CH Plant Propagation

Question 1

Which type of cutting is taken from the actively growing, soft tip of a stem and roots most quickly but wilts most easily?

Accepted Answer

Softwood cutting

Answer

Softwood cuttings taken from new, non-lignified stem tips root rapidly because cells are actively dividing, but require high humidity to prevent wilting before roots form.

Question 2

Stratification of seeds is a pre-germination treatment that involves:

Accepted Answer

Exposing seeds to a period of cold and moist conditions to break dormancy

Answer

Cold-moist stratification mimics winter conditions, breaking physiological dormancy in many temperate woody plants so they germinate in spring.

Question 3

Scarification of seeds is performed to:

Accepted Answer

Break or weaken the hard seed coat to allow water imbibition

Answer

Scarification physically or chemically abrades the impermeable seed coat of hard-seeded species, allowing water and oxygen to enter and initiation of germination.

Question 4

Grafting is a vegetative propagation technique primarily used to:

Accepted Answer

Combine desirable scion traits with rootstock vigor, disease resistance, or adaptability

Answer

Grafting unites a scion (desired cultivar) with a rootstock chosen for vigor, soil adaptation, pest resistance, or size-controlling properties, combining the best traits of each.

Question 5

Auxin (IBA or NAA) is applied to stem cuttings to:

Accepted Answer

Promote adventitious root formation

Answer

Indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA) are synthetic auxins that stimulate the formation of adventitious roots at the base of cuttings.

CH - Certified Horticulturist Practice Test

CH - Certified Horticulturist Practice Test

CH Plant Propagation