Back
December 8, 2010

Dry Weather Endangers Argentine Crops

The current dry conditions in southern South America are putting the crops in Argentina at serious risk of lower yields. The corn crop in Argentina is more at risk than the soybean crop because it is now entering into its most critical reproductive phase, which is pollination. The month of December could be a make-or-break month for the Argentine corn crop. The areas of most concern in Argentina are the provinces of Cordoba, Santa Fe, Entre Rios, and northern Argentina. The province of Buenos Aires is doing OK, at least for the time being.

Corn - The month of December is very important for the corn crop in Argentina because it is the month when the corn is in pre-pollination and pollination. During pre-pollination the size of the ear is being determined. Hot and dry conditions during that period can result in smaller ear size, fewer kernels, lighter kernels, and lower yields. Later in the month most of Argentina's corn crop will be pollinating and continued stressful conditions in Argentina during the month of December could affect the corn crop's only chance at successful pollination.

The corn crop in Argentina is about at the same stage as the U.S. corn crop would be during early July. Some of the very early corn is already pollinating, but most will pollinate over the next several weeks. The soils in Argentina are prairie soils very similar to those found in Illinois or Iowa and the latitude of most of the corn grown in Argentina as about the same latitude south of the equator as Kentucky/Tennessee are north of the equator. Many of the corn hybrids grown in Argentina are very similar to the corn hybrids grown in the far southern Corn Belt. Therefore, the potential response of the Argentine corn crop to hot and dry conditions should be very similar to what you would expect here in the U.S. under similar circumstances.

Soybeans - The risk factor of soybeans is not as high as it is for corn at the present time because soybeans can recuperate much better from stressful conditions than corn. The soybean crop can have a very problematic start, but if conditions improve later in the growing season, the eventual yield could still be acceptable.

The soybean crop in Argentina is about at the same stage as the U.S. soybean crop would be during early June. Approximately 60% of the crop has been planted and recent planting progress has been slow due to dry conditions. About half of the remaining soybeans will be planted as double crop soybeans after the wheat is harvested.

Some of the farmers are particularly concerned about their double crop soybeans. The source of their concern is the fact that the wheat crop is depleting the soil moisture reserves, which could make it even more difficult to get the soybean crop established once the wheat is harvested. Without additional rainfall, it could be difficult to get acceptable germination of the double crop soybeans.

Due to the recent delays in planting, more of the 2010/11Argentine soybean crop will behave similar to double crop soybeans than would normally be expected. Double crop soybeans in Argentina generally have a lower yield expectation than full season soybeans. If soybeans in Argentina are planted after about the third week of November, the yield potential starts to decline for each day that planting is delayed. The declines start out small, maybe a quarter of a bushel per day and if the planting is delayed until after the first week of December, potential yield reductions could be as high as a half a bushel per day. Yield reductions continue to increase for each week planting is delayed.