Seed Technology Test - 1

Soil, Perlite, and sphagnum moss can be growing media for raising the seedling in the nursery.

Key Points

• Growing media are materials that plants grow in. They are specifically designed to support plant growth.
• They can be either solid or liquid.
• Important components of growing media:
  • Physical support
  • Aeration
  • Water Supply
  • Supply of mineral nutrients.
• Examples: Peat moss, Vermiculite, Perlite, shredded coconut husk, or compost materials plus starter nutrients and wetting agent.

Additional Information

Important components of nursery:

• Water pond/ tank
• Water pump
• Seed and fertilizer storeroom
• Implement shed
• Mother bed/ germination area
• Potting area
• Seedling raising area, etc.,

The correct answer is Heading Back.

Key points:

• Heading Back: When the terminal portion of a branch or a shoot is removed partially, leaving the basal portion intact.
• Pruning is the art and science of cutting away of portion of plant to improve its shape, to influence its growth, flowering and fruitfulness and to improve the quality of the product.
• Pruning is done to divert a part of plat energy from one part to another.
• If a small portion of a terminal of a branch or shoot is removed, it is called ‘light pruning’.
• When a longer terminal portion is removed, it is called ‘medium pruning’, and
• If the pruning is severe it is called as Bulk or Heavy pruning.
• For good fruit production only judicious heading back or thinning out should be preferred.

Additional Information

• Dehorning refers to cutting away the main limbs or thick major branches.
• Staking is a practice to support the plants and keep the plants and fruits off the ground.
• Staking is especially practiced in Tomato crop.
• Staking helps in maintaining the health of the plant.
• There are lesser chances of plants getting infested with pests and diseases by staking.

The correct answer is Chlorpropham

• Chlorpropham is used as anti-sprouting in Potato.
• Chlorpropham (or CIPC) is chemically isopropyl-N-(3-chlorophenyl) carbamate, it is the most generally used anti-sprout in potatoes.
• This chemical interferes with cell division and inhibits sprout development.
• The anti-sprout chemical is used to maintain the quality of substance in storage.
   

Important Points

•  Chlorpropham is the herbicide that is used to stop the growth of weeds. this is used to prevent the sprouting of potatoes.

The correct answer is Nucleus seed.

• Seeds which are the initial seed of an improved variety with limited quantity is known as Nucleus seed.
• These seeds are genetically cent percent pure.
• These seeds are produced directly by the originating plant breeder at the research institute.
   

Additional Information

The correct answer is Both Statement I and Statement II are false.

Explanation

Statement I

• The moisture content is a measure of the amount of water present in the grain.
• Moisture content on a wet basis (wb) is always lesser than the moisture content on a dry basis (db) because the wet basis considers the total weight of the grain whereas the dry basis considers only the dry weight of the grain.

Total weight = Wet weight + Dry weight

Moisture content (wb) = Wet weight ÷ Total weight 

Moisture content (db) = Wet weight ÷ Dry weight

• Since the Total weight > Dry weight, the denominator value of wet basis is always higher than the dry basis making the value Moisture content (wb) is lesser than the Moisture content (db).

• The grain will lose moisture if the water vapor pressure of grain is more than the water vapor pressure of air.
• The grain will gain moisture if the water vapor pressure of grain is less than the water vapor pressure of air.
• If the water vapor pressure of grain is equal to the water vapor pressure of air, then the grain is in an Equilibrium Moisture Content (EMC) state.

the correct answer is the Tetrazolium chloride test.

• The tetrazolium chloride test is also knowns as the biochemical test.
• This test is used for testing the viability of the seed.
• In this method, seeds are soaked in 0.5 to 2% solution of tetrazolium chloride (2,3, S-triphenyl tetrazolium chloride).
• The viable or living seed takes bright red coloration which becomes more intense in the embryo while the dead seed remains in its original color.

The correct answer is 200 meters.

• The isolation distance varies from 3 m in self-pollinated crops like wheat, rice, etc. to 200 m in the case of maize, bajra and jowar to even 400 m in case of jowar when the isolation is from Johnson grass (Sorghum halepense).
• Isolation distance: Isolation distance is the minimum distance required in between two or more varieties of the same species for the purpose of keeping the seed pure.

Additional Information

Minimum Isolation distance of different crops (hybrid) for seed production

Important Points

• Isolation distance is usually more in cross-pollinated crops because there will be more chance of unwanted cross-pollination by different mediums.
• The isolation distance will be more to maintain the purity of seeds in cross-pollinated crops

The correct answer is Enforced dormancy.

• Enforced dormancy is an inability to germinate due to an environmental restraint such as shortage of water, low temperature, poor aeration.
• It occurs when the seed is simply being deprived of its requirements for germination.
• It is due to the deep placement of seeds in the soil during ploughing of the field.
• Enforced dormancy is a non-specific character of seed.
• Cultivation encounters enforced dormancy by bringing the seeds to the surface where they are exposed to light besides better aeration.
• High soil temperature and NO₃ content of surface soil may further help in breaking seed dormancy.

The correct answer is Rhizophora.

• Many mangrove species show some form of vivipary. Rhizophora is an example.
• The ovum is fertilized while still on the parent tree and grows by a combination of photosynthesis and acquisition of nutrients from the parent.

Important Points

• In viviparous germination, the seeds germinate while still attached to the parent plant.
• The growth of the embryo continues until it pierces the seed coat, while still attached to the mother plant, without cessation of activity.

Key Points

• Difference between germination and vivipary:

  Germination	Vivipary
  The embryo of the seed becomes activated and begins to grow into a new plant.	The germination of seed within the fruit, while it is still attached to the parent plant.

The correct answer is All the given statements are correct. 

Key Points Seed treatment refers to applying fungicide, insecticide, or a combination of both, to seeds to disinfect and disinfect them from seed-borne or soil-borne pathogenic organisms and storage insects.

Examples: 

• Paddy -Seeds can be soaked in 1% KCL solution for 12 hours to improve the germination and vigour potential
• Sorghum-Seeds could be soaked in NaCl2 (1%) or KH2PO4 (1%) for 12 hours for improving the germination and vigour potential.
• Pulses-Seeds can be soaked in ZnSO4, MgSO4 and MnSO4 100ppm solution for 4 hours to improve the germination and vigour potential

Benefits of Seed Treatment: 

1. It prevents the spread of plant disease
2. Protects seed from seed rot and seedling blights
3. Improves germination
4. Provides protection from storage insects
5. Controls soil insects.

Additional InformationTypes of Seed Treatment:

1) Seed disinfection: 

• Seed disinfection refers to the eradication of fungal spores that have become established within the seed coat or more deep-seated issues. 
• For effective control, the fungicidal treatment must actually penetrate the seed in order to kill the fungus that is present.

2) Seed disinfestation:

• Seed disinfestation refers to the destruction of surface-borne organisms that have contaminated the seed surface but not infected the seed surface.
• Chemical dips, soaks, and fungicides applied as dust, slurry or liquid have been found successful.

3) Seed Protection: 

• The purpose of seed protection is to protect the seed and young seedlings from organisms in the soil
• Which might otherwise cause decay of the seed before germination.