Submitted to: Crop Protection Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 8, 1997
Publication Date: N/A
Interpretive Summary: Synthetic sugar esters (SE) with structures similar to those produced by wild tomatoes and wild potatoes are known to be toxic to sweetpotato whiteflies and tobacco aphids. These were also strongly inhibitory to seed germination of the weed species proso-millet and velvetleaf. When tested on young sweet pepper and broccoli plants, no adverse effects on growth were detected, even at concentrations much higher than needed for effectiv insecticidal activity. Those which were most active against seed germination were also most insecticidal. It was concluded that the most active SE are good candidate insecticides since they are non-toxic to humans or higher animals, fully biodegradable, are easily synthesized and not harmful to the crops tested.
Technical Abstract: Synthetic O-acylated sugar ester (SE) products with C7-C10 chain lengths of their acyl groups and varying degrees of esterification were tested for their influence on seed germination of proso-millet and velvetleaf and growth of crop plants. The SE, known to be insecticidal, caused virtual total inhibition of germination at 100 ppm; at lower concentrations the parameters tested showed differences. Increasing degrees of esterification, or increasing acyl chain lengths, caused decreased inhibition of seed germination with respect to their published insecticidal activity, the structure-activity relationships paralleled their germination inhibitory effects. Young broccoli or sweet pepper plants, treated with the 10 different SE samples tested for effect on germination, were not affected by concentrations far above those needed for effective insecticidal action. Since similar SE products are potent insecticides, non-toxic to humans and higher animals, fully biodegradable and not harmfu to the crops tested, they appear to be good candidate insecticides.