This presentation provides a brief overview of the most common micronutrient deficiencies observed in vineyards of the San Joaquin Valley of California, and how to remedy them.

1. Grapevine Micronutrients:
Use & Deficiency Symptoms in
the San Joaquin Valley,
California
Matthew Fidelibus
Viticulture Specialist
Department of Viticulture and Enology
University of California, Davis

2. L. Peter Christensen
Developed much of the
mineral nutrition, diagnostic,
and fertilizer recommendations
we now use in California vineyards

3. Outline
• Macro and micronutrients
• Micronutrients typically measured in
tissue analyses
– General properties, physiological roles, and
symptoms of deficiency and excess
• Management
– Soil and tissue sampling
– Examples of possible management strategies

4. Macro and micronutrients
typically measured in
tissue analyses
Macronutrients Micronutrients
Nitrogen (N) Boron (B)
Potassium (K) Zinc (Zn)
Phosphorus (P) Iron (Fe)
Magnesium (Mg) Manganese (Mn)
Calcium (Ca) Copper (Cu)

5. Nutrients Removed in 1 Ton
of Grapes
Nutrient Lb/Ton
Potassium K 4.94
Nitrogen N 2.92
Phosphorus P 0.56
Calcium Ca 1.0
Magnesium Mg 0.2
Iron Fe 0.01050
Zinc Zn 0.00065
Copper Cu 0.00115
Boron B 0.00110

6. Mineral nutrient deficiencies
Common Infrequent Rare
N P S
K Mg Cu
Zn Fe Mo
B Mn Ca

7. Boron (B)
• B is a “metalloid”, with properties
intermediate between metals and non-
metals
• Uptake of B depends on concentration of
B in soil, soil pH, and transpiration stream

8. Boron in Vineyard Soils
Deficiency <0.2 ppm
Toxicity Beginning symptoms 0.6 - 0.75 ppm
Increasing severity >1 ppm
Severe >2 ppm

9. Boron Excess Potential – Marine Sedimentary Soils

10. Boron Deficiency Potential – Sierra Nevada Alluvial Plains

11. Boron (B)
• Essential but poorly understood physiological
role
• Appears to be involved in cell wall development
• Might be involved in biochemical “cascades”
• Deficiency symptoms: stunted shoots w/ “zig-
zag” growth, swollen internodes, “hen &
chickens” with pumpkin-shaped berries

12. Boron deficiency symptoms

13. Boron Deficiency
Thompson Seedless

14. Boron Deficiency – White Riesling

15. Boron Transport Is Important to
Deficiency
• Xylem transported
constant supply needed
• Limited phloem mobility
localized, temporary deficiencies
• Availability reduced in dry soil
drought-induced deficiency

16. Drought-induced
B Deficiency
Pinot noir

17. Boron Deficiency
• Early Season, Temporary “Barnes Effect”
Drought-induced in previous
fall and winter
• Spring to Early Summer
Naturally low soil and plant status
• Mid to Late Summer
Low soil water status

18. Boron toxicity

19. Boron (B)
• Very narrow window between B
deficiency and B toxicity (30 to 80 ppm,
respectively, in blades at bloom)
• Deficiencies can be prevented or
remedied with broadcast, soil spray, foliar,
or drip applications. Follow directions
carefully to avoid toxicities

20. Always Monitor Boron
Fertilization with Tissue
Analysis
•Leaf Petiole or Blade
samples can be used

21. BORON APPLICATION
BROADCAST or
HERBICIDE BAND
4 lb B/acre
• 3-4 years
FOLIAR ½ to 1 lb B/acre
• Annual (Fall)
DRIP 1 lb B/acre
• Initial
1/3-½ lb
• Annual

22. Causes of Zn deficiencies
• Soil is low in Zn
sands
cut areas
• Low Zn availability
calcareous soils
high pH
high P – manure, corrals, poultry yards
• Cool temperatures
• High N and vigor
• Rootstocks (American Vitis species)

23. Zinc Deficiency
• Low soil zinc
sands
cut areas
• Lowered availability
calcareous soils
high pH
high P – manure, corrals, poultry yards
• Cool temperatures
• High N and vigor
• Rootstocks (American Vitis species)

24. Zinc deficiency symptoms
• Stunted shoots
• Small asymetrical leaves with open petiolar
sinus, sharply toothed margins, and mottled
chlorosis
• Poor fruit set and “hens and chickens”

28. ZINC FOLIAR SPRAY
2 weeks pre-bloom to bloom
Dilute application
2 to 3 lbs zinc/acre
Neutral zinc 4 to 6 lbs/ac
(50-52%)
Zinc oxide 2.5 to 4 lbs/ac
(75-80%)

29. Iron
• Fe is the most abundant metal on earth,
and the most abundant micronutrient in
grapevines, but is extremely insoluble in
aerobic environments
• Chelates of Fe(III) or Fe(II) dominate
soluble forms in soil & solutions

30. Iron
• Fe easily changes its oxidation state and
has special importance in biological redox
systems such as electron transport chains
• Fe deficiency has a particularly negative
effect on chloroplast size, protein content,
& photosynthetic efficiency
• Fe deficiency eventually decreases
photosynthesis & carbohydrate
production

31. Iron
• First, youngest leaves may
remain small, fail to unfold,
and become chlorotic
• Leaf chlorosis begins at
margins, becoming interveinal
• Lateral shoots may be stunted,
with pink internodes
• Poor fruit set

32. Iron
• Petiole levels commonly range from 70 to
200 ppm, but lab results do not often
correlate well with deficiency symptoms,
possibly partly due to the ease of sample
contamination
• Deficiencies on high lime soils are best
avoided by using lime-tolerant rootstocks
(for example, 5BB, 140Ru)

33. Manganese (Mn)
• Uncommon to observe Mn deficiency in
California
• Vines with Fe deficiency are sometimes
also deficient in Mn, and often corrected
by addressing Fe deficiency
• Toxicities (>1,200 ppm) could occur in acid
soils, but pH would be <5.5

34. Copper (Cu)
• Cu, like Fe, forms stable complexes &
easily transfers electrons
• Main role of Cu in plants is enzymatic
redox reactions
• Deficiencies are rare, restricted to soils
with very high organic matter
• Cu toxicity can occur with young vines on
acid soils & sites where Cu-containing
pesticides were overused

35. Management
• Preplant soil analyses to determine soil
depth, physical characteristics, mineral
nutrient levels, chemistry, soil pests
• Groundwater quality and irrigation plan
• Rootstock and scion selection
• Visual inspection
• Tissue sampling

37. Rootstocks affect uptake of
mineral nutrients
B
(total)
Zn
(total)
Mn
(total)
Fe
(total)
Cu
(total)
Na
(total)
Cl
(IC)
Cultivar (ppm) (ppm) (ppm) (ppm) (ppm) (ppm) (%)
RS-2 55.2 bc 55.8 b 124.9 a 46.4 a 32.6 299 e 0.01 b
RS-9 54.5 c 65.6 a 129.5 a 44.7 ab 29.5 273 e 0.01 b
Freedom 54.7 c 37.8 de 102.2 ab 42.4 abc 23.9 272 e 0.04 b
RS-3 52.6 c 44.9 cd 93.9 bc 44.1 ab 27.3 262 e 0.02 b
10-17A 53.3 c 34.4 e 36.8 d 37.3 c 30.3 134 f 0.02 b
10-23B 53.0 c 16.9 f 69.0 c 40.6 abc 26.8 255 e 0.32 a
6-19B 62.4 a 50.7 bc 91.7 bc 39.5 bc 27.2 499 c 0.02 b
1103-P 58.5 b 40.4 de 74.4 c 38.6 bc 25.0 146 f 0.12 b
Schwarzmann 52.1 c 51.7 bc 122.7 a 42.5 abc 25.6 400 d 0.01 b
Own Roots 47.7 d 57.2 b 109.1 ab 37.8 c 25.2 727 b 0.30 a
Significance <0.01 <0.01 <0.01 0.01 0.10 <0.01 <0.01
Scarlet Royal, Arvin, 2012.

38. Visual Symptom Quiz!

39. Boron, Iron, or Zinc?

40. Boron, Iron, or Zinc?

41. Boron, Iron, or Zinc?

42. Tissue sampling objectives
• Survey vineyards to determine general
nutrient status and evaluate fertilizer needs
or practices
• Follow-up to confirm status of nutrients that
were possibly deficient
• Diagnose visual symptoms observed

43. Table 1. Interpretive Guide for Grape Tissue Analysis at Bloom and Veraison
Deficient Adequate Excessive2
Toxic3
Nutrient (below) (above) (above) (above)
NO3-N, ppm 3501
500 2,000 8,000
P (total), % 0.10 0.15
(0.08)4
(0.12)4
K (total), % 1.0 1.5
(0.5)4
(0.8)4
Mg (total), % 0.2 0.3
Zn (total), ppm 15 26
Mn (total), ppm 20 25 300 2,000
B (total), ppm 25 30 80 (100)4
120 (300)4
in
blades
Na (total), % 0.5
0.3 in blades
Cl (total), % 0.5-1.0 1.5
0.5 in blades

44. Acknowledgements
L Peter Christensen, Larry Williams
California Table Grape Commission
Pictures on slides 30 & 40 from Yara, Australia
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