As soybean harvest gets rolling Brazil, there are growing concerns about a shift in the weather in parts of South America and what that shift might mean to the region's corn crop during a critical time period.

On Monday, the Mato Grosso Institute of Agricutural Economics released data showing soybean harvest in that Brazilian state is underway, with 2% of the crop out of the field. Other areas are seeing more advanced progress, and early yield reports are coming with average productivity.

"In the southern state of Paraná, harvest also already started in some areas. The state’s Department of Rural Economics says that 95% of the crops are in good condition. In Rio Grande do Sul, the third main producer, most soybean crops are under the period of germination and plant development," Vieira says, adding that farmers in Mato Grosso planted more than 20 million acres of soybeans this year.

In nearby Argentina, however, the optimism pacing early soybean harvest in Brazil isn't shared. That's because the weather's taken a bad turn at a bad time. Heat and dryness are the main features of the weather there this week, and it could have some long-lasting implications, coming smack-dab in the middle of pollination for the area's corn crop, according to Commodity Weather Group (CWG) Tuesday morning.

"Argentina turns quite hot from Thursday through next Wednesday. Breaks in the heat early to mid-next week appear weaker on the latest Euro model, and the extent of 100s°F. is greater as well (as many as six days of 100°F+ heat supported for southwest Corn Belt on latest Euro guidance)," according to CWG. "This will cause significant stress to pollinating corn, particularly in far southern Cordoba, central/western Buenos Aires, and La Pampa. In total, at least 40% of the Corn Belt is likely to encounter heat/moisture stress, with about half the crop pollinating in the affected areas and subject to the more notable losses."

And, that heat is not just restricted to Argentina. Vieira says it's hitting central portions of Brazil, and on top of the general crop stress, it's causing another problem to flare up: soybean rust."There are at least 300 occurrences of soybean rust in Goiás, in the center-western state in Brazil, next to Mato Grosso. The occurrences are spread in 10 municipalities and represent five times more cases when compared to last year," Vieira says. "Local farmers are being oriented to apply fungicides with a frequency of less than 15 days."

Source - http://www.agriculture.com/