Performance of Equipment for Applying Chemical Preservatives to Corn

Abstract

ABSTRACT THE feasibility of storing corn with moisture contents higher than normal is important to farmers. Feeding value and palatability are often better for high moisture grain than for dry grain (Wilson, 1973). Yields are highest when grain is harvested at maturity. Corn matures when the kernel moisture is 30 to 33 percent. Yields decrease after that because of damage from fungi, insects, birds, rodents, and weather. The possibility that artificial drying might be curtailed to conserve energy has increased interest in chemical preservatives. Ensiling was the only way to store high moisture grain until about 10 years ago when it was demonstrated that organic acids effectively preserve grain. Propionic acid, alone or in combination with related acids or for-maldehyde, is the principal chemical used. The organic acids kill fungi and related microorganisms and inhibit fungal growth almost in-definitely (Campbell, 1972). The acid also destroys seed viability and eliminates seed respiration. Uniform ap-plication of the acid is highly important to inhibit fungal development (Young, 1971; Sauer, 1973). Mold is likely to develop in any extensive pockets of untreated grain. There are two approaches to obtaining uniform ap-plication. One is to treat part of the kernels and then mix them uniformly with untreated kernels. The other is to apply acid to every kernel. The more uniformly it is ap-plied, the less acid needed. This paper compares unifor-mity of acid distribution by three commercial ap-plicators, a static mixer adapted for acid application, and a new applicator designed as part of this study.