First Galls of Cedar Apple Rust Were Visible 3 April; Yes, Cedar Apple/Quince Rust Infections Happening With 3-7 April Rains

As we predicted in the previous blog post: from 3 – 7 April, Major Fire Blight and Apple Scab Infections Predicted With Rains From 3 – 6 April in All Virginia, Varying Slightly Depending on Location: Look at Your Disease Models, Juniper rusts started being viciously active during the intense rain events of 3 – 6 April when the galls fully developed (Fig. 3) and are now releasing basidiospores to infect apple leaves and fruit. To predict how sever infections will be, use the model in Figure 1 below. You should have applied before these rains and continue to apply SI, also known as DMI fungicides, like Inspire Super, or Cevya, or Indar, or Rally, or Sonoma, or Topguard, or Rhyme, or Procure + Manzate Pro-Stick every 14 days for rust control (all the way until 2nd cover). In between the 14 days of using SI/DMI fungicides, apply SDHI fungicides Fontelis, Sercadis, Miravis or Excalia + Manzate Pro-Stick to protect against apple scab and powdery mildew.

As per the analogue table model below (Figure 1), we are destined for severe rust infections at average temperatures and constant wetness for almost 48 h in the recent past like shown in the RIMpro weatehr data website for Winchester VA (Figure 2). This is applicable for all VA locations that grow apples.