**15. Harvest**

Cassava is due for harvesting any time from 6 month. The crop does not have a specific time or season for its harvest; it can be harvested all-year-round. The fact that it can stay long and be preserved in the soil gives it the utmost advantage of being harvested piecemeal over a long period. The root is cooked and consumed as a local delicacy. Also, it could be processed to give a varieties of products (**Figures 6**–**8**) as a result of value addition. Cassava leaves can be fed upon as vegetable, and it is used as such in many homes where they are planted in West African countries. Moreover, cassava leaves and root serve as a good source of nutrients for livestock. The leaves are rich in vitamins.

**Figure 6.** *Cassava coarse (grains) flour.*

**Figure 7.** *Cassava (smooth) flour.*

**Figure 8.** *Cassava end (food) products.*

#### *Cassava Production Enterprise in the Tropics DOI: http://dx.doi.org/10.5772/intechopen.104677*

Cassava has a number of advantages, one of which is, it does not have a set harvesting season. They can be collected whenever needed during times of food scarcity, frequently one plant or even one root at a time. Harvesting for human consumption takes roughly 8–10 months; for industrial purposes, a longer growth time yields a higher root and starch output. Roots can be eaten directly by farm families, given to livestock, or sold for processing into a wide range of value-added products, from coarse flour ('Garri')to high-tech modified starch gels. The root of the plant is not the only portion that can be useful. The green section of the upper stem, which includes the leaves and petioles, is fed to cattle and buffaloes in several countries, while the leaf blades are fed to pigs and chickens. Fresh leaves are used to raise silkworms in China, Thailand, and Vietnam. Woody stems are crushed up and used as a substrate for growing mushrooms. Stumps are burned as fuelwood [12].

Cassava roots are typically collected by cutting the stems approximately 20 cm above ground and then dragging the entire root system out of the ground using the stump. If the soil is too hard or the roots are too deep, it may be necessary to remove the soil around the roots with a hoe, spade, or pick while avoiding injury to the roots. A harvesting blade mounted to a tractor is occasionally employed in heavy soils that can become quite hard in the dry season. The sword slashes through the soil material. The tractor's forward momentum pulls the root clusters to the surface as the blade slices through the dirt right below the roots. The roots are then removed from the stump and transported in baskets or bags.

Large cassava fields are frequently harvested by middlemen who employ teams of labourers and deliver the roots to marketplaces or processing plants via trucks. Plant tops are harvested after the root harvest. Plant tops are generally left to dry on the ground after root harvesting and then integrated into the soil to help preserve its fertility. However, by trimming the green tops every 3 months during the plant's growth cycle, farmers can considerably increase the total amount of cassava foliage available for feeding to animals. Within 2–3 months after each trimming, the remaining stems will sprout and produce a new crop of leaves. Cassava stakes should be planted at a closer spacing of about 60 × 60 cm for maximum foliage output. Young leaves harvested at regular intervals during the cassava growth cycle have a higher protein and lower fiber content than those gathered at the end of the cassava growth cycle, when plants are generally harvested between 11 and 12 months. Younger leaves are more pleasant and give better nutrition.

The ultimate root production decreased as the frequency of leaf cutting increased, from roughly 40 tonnes per ha when leaves were collected only once at the time of root harvest to less than 25 tonnes when leaves were removed 5 times [27]. This approach may or may not be cost-effective, depending on labour costs and the relative pricing of fresh roots and dry leaves. Harvesting the plant tops four or five times over a one-year growth cycle takes a substantial amount of nutrients, particularly nitrogen, from the field, and would be unsustainable unless large amounts of mineral fertilizer were applied to maintain soil fertility.
