The occurrence of insects and Fungi, and aflatoxin B1 contamination of stored sorghum Indemak and Wonogiri regencies, Central Java

Abstract

The objectives of this study were to collect informations on the method of postharvest handling of sorghum and to investigate the moisture contents, insects infestation, fungal infection, and aflatoxin B1 contents of stored sorghum grains collected from various stages of the delivery chain in Demak and Wonogiri regencies, Central Java. In Demak regency sorghum cultivation was monoculture, variety cultivated was UPC-S1. In Wonogiri regency sorghum cultivation was intercropping with secondary crop and cassava. Sorghum varieties cultivated were Kawali, Numbu, ZH30, Mandau and Hibrida hybrids. There was a difference between the method of postharvest handling of sorghum at farmer and collector levels in Demak and Wonogiri regencies. In general the method of postharvest handling of sorghum in Demak regency was more appropriate and more advance compared to that in Wonogiri regency. The moisture contents of sorghum at farmer as well as at collector level in Demak regency (13.0%) and Wonogiri regency (12.9%) were still lower that that of normal (safe) moisture content of sorghum. The number of insect species associated with sorghum in various distribution level in Demak and Wonogiri regencies was 10 and 17 species, respectively. The dominant insects species were Sitophilus zeamais and Tribolium castaneum. The number of fungal species found in sorghum at various distribution level in Demak and Wonogiri regencies was 23 species, respectively. In general, the dominant fungal species were Aspergillus flavus, Fusarium semitectum and F. verticillioides. In Demak regency aflatoxin B1 contents of sorghum at farmer and collector levels were 22.50 and 15.45 ppb, respectively, while in Wonogiri regency 2.27 and 10.28 ppb, respectively.