|Richard Jr, Edward|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: May 1, 2008
Publication Date: October 15, 2010
Citation: Richard Jr, E.P., Dalley, C.D. 2010. Herbicide effects on sugarcane. Brazilian Symposium of Ecophysiology, Maturation, and Ripeners of Sugarcane Proceedings. 1:85-88. Technical Abstract: Of all the areas of the world where sugarcane is grown, Louisiana lies furthest from the Equator. As such, its growing season is the shortest as it is affected by frost in the late–winter (February/March) at the start of the growing season and the fear of freezing temperatures during the harvest season, which necessitates an early fall start of the harvest season. With such a short growing season, the use of herbicides to control weeds and optimize cane yields is an important tool in the production of sugarcane in Louisiana. However, the margin of selectivity between the crop and weed is often narrow and growers must be constantly reminded of the consequences of a miss-application, which can result in either poor weed control at one end of the spectrum or crop injury and possibly death of the crop at the other end of the spectrum. Several methods to minimize the potential for crop injury from the application of herbicides were proposed. These include: (1) ensuring that the newly planted stalks have at least 8 to 10 cm of packed soil at planting to serve as a buffer between the zone of residual herbicide activity and the germinating vegetative root and shoot buds of the sugarcane stalk; (2) utilization of rates specific to the weed problem and the soil type with rates generally being lower for sandy soils and higher for clay soils; (3) identifying rates that will give the level and length of weed control necessary to maximize benefits while reducing chances of herbicide injury and reduced yield; (4) ensuring that tank-mix combinations do not compromise the safeness of the application when the herbicides are applied separately (2 x safety factor); (5) timing the herbicide application to reduce the vulnerability of the crop e.g. application of herbicides: prior to the crop’s emergence from winter dormancy (preemergence and postemergence herbicides), before the crop goes into the tillering phase (population impact), and before the crop enters the grand growth phase (stalk height and weight); and (6) selective placement to minimize foliar contact (directed postemergence). By minimizing the stress associated with weed competition and herbicide injury, sustainable cane and sugar yields even under Louisiana’s short growing season can be obtained.