Mississippi Rice Progress – May 31, 2013

In general, rice planting is nearly completed and most rice planted before early May is going to flood.  According to USDA’s Crop Progress Report, growers in Mississippi had planted 72% of the expected acreage by Sunday, May 26.  Other than a few thundershowers in places, we have continued to make progress with planting this week.  More and more rice is going to flood which is good considering the difficulties and slow start we had this spring.  Later planted rice is progressing at a rapid pace.  The biggest problem encountered this week is continued cases of sick rice due to herbicide drift.  This week, I have seen more paraquat drift symptoms.  Typically, rice is more resilient to drift of paraquat compared with glyphosate; however, paraquat is seldom applied alone.  Metribuzin (Sencor) and S-metolachlor (Dual Magnum), sold as Boundary in a premix, are often included.  The herbicide from that mixture that can be most troublesome for rice is metribuzin.  The residual activity of metribuzin can inhibit rice growth or cause death.  Just like all drift situations, each field responds differently, so we literally have to “shoot from the hip” with post-drift management recommendations.

Glyphosate-resistant Palmer amaranth has definitely changed farming systems in the Delta.  The environmental conditions this spring have created the perfect storm for the number of drift incidents.  Because of limited herbicide options and a narrow window for control of Palmer amaranth, growers are more pressured to spray in sub-optimal conditions.  Continuing the theme of the rice/soybean system, and the relatively late planted soybean crop in 2013, it is important to consider the crop rotation restrictions for some of the primary herbicides used in soybean weed control.  Products that contain the active ingredient fomesafen have a 10-month rotation restriction for rice.  If Prefix, Reflex, Flexstar, Flexstar GT, or any other product that contains fomesafen are applied to soybean after June 1, rice cannot legally be planted until after April 1 the following year.  Obviously, the later the application, the longer the waiting period to plant next year’s rice if rice is in the planned rotation with soybean.  Additionally, products that contain the active ingredient chlorimuron (Classic, Canopy, Envive, Valor XLT, and others) will negate rice planting in rotation for 18 months.

Rice is an important crop in the Delta.  Unfortunately, it is very sensitive to many of the herbicides currently available to combat glyphosate-resistant Palmer amaranth in other crops.  It is a challenge the agricultural industry will have to address together to keep current farming systems viable.

Gramoxone plus Boundary drift on rice