New Preplant and Maintenance Soil Preparation Recommendations for Maximum Honeycrisp Tree Performance

Posted on by mrb254

New Preplant and Maintenance Soil Preparation Recommendations for Maximum Honeycrisp Tree Performance

(Remarks presented by Dr. Terence Robinson at the recent Honeycrisp intensive school in Syracuse).

Soil targets for Honeycrisp:

Soil pH

  • Raise pH to 7.2-7.3
  • Soil organic matter
    • 2-3% Organic matter
    • Every 1% of organic matter generates about 20 lbs N per year
    • Soils high in organic matter (>4%) will have greater tree growth but more bitter pit
  • Soil Ca content
    • Target 5,000-6,000 lbs per acre
  • Soil K content
    • Soil K content should be 15-20X lower than Ca content.
    • In the past we have suggested that the ratio of Ca:K of the soil should be at least 15:1
    • For Honeycrisp, we suggest the ratio of Ca:K should be 20:1
    • High K content results in large fruit size but high bitter pit
    • Most corn growers put on little K so planting Honeycrisp on corn ground is often desirable

Target of 5,000 to 6,000 lbs of calcium per acre for Honeycrisp:

  • High Ca content in the soil will help ensure that the maximum amount of Ca will be deposited in the fruit (depending on the many factors that influence Ca uptake and movement into the fruit each year).
  • Since both K and Mg are involved in high incidence of bitter pit, it is desirable to apply only calcitic lime (CaCO3) to Honeycrisp blocks (avoid dolomitic lime which has Mg).

Maintenance plan for soil calcium:

  • The pre-plant loading of the soil with Ca will last for several years.
  • To maintain soil Ca levels at 6,000 lbs/acre, add 1-2 tons of calcitic lime every 2-3 years beginning in year 4.

Target of soil K or Mg content per acre should be 15-20X less than Ca:

  • If Ca content is raised to 6,000 lbs /acre then K or Mg should be ~300 lbs/acre

Other recommendations for pre-plant soil modification:

  • Add P preplant as Mono Ammonium Phosphate ~125 lbs MAP
  • MAP is 52% P2O5 thus 125 MAP=65 lbs P2O5
  • Other elements such as B and N can be added as a part of the annual fertilization

Conclusions:

  1. Apple trees grow very well at pH’s above 7.0 We suggest a target pH of 7.2-7.3.
  2. Lime applications before planting can be plowed down and are more effective than lime applications after planting (Ca as lime moves down in the soil about 1 inch per year)
  3. Target 5,000-6,000 lbs of Ca /acre
  4. Apply ~60 lbs of P before planting and plow it down since P moves very slow in the soil.
  5. Apply K sparingly if needed.
  6. Add 1-2 tons of lime every 2-3 years beginning in year 4.