Comparison of Pneumatic and Manual Probe Sampling of Kansas Farm-stored Grain Sorghum

Abstract

Six circular metal farm bins containing grain sorghum were sampled in northeastern Kansas with a pneumatic grain sampler. The grain mass ranged in volume from 109.6 to 429.6 m3. A stratified random sampling method was used. Samples were analyzed in the laboratory for species and numbers of live insects, percentages of fungal-invaded kernels, and percent moisture content Cryptolestes ferrugineus (Stephens) was the only insect species collected in all six bins. High numbers of C. turcicus (Grouvelle) were collected, while few C. pusillus (Schonherr) were found. In five of six bins, more live insects were found at or near the floor; in four, moisture content was greater on the floor. In comparisons with a manual gravity-fill probe, equal numbers of insects and broken grain were collected. Regression analysis was used to propose practical sampling schemes in which manual probes were used to sample upper areas of the grain mass.