Effect of harvest seasons on the incidence of seed-borne mycoflora of three Amaranthus cultivars.

Fifteen fungal species were found to be associated with seeds of three cultivars of Amaranthus cruentus L. There was a seasonal variability in the frequency of isolation, distribution and quantity of these seed-borne fungi among cultivars. The wetness, high temperature and air humidity that accompanied harvests of the first and second seasons greatly increased the number and amount of seed-borne fungi. Least number and mean percentage seed infection were recorded for NHAc while NHAc and NHAc carried highest percentage inoculum of these pathogens. The seed testa of all cultivars was found to harbour the highest number and amount of some of these pathogens also in the second season. These seed-borne fungi, Choanephora cucurbitarum, Rhizoctonia solani and Pythium aphanidermatum were highly pathogenic on seedlings of NHAc and NHAc. Five of these seed-borne mycoflora have not been recorded on Amaranthus in Nigeria. [ABSTRACT FROM AUTHOR]