By Dr. Thomas T. Yamashita

Our approach to reducing freeze works by facilitating the acclimation response of the plant in converting saturated fatty acids to polyunsaturated acids. These reactions are energy expensive and can only occur in the presence of sufficient carbon compounds and catalysts necessary to promote this acclimation response. Most plants attempt this reaction in the face of cold weather, but the unassisted process takes too long, and plants are unable to mount this defense in a timely fashion.

By providing plants with carefully balanced nutrition, we can give them the energy needed to undertake the conversion of saturated fatty acids to their polyunsaturated counterparts needed to resist the effects of cold weather.

Case Study: Freeze Damage Reduction in Almond Trees

Conditions

Almond orchards in mid-April were subjected to two consecutive days with lows of 26 degrees Fahrenheit for 4.5 hours and 4 hours, respectfully. Almonds had reached about 1/3 their size.

One 800 acre, 22 year old orchard was sprayed 7 days prior and 1 day prior to the freezing event with:

• 3 gal/100 gal spray of FG31
• Integrity Calcium at 4 quarts/100 gal
• Integrity Z-422 at 1 quart/100 gal
• 4 ounces 10% Boron
• KNO3 @ 3 lb/100
• Light Rate of Fungicide (Preferably a benzimidazole or EBDTC general purpose, low phytotoxicity form)
• Silwet L77 at 2-3 ounces/100 gal (40 gpa)

An adjacent check block, an 800 acre orchard, was on the same soil fertility program was not treated with Fusion 360 products.

Outcome

24 hours after the second consecutive day of 26 degree Fahrenheit freezing temperatures, the orchards were evaluated for the extent of freeze damage. The check block sustained 87% damage and aborted the nuts within a week. The block treated with Fusion 360 products sustained approximately 2.5% damage on the perimeter of the orchard.

Case Study: Freeze Damage Reduction in Lemon Trees

Conditions

A young, second year lemon grove was subjected to two consecutive days in January with temperatures dropping to roughly 26 degrees Fahrenheit for 3.5 hours on each of the two days. The trees were sprayed with:

• Foliar FG-31 at 2 gal/100 gal
• Nutri-Phite Magnum at 1 quart/100 gal
• Integrity Calcium at 3 quarts/100 gal
• Integrity Z-422 at 1 quart/100 gal
• Integrity FG-Micros at 1 pint/100 gal
• KNO3 @ 5 lbs./100 gal
• Silwet L77 @ 2 ounces/100 gal

This mixture was sprayed once at a density of roughly 60 gallons per acre. A few rows were left untreated.

Outcome

Damage to the lemon trees were assessed 24 hours after the freeze. Of the untreated trees 100% were killed. Neighboring mature citrus groves were also severely affected. However, the treated trees were completely unscathed.

Case Study: Freeze Damage Reduction in Peppers

Conditions

Young transplants were subjected to freezing temperatures between 26 and 27 degrees Fahrenheit. The seedlings were sprayed twice at a 4 day interval using the following mixture at a density of 40 gallons per acre:

• Folar FG-31 at 3 gal/100 gal
• Nutri-Phite at 1 quart/100 gal
• Integrity Calcium at 4 quarts/100 gal
• Integrity Z-422 at 1 quart/100 gal
• Integrity FG-Micros at 1 pint/100 gal
• 10% Boron at 2 ounces/100 gal
• KNO3 at 3 lbs./100 gal
• Manex at 1 pint/100 gal
• Silwet L77 at 2-3 ounces/100 gal

Outcome

24 hours after the freeze, damages were assessed. Untreated seedlings incurred a loss of more than 65%. Seedlings that were treated with the above mixture were not affected by this frost at all. The treated seedlings resumed growth immediately, and went on to produce an excellent crop.

General Guidance on Freeze Damage Mitigation

The amount of spray used and the time between applications may vary from crop to crop, and also according to varying weather patterns. Furthermore, many plants growing out of the dormant period are typically very low in physical integrity and physiological efficiency. Thus, initial sprays directed at these sensitive tissues need to be toned down in their concentration. After acclimation following 2 reduced sprays, it may be safe to begin gradual rate increases.

General Foliar Program for Preventing Freeze Damage

Timing: Preferably more than 6 hours before the event.

Materials and Rates/100 Gallons:

• Foliar FG-31: 1-3 gallons
• Nutri-Phite Magnum: 1-3 pints
• Integrity Calcium: 2-4 quarts
• Integrity Z-422: 1-2 pints
• Integrity FG-Micros: ½-1 pint
• Borosol – 10% Solution: 2-6 ounces
• KNO3: 1-5 pounds
• Kocide 101 (optional): ¼-1 pound
• Silicon Surfactant: 1-3 ounces

Instructions: Fill the spray or mix tank at least ¾ full with water and start agitation. Follow gradually with materials in the order given. Apply in a mist for thorough coverage. (If freezing is common to the region, apply more than 1 spray, at 3 to 5 day intervals.)

Note: If the plant tissues are thin and sensitive to osmotic stress, begin sprays with a low concentration. Gradually build the concentration with successive sprays and hardening off of tissues.

General Soil Program for Preventing Freeze Damage

Timing: Preferably more than 6 hours before the event.

Materials and Rate/Acre:

• Water: 10 gallons
• Thiocal: 3-5 gallons
• K-Mend: 3-5 gallons
• Fusion 360 Soil: 5-20 gallons
• Iota: 1-2 quarts

Instructions: First, place the required water into a mix tank and start agitation. Gradually add the materials, taking care to avoid any sudden dumping of materials. Inject the mixture into a drip or mini-sprinkler system for even distribution.

Regarding High Volume Use of Fusion 360 Soil

Please note, if you elect to inject levels of F360 Soil greater than 5 gallons per acre, be sure to include nitrogen (N) and phosphorus (P) as supplementary elements as follows:

1. During frost season, keep the soil N levels between 10-15 ppm. Within the top 6 inches of the soil, for every ppm N, you will be dealing with about 2 units of N, and for every ppm P you will have about 2 units of P.
2. If you inject 1 gallon of F360 Soil per acre, you can assume that about 2 units of N and 0.75 units of P will be needed for microbial assimilation. This means that if you were to inject 20 gallons per acre of F360 Soil, you would need 40 units of N and 15 units of P. If a 6 inch depth soil evaluation finds your soils are holding 15 ppm N and 35 ppm P, then your soil holds 15 ppm x 2 units N/ppm = 30 units of N, and 35 ppm x 2 units P/ppm = 70 units of P.
3. To calculate what we must add to avoid N and P deficiencies brought about by microbial activation:
   1. Needed N for 20 gallons per acre addition of Tilth = 40 units
   2. We already have 15 ppm N in the soil = 30 units
   3. Needed P for 20 gallons per acre addition of Tilth = 15 units P
   4. We already have 35 ppm P in the soil = 70 units P

Questions

Question 1: What ppm N and ppm P do we want in the soil following microbial assimilation?

Answer: Retain the 15 ppm N and 35 ppm P in the top 6 inches of the soil. Thus, supplemental N = 40 units. We’ll also add 15 units of P.

Question 2: If mineral tie-up is a major deterrent to efficient plant growth and development, will it not be necessary to add compensating levels of N and P?

Answer: For soils not treated with F360 Soil and Iota, the answer would be “Yes.” Many soils, for example, host an average efficiency of mineral release of barely 20%. Therefore, pure mathematical analysis says we’ll have to divide our calculated additions for N and P by 0.20 to give an actual requirement of roughly 200 units N and 75 units P. However, for soils receiving Tilth & Iota Activation, one of the greatest benefits is the conversion of soil with high mineral tie-up to soil with minimal to no mineral tie-up whatsoever. Thus, the additional 40 units N and 15 units P would suffice for the example above.

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