Theory question 106
Crop Propagation(a) Define the terms budding and grafting
(b) List four materials required for budding.
(c) Give two reasons why the improvement of crops by selection may not produce the desired results.
(d) State four disadvantages of asexual reproduction and four advantages of sexual reproduction in crop plants.
Show the model answer
(a) Budding: inserting a bud from a desired plant (scion) under the bark of a rootstock so they unite and grow as one plant. Grafting: joining a shoot/stem piece (scion) of a desired plant onto a rooted stock so they grow together
(b) Any four: budding knife; budwood (scion) from the desired plant; rootstock seedling; budding tape/polythene strip/raffia; grafting wax; secateurs; sharpening stone
(c) Any two: selection only uses existing variation and cannot create new characters; the desired trait may be due to environment, not genes; traits may not be passed on (heterozygous plants segregate); it is slow
(d) Asexual disadvantages (any four): no new variation; diseases carried in planting material; bulky planting materials hard to store and transport; overcrowding near the parent; plants may be less vigorous; needs skill (budding/grafting)
Sexual advantages (any four): variation for breeding new varieties; seeds easy to store and transport; seeds can stay dormant; hybrid vigour; seeds are usually disease-free; large numbers produced
Clear definitions, then lists.