To prevent direct damage, make applications of insecticides when 20 percent of plants show signs of thrips damage, or when 5 or more thrips per bloom are found. Thrips are very small, so close observation is necessary. Thrips may be monitored in a variety of ways including various methods of beating plants to dislodge thrips from foliage into a collection device (Styrofoam cup, white tray, sticky trap). An effective in-field survey method for thrips in blooms is to place several blooms in a vial of alcohol and count the thrips as they die and settle to the bottom.
The first step in a weed management program is to identify the problem; this task is best accomplished by weed mapping. Develop surveys each fall to provide a written record of the species present and their population levels. 153554b96e