Discuss the production of yam under the following headings : (a) materials of propagation; (b) soil requirement; (c) land preparation; (d) planting and spac...

Yam is a tuber crop that is commonly grown in tropical and subtropical regions for its edible tubers. Here are the major factors to consider when producing yam:

(a) Materials of propagation: The best materials of propagation for yam are healthy and disease-free yam tubers. The yam tubers should be cut into seed yams, and each seed yam should have at least one eye or sprout.

(b) Soil requirement: Yam grows best in fertile, well-drained soils with a pH range of 5.5 to 6.5. It prefers sandy loam or loamy soils, which are rich in organic matter.

(c) Land preparation: The land should be cleared of all weeds, rocks, and other debris. The soil should be plowed, harrowed, and leveled to provide a good seedbed for planting.

(d) Planting and spacing: Yam should be planted at the beginning of the rainy season. The seed yams should be planted 10-15 cm deep and 60 cm apart in rows that are 1-1.2 m apart. This will provide enough space for the yam vines to grow and spread.

(e) Cultural practices: Weeding is a crucial cultural practice to prevent weed competition and to maintain the soil moisture. Also, it is important to mulch the soil to reduce evaporation and retain soil moisture. Applying fertilizer, especially organic fertilizer, is important to boost growth and yield of the yam.

(f) Three major pests and their control: Yam beetles, nematodes, and yam tuber moths are the three major pests that attack yam. To control yam beetles, handpicking of beetles from the plants and the use of insecticides like cypermethrin and chlorpyrifos could be applied. Crop rotation and soil sterilization with solar heat help in controlling nematodes. The use of insecticides like fumigants and carbamates help in the control of yam tuber moths.

In summary, yam production requires healthy seed yams, well-drained fertile soil, and proper land preparation. Planting should be done at the beginning of the rainy season, and adequate cultural practices like weeding, mulching, and fertilization should be applied. Also, yam beetles, nematodes, and yam tuber moths are major pests that attack yam, and they can be controlled using various methods like crop rotation, handpicking, and the use of insecticides.