A call last week revealed a disease issue in which there are very few solutions. A grower called with concerns of several trees recently collapsing from the heat. The decline has been relatively gradual until a week or go, in which the trees suddenly turned brown and are now dead (Picture 1). This problem has been ongoing for several years in which he would replant the trees after a tree site fumigation. The orchard was a 10th leaf Nonpareil, Fritz, and Aldrich orchard, planted on Nemaguard. Picture 1: Overview of an almond tree affected by a root disease. The orchard was in a clay-loam soil series, flood irrigated with district water once every 10-13 days, and appeared to be in good shape outside of the affected areas. Affected trees were usually surrounded by younger, replanted trees confirming the replanting that the grower has done in the area (Picture 2). Furthermore, the affected trees appeared to be in groups, and this was confirmed by a Google Earth image once I returned back to the office (Picture 3). All this suggests a biotic agent causing disease, and seeing a total collapse of the tree, I began to investigate the root system. Picture 2: “Hotspot” of area infected by Armillaria root rot. Picture 3: Google Earth Aerial Image of the orchard affected by Armillaria Root Rot. Please note the large holes within the orchard canopy indicating missing or dead trees. Upon root excavation, the tell-tale signs of Oak Root Fungus or Armillaria Root Rot became relevant. Hitting a surface root and scraping back the bark, the white mycelial fans became evident (Picture 4). Furthermore, the roots possessed a smell similar to what we would expect from mushrooms – similar to the smell of mushrooms in the grocery store. Further bark removal and scraping