jan-feb-2020

IN YOUR ORCHARD For detailed information on frost control, including tables for critical temperatures and bloom stage see sacvalleyorchards.com/almonds/horticulture/frost- protection-2. Additional valuable resources include those at biomet.ucdavis.edu/index.php/frost-protection- mainmenu-33. Planting Proper planting is critical to orchard health and success. Some important points in planting a bareroot orchard are as follows. Planting holes should be large enough to accept the nursery tree without having to jam the tree down into hole to make it fit and producing a J-rooted tree. Tree roots should be planted pointing downwards. Building a mound in the center of the planting hole helps with directing roots downwards, especially if the holes have been dug with an auger as soil often falls back in to the hole around the sides after the auger is pulled out. If holes are dug with an auger on finer textures soils (loams, clay loams, etc.), make sure the sides of the hole are roughed up with a shovel to remove auger “glaze.” Finally, irrigate the trees immediately after planting — even when the soil is wet. This will help settle the soil around the bare roots or the potting media. Experienced growers swear by tanking with a hose the day of planting vs tanking later or watering with a pressurized probe. For extensive information on care of a new orchard, view UCANR’s New Orchard Handbook (ccfruitandnuts.ucanr.edu/ files/238596.pdf) developed by Dr. Katherine Jarvis-Shean, UCCE Tree Crop Advisor in Sac/Solano/Yolo region. Pruning Good scaffold selection in the first dormant season for spring planted trees (bareroot or potted) is critical for long-term orchard performance. Make sure pruning crews can identify a “bad” branch angle with occluded bark and cut out that branch (see photos for good and bad branch angles). Protect pruning wounds, especially in young blocks where relatively big cuts, close to the trunk are commonly made, with fungicide immediately after pruning if rain is in the forecast. In recent UC trials by Leslie Holland, Ph.D. candidate in Dr. Trouillas lab at UC Kearney, Topsin-M ® consistently delivered the best reduction in wound infection in almonds. Fertilization Pre-bloom is a key time for nitrogen (N) planning. The annual target N rate for an orchard should be set before Bad Branch Angle Good Branch Angle 4 4 A L M O N D F A C T S