Rice Response to Boron Application Rate and Time in Arkansas , Louisiana , and Missouri

Boron (B) deficiency of soybean has been routinely observed in numerous fields in northeast Arkansas since 2001 and has stimulated interest in B fertilization of both rice and soybean in Arkansas. In 2002, scientists from Arkansas, Louisiana, and Missouri established similar research trials in each state to investigate rice yield response to B fertilization. Boron fertilizer was applied at rates of 0, 0.33, 0.67, and 1.0 lb B/acre at three or four different times during the season including preemerge, preflood, latetillering or panicle initiation, and the late-boot stage. Boron fertilization increased rice yields only in Arkansas. Although the yield increase was statistically significant it was relatively small (+5.0%). In general, B does not appear to be a major yield-limiting factor for rice production in the Midsouth. Additional research data are needed to determine if the positive yield response observed in Arkansas in 2002 can consistently be repeated before recommendations can be made to growers.