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Pome fruit

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Foliar fertilization in fruit-growing

The foliar fertilization with micro-nutrients (e.g. manganese, iron, magnesium) is well established since many years.

Foliar fertilizers can be used preventive as integrated part of the fertilizer strategy or if it comes to an undersupply with nutrients and visible symptoms. The leaf analysis can help to analyze and recognize the availability for each element.


Nutrient availability

Many parameters in the soil can limit the availability of nutrients – high pH-values can block micro-nutrients, low pH-values can block macro-nutrients. 

 But also dry and cold weather conditions, soil texture and some nutrient antagonism (e.g. oversupply with potassium vs. magnesium and calcium) can lead to a deficiency of nutrients.

Specific requirments

Apple trees are more sensitive to fertilization compared to pear trees. The nutrient nitrogen is necessary for high yield and potassium and phosphorus are stimulating the coloring and quality. But also a certain ratio between potassium and calcium is crucial for the fruit quality. An optimized nutrion with mangnesium and manganese will help to avoid leaf spots. Pear trees are more susceptable for iron chloroses.

Leaf spots and early leaf fall

Some varieties, especially Gold Delicious, Jonagold, Elstar, Gala and Cox are tending to nutrition based and physiological leaf necrosis and early leaf fall. This is caused by an undersupply and lack of manganese and magnesium. The combination of Lebosol®-Magnesium 400 SC with Lebosol®-Manganese 500 SC can optimize nutrition and reduce these effects.

Manganese-deficiency

Calcium-deficiency

Flowering, fruit setting and skin stability

Boron in combination with calcium (Lebosol®-Robustus SC), zinc (Lebosol®-Zinc 700 SC) and amino acids (Aminosol®) are crucial for the pollen tube growth, flowering and the fruit setting. The susceptibility to rust will be reduced. These products can be applied before flowering or after harvest. The application of Lebosol®-Robustus SC before flowering will enhance fruit coloration, the nutrients boron and zinc stimulating the calcium absorption, too.

Coloration

Phosphorus and potassium are stimulating the coloration of the fruit. Lebosol®-PK-Max, containing both nutrients, can be applied from the beginning of fruit setting to stimulate the red coloring. The nutrient manganese is stimulating the green “background” color and can be applied with the product Lebosol®-Mangan GOLD SC especially in two-color varieties.

Iron chlorosis

As mentioned above, pear trees are sensitive to iron deficiency. Symptoms are iron chloroses and will be visible by a yellowness of the youngest leaves with dark veins. Different paramters, e.g. soil structure, moisture and pH value will influence the iron availability. The foliar fertilizer Lebosol®-Eisen-Citrat GOLD – containing iron and manganese - will enhance the iron and manganese supply and availability. For better spreading and uptake, the product is formulated with amino acids as well.

Main recommendations

Aim/Problem Recommendation Time
Improvement in effectiveness and tolerability of plant protection products and calcium fertilisers 150 - 300 ml Aminosol® (per 100 l spray water) With plant protection products and calcium fertilisers
Promotion of fruit set, fruit size and colouration, minimisation of russeting 2 times 5 - 7,5 l/ha Aminosol® In apples: first pink and full pink stage; pears: before and after flowering
Improvement in flowering quality, fruit set, calcium transport, fruit quality, colouration 2 times 2 l/ha Lebosol®-Robustus SC +
2 times 0,25 l/ha Lebosol®-Zink 700 SC
First pink to beginning of flowering
Boosting of resistance to illness 2 - 4 times 2 - 4 l/ha Lebosol®-Kalium-Plus First pink to June fruit drop
Vitalisation, improvement in the photosynthesis rate and resilience 4 times 4 - 6 l/ha VITALoSol® GOLD SC First pink, full pink stage, hazelnut size, walnut size
Boosting of the restistance of the flowers to frost, yield 1 - 2 times 2 l/ha Aminosol® +
1 - 2 times 1 l/ha Lebosol®-Robustus SC +
1 - 2 times 5 l/ha Lebosol®-Kalium 450
From first pink before frost
Strengthening of flower buds, yield 4 times 5 - 7,5 l/ha Phytoamin® Full bloom, end of flowering, shortly after flowering, hazelnut size
Improvement in leaf quality, photosynthesis rate, N efficiency 2 - 4 times 1 l/ha Lebosol®-Mangan GOLD SC From the end of flowering to June fruit drop
Increasing stress tolerance 2 - 3 l/ha Aminosol® End of flowering to harvesting, at stressed sites
Increase in fruit firmness, storage stability and resilience 4 - 6 time 5 - 8 l/ha Lebosol®-Calcium-Forte SC End of flowering to harvesting
To prevent premature leaf drop; increased vitality, leaf quality, photosynthesis rate 2 - 4 times 3 - 5 l/ha Lebosol®-Magnesium 400 SC End of flowering to harvesting
Prevention and alleviation of iron chlorosis, improvement in water transport, leaf quality 2 - 5 times 3 - 7 l/ha Lebosol®-Eisen-Citrat GOLD End of flowering to harvesting
Improvement in skin quality, calcium transport, flower bud quality 2 times 2 l/ha Lebosol®-Robustus SC +
2 times 0,25 l/ha Lebosol®-Zink 700 SC
Fruit set to harvesting
Promotion of green background colour 2 - 4 times 1 l/ha Lebosol®-Mangan GOLD SC Between June fruit drop and harvesting
Promotion of red top colour, fruit size, fruit firmness 2 - 4 times 5 l/ha Lebosol®-Kalium 450or2 - 4 times 6 - 8 l/ha Lebosol®-PK-Max Between June fruit drop and harvesting
Depositing of reserve substances, regeneration, winter hardiness, flower quality 2 times 1 l/ha Lebosol®-AqueBor SC +
2 times 2 - 3 l/ha Aminosol® +
2 times 0,5 l/ha Lebosol®-Zink 700 SC
After harvesting
Treated crops are avoided by furred game 2 l Aminosol® (With 2 l water 2 - 3 days beforehand (quantity for 1 ha)) When required