25th Anniversary Iowa State University Extension's answer line turns 25 this spring. The 800 line funded by ISU Extension is available within Iowa and answers nearly 33,000 calls annually. Nearly 60 percent of the callers want information about food preparation, nutrition, food preservation or food safety. Dormant Oil Sprays Dormant oil sprays are highly refined petroleum products that are mixed with water and applied to fruit trees and shrubs to control aphids, spider mites, and scale. The dormant oils destroy pests by suffocating them.
Proper timing is critical when using the sprays.
They need to be applied in late March or April before the plants show signs of breaking dormancy or before bud break. Scots Pine Not Recommended Scots pine is no longer recommended in windbreaks or the landscape because a widespread problem that may kill the trees. The problem is the pinewood nematode that can infest the trees and block the water system in pines and kill them. The most susceptible pine is the Scots or Scotch pine. The nematode problem was diagnosed as pine wilt in Illinois and Missouri in the late 1970s.