Prowl H₂O: A New Prowl Formulation

May 10, 2004

By Jim Griffin                                                          Printer friendly version

A new formulation of Prowl herbicide is being marketed in the sugarcane growing areas.  The new formulation, Prowl H₂O, is water based as compared with the Prowl EC (emulsifiable concentrate) formulation which is oil based.  For the EC formulation an emulsifier is added that allows the herbicide to be mixed with water without separating out.  In contrast, the new formulation is micro-encapsulated where the herbicide is coated with a polymer.  Micro-encapsulation allows the herbicide to be suspended in water and eliminates the need for an emulsifier.  The advantage to micro-encapsulation of Prowl is that both odor and staining are reduced.  Another key difference between the formulations is that Prowl H₂O does not have to be incorporated if rainfall is not received within 7 days after application.  The new formulation of Prowl is a 3.8 CS (capsule suspension) and contains 3.8 lbs active ingredient per gallon, which means that it is slightly more concentrated than the 3.3 EC formulation which contains 3.3 lbs active ingredient per gallon.  To convert rates, divide the Prowl EC rate by 1.15 to calculate the Prowl H₂O rate.  Where 4 pts/A of Prowl EC is used you will apply 3.5 pts of Prowl H₂O.  The cost per gallon of Prowl H₂O is greater than Prowl EC, but remember that a gallon of the micro-encapsulated formulation will treat more acres, so always calculate the cost on a per acre basis. 

We have tested the new micro-encapsulated Prowl formulation applied both at planting and in spring and when applied at the same rate of active ingredient per acre as the EC formulation, weed control and sugarcane response was the same.  Most definitely the odor is reduced with the micro-encapsulated formulation.  When we used a plastic graduated cylinder to measure Prowl H₂O, the plastic did not stain and was easily rinsed.  For your information I have included below the recommendations from the LSU AgCenter Sugarcane Weed Control guide for use of Prowl at layby, in fallowed fields, and at planting. 

Where Prowl is a component of a growers weed control program, use of the new Prowl H₂O formulation should be considered especially when residential areas, businesses, schools, or hospitals are adjacent to treated fields.  The increase in cost associated with the new formulation compared with the older EC formulation may be offset by reduced complaints due to odor.

________________________________________________________

Dr. Jim Griffin is with the LSU AgCenter in the Department of Agronomy and Environ mental Management and has research and extension responsibilities in the area of sugarcane weed management.  Results from sugarcane weed control research and specific sugarcane weed control recommendations can be viewed at old.lsuagcenter.com/weedscience under “Related Publications”.