Tuesday, July 6, 2010

Circles for Rice | Weekly Update

The 2010 rice crop season continues to be a challenge; but, then again, how many years are not!

Weeds are a continuous issue in both the United States and Ukraine.  However, the fields with full ground shading are ahead of the game.  In the past week, we have seen in some fields development of patches of Johnson grass and shatter cane, and, of course, pigweed is a problem.  The Delta Farm Press recently published an article by Ford L. Baldwin on the current weed situation in (flooded) rice fields:
"I am getting the normal midseason rice herbicide questions. With the difficulty a lot of folks had getting herbicides applied timely, there will be some escaped grass."
Please click here to read the article in its entirety.

Overall, though, the Rice Team has rated the weed control as good/excellent across the fields.

Irrigation management is a continuously critical factor, and we recommend applying more water as the rice crop matures (per our observations on the loamy sand to clay loam soils); HOWEVER, we do not want the water moving from where it is applied (ie: runoff - photo on the right).  Some fields can take up to .75", while other fields are limited to only .5".  We must also be careful to cover the field and return to the driest areas in a timely fashion.  Remember that the rice root system is much shallower than corn, cotton, and soybeans, which means that there is a small volume of soil to manage.

We also need to keep an eye on the pressure at the pivot point (photo at left).  As pumping levels change, we have observed a reduction in the pivot pressure; if the pivot pressure is below the sprinkler chart (design pressure), the depth of water applied is reduced.  This reduction can lead to the situation as shown in the picture below where, due to reduced pressure, the correct overlap is not maintained and streaking has developed in the field.  The darker areas are rice plants exhibiting signs of moisture stress, while the lighter areas are plants that have adequate moisture.

We have started to collect infrared images to help identify issues in the fields, which we then compare with adjacent flood fields (photo at right).  Please note the half-circle center pivot and the flood field in the lower right-hand corner.  We like to see uniform color across the field.

I know this is a lot of information for one update!  If you have any questions about any of the observations, please ask away in the Comments box below.