The effects of grasshopper carcasses as dockage in stored wheat. (January 2020)

• Record Type: Journal Article
• Authors: Sharma, Akriti; Demianyk, Colin J.; White, Noel D.G.; Jayas, Digvir S.
• Is Part Of: Journal of stored products research. Volume 85(2020)
• Publication Date: 2020-01
• Subjects: Grain storage -- Grain-quality criteria -- Melanophus bivittatus -- Post-harvest fungi -- Climate change; Food -- Storage -- Periodicals; Farm produce -- Storage -- Diseases and injuries -- Periodicals; Entomology -- Periodicals; Food Contamination -- Periodicals; Food Preservation -- Periodicals; Insect Control -- Periodicals; Aliments -- Entreposage -- Périodiques; Produits agricoles -- Entreposage -- Maladies et dommages -- Périodiques; Electronic journals; 631.568
• DOI: 10.1016/j.jspr.2019.101533
• Languages: English
• ISSNs: 0022-474X

Abstract

Abstract: In years of high grasshopper field populations, large numbers may be collected with harvested grain and deposited into storage. Little is known about the impact of grasshopper carcasses on stored-wheat quality; therefore, this study was conducted to determine such effects. Ninety-six glass bottles (237 mL capacity) were filled with 120 g of clean No. 1 wheat conditioned to 14.5% or 15.5% moisture content. Two-striped grasshoppers, Melanoplus bivittatus were collected in the summer of 2004 near Elie, MB, Canada and euthanized. Six grams of whole grasshoppers were mixed into half the bottles of each moisture content. All bottles were sealed and 12 bottles with and without grasshoppers were incubated at 25 °C and 50% relative humidity (r.h.), 25 °C and 75% r.h. 30 °C and 50% r.h. and 30 °C and 75% r.h. for 24 wk. Four bottles with and without insects were assessed every 4 wk for fat acidity value, seed microfloral infection and germination. The experiment was repeated and data pooled for statistical analysis (ANOVA). Significant differences ( P < 0.05) arose between grasshopper and control treatments. Mean fat acidity values for wheat reached 32.99 mg KOH/100 g with grasshoppers compared to 25.23 mg KOH/100 g without carcasses. Initial seed germination of 98% rapidly declined to below 20% with grasshoppers between 4 wk and 8 wk; the majority of seeds were dead in the 75% r.h. treatments by 12 wk. Mean infection by the post-harvest fungi, Aspergillus glaucus group with grasshoppers ranged from 80.5 to 92% compared to 25–79.8% in controls. Penicillium spp. infection at 25 °C and 75% r.h. was 16.8% with grasshoppers and 4.2% without. Results from this experiment clearly demonstrate that the presence of grasshopper carcasses in stored wheat has negative consequences on grain quality. The implications of our research are discussed with respect to harvest practices and climate change. Highlights: Binned grain may have high numbers of grasshopper carcasses in years of high abundance. Carcasses reduced germination and increased fat acidity values in stored grain. Carcasses increased incidence of post-harvest fungi in stored grain. Grasshopper carcasses can act as a focal point for fungal infection. With climate change, the impact of grasshopper dockage may increase.