3. Symptoms Boron deficiency in lo bok
Cole crops have a moderate to
high boron requirement.
Symptoms of boron deficiency
vary with crop type. Most boron
deficient cole crops develop
cracked and corky stems, petioles
and midribs. The stems of
broccoli, cabbage and cauliflower
can be hollow and are sometimes
discolored. Cauliflower curds
become brown and leaves may
roll and curl, while cabbage
heads may be small and yellow.
Of all the cole crops, cauliflower
is the most sensitive to boron
deficiencies.
Boron Deficiency
4. Recommendation for boron Control
It is recommended in broccoli and kale to apply 1.5-3 pounds
of boron (B) per acre in mixed fertilizer prior to planting. In
Brussels sprouts, cabbage, collards and cauliflower, boron and
molybdenum are recommended. Apply 1.5-3 pounds of boron
(B) per acre and 0.2 pound molybdenum (Mo) applied as 0.5
pound sodium molybdate per acre with broadcast fertilizer.
Boron may also be applied as a foliar treatment to cole crops if
soil applications were not made. The recommended rate is
0.2-0.3 lb/acre of actual boron (1.0 to 1.5 lbs of Solubor
20.5%) in sufficient water (30 or more gallons) for coverage.
Apply foliar boron prior to heading of cole crops.
(broccoli, Brussels sprouts, cabbage, cauliflower, cole crops,
micronutrient deficiency, physiological disorders)
5. Symptoms
Growth dwarfed; leaves
lustreless dark green,
laminae and petioles
dull purple tints; older
leaves marginal scorch
and wither early.
Phosphorus deficiency
6. Symptoms .
Older leaves deep
purple tints changing
to red
Phosphorus deficiency
7. Symptoms
Plant has remained
stunted; leaves bluish
green with dull purple
tints
Brussels Sprout Phosphorus deficiency
8. Symptoms
Growth dwarfed, erect
and stem thin; leaves
pale green and older
leaves bright orange,
red and purple tints.
Cauliflower Plant Nitrogen dificiency
9. Symptoms
Hooking of young
leaves and severe
collapse of tissues
Cauliflower Plant Calcium deficiency
10. Symptoms
Calcium deficiency
shows as collapse of
mesophyll tissues
and manganese
toxicity as incurling
of leaf margins
followed by
marginal spotting
and scorching.
Cauliflower Plant Calcium deficiency and manganese
toxicity (soil scidity complex
11. Symptoms
Older leaves
chlorotic marbling
followed by strong
orange, red and
purple tinting.
Cauliflower Plant Magnesium deficiency
12. Symptoms
Plants in seed bed.
Older leaves strong
yellow, red and
purple tints as
"marbled" pattern
deficiency
13. Symptoms
General field view
at cutting time.
Older leaves strong
chlorotic marbling
and tinting.
Cauliflower Plants Magnesium deficiency
14. Symptoms
Magnesium
deficiency shows as
chlorotic marbling
of older leaves and
manganese toxicity
as incurling and
necrosis of margins
of younger leaves.
Manganese toxicity (soil acidity complex
15. Symptoms
Leaves bluish green
and slight
intervenal chlorosis
near margins;
backward curling of
laminae, and
scorching and
forward curling of
margins
Cauliflower Plant Potassium deficiency
16. Symptoms
General field view
at cutting time;
curling and severe
marginal and
intervenal
scorching of leaves.
Cauliflower Plants Potassium deficiency
17. Symptoms
Laminae of leaves
restricted and may
fail to develop,
leaving only bare
midribs. Growing
point dies.
Cauliflower Plant Molybdenum deficiency
18. Symptoms
Cauliflower Plant
Manganese toxicity
(soil acidity complex)
Restricted lateral
growth of leaf
laminae and
incurling and brown
spotting of margins
molybdenum
deficiency).
Cauliflower Plant Manganese toxicity (soil
acidity complex)
21. Numerous vegetables
including brassicas,
cucurbits, peas,
spinach, tomato, etc.
Vegetables with waxy
leaves, e.g., brassicas,
tend to be most
susceptible.
Host Crops: