David Doll2 CommentsAugust 16, 2010Horticulture

2010 Almond Harvest Around the Corner…

Harvest has started in the Southern San Joaquin Valley, and will be starting in the Northern San Joaquin Valley in the coming week. Here are some points to consider for the upcoming harvest: A few articles posted last year can provide a few tips to help with the decision of harvest timing:1. Preparing for Harvest. 2. Taking a Harvest Sample for an IPM checkup. Keep in mind that earlier harvested nuts may have to dry on the ground for 1-2 weeks, while nuts partially dried on the tree will require less time. Nuts that remain in the tree will have a longer period of susceptibility to NOW, while almonds on the ground are susceptible to ants, mold (due to increased humidity), and rain events. A quick orchard walk through looking for fire ants and pavement ants should provide the information needed for this decision. As soon as the almonds are picked-up, irrigate the trees. Adding a little nitrogen at this point is also advised. It may be possible to water the trees earlier dependent upon the irrigation system. Drip users may be able to irrigate as soon as the trees are shaken, while some micro-sprinklers may have small enough pattern that does not wet wind-rowed nuts. If stockpiling in the field, cover the almonds with a white tarp – or better yet, a two tarp system that includes a black under layer and a white tarp on top. The white tarp or b/w combo has been shown to reduce stockpile temperature and condensation, helping to reduce the environmental conditions favorable for aflatoxin production. Uncover the piles when possible to prevent the accumulation of moisture underneath the plastic. Fumigation of the stockpiles may be necessary. If rain is imminent, keeping the almonds in the tree will increase the dry time of

Read More
David Doll0 commentsAugust 11, 2009Horticulture

Preparing for Harvest

It looks as if harvesting will be underway for Merced County within the next week to 10 days, with the date occurring earlier for growers on the West and South Sides of the county. With harvest, there are many preparations that must be taken into consideration. Water Management:In order to determine the last pre-harvest irrigation, a target harvest date must be set. Approximately two weeks after the last irrigation are required to “dry down” the trees enough to minimize bark damage from shaking. This time period does vary upon soil textures, with sand and clay requiring less and more time, respectively. This depletion of soil moisture tightens the bark to the trunk and prevents damage from the shaker attachment. Also, as the season progresses, the bark adheres tighter to the trunk. Therefore, with an earlier harvest, the chances of shaker damage are increased. In soils of low water holding capacity (i.e. sand) it may be necessary to irrigate between the harvesting of the varieties. Proper water management between varieties is just as critical as water management before harvest because during this period the tree is developing the fruit bud for the coming season. Any moderate to severe water stress during this period will reduce the formation of fruit bud. Timing of Harvest:Harvest timing should be considered using the following criteria: – The need to avoid naval orange worm damage to nuts on the tree and ant damage once nuts are on the ground; – The ability to achieve maximal nut removal; – The ability to maintain yield and quantity; – Minimization of tree injury; – Availability of harvest equipment; – weather conditions that may cause crop loss or damage (i.e. rain). A few of these points are highlighted below: Damage caused by Navel Orange Worm and Ants:Early harvest prevents the

Read More
David Doll16 CommentsJune 22, 2009Horticulture

The Seasonal Patterns of Almond Production

When reviewing previous posts of this blog, I realized that not much information has been provided about the general biology of the almond tree. To cover this area, I decided to focus on the seasonal cycle of almond trees. In general, the season progresses in the following pattern: Dormant,Delayed Dormant, Bloom, Post-Bloom, Fruit Development, Harvest, and Post Harvest. Each period will be broken down and discussed. Dormant:As the temperatures from the late fall continue to drop, the tree enters a period of rest that lasts through December/Early January. At this time, the tree has dropped all of its leaves naturally or through an application of zinc, and is maintaining a low level of water use and starch consumption. This “low” flow of starch through the tree is needed as the catabolic breakdown of starch to sugar prevents the sap from freezing. This is, of course, only if the tree was able to develop enough starch reserves in the previous fall. In the rare occasion of low starch reserves, cold damage can occur leading to canopy and scaffold loss. Picture 1: A dormant spur. The cold temperatures that the tree is exposed to at this time helps with the development of the fruit buds. The tree requires a certain amount of moisture and chilling hours to come out of dormancy. Once the chilling hour requirement has been met, bud grown will begin with warmer temperatures. Chill hours are dependent upon the variety,but almonds generally need between 500 and 600 chill hours. In general, chill hours are the number of hours between the temperatures of 32-45 degrees Fahrenheit. Winter hours above 60 degrees are subtracted from the totals. Delayed Dormant:In late January/early February the tree begins to push a flush of fine feeder roots. These roots provide moisture and nutrients for the

Read More
  • 1
  • 2