This phenological event signals the start of the infection period for rhabdocline needlecast. At sites were bud break has occurred, the rhabdocline fruiting bodies are mature and are opening to release spores. Rhabdocline sprays, like all needlecast sprays, are not intended to kill the disease organism but are used to protect new tissue and prevent infection. With the buds breaking and spores maturing, now is the time to apply the first of three to four sprays of an approved fungicide. The second application must be made one week after the first.
Thorough coverage is very important to prevent infection.
Another pest that is perfectly in tune with Douglas fir budbreak is the Cooley adelgid. Late this week, newly emerged crawlers were observed in the new growth of Douglas fir in Perry and Snyder County. At this time of year, feeding on the new growth causes the characteristic kinks in needles of infested trees. Although Cooley damage on Douglas fir is largely aesthetic, heavy populations may stunt growth of trees. Control at this time is not possible and growers should wait until fall to control this common pest.