Accessibility
  • Change text size

    • Normal Text
    • Medium Text
    • Large Text
  • Contrast

    • Black&white
    • High
    • Normal
  • Display

    • Cursor White
    • Cursor Black
  •  

You are here

Grow Better Blueberries with Haifa products

Nutrition of bluerries: general rules

♦ Setting application rates, consider expected yield required balance of nutrients.
♦ Provide a complete fertilization, with macro and micronutrients
♦ Consider cation ratios Ca/K, Ca/Mg, (Mg+K)/Ca.
♦ Consider NH4/NO3 ratio. The majority of nitrogen should be supplied as nitrate
♦ Use soluble and chloride-free potassium
♦ Use diagnostic tools such as soil analysis, foliar, suction probes, chlorophyll meters, etc.
♦ Split applications according to the plant’s uptake dynamics

 

Berries hate salinity:

Berry type

EC (dS / m) at which the yield decreased by:

 

10%

25%

50%

Blackberry

1.5

2.0

2.5

Blueberry

1.0

1.5

2.0

Raspberry

1.5

2.0

2.5

Considerable yield reduction occurs at relatively low EC levels.

 

Nitrogen Deficiency:

  • Nitrogen leaching, resulted from intensive rains or excessive irrigation,is a common cause of deficiencies
  • Typical symptoms: small pale leave, sometimes with tiny red spots
  • Blueberries are salt-sensitive, so excessive N fertilization may cause mortality of young plants
  • Ammonium is the preferred form of nitrogen for blueberries
  • Ammonium nitrate can be used in fertilizer mixes: 

       ​- Where the nitrate portion of the mix constitutes a minor part of the total nitrogen in the mix and the soil pH is below 5.3.
       - For very light (20 pounds per acre or less) applications of nitrogen where a small amount of nitrogen is needed.

  • Urea and controlled release fertilizers are also suitable sources of nitrogen for blueberries
  • In the soil, urea is a rapidly converts to ammonium and readily absorbed by the plant
  • In soils where the pH is on the high end of the range for blueberries (above 5.0), use more acid forming fertilizer such as ammonium sulfate

 

Timing of nitrogen applications for blueberries in Alabama

Phosphorus in Blueberries:

 

  • Phosphorus is very important for the root establishment and for energy transfer in the plant
  • Many blueberry fields are low in P:

         ​ - In acidic soils P availability is low

          - In sandy soils P is prone to leaching
 

  • Pre-plant application of P is advisable
  • High levels of phosphorus in the soil can tie up iron, making it unavailable to the blueberry plant
     

Recommended application rates

Application rate

Soil test P (0-45 cm / 0-12”)

Lb/acre

Kg/ha

NaHCO3

Bray I

NaOAc

100

112

0-4

0-10

0-1

80

90

4-8

10-20

1-2

60

67

9-11

20-30

2-3

30

34

12-14

30-40

3-4

10

11

15-17

40-50

4-5

0

 

18-25

50-100

5-10

0

 

Over 25

Over 100

Over 10

 

Potassium in blueberry:

  • Potassium is essential for photosynthesis and water regulation. 
  • On bearing plants, the annual potassium requirements can be supplied by 1-2 applications

 

Potassium recommended rates:

Application rate

Soil test K
(0-45 cm / 0-12”)*

* Soil extract
in sodium acetate

Lb/acre

Kg/ha

80

90

0-50 ppm

50

56

50-75 ppm

30

34

75-100 ppm

0

0

Over 100

  • For established plants, determine K application rates according to soil analysis
  • In general:

           - To correct shortage apply 113-224 kg/ha (100-200 lbs/acre) K2O

           - To maintain adequate level apply 56-113 kg/ha (50-100 lbs/acre) K2O

 

 

Secondary elements:

  • Blueberries have low calcium requirement
  • Excessive calcium may cause iron deficiency
  • Liming

           - Only when soil pH is below 3.6

           - Lime application rate: 560 kg/ha (500 lbs/acre)

           - Do not exceed this rate 

 

 

On highbush blueberries, classic magnesium deficiency is a green "Christmas Tree"
in the center of a chlorotic leaf. 

It usually occurs on the older leaves

 

 

 

On young rabbit-eye plants

magnesium deficiency is commonly shown as

pink edges and interveinal yellowing of leaves
 

 

 

Ca-Mg balance:

  • Calcium - magnesium levels should be kept in balance
  • The normally 1:8 to 1:10 (Mg:Ca)
  • Too high calcium levels induce magnesium deficiency
  • To correct magnesium deficiency, apply 16.8 kg/ha (15 Lbs/acre) magnesium

 

Calcium and fruit quality

  • Pre-harvest calcium sprays. 

           - Increase firmness of the berries

           - Extend shelf-life

           - Reduce Botrytis rot

Blueberry showing Ca deficiency (left); inside view, note corky area (right).

 

Iron in blueberry:

 Iron deficiencies is likely to occur when soil pH is too high

♦ The best treatment is lowering soil pH

♦ Foliar sprays of Iron chelate may alleviate some leaf symptoms but usually do not improve overall plant vigor 
 

 

 

 

Nutrigation™  program for blueberries:

Recommended fertilizers (kg/ha)

Nutrients required (kg/ha)

Timing

Multi-K

MAP

A-S

K2O

P2O5

N

60

12

32

30

7

15

Leaf emergence

90

16

42

40

10

20

Flowering

110

21

53

50

13

25

Fruit set

110

20

53

50

12

25

Fruit growth

60

13

30

30

8

15

Fruit maturation

430

82

210

200

50

100

Total

 

Texas fertigation schedule for blueberries:

Grams/plant/week

Plant diameter
(feet)

K

P

N

0.5

0.5

1

1

0.75

0.75

1.5

2

1

1

2

3

1.2

1.2

2.5

4 and up

 

 

Nitrogen fertigation for blueberries:

1.Reduce annual N rate by 1/3, compared to soil application

2.Start application 2-3 weeks after bud break, continue into July

 

 

Leaf analysis

Suggested critical levels of nutrients in highbush and rabbiteye blueberry leaves

Excess

Normal:

rabbiteye

Normal:

highbush

Deficiency

Nutrient

2.5%<

1.2-1.7%

1.8-2.1%

< 1.7%

N

0.8%<

0.08-0.17%

0.12-0.4%

< 0.1%

P

0.95%<

0.28-0.6%

0.35-0.65%

< 0.3%

K

1%<

0.24-0.7%

0.4-0.4%

< 0.13%

Ca

0.45%<

0.14-0.2%

0.12-0.25%

< 0.08%

Mg

NA

NA

0.12-0.2%

< 0.1%

S

 

Excess

Normal:

rabbiteye

Normal:

highbush

Deficiency

Nutrient

450 ppm<

25-100 ppm

50-350 ppm

< 23 ppm

Mn

400 ppm<

25-70 ppm

60-200 ppm

< 60 ppm

Fe

80 ppm<

10-25 ppm

8-30 ppm

< 8 ppm

Zn

100 ppm<

2-10 ppm

5-20 ppm

< 5 ppm

Cu

200 ppm<

12-35 ppm

30-70 ppm

< 20 ppm

B