**6. Pest and disease management in turmeric (***Curcuma longa***)**

In Nigeria many pests attack turmeric in the farm. According to [106] such pests include leaf roller, shoot borer, scale insects to mention but a few. The diseases includes leaf blotch, leaf spot and rhizome rot. The symptoms appear as small oval, rectangular or irregular brown spots on any side of leaves and soon turning to dirty brown, they decrease yield and are controlled by spraying chemicals. The incidence of rhizome rot, leaf spot, leaf blotch, thrips, leaf folder and cutworm are the major cause of the yield loss in turmeric [107]. Nirmal et al. [108] reported that the rhizome rot results in 50–80% loss during storage. Jagtap et al. [109] recorded 34–57% yield loss due to the incidence of leaf spot *Colletotrichum capsici* ((Syd.) Butler and Bisbyl). The survey conducted in various turmeric growing states of South India revealed that the rhizome rot is caused predominately by *Pythium aphanidermatum* (Edson.) Fitz. [110, 111]. Fungicides like metalaxyl, mancozeb, carbendazim, alliete, propiconozle, hexoconozole etc. are widely used by the farmers for the management of disease complex in turmeric [107].

Sarathi et al. [111] has evaluated the efficacy of *C. longa* (Turmeric) as possible botanical pesticide for managing insect pests of okra on the field and they observed differences in efficacy and yield between lambda-cyhalothrin and *C. longa* which was used as the extraction solvent. Their study revealed that *C. longa* compete well with lambda-cyhalothrin in controlling pest infestation and produced yields that were significantly higher than plots without treatments. Therefore, they recommended that farmers should consider using it as a botanical pesticide. Sarathi et al. [111] also reported the antifungal activity of two varieties of turmeric (white and red) rhizome extracts on fusarium wilt pathogen (*Fusarium oxysporum* f. sp. *lycopersici*). Their findings revealed that both varieties had comparable antifungal activity on the mycelial growth of the test pathogen at 15% extract concentration and that the highest mycelial growth was 17.7 and 25.2%, respectively.
