Abstract:
This study was performed to identify the best temperatures for germinating peanut seeds with fungi on a paper substrate. Eleven seed lots from the cultivars IAC-886 and IAC-503 were selected with different levels of fungi. Two of these seed lots with a high rate of Aspergillus spp., Penicillium sp., and Rhizopus sp., as detected by the blotter test method, were used for selecting a fungicide for seed treatment. Considering the active ingredients evaluated, thiram, at the rate of 300 g of commercial product per 100 kg of seeds, was most efficient in controlling fungi, preventing their interference in germination. All the seed lots, treated with this product or not, were subjected to the germination test on rolls of paper at the temperatures of 25 °C, 30 °C, 35 °C, 20-30 °C, 20-35 °C, 25-30 °C, and 25-35 °C. Alternating temperatures of 20-35 °C, 20-30 °C, and 25-30 °C led to higher germination of peanut seeds, treated with fungicides or not. Constant temperatures are not recommended, because they are more favorable to the development of fungi associated with these seeds than to the germination process, thus underestimating the germination potential of the seeds subjected to the test.
Index terms:
Arachis hypogea; viability; optimal temperature; pathogens; fungicide