module 6 seeds

Question 1

why is canterbury main seed production area

Answer 1

temperate climate

Late summer/autumn sowing with harvest in Jan/Feb/Mar (10-12 months) vernalisation can be achieved

• Rainfall – relatively low

Irrigation available

Flat land & a range of suitable soil types

Close access to ports

Question 2

The isolation distance in seed production may refer to:

(A) the minimum separation required between two cultivars during a single seed production season;

(B) the minimum time (in years) between changing cultivars of the same species at the same site;

(C) a distance of 50 – 200 m, depending on certification class and paddock size for ryegrass cultivars;

(D) all of the above;

(E) none of the above.

Answer 2

(D) all of the above;

Question 3

When a crop plant falls over during the growing season, thus reducing light interception and therefore seed yield, it is said to be:

(A) windrowed;

(B) lodged;

(C) recalcitrant;

(D) viviparous;

(E) self-incompatible.

Answer 3

(B) lodged;

Question 4

Vivipary is the phenomenon when:

(A) seeds lose viability after they dry to seed moisture contents <14%;

B) seeds maintain viability after they dry to seed moisture contents <14%;

(C) seeds cannot germinate because of a special dormancy condition;

(D) seeds germinate precociously while still attached to the parent plant;

(E) seeds become fully developed and able to survive on their own.

Answer 4

D) seeds germinate precociously while still attached to the parent plant;

Question 5

One of the main reasons that germination tests are done under controlled and ideal conditions in the seed lab is:

(A) to replicate conditions that seeds will be exposed to in the field;

(B) to take into account seed deterioration over time;

(C) to reduce variation of results between different seed testing labs;

(D) all of the above;

(E) none of the above.

Answer 5

(C) to reduce variation of results between different seed testing labs;

Question 6

Which of the following seed crops is predominantly cross-pollinated by insects?

(A) narrow-leaved plantain;

(B) subterranean clover

(C) red clover;

(D) perennial ryegrass;

(E) peas.

Answer 6

(C) red clover;

Question 7

Which of the following seed crops is predominantly cross-pollinated by the wind? (

A) wheat;

(B) subterranean clover;

(C) perennial ryegrass;

(D) peas;

(E) red clover.

Answer 7

(C) perennial ryegrass;

Question 8

Which of the following is not a type of seed dormancy?

(A) after ripening;

(B) hardseededness;

(C) immature embryo;

(D) photo-dormancy;

(E) vivipary.

Answer 8

(E) vivipary.

Question 9

A seed lot is a specified quantity of seed of one ….…………………, of which the origin, history and ….………………… are known.

Answer 9

cultivar and weight

Question 10

List and briefly describe how seed quality can be assessed either with the senses or by other methods.

Answer 10

visually; insect bodies, insect activity eg holes in seeds’ insect frass, mould, off colours

aroma; mold, insect activity

touch; damp, heated seed

Question 11

List five (5) seed crop management techniques applied in the spring which will lead to an increase in ryegrass seed production.

Answer 11

1. Weed control to be maintained
2. Closing date i.e. no more grazing/cutting • Delay closing date = higher yield
3. Split Nitrogen applications 50 kg autumn 50 kg late winter/ early spring (closing) 100-150 kg spring (~ 3 weeks later)
4. Plant Growth Regulators; less lodging DM partitioning from stems to seeds
5. Irrigation