Jun 02, 2010
U.S. Crops Off to Good Start, No Major Concerns As Yet
Author: Michael Cordonnier/Soybean & Corn Advisor, Inc.
Corn planting in the U.S. advanced to 97% complete last week and the soybean planting advanced to 74% complete. Last week's weather was also very beneficial for rapid emergence and stand establishment of the crops. With the corn crop rated as 76% good to excellent and the soybean crop expected to be rated similar next week, both the corn and soybean crops continue to get off to a generally good start. The long-range forecast for the first half of June indicates generally average to above average conditions for the next several weeks. If that forecast verifies, both the corn and soybean crops should continue to develop normally.
The forecast can change of course so below are listed some of the factors that could lead to either improving yield forecasts or declining yield forecast. The list is not all inclusive, but it can serve as a starting point for evaluating the 2010 U.S. corn and soybean crops.
Factors that could lead to improving yield estimates:
- Early planting - The corn crop was planted early and its development continues to be 5-7 days ahead of the average pace. Generally, if corn is planted earlier than normal and it continues to develop at a rapid pace throughout the summer, there is a greater chance that the crop could end up with an above trend line yield.
- Limited amount of replant - There was only a limited amount of the 2010 corn crop that needed to be replanted due to localized flooding, ponding, or frost damage and certainly the amount of corn that needed to be replanted this year was less than the last couple of years. The yield of replanted corn is generally below trend line, so if there is less replanted corn, the yields tend to hold up better.
- High plant populations - Most of the corn was planted under very good conditions, which should result in high plant populations and eventually a high number of ears per acre.
- Limited dryness in June - A little dry weather during June is a good thing because it forces the corn to send its roots deeper in search of moisture, which allows the plant to better able mine the soil for moisture later in the summer. The key is a limited amount of moisture stress; too much would be detrimental to yields.
- Early pollination - Since the corn is ahead of its normal developmental pace, it should pollinate ahead of normal allowing it to get ahead of any potential dryness that could negatively impact pollination.
- Improved hybrids - Without a doubt, the corn hybrids of today are better able to withstand short periods of stress compared to the corn hybrids of just a few years ago. If there are no prolonged periods of hot and dry weather this summer, the improved corn hybrids should perform very well.
- Weak La Nina or delayed transition to La Nina - If only a weak La Nina develops this summer, then any adverse affects on the summer crops should be limited. Additionally, the timing of the development of a potential La Nina is also important. If it doesn't develop until late in the summer, then there should be limited affects on this year's crops.
- Soybeans off to an average start - It's too early to make any judgments about the soybean crop other than the fact that it looks like the soybeans are going to be planted at an average pace. If soybeans are planted at a normal time, then the soybean yields are determined by the weather during the second half of July and August, so good weather during that period (ample soil moisture and a lack of excessive heat) should result in trend line or above yields.
Factors that could lead to declining yield estimates:
- Excessive dryness during June - Moderate dryness during June is actually beneficial in the long-run, but if the dryness is extensive or prolonged, then it becomes a negative because June is usually the wettest month of the summer and if June runs a moisture deficit, then moisture stresses are more likely to occur during July and August.
- Dryness during pre pollination - The two weeks prior to pollination is when the corn plant sets the number of rows on the ear. If the plant is under moisture stress during that period, the number of rows per ear could be low, 12-14-16 rows and as a result, the yield could be low as well.
- Excessive heat during pollination - Hot temperatures alone are not that detrimental to corn pollination, it's the combination of heat and moisture stress that can severely impact corn yields. Corn pollination is going to be a little earlier than normal this year so any potential heat and moisture stress would have to develop before the end of June to have a significant impact on the corn pollination.
- A strong La Nina and early transition - A strong La Nina would probably result in a higher probability of below normal rainfall this summer, so a strong La Nina could be more detrimental than a weak La Nina. If we transition to a La Nina before the end of June, then the possibility of a dryer than normal summer increases.
- Excessive dryness during July and August - The corn crop is filling grain during this period and dry weather can result in kernel abortion at the tip of the ear, shallow kernel depth, lighter test weights, and eventually lower yields. This is also the critical time for soybean yields. Soybeans are setting pods and filling pods during this time and excessive dryness can be detrimental to this process resulting in lower yields.