Did the Rain Last Week Affect Preemergence Herbicide Efficacy?
… Dr. John Street explains “no – for two reasons: 1) Pre-emergence herbicides are not very soluble and do not readily leach from soils. 2) Herbicides can be broken down by soil microbes if the soil temperatures are warm enough for microbial activity. Soil temperatures are still cool at this time of year. In summary, it is highly unlikely that the pre-emergent herbicides applications made prior to the spring rains will be leached away or broken down at this time.” Spring Fertilizer Applications … If a late season fertilizer application was made last Nov/December, the turf should have had quick spring green-up and good color until around mid-April. At that time, some fields will have been fertilized again in conjunction with a preemergence herbicide application. However, most fields do not get a preemergence herbicide application because they need to be re-seeded after the previous fall play. If fields were not fertilized in conjunction with the preemergence herbicide application, no
