May 9, 2017

Select Max labeled for tree fruit

The U.S. Environmental Protection Agency (EPA) has approved a new Supplemental Label for use of the graminicide Select Max 0.97 EC (clethodim) for use in several crops, including pome and stone fruit. This includes apples, pears and all other pome fruits, and apricots, cherries, nectarine, peaches, plums and related hybrids. The label also includes low-growing berry crops (except cranberry and strawberry), including low-bush blueberry.

Select Max is similar in activity to the other graminicides labeled in fruit crops (Poast, Fusilade), and can be used in in rotation with the other herbicides. Each of the graminicides has a slightly different weed spectrum, so it is a good practice to rotate them. Select Max is effective against all annual grasses, and is especially effective against annual bluegrass, which Poast tends to miss. Select Max at the highest labeled rate is moderately effective against quackgrass, orchardgrass and other perennial grasses.

The label allows use of 12 to 16 fluid ounces (0.09-0.12 pounds active ingredient) per acre of Select Max in each application, with a maximum of 64 fluid ounces per acre per year. There is a 14 day pre-harvest interval (PHI) for all the tree fruit. The PHI for small fruit is 45 days. Always include 0.25 percent v/v non-ionic surfactant in the herbicide solution. That is 1 guart in 100 gallons of spray solution, or 25 fluid ounces in 20 gallons of solution.

Select Max is similar to the other graminicides, in that it kills grasses slowly. Visual symptoms (yellowing of the leaves) appear about one week after application. Normally, about four to five days after application, the tallest part of the grass plants can be pulled off and will have yellow discoloration at the node where it breaks off. Large, well-established grasses, especially perennials, may need a second application of Select Max or other grass herbicide three to four weeks after the first application to kill them completely.

The Select Max Supplemental Label is part of the Select Max Section 3 Federal label. The Supplemental Label expires in May 2019. By then these uses should be included on the Federal label attached to containers. The new Supplemental Label is available from the internet at CDMS.

– Bernard Zandstra, Michigan State University