Fungal succession on sorghum seed harvested at different stages of maturity.
Rao, P. H. V.; Giridhar, P.; Reddy, S. M.;
Indian Phytopathology Year: 2000 Vol: 53 Issue: 1 Pages: 102-104 Ref: 8 ref.
2000
บทคัดย่อ
In order to correlate the succession of seed mycoflora with crop growth stage, sorghum spikes were collected randomly at three stages of crop maturity: pre-harvest (PH: 3 weeks before final harvest), before threshing (BH: collected from the heap of the harvest) and after threshing (AT: collected after normal threshing). Seed of all these samples were stored at room temperature (27-29 deg C) under laboratory conditions in cloth bags for one year and the mycoflora was analysed at bimonthly intervals using the blotter technique. The results clearly show qualitative and quantitative differences in the mycoflora of seeds harvested at different times. Aspergillus niger and Rhizopus stolonifer were commonly associated with BT and AT samples but could not be detected in the PH sample. In contrast, Drechslera halodes [Setosphaeria rostrata] and D. maydis [Cochliobolus heterostrophus] could not be traced in the AT sample but was detected in the PH and BT samples, while Aspergillus ustus, Colletotrichum ca
psici, Fusarium oxysporum and Trichoderma viride could only be detected in the PH sample. Alternaria alternata, Aspergillus flavus, Curvularia lunata [Cochliobolus lunatus], Curvularia pallescens [Cochliobolus pallescens] and Drechslera spicifer [Cochliobolus spicifer] were detected in all the samples analysed. A significant change in the composition of the mycoflora was observed with the advancement of storage which, however, varied with the sample. In general seeds collected at BT were infested with more fungi than the PH and AT samples. The percentage of seed germination decreased with progress of storage, however, it was lowest in PH seeds. The final seed moisture content decreased with some fluctuations in all the seed samples with the storage time. It can be concluded that populations of A. flavus, A. niger and R. stolonifer increased with the progress of storage, whereas, populations of Alternaria spp., Curvularia sp. and Drechslera sp. declined with storage time. The incidence of Fusarium sp. remaine
d static.