Category Archives: Horticulture

Big Data

Horticulture

We farmers look for ways to maintain productivity. Aerial study by camera drone, soil moisture sensors and weather from satellites are tools for data focused farming. In a recent post we discussed irrigation water testing. Last month almond tree leaf samples were collected and the leaf tissue analyzed and our West Block and East Block results are in. For almond, leaf analysis is more useful in diagnosing mineral deficiencies and toxicities than is soil analysis. This is because soil analysis does not indicate whether plants are able to uptake the nutrients. The leaf tells us about [nitrogen] nutrient levels which is crucial for plant health and yield. (‘you are what you eat‘)

D & D Agricultural Laboratory performs the service for us. It would be interesting to be on site to witness the leaf collection method. For example, do they sample the 4th tree in every 4th row? Should you look at strong trees or weak ones? From which part of the tree to they take the leaf and why? answer

In the laboratory, they wash sample leaves in a weak detergent mixture, rinse them in distilled water and dry them at 65 degrees C. The leaves are then ground and a subsample analyzed to determine the content of the requested elements. The macronutrients N, P, K, Ca, Mg and S are usually expressed as a percentage and the micronutrients in part per million (ppm). These results are judged against known standards. For each nutrient, there is a correlation between its concentration in the plant and the yield of the plant.
The curve below describes this correlation. This curve is referred to as a “yield response curve”.  [ reference , reference2 ]

Interpretation is provided graphically and comparatively over previous year efforts by our lab. Tissue testing does little to explain the reason for the nutritional disorder. It is only an alert and can help to identify or explain visual cues.

So, how are we doing? Sampling is best done in July but in this early peek; things look good. Someday technology may allow growers to identify what an orchard needs and provide remedy on a tree by tree basis. That would truly be Big Data.

Blue Diamond Growers Crop Progress Update Report for April

Several storm events during the period dropped significant amounts of rainfall over the orchards, with precipitation totals for the month ranging from  ½ to 1 inch from Fresno County south. Growers also endured several windy days that knocked nuts from the trees, broke branches and blew over a few trees.

Observers are reporting that the 2017 crop is developing well. Nuts are now fully sized, with the most advanced examples of the Nonpareil now beginning to show the first signs of solidification. Trees in all areas of the state have been shedding unfertilized nuts and those that they are unable to carry to maturity. However, this normal process has been a bit aggravated by the winds experienced during the month. Many have reported lush tree growth this year as the orchards take advantage of the mild temperatures. However, growers throughout the Central Valley have reported that the extended period of saturated soils during the winter and spring has resulted in weakened and dying trees. The repeated heavy rains experienced this year have promoted phytophthora root rot infections in many areas. As temperatures rise and water requirements increase, the dying roots of the infected trees are unable to draw water from the soil, resulting in weakened or dead trees. The continuing rain has inspired growers in the Sacramento and northern San Joaquin Valley’s to begin treatments to prevent Scab and Rust. These fungal infections can defoliate trees later in the season. However, the only effective method of control is through preventative treatments made prior to the appearance of the disease.

It’s the Water

Horticulture

Irrigation water contains soluble (dissolved) mineral salts. Overtime, these salts can build-up in the plant root zone. Excess salinity creates osmotic stress. A plant must expend competitive energy to absorb water from a saline soil. In addition to total salt content we are concerned about specific salts such as sodium, chloride, and boron. For the most part, roots normally exclude between 95-99% of the dissolved mineral salts applied. The tree sucks up the water leaving the salt behind. At some point however, the concentration of salts exceeds the tree’s ability to exclude them. The salt is then picked up by the tree, moves to the leaves, and burn occurs. Leaf burn reduces photosynthesis.

Leaf Burn

… not to be confused with Leaf Scorch, a biological cause

Water sources are not created equal. For example, our new Well #3 has sweeter water than our Well #2. We have this awareness because we test for water quality annually. The agricultural laboratory with which we contract, scientifically measures the salinity by electrical conductivity (EC) in units of decisiemens per meter (dS/m) Water salinity of up to 1.0 dS/m and average root zone soil salinity 1.5 dS/m is a-okay. [source]

The 2016 lab water analysis report:

  • Well #3 Soluble Salts @ 0.53 dS/m
  • Well #2 Soluble Salts @ 0.83 dS/m

But, specific salts (Sodium, Chloride, Boron) accordingly are well above optimum range.

There is relief! We cannot easily procure a better water source but we can dissipate the salts from the soil through leaching. Essentially, the soil can hold water moisture up to a point at which time, thanks to gravity, its ability to retain is overcome and water passes through** flushing the salts with it.

Our Sandy Loam soil type has a water holding capacity of .07 to 1.4 inches per foot of soil. Rainfall is nature’s way of cleansing (and it costs very little) but we must assist the leaching process with remedial applied irrigation.

How much is needed? For Well #3, that has irrigation water with electrical conductivity of 0.53 dS/m; the percentage of water that needs to pass beyond the root zone is 7% or 3.9 inches of water. This is in addition to Evapotranspiration* (what the trees ordinarily need to drink). The requirement for Well #2 is double at 14% and nearly 9 inches of extra water. So a takeaway is to favor Well #3. [source]

When? We like to leverage the leaching period with the rainy winter months when trees are dormant and soil fertilization (Nitrogen) has not been applied. This year we had abundant rainfall.  The CIMIS estimates 11.45 inches since the first of the year. Whoohoo!

*Evapotranspiration is the loss of water through soil surface evaporation and transpiration through openings in the leaves.

**assumes no barrier e.g. hardpan we rip the soil before planting

Blue Diamond Growers Crop Progress Update Report for March

Observers are reporting that crop development increased dramatically in all regions under the influence of the warm conditions experienced during the first week of the period. As seen in the photos accompanying this report, nutlets have been differentiating in size, with the largest breaking free from their protective jackets. Leaf cover on the trees has also developed vary rapidly, allowing the trees to begin pulling nutrients and water from the soil. The trees have also begun the normal process of casting the smallest nutlets to the ground, while preserving the largest. Continue reading Almond Update →

Pollination Fini

Blue Diamond Growers update report:

Bloom has concluded for most of the state. Butte and Padre orchards have less than 10% viable flowers remaining throughout the state. Bees are beginning foraging elsewhere for pollen. Leaves are emerging in all varieties and nutlets are starting to break through their jackets in early blooming varieties. 
Continue reading Pollination Fini →

  • Dormant
  • green tip
  • pink bud
  • popcorn
  • bloom
  • petal fall          1%
  • jacket            97%
  • out of jacket 2%

source: Blue Diamond Growers newsletter

 

The Bees Go To California

This is a 23 minute Podcast…

Every spring convoys of trucks arrive in the almond orchards of central California. They are carrying bees. Millions of them.

They arrive from all over the country, but especially southern states like Louisiana, and they have to get there at just the right time, when the almond trees start to flower so the bees can pollinate hundreds of acres of almond fields. Continue reading The Bees Go To California →

  • Dormant
  • green tip
  • pink bud
  • popcorn
  • bloom       3%
  • petal fall 19%
  • jacket      78%
  • out of jacket

source: Blue Diamond Growers newsletter

Tree Disposal Dilemma

Horticulture

Recycling the trees is ongoing. When a tree is blown down or keels over from weakness or disease it must be removed from the field. Depending on the number, this can result in a sizeable biomass. The dead wood can be chipped into mulch and lighter branches shredded. The mulch can be used by a nursery or converted into compost, a soil enhancement or placed on our dirt road to help control dust. Continue reading Tree Disposal Dilemma →