Brazil's soyabean farmers have harvested only 1.8% of the soyabean area so far this season, agribusiness consultancy AgRural said on Monday, reducing the ideal window for planting of the country's second corn that is sowed after the oilseed is collected.

Most of the soya harvested through last Thursday is in Mato Grosso, Brazil's largest grain state. In other states, harvesting is expected to pick up in February due to planting delays, AgRural said.

At this point last season, Brazilian farmers had already harvested 6.1% of their fields, according to the consultancy, which added projected yields indicate Brazil will collect another bumper crop.

"For it to be a truly great harvest, we need rains lasting until the end of April and if possible beginning of May," Antonio Galvan, a grain grower in Mato Grosso, told Reuters when asked about the prospect of planting corn outside the ideal window.