David Doll5 CommentsAugust 29, 2016Diseases, General

Considerations for Replanting Almond Orchards

It is the time of the year when many operations begin the process of replanting almond orchards. Orchard removal and eventual replacement is one of the more critical times of farm operations. The decision to remove a block varies by farmer. Some remove blocks based on a cycle of redevelopment, meaning that blocks are removed on a schedule based on age to assist with cash-flow. Some are removed due to expensive or inadequate resources (e.g. water). Many are removed when production drops below a certain profitability level. Removing a block on profitability can be tricky. Blocks tend to alternate bear. An off year may trigger removal, but it could be coming into an on year. Prices also fluctuate. Therefore, this may not be the best way to decide on removing a block. Another consideration should be determining the the stand of trees remaining in the orchard and the rate of tree loss over the past few years. Commonly, in old orchards, trees are lost to heart rot decay fungi and corresponding wind throw. These losses tend to increase as the orchard ages. If this rate is increasing and the orchard stand is below 75%, removal and replanting should be considered. This is a conservative estimate, and should be evaluated with production records and tree stand for your own operations (This estimate is based on an 80% canopy coverage at maturity with minimal tree losses). Once the decision to remove is made, the work begins. Consider harvesting the later varieties earlier to allow more time in the process.  Nematode sampling should occur prior to removal to determine which species are present and assist in rootstock selection. This can be done one to two years prior to removal. Line up the resources for orchard removal, which can be done by tub grinders, whole orchard incorporation, or removal

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David Doll0 commentsSeptember 15, 2015Horticulture

Planting Potted Plants: Preventing Root Girdling

It is the time of the year when many operations plant potted almond trees. Although potted trees are convenient with the year round availability and planting time (almost any month if properly irrigated),  there are a few considerations at planting that must be considered in order to prevent root girdling and future orchard loss. Root girdling of trees occurs when roots grow in odd directions. These roots wrap over or around other roots or the trunk, eventually preventing the flow of water and nutrients while limiting structural integrity. The problem is usually not noticeable at first, but 6-8 months after planting, the trees begin to show reduced growth. Later, these trees often become victim of wet feet or Phytophthora due to over-irrigation of the tree. Over-irrigation occurs from to the inability to pull water at the same rate due to the constricted xylem and reduced canopy size in comparison to healthy trees. In cases in which the trees survive and are kept through the third leaf, they may snap off at ground level from the shaking process. The issue seems to be more severe with more vigorous rootstocks. Root girdling is often caused by root kinks. Root kinks occur due to the misdirected growth of roots as they become pot-bound. It is not uncommon to see tree roots growing up or around when left in a pot too long. Some modern pot technology may help reduce the occurrence, but any tree, if kept to long, would have excessive root kinks. Root girdling can be prevented by planting trees that do not have observed root kinks. Trees should be examined prior to planting. If the trees have lignified roots (woody roots) which are growing in multiple directions, it is important to return the plants or break the root ball up in attempts

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