Amaranth is one of the most consumed leafy vegetables in Africa. Its leaves are a good source of minerals and vitamins. However, its production is constrained by field infestation of Hymenia recurvalis, a major insect pest causing considerable damage to Amaranthfoliage. Plate 1 shows the larvae forms a sheltering web around the leaves and feeds on them until it skeletonizes the foliage
In order to maximize Amaranth yield and promote food security, there is a need to address the problems constituted by this insect/pest. Pesticides have traditionally played a central role in the control of insect pest populations; however, their off-target actions, toxicity to humans and adverse effects on the environment limit their utility. Furthermore, pesticide resistance is an emerging threat to food production globally. This necessitates the development of alternative approaches to pest control that are affordable, effective and sustainable.
The role of biochemicals in insect plant interactions is currently poorly defined. Understanding how various biochemicals in Amaranth affect the nutritional behaviour of H. recurvalis could be a first step in the development of sustainable and effective biological control strategies, providing an alternative to chemical insecticides.
The main idea is to examine certain biochemicals that are known to deter insect pests in cultivated crops and determine if there is a relationship between them and the abundance of H. recurvalis in Amaranths. This relationship, which will be expressed as a correlation between the quantities of the biochemicals and the population of the insect pest, is expected to form a basis for further research. Specifically, if there is a relationship between the biochemicals and insect pest abundance, collaborations will be made with biotechnologists and geneticists with the aim of producing Amaranth species that are resistant to the insect pest. It is expected that this will lead to a sustainable method of preventing H. recurvalis infestation.
Amaranth farmers, who will no longer need to invest heavily in chemical pesticides, will benefit the most from this translational research. The technology, when adapted to other crops, could revolutionize farming practices and dramatically increase agricultural yields while protecting terrestrial and marine ecosystems from the adverse effects of pesticides.
Seeds of Amaranthus species obtained from a research institute in Nigeria based on socio-economic features such as palatability will be planted in a randomized complete block design in four replicates. The comparative field abundance of Hymenia recurvalis on the surface of the leaves of each species will be assessed at two weekly intervals from four weeks after sowing (WAS) till 10 WAS. Following this, relevant biochemicals present in the leaf samples of these Amaranthus species will be quantified at 4, 6, 8 and 10 WAS and their relationship to abundance of Hymenia recurvalis will be determined using descriptive statistics and correlation analyses.
I have always been passionate about the provision of sustainable and economical solutions to the problem posed by insect pests to Agriculture. Having investigated the relationship between secondary metabolites and insect pests in various Amaranthus species at masters level, my interest has gravitated towards studying biochemicals present in Amaranthus species and their relationship with H. recurvalis abundance.
Alade Ifeoluwa Adenike, Nigeria