Which of the following is NOT one of the four main mechanisms involved in biological control?

Photosynthesis Signup and view all the answers

What is the primary disadvantage of chemical methods for controlling soil-borne diseases?

They can create residual problems. Signup and view all the answers

How does Trichoderma sp. contribute to the lysis of pathogen cell walls?

By secreting hydrolytic enzymes Signup and view all the answers

What is the primary purpose of the polymerase chain reaction (PCR)?

To amplify specific DNA sequences Signup and view all the answers

Which component is essential for starting DNA synthesis during PCR?

Oligo nucleotide primers Signup and view all the answers

What role does Phenazine-l-carboxylic acid play in biological control?

It inhibits pathogen growth. Signup and view all the answers

At what temperature does the denaturation of template DNA occur in PCR?

95°C Signup and view all the answers

Which organism is known to cause hyphal lysis of Gaeumannomyces graminis?

Bacillus sp. Signup and view all the answers

Which of the following statements is true about biological control agents?

They offer protection throughout the crop growth. Signup and view all the answers

What is the role of Taq polymerase in PCR?

To initiate DNA synthesis Signup and view all the answers

How long should the priming region of a PCR primer typically be?

20 to 25 bases Signup and view all the answers

During the annealing step of PCR, which temperature is typically used?

55°C Signup and view all the answers

What happens to the temperature during the last step of PCR?

It remains constant at 72°C Signup and view all the answers

Which of the following statements is true regarding PCR specificity?

The specificity arises from the synthetic oligo nucleotide primers Signup and view all the answers

What is the primary role of an immunoassay?

To reveal the presence of specific complexes between antibodies and antigens Signup and view all the answers

Which type of test involves observing agglutination under a microscope?

Slide Agglutination Test Signup and view all the answers

In an agglutination test, what indicates a positive result?

Visible aggregation of antigens and antibodies Signup and view all the answers

How do antibodies recognize antigens in the body?

By recognizing specific binding sites unique to the pathogen Signup and view all the answers

Which method allows for the separation of mixtures of antigens prior to immuno diffusion?

Immuno electrophoresis Signup and view all the answers

What condition must be met for a precipitation test to be considered positive?

Precipitation of antigens at the interface with the antiserum Signup and view all the answers

Which component of the immune system is primarily involved in recognizing pathogens?

Antibodies Signup and view all the answers

What occurs during the immuno electrophoresis process?

Individual antigens move in distinct patterns according to charge Signup and view all the answers

What is the primary function of wetting agents in aqueous fungicidal preparations?

To reduce surface tension and enhance deposition Signup and view all the answers

Which of the following adjuvants are specifically used to prevent particles from aggregating in a suspension?

Dispersing agents Signup and view all the answers

What distinguishes spreading agents from wetting agents in their application?

Wetting agents must be applied before spreading agents. Signup and view all the answers

Which of the following materials is commonly used as a spreading agent?

Soap Signup and view all the answers

What role do emulsifying agents play in a fungicide formulation?

They help in uniform mixing of immiscible liquids. Signup and view all the answers

Which adjuvant is known for increasing the residual action of fungicidal preparations on plant surfaces?

Stickers Signup and view all the answers

What is the function of soluble formulations such as Soluble Liquid (SL) in pesticide applications?

They provide a means of applying pesticides in a liquid form. Signup and view all the answers

What is a common example of a dispersing agent in fungicide formulations?

Gelatin Signup and view all the answers

What is the primary reason for packaging seeds in dry containers?

To maintain high germination capacity and vigor Signup and view all the answers

Which action is NOT advised when applying pesticides?

Applying at the recommended dose Signup and view all the answers

What should be done with leftover spray solutions?

It should be thrown in barren isolated areas Signup and view all the answers

What type of container is recommended for large quantities of seeds?

Metal or plastic jerricans, or drums Signup and view all the answers

Why is it advised not to reuse empty pesticide containers?

They can hold residues that are harmful Signup and view all the answers

Study Notes

Laboratory Manual for Management of Plant Diseases PAT 101 (1+1)

This manual covers the management of plant diseases.
The manual is prepared by Dr. Shivalingappa Hotkar.
The university is the University of Agricultural Sciences, Dharwad.
The diseases covered include those caused by fungi, viruses, bacteria, nematodes, and mollicutes.
The manual details symptoms of post-harvest diseases.
It discusses diagnosis and detection of post-harvest diseases, based on symptoms.
Seed health testing techniques are included in the manual.
Topics covered include seed-borne diseases, seed treatments, and biocontrol agents.
In-vitro and in-vivo evaluations of fungicides and bactericides are included.
Also, methods of applying plant protection chemicals are detailed.
Symptoms of post-harvest diseases, caused by fungi, viruses, bacteria, and nematodes, are discussed.
Different types of symptoms are grouped into categories: necrosis (death of cells or tissues), hypertrophy and hyperplasia (abnormal increase in size or number of cells), atrophy (reduction in size or number of cells).
Methods for diagnosing diseases based on symptoms, including visual observation, are described.
Diagnosis and detection of plant diseases based on visual symptoms are also covered.
Different diagnostic methods for diseases are discussed, including immunological techniques (immunodiagnostic assays), nucleic acid probe-based methods (PCR), and fluorescence in-situ hybridization (FISH).
Flow cytometry and immuno-sorbent electron microscopy are also mentioned.
Post-harvest diseases including seed infection, seed deterioration, and infection of fruits and vegetables are covered.
The manual includes exercises and content on diagnosis, detection, seed health testing techniques and the management of seed-borne diseases.
Biocontrol agents are also covered as well as their production and application.
Formulation of fungicides are explained.
The manual includes various diagrams, tables, and images of plant diseases.

Seed Health Testing Techniques

Seed health testing is a science to determine the presence or absence of diseases in seeds.
The objectives of seed testing is: detecting the presence of diseases, assessing the health status, and checking for new pathogens during quarantine.
Generalized tests are detailed including: examination of dry seeds, examination of seed washings, incubation methods, seedling symptom test, grow-out test, indexing on indicator test plants, and salvage tests involving fumigation, hot water treatment, hot air treatment, and irradiation.
Specialized tests are also included like X-ray radiography and seed transparency test.
Specialized tests for identifying pathogens like nematodes (sedimentation test, Baerman funnel test), bacteria (phage-plague technique), fungi and viruses (washing test, serological tests, indicator test plants), and electron microscopy (identification/characterization of plant viruses) are included.
Immunological techniques, such as agglutination (slide and tube), precipitation tests are included.

Seed-Borne Diseases and their Management

Seed-borne diseases are caused by pathogens that attack seeds during development, processing, transport, and storage.
There are three main types; internally seed borne (pathogens affect the seed itself), externally seed borne (pathogens are on the seed surface), and those caused by fruiting bodies/spores.
Seeds affected by any type of pathogen lead to reduced germination, morphological changes, and decreased market value.
Seed treatments are methods of disease prevention. This involves mixing, coating, or soaking seeds with chemicals, protectants, nutrients, growth regulators, etc.
Seed treatments are important in preventing seed-borne diseases and improving germination success.
This includes methods to identify potential pathogens, seed disinfection, and seed disinfestations.
A range of crop types (Wheat, Chickpea, Crucifers, Rice, Cotton, Maize, Pearl millet, Sorghum, Soybeans, Cucumis spp., Brinjal, Carrot, Onion, Pepper chilies, Radish, Tomato) and their associated pathogen issues are covered.
The importance and usefulness of seed treatments are also highlighted.
Techniques and considerations are discussed when dealing with seed treatments (e.g., dry treatment, wet treatment and slurry treatment).

Isolation and Testing of Biocontrol Agents

This method is detailed on how to isolate and test the effectiveness of biocontrol agents.
Isolation procedures use serial dilution method on different mediums like Potato Dextrose Agar, Rose Bengal Agar, and Pseudomonas Agar to identify fungal/bacterial colonies.
Techniques for purification of biocontrol agents are discussed, using a single spore isolation method.
There is also an evaluation of how these biocontrol agents (e.g., Trichoderma species, Bacillus species) work in vitro, by comparing in vivo results against control.

Biocontrol Agents, Production and Application

Biological control focuses on managing diseases effectively by using beneficial microorganisms, sometimes called antagonists.
Methods of production and application are detailed.
Mass production of biocontrol agents is important and several production techniques are described which involve different mediums and processes.
The efficacy of various biocontrol agents for managing several post-harvest diseases in various crops is discussed.
Methods such as parasitism, antibiosis, competition, lysis are important factors in biocontrol, affecting pathogens negatively.

Formulations of Fungicides

Different types of fungicide formulations are discussed, including emulsifiable concentrates (EC), wettable powders (WP), dusts, granules, and solutions, which are mixtures of active ingredients (a.i.) and other components.
Properties (e.g., wettability, spreading, sticking, etc) of formulations are mentioned, with potential benefits in agricultural spraying techniques and other aspects.

Safety Measures in Pesticide Usage

This section focuses on safety procedures when handling pesticides.
It outlines critical elements like purchase quantities, storage precautions, proper handling methods, and appropriate disposal techniques.

Methods of Application of Plant Protection Chemicals

This section covers the different approaches of applying plant protection chemicals.
Plant protection chemicals (e.g., fungicides, insecticides, herbicides) are frequently used.
Common approaches described include foliar sprays, dusts, treating tubers/bulbs/fruits, and seed dressing.
Important aspects for each method are detailed.

Plant Protection Appliances

Various plant protection equipment are categorized and described, including sprayers (hand-operated, hydraulic, power) and dusters (hand, power, rotary).
There are descriptions of the construction, function, and applicability of each type in different agricultural contexts (e.g., gardens, nurseries, etc).

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Description

This quiz explores various methods of seed treatment, including seed pelleting and biological control mechanisms. It covers key ingredients, equipment used, and efficiency formulas relevant to enhancing seed treatment processes. Test your knowledge on the different practices implemented in seed treatment.