Biochar effect on nematodes and insects population density, soil improvement and yield of okra

Okra (AbelmoschusesculentusL. Moench) is an economically valuable crop in Ghanafor its culinary significance and income generation potential. Agricultural production worldwide is constrained by abiotic and biotic factors. Chemical fertilizers are usually used to solve soil infertility problems. However, chemical fertilizers areexpensive and when applied continuously, degrade agricultural lands (Savci, 2012; Bhattacharyya et al., 2015). Biotic factors such as plant parasitic nematodes (PPN) and foliar insects have been implicated as major constraintsto okra production (Asare-Bediakoet al., 2014b). The attack of root-knot nematodes (Meloidogynespp.) has been reported asthe most serious, widespread and alarming which causestremendous yield losses (Hussain et al., 2011; Kayaniet al., 2013; Barros et al., 2014).Flea beetle (Podagricaspp.) is the most important insect pest of okra in Ghana and Nigeria (Obeng-Ofori&Sackey,2003; Asare-Bediakoet al., 2014a, Moboladeet al., 2014). It has been estimated thatinsect pests attackled to great reductionin okrayield (Echezona&Offordile, 2011). Management interventions such as crop rotation, antagonistic plants, bio-control agents, host resistance, soil amendments and chemicals usage have routinely been employed to minimize plant parasitic nematodes and insects’infestation (Mukhtar et al., 2013). Chemical usage has been identified as the most efficientmanagement strategy(Mall etal., 2018).However,the deleterious effects of chemicalstrategy on man and the environment discount any benefitsthe strategy might import. Okra does not do well on infertile soil and is highly susceptible to root-knot nematodes infection (Hussain et al., 2014). The use of carbonized materials such as biochar in food production could contribute to the sustainability of crop husbandry. According to Sokcheaet al.,(2013), incorporating rice husk biochar in a loam soil increased yields of rice grain by 30%.