CITRUS POLYMETHOXYLATED FLAVONES CAN CONFER RESISTANCE AGAINST PHYTOPHTHORA-CITROPHTHORA, PENICILLIUM-DIGITATUM, AND GEOTRICHUM SPECIES

The polymethoxylated flavones observed in the essential oils of the by products of various Citrus fruits after industrial processing were as follows: sinensetin, nobiletin, and heptamethoxyflavone in clementine; sinensetin, quercetogetin, nobiletin, heptamethoxyflavone, and tanger etin in sour orange and sweet orange. Penicillium digitatum was totall y inhibited (100%) by application of the polymethoxylated flavones pre sent in the extracts from the clementine and sweet orange oils and 77% inhibited by those extracted from the sour orange oil. Phytophthora c itrophthora was 100% inhibited by sour orange oil, 72% by clementine o il, and only 14% by sweet orange oil. Geotrichum sp. was more sensitiv e to the sour orange extract, being inhibited by similar to 57%, where as clementine and sweet orange produced inhibition rates of 47 and 34% , respectively.