Theory question 103
Crop Husbandry(a) Discuss the cultivation of Citrus spp under the following headings: (i) method of propagation; (ii) spacing in the field; (iii) two nursery practices; (iv) two pests; (v) two diseases.
(b) Define each the following terms: (i) surface irrigation; (ii) surface drainage.
(c) Give three advantages each of the terms in 3(b). (i) Surface irrigation (ii) Surface drainage.
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(a)(i) Budding (sweet orange buds on rough lemon/sour orange rootstock); also seeds for rootstocks and grafting.
(ii) About 6 m × 6 m (7.5 m × 7.5 m).
(iii) Any two: watering; shading; weeding; budding the rootstock; pest and disease control; hardening off; pricking out.
(iv) Any two: fruit flies; aphids; scale insects; citrus butterfly (leaf eater); mealybugs; termites.
(v) Any two: citrus tristeza; gummosis; citrus canker; scab; sooty mould; greening.
(b)(i) Surface irrigation: applying water over the soil surface so that it flows by gravity (basin, furrow, flooding).
(ii) Surface drainage: removing excess water from the soil surface through open ditches/channels.
(c)(i) Surface irrigation (any three): cheap and simple; needs no special equipment; uses gravity; suitable for crops like rice; easy to operate.
(ii) Surface drainage (any three): cheap to construct; prevents waterlogging; improves soil aeration; easy to inspect and maintain; allows early working of the land.
Name the rootstock used for budding citrus.