Dormant Practices and Wet Weather

Over the past week, a lot of rain has fallen across California. Orchard access should be limited during periods of wet soil to reduce soil compaction as well as stuck equipment. Limiting access, however, creates challenges in performing a variety of orchard operations, including the list below.   Winter Sanitation. Removal of almond mummies from trees is critical for Navel Orangeworm management (NOW). Many operations usually wait for the first rains to help with leaf drop and to help “loosen” the mummies. In wet years, however, it becomes difficult to winter shake the trees as orchard conditions remain too wet for access of shakers. Furthermore, the “window” to winter shake is limited on the late end as fruit bud loss increases as trees enter delayed dormancy and buds swell (Mid to late January, depending on location). To manage this limited access, operations should consider poling crews. If these aren’t available, and sanitation is not performed, a spring timed (usually late April through early May) insecticide can reduce overwintering NOW. This strategy is not as effective as winter sanitation, but is better than doing nothing. Insecticide sprays targeting NOW in the dormant period are NOT effective due to NOW pupae being inside of the almond mummies. Planting bare root trees. Hand planting crews have an easier time than machine planting due to limited field access. If planting delays occur, trees should be placed into cold storage at the nursery as soon as possible to reduce the risk of leaf out and weakened trees. Keep trees in cold storage until ready to plant. Unless there is no other option, do not take delivery of trees in bins or plant them in a temporary location at the farm. On delivery, check tree roots to make sure they are healthy and living (should be

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Proper Almond Tree Planting

When planting a new orchard, precautions should be taken to prevent tree loss. Care should be taken to reduce direct damage to the trees. Trees should be planted as soon as possible once received from the nursery. Always cover bare roots with a tarp when transporting trees on back of a trailer, making sure to keep the roots moist. If the trees are heeled in, fumigated soil or sawdust should be used and excess moisture should be avoided. Cold storage should be avoided if possible. If cold storage is necessary, then trees should be fully dormant and the roots kept moist. Care should be taken to ensure that trees are properly planted. In heavy soils, planting on berms is recommended to help drain water away from the crown of the tree. Berms should be pulled before planting to ensure that the graft union is above the soil. Do not pull a berm after planting as this may cover the graft union. Planting depth after settling should be no deeper than in the nursery and the graft union should always be well above the soil line. Holes should be dug deep enough to accept the root system; no deeper. If a crust or soil glaze occurs, break up or slice to ensure proper root growth. Planting trees high will help reduce losses to the root disease Phytophthora. The only exception is trees grafted to Marianna 2624 plum rootstock; they should be planted at the same depth they were at the nursery to avoid suckering from the roots. When planting, try to follow some of these tips: 1. Dig a hole deep enough so the roots are spread out and not cramped, 2. plant the trees so that the nursery soil line is above the current soil line, 3. plant the highest

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