Search

Integrating varietal resistance with temperature manipulation during storage may provide a better option for protection of stored grains and may decrease reliance on the use of synthetic chemicals. The current study was conducted to determine the susceptibility of different varieties of wheat seed to the infestation by the granary weevil, Sitophilus granarius (L.), and rice weevil, Sitophilus oryzae (L.), at optimal (30 °C) and sub-optimal (19 °C) temperatures. Kernels of six wheat varieties namely, Danda'a, Digalu, ET-13-A2, Kakaba, Millennium, and Pavon-76 were examined over a period of 90 d. Significant interactions were detected between wheat varieties and storage temperature for progeny emergence, percentage of insect damaged kernels, grain weight loss, and amount of powder produced per gram of wheat. Kernels of Danda'a, infested with S. oryzae at 30 °C exhibited significantly lower mean progeny counts (13.3 live insects), lower percentage of grain weight loss (4.2%) and insect-damaged kernels (6.4%), and powder production (1.5 mg/g). Kernel weight and hardness index were negatively associated with percentage of insect damaged kernels and grain weight loss. Kernel diameter was positively associated with both of percentage of insect damaged kernels and grain weight loss. Wheat varieties with high Zeleny sedimentation values had lower percentage of insect-damaged kernels and grain weight loss. These results indicated that kernel weight, hardness index, and protein content are predominant factors contributing to wheat resistance against S. granarius and S. oryzae. The varieties Millennium and Danda'a can be considered with other integrated pest management approaches to reduce stored grain losses of wheat in Ethiopia.

Chickpea is an economically important pulse produced by millions of smallholder farmers as a source of food, income and nutrition in Ethiopia. Mold infection and mycotoxin production can potentially lead to significant losses of chickpea during storage. Under laboratory conditions we tested comparative effects of hermetic and traditional storage structures on mold infection, germination and mycotoxin levels of chickpea. Purdue Improved Crop Storage (PICS) bags, Super GrainPro (SGP) bags, and small metal bins were compared to the traditional and popularly used chickpea storage structures such as polypropylene (PP) bags and jute bags over a six-month storage period. Oxygen and carbon dioxide levels, chickpea temperature and moisture, seed infection with molds and percentage germination and mycotoxins levels were determined every two months for six months. In PICS bags, SGP bags and metal bins chickpea temperature and moisture changed very little during storage, whereas in jute and PP bags significant temperature and moisture increases were observed. Oxygen levels in PICS and SGP bags decreased from 20% to 8–10% in six months and carbon dioxide levels increased from 0.4% to 10% in PICS bags and from 0.1% to 17% in SGP bags. In jute and PP bags, oxygen levels were around 20% but carbon dioxide levels increased from 0.05% to 0.1–0.2%, perhaps due to mold activity. Mold infection decreased over time in chickpea stored in PICS bags, SGP bags, and metal bins, and seed germination was high (82–92%). Mold infection increased and seed germination decreased in chickpea stored in jute and PP bags. Increases in levels of aflatoxin, fumonisin, deoxynevalenol, and ochratoxin were observed only for chickpea stored in metal bins, and in jute and PP bags. Our study showed that PICS and SGP bags can effectively arrest mold growth, mycotoxin accumulation and preserve germination of chickpea during six months of storage.