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The Essential Role Of Nutrition For Pip Fruit
For Quality Fruit, The Health Of The Tree Is Important At All Stages
 | Bud break, flowering and fruit set affect potential yield
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| Vegetative growth - it is essential to prevent deficiencies
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| Fruit development - nutrients are vital at this stage for quality factors such as size, colour and firmness |
A Healthy Tree Will Ensure Maximum Yield
| The main consideration is that bud break is even and strong (zinc and boron)
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| Chlorosis or stunted new growth will later reduce the number, size and quality of fruit produced |
Bud Break And Early Shoot Growth
| Both zinc and boron are needed for the correct growth and development of new tissues (shoot and leaves)
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| Root absorption only starts at 5 to 6 leaf stage so tree nutrient reserves are crucial |
Flowering To Fruit Set
| Zinc and boron - 2 essential nutrients for flower development and fruit set.
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| Parameters affected include: |
# Fruit number (number of flowers that set)
# Fruit size (number of seeds that form)
# The potential for good fruit skin finish is established now | in Autumn or Spring or both |
Early Fruit Development Affects Quality
During the 6-week period after petal fall, cell division occurs in the developing fruits with important implications for the final structure of the fruit i.e.:
| fruit size
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| fruit firmness
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| resistance to bruising
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| reduction of internal breakdown etc.
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| storage potential of fruit |
Calcium and Phosphorus are the key nutrients!
Fruit Size Is Influenced By...
| Initial cell division (phosphorus)
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| Cell expansion during season (general nutrition but with sugar production a key factor, the micronutrients that influence photosynthesis are important |
# i.e. avoid yellowing of leaves (zinc, manganese, iron or magnesium)
Fruit Firmness Calcium And Phosphorus
# Cell to cell adhesion is improved with better calcium status which means a harder flesh # Phosphorus is crucial for cell division
# more cells means a denser, firmer fruit
A firmer fruit is less prone to bruising or tissue breakdown = better storage potential!
Phosphorus Deficiency Can Lead To Internal Breakdown Of Apple Flesh
| Reduced firmness during storage
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| Low temperature breakdown (starts in central tissues)
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| Senescent Breakdown (starts under skin) |
Other Quality Problems Are Clearly Influenced By Calcium
| Bitter Pit |
# A localised cell breakdown greatly influenced by fruit Calcium | Cork Spot in Pears |
# Cell breakdown related to calcium deficiency | Superficial Scald - calcium can help |
Iron Deficiency Will Produce A Strong Chlorosis (Almost White) In Some New Leaves
| New leaves are evenly chlorotic except for midrib and veins
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| Brown, necrotic regions develop on leaves
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| Die-back may occur
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| Extension growth can be thin and stunted |
Zinc Deficiency Can Produce `Little Leaf' And Yellowing
| Small malformed younger leaves
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| Yellowing between veins
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| Formation of leaf rosettes
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| Poor flowering and fruit set
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| Poor skin finish of fruit |
Manganese Deficiency Shows A Blotchy Yellowing
| Light green mottling between main veins of recently matured leaves
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| New growth may be retarded
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| Fruit yield and quality may be reduced |
Magnesium Deficiency Is Seen In Older Leaves First
| Chlorotic areas are later scorched and premature leaf fall is common
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| Extension growth can be inhibited
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| Fruit ripen prematurely
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| Pre-harvest fruit drop is accentuated
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