How to Successfully Cultivate Yam
Commonly referred to as white yam or table yam in the greater Mbam or Ngaoundal regions of Cameroon, its scientific name is *Dioscorea spp*. This plant originates from Asia and belongs to the Dioscoreaceae family, with a growth cycle lasting between 6 to 7 months.
As a starchy food, yam has the following nutritional values:
– 23% carbohydrates
– 2% protein
– 0.1% fat
It can be used in various forms, including flour, chips, and cooked dishes.
FAVORABLE CONDITIONS FOR YAM CULTIVATION
For optimal growth of this yam variety, the following conditions are required:
– A deep, loose, organic-rich soil, well-drained, with a pH ranging from 6 to 7.
– An altitude of up to 1500 meters and average temperatures between 23 to 25°C.
– A rainfall of at least 1500 mm is important for its establishment, with the best results obtained in areas with at least 5 months of rainy season.
YAM CULTIVATION SETUP: TECHNICAL GUIDELINES
Here is a technical sheet for successfully cultivating yam in Cameroon and throughout Africa and the world.
Seed Procurement
Seeds can be obtained by fragmenting yam tubers from the previous season or purchased ones. The process includes:
1. Select healthy, whole tubers that are fully mature and ready to sprout (after dormancy of 2 to 4 months).
2. Cutting the tubers into disks about 4 cm thick or transversely to obtain fragments weighing 15 to 30 grams.
3. Soaking the fragments in a solution made of approximately 150 grams of kitchen ash in 8 liters of water or using a fungicide like Maneb plus an insecticide. The fragments should rest in the solution for 10 minutes before being removed and dried in the shade.
It is important to note that 2 to 4 tons per hectare of yam will be needed, depending on the size (200 to 400 grams), variety, and planting density.
Soil Preparation
This takes place from December to January, before the onset of rains, and involves:
– Clearing and cutting down trees in the plot.
– Forming high and wide ridges (approximately 30 cm high and 50 cm in diameter).
– Marking out the plot according to the chosen planting density.
– Enriching the ridges with well-decomposed organic manure (such as chicken droppings, cow dung compost, etc.) whenever possible.
Planting
It is advisable to plant with a spacing of at least 1 meter by 1 meter, which results in a density of 10,000 ridges per hectare. However, the best yields are achieved with a spacing of 1.5 meters by 1.5 meters (4,444 ridges per hectare), as this allows for larger, more resilient ridges capable of accommodating up to 4 fragments. This yam variety can be associated with pistachio (Bafia variety) and plantain banana.
Once the ridges are formed, sowing can take place with 3 to 4 fragments or seeds per ridge, approximately 10 to 15 cm deep, from mid-February to mid-March. It is important to note that later sowing will result in lower yields.
MAINTENANCE
Maintenance includes:
– Weeding (2 to 4 times depending on weed growth).
– Staking, which involves placing a sturdy stake (about 1.5 meters high) at the center of each ridge once the plants reach at least 10 cm in height.
– Fertilization: For good soil fertility management, soil analysis should be conducted beforehand to determine the necessary amounts of fertilizers and organic matter for optimal yields.
HARVESTING AND STORAGE OF YAM
Harvesting
Harvesting occurs 9 months after sowing when the above-ground parts of the plant have yellowed and dried. This is usually done using a hoe, machete, and trowels to open the ridges and extract the tubers, which must be stored afterward.
During harvesting, it is essential to know that small tubers should be replanted in the soil to serve as seeds for the next season. Yields typically range from 5 to 12 tons and can reach up to 25 tons with the use of fertilizers.
Storage
Storage can be done in underground, elevated, or improved stores:
– Underground storage: Once the tubers are harvested, any injuries should be treated with ash before storing to slow down rotting. A pit should be dug and lined with straw, then tubers placed horizontally with each horizontal layer separated by a layer of straw
