Peanut Disease Management Utilizing an Infurrow Treatment of Azoxystrobin

Applications of azoxystrobin in-furrow have shown inconsistent results in terms of yield and disease control in experimental peanut plots. Two trials were conducted in both 2000 and 2001 to better define the effects of this treatment on peanut disease control and pod yield. Treatments included: azoxystrobin in-furrow alone (102 g ai/ha), azoxystrobin mid-season alone (two applications at 335 g ai/ha), azoxystrobin both in-furrow and mid-season, and a nontreated control. Destructive sampling was conducted throughout the growing season to determine treatment effects. The in-furrow treatment of azoxystrobin had minimal impact on plant stand counts, tomato spotted wilt incidence, yield, and crop value. However, in-furrow applications of azoxystrobin did suppress levels of Aspergillus crown rot (Aspergillus niger) and early season (prior to 60 days after planting) southern stem rot (Sclerotium rolfsii). However, season-long control of stem rot was only accomplished through the use of mid-season applications of azoxystrobin. Similarly, yields and crop value were only significantly increased when in-season applications of azoxystrobin were made. These trials were conducted under optimal planting and growing conditions using high quality seed. Testing under adverse conditions or heavier disease pressure, which may reveal more benefits from a treatment of azoxystrobin in-furrow, needs to be conducted. Accepted for publication 13 August 2002. Published 16 September 2002.