Control of Penicillium Decay of Citrus Fruits with 2-Aminobutane

Abstract

IN evaluating a number of simple aliphatic amines as volatile post-harvest fungicides for use on citrus fruits, we found that 2-aminobutane (Sec-butylamine) was remarkably effective in reducing decay incited by Penicillium digitatum Sacc.¹. Subsequent experiments² revealed that effectiveness of this amine is mainly due to the fungistatic action of butylammonium salt residues persisting on the fruit after fumigation. In vitro tests showed that germination of Penicillium spores was almost completely inhibited by 10⁻³ M 2-aminobutane, and, furthermore, that this inhibition could be completely reversed by washing the spores in neutral phosphate buffer, followed by transfer of the spores to amine-free medium. A number of other lower (> C₆) primary monoamines were tested by this procedure and found to be ineffective in preventing spore germination. These results prompted an evaluation of 2-aminobutane in fruit washes and wax emulsions for control of Penicillium decay of citrus fruits.