EXAMINATION OF FLORAL NECTAR OF CITRUS, COTTON, AND ARIZONA DESERT PLANTS FOR MICROBES

Abstract

SUMMARY Floral nectar from 3 cultivars of field-grown cotton, 9 cultivars of cotton grown in a greenhouse, 5 cultivars of citrus, saguaro cactus, and prickly pear cactus were examined for bacteria, yeasts, and molds by plating on selective microbiological media. No microbes were isolated from nectar of any cotton flowers. Of 23 samples of citrus nectar, 3 contained a few gram-negative rod-shaped bacteria. Nectar from prickly pear cactus contained no microbes, although nectar from saguaro cactus contained a few bacteria (gram-negative rods, gram-positive rods, and gram-positive cocci). These results are discussed in relation to possible antimicrobial substances in nectar as well as the origin of the microflora of honey bees.