EPTC Effects on Total Leaflet Fatty Acids and Hydrocarbons

Abstract

Total foliar fatty acid and hydrocarbon content of sicklepod (Cassia obtusifoliaL.) treated with 0, 0.14, 0.28, 0.56, 1.12, 2.24, or 4.48 kg/haS-ethyl dipropylthiocarbamate (EPTC) was measured by gas-liquid chromatography. Total leaflet fatty acid content increased at sublethal rates of the herbicide, but qualitative composition of the fatty acids was not affected. Percent of long chain alkane (≥ C28) content decreased as EPTC application rates increased. Palmitic (23.9%), stearic (9.1%), oleic (3.8%), linoleic (13.6%), and linolenic (33.2%) acids accounted for 83.6% of the total leaflet fatty acid content of sicklepod. Leaflet cuticle thickness of upper and lower epidermal layers decreased 15 and 20%, respectively, as herbicide concentration increased.