Indian Forest Service Examination Forest Tree Seed Technology: practice questions

Indian Forest Service Examination (IFoS) — Forestry optional · India · Union Public Service Commission

Original practice questions written to the published syllabus · not past papers

7worked here, free

16written to this exam in this subject

10syllabus units

What this subject covers

Collecting, processing, storing, testing and certifying tree seed so that nurseries get the right seed of known quality and origin.

In the exams: ICAR AICE-JRF 59 Unit 2 (seed collection, dormancy, testing, ISTA rules, certification); IFoS Forestry Paper I Section B; ICAR AIEEA-PG Group 09 (tree seed technology)

Seed development, maturity indices and seed years
Seed collection methods and timing
Seed extraction, cleaning and processing
Orthodox, intermediate and recalcitrant seed and their storage
Seed dormancy types and pre-treatments
Seed testing: purity, moisture, viability (tetrazolium), germination
ISTA rules and seed testing standards
Seed certification and the OECD Forest Seed and Plant Scheme
Seed zones, seed sources and documentation of origin
Seed pests and seed health

Where the 16 questions fall

How our questions for Indian Forest Service Examination spread across the units of Forest Tree Seed Technology. Difficulty: 0 easy, 8 medium, 8 hard.

Seed collection methods and timing	2
Orthodox, intermediate and recalcitrant seed and their storage	2
Seed dormancy types and pre-treatments	2
Seed testing: purity, moisture, viability (tetrazolium), germination	2
Seed zones, seed sources and documentation of origin	2
Seed pests and seed health	2
Seed development, maturity indices and seed years	1
Seed extraction, cleaning and processing	1
ISTA rules and seed testing standards	1
Seed certification and the OECD Forest Seed and Plant Scheme	1

7 practice questions, worked

Choose an answer, then open the working. Each explanation says why the right answer is right and why the others are not.

1 · Seed development, maturity indices and seed years · medium

In the cutting test for maturity, a mature seed typically shows:

An empty cavity and a soft, milky endosperm
A fully formed embryo and firm endosperm
A green, watery embryo and no endosperm
A seed coat that dissolves when cut open

Answer and working

B. A fully formed embryo and firm endosperm

A fully developed embryo and firm reserves indicate maturity. Milky or watery contents mean the seed is immature.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

2 · Seed collection methods and timing · hard

Why is seed collected from many well-spaced trees rather than from a few trees?

Because spaced trees always produce larger seeds
Because the law limits collection to one kilogram per tree
To keep a broad genetic base and avoid relatives and inbreeding
Because isolated trees never produce viable seed

Answer and working

C. To keep a broad genetic base and avoid relatives and inbreeding

Many unrelated parents give genetically diverse seed lots. Spacing reduces the chance of collecting from close relatives. The other claims are false.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

3 · Orthodox, intermediate and recalcitrant seed and their storage · hard

A seed store in a humid tropical town keeps orthodox seed in open sacks. What is the most effective low-cost improvement?

Spray the sacks with water daily to keep the seed alive
Dry it well and seal it in containers in a cool room
Move the sacks into direct sun to keep them warm
Mix the seed with moist sand so that it stays fresh

Answer and working

B. Dry it well and seal it in containers in a cool room

Drying and sealing prevent moisture uptake, the main cause of deterioration. Wetting, heating or mixing with moist sand speeds it.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

4 · Seed dormancy types and pre-treatments · hard

Why should pre-treatment prescriptions be confirmed on the actual seed lot?

Dormancy varies between seed lots and provenances
Pre-treatments are illegal unless repeated on every lot
Seed lots never differ, so testing is only a formality
Pre-treatment changes the species of the seed

Answer and working

A. Dormancy varies between seed lots and provenances

Depth of dormancy differs with provenance, year and storage, so a small trial avoids over- or under-treating.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

5 · Seed testing: purity, moisture, viability (tetrazolium), germination · hard

Two lots both show 85 per cent germination, but one germinated slowly and unevenly. What does this suggest?

Both lots will perform identically because final germination is the same
The slow lot probably has lower vigour and will perform worse in the nursery
The slow lot has higher purity because it contains fewer other seeds
The slow lot must be a different species from the faster lot

Answer and working

B. The slow lot probably has lower vigour and will perform worse in the nursery

Speed and uniformity reflect vigour; aged or stressed lots germinate slowly and do worse under nursery stress.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

6 · Seed pests and seed health · medium

Storage moulds such as Aspergillus and Penicillium thrive when seed is stored:

Too dry and too cold
In sealed tins at low moisture
Too moist and too warm
In freezers below −18 °C

Answer and working

C. Too moist and too warm

Moulds need moisture and warmth; drying and cool storage control them.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

7 · Seed pests and seed health · hard

Which is the most important single defence against insects and fungi in stored orthodox seed?

Storing the seed in open jute sacks for ventilation
Mixing the seed with fresh leaves to repel insects
Drying the seed to a low moisture content before storage
Keeping the seed warm to speed up its respiration

Answer and working

C. Drying the seed to a low moisture content before storage

Low moisture stops most fungi and many insects and slows ageing. Open sacks, leaves and warmth increase problems.

Further reading: Schmidt, Guide to Handling of Tropical and Subtropical Forest Seed (2000); Bonner & Karrfalt, The Woody Plant Seed Manual (2008); ISTA International Rules for Seed Testing

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