Title : Fungal infection and mycotoxins contamination in on-farm-stored chickpea in major- producing districts of Ethiopia
The susceptibility of the crop, the moisture level, favorable temperature, contamination with mycotoxigenic fungi and the quality of farm storage facilities all contribute to fungal infections and mycotoxin contamination, resulting in post-harvest chickpea grain loss. The purpose of this research was to investigate the incidence of fungal infection and mycotoxin levels in farmer-stored chickpea across five major-growing districts (Dambia, Gondar Zuria, Laeilaymaichew, Ada’a and Meskan) in Ethiopia. In this study, fungal infection and mycotoxin concentrations were determined in two chickpea varieties (Desi and Kabuli types) of samples containing 150 chickpea kernels collected from the five selected districts in 2017 cropping seasons. In addition to identifying fungal infections and mycotoxin analysis, moisture content of kernels, and relative humidity and temperature of storage were measured during grain sampling. Grain moisture levels ranged from 13.3 to 22.3% in chickpea samples, with a mean value of 16.4% across five districts. Regardless of moisture, temperature, or relative humidity, there was no significant difference between the two types of chickpea varieties. Survey of different storage methods used by farmers showed that polypropylene bags were commonest and accounted for 54.7%, followed by gotta (45.3%). The total fungal infection in chickpea kernels across the sampled districts was 48.7% (range: 23-79%). Infection with the genus Aspergillus was predominant, accounting for approximately 44.3% of the total (range 25-62.5%), followed by Penicillium at 34.3% (range 10.9-55.3%), while Fusarium infection was at its lowest, 21.4% (range 9.6-42.3%). A germination study on chickpea samples revealed that across all growing districts, chickpea germination ranged from 68.8 to 75.5%. Total aflatoxin levels ranged from 2.5 to 31.1 ppb in positive samples, with a mean of 17.4 ppb. The means of ochratoxin A concentration in positive samples ranged from 4.3 to 35.0 ppb, with an overall mean value of 10.6 ppb. Total fumonisins were detected on 18.7% of chickpea samples, with mean concentrations ranging from 320 ppb to 2,900 ppb. Deoxynivalenol was detected in 6.7% of samples and the mean concentrations ranged from 500 to 4900 ppb. It was found that chickpea samples had a high level of total aflatoxins, followed by ochratoxin A. The current co- occurrence of mycotoxins found in chickpea samples, even at low levels, may adversely affect the health of regular chickpea consumers and affect the quality of chickpea. This study confirmed the presence and prominence of mycotoxins in Ethiopian grown chickpea, and that humans may be exposed to mycotoxins. The study emphasizes the importance of farmers improving storage facilities and harvest management to reduce mycotoxin contamination in chickpea crops and prevent fungal infections.
Keywords: Aflatoxin, Aspergillus, deoxynivalenol, Desi, Fusarium, humidity, Kabuli, moisture, ochratoxin A, Penicillium, temperature