**5.7 Cultivation**

Kapok is a tropical plant found at height of 1200 meters, however, productivity declines beyond 460 meters [144]. Optimal growth is achieved in locations with yearly daytime temperatures range of 17–38°C, and kapok can withstand 12–40°C. The plant could die at −1°C or less [72]. Fruit production could be delayed at nocturnal temperature of 20°C. Kapok enjoys a mean rainfall of 1500 to 2500 mm per annum, although it withstands 750 to 5700 mm [72]. It tolerates long dry period range of about 0–6 months [157]. Kapok is the tallest indigenous plant in Africa [158]. It thrives in a fertile, deep, moisture-retentive but well-drained loamy soil is preferred

*Lesser Known African Indigenous Tree and Fruit Plants: Recent Evidence from Literatures… DOI: http://dx.doi.org/10.5772/intechopen.104890*

[139, 159]. It does well at a pH range of 5.5–6.5 and it can also tolerate 5–7.5 [74]. Kapok is prone to wind; it prefers wind break for protection against strong winds [139]. The tree may start bearing fruit at 4–5 years, with increased production till 8 years. The economic or production life of kapok tree can last for almost 60 years [74]. Leaf and flower production season are stable in drier regions where the plant is distributed; in wet regions, production of leaf and flower are not regular. Anthesis occurs in the night and ended at midday. The flower releases strong scent and secretes nectar at the flower base, which is large and bisexual. Ripening of fruits occurs at 80–100 days after flowering, the dehiscent types splits with loosely fixed seeds released and dispersed [74]. The light seeds are spread widely and find ideal germination conditions in abandoned agricultural land [74]. A single tree can produce over 300 pods yearly with an output of 20 kg of fiber from 5 years to 50 years [139]. The tree responds positively to coppicing. It has vigorous root system causing damage to buildings and roads [160].

#### **5.8 Fertilizer requirement**

Soil degradation as a result of deforestation, nutrients lost through leaching and erosion has led to depleting fertility and caused decline in soil organic matter levels [161, 162]. Soil amendment using organic manure is vital in increasing crop yield. A fertile soil should possess an organic matter content of more than 3%. Soil amendment could be in form of organic or inorganic or combined [14]. Previous studies confirmed that combined application of organic and synthetic fertilizers supports the best crop performance [129, 130]. Olajide and Baiyeri [163] who worked on the effect of these rates (No fertilizer, 5 t ha−1 PM + 200 kg ha−1 NPK, 10 t ha−1 PM, 20 t ha−1 PM, 450 kg ha−1 NPK and 20 t ha−1 PM + 100 kg ha−1 NPK) on growth of kapok in the field reported that 20 t ha−1 of PM applied solely increased the performance of kapok plants. Olajide and Baiyeri [163] also found that soil amendment using 450 kg ha−1 of NPK and other treatments combined with NPK reduced the growth of kapok when compared with the plants in plots where no fertilizer was applied. Inability of NPK fertilizer in increasing kapok might be associated with acidification of the rhizosphere. It has been established that application of NPK reduces soil pH and boosts soil acidification but addition of organic manure improves soil acidification [164].

#### **6. Conclusion**

It is quite evident from this review that tropical plant species provide a lot of benefits to ensure food security, improve the health and socio-economic status of the populations. These crops have nutritional, economic, medicinal and industrial potential and can ensure healthy food system for the people. They can also play an important role in climate resilience for sustainable environment. Their full potential should be harnessed as it has been established that these crops are highly responsive to fertilizer. They can be brought under regular cultivation culture and the fruits and leaves accessed without the traditional search for them. This information could encourage the domestication of these indigenous plant species and guide the utility of these crops*.* Empirical studies [23] copiously quoted in this review supports the possibility of adapting these forest species to regular cultivation culture.

Furthermore, in harnessing the potential of these tropical plant species to the fullest, this review outlined some key factors that could unlock their vast potential.

