Early corn seedling growth response to acetic, propionic and butyric acids

Corn (Zea mays L.) responses to crop rotation, tillage practice and/or plant residue placement may be due to differential production of acetic, propionic and butyric acids which are associated with the anaerobic decomposition of plant residues. To evaluate early corn growth response to acetic, propionic and butyric acids, a series of bioassays was conducted in which seeds of three commercially available corn hybrids, Pioneer 3737, Pioneer 3949 and Hyland 2260, were germinated and allowed to develop in solutions containing these acids alone or in combination at four concentrations (1.0 ×10−4 M, 1.0 × 10−3 M, 5.0 ×10−3 M, and 1.0 × 10−2 M) which were adjusted to two solution pH levels (4.5 and 7.5). None of the acids or acid mixtures tested affected seed germination. However, all three acids inhibited corn radicle growth. The magnitude of inhibition was butyric > propionic > acetic. Reducing solution pH tended to increase the degree of radicle growth inhibition. Particularly with propionic and butyric acids, the extent of radicle growth inhibition was affected by hybrid. Results indicated early corn growth inhibition associated with these acids is affected by acid type, acid concentration, solution pH and corn hybrid. Key words: Allelopathy, acetic, propionic, butyric, corn, hybrid response