Ferrous sulfate is the essential trace nutrition element of apple trees. Lacking of ferrous, the apple tree will directly influence the generation of chlorophyll land its function. If chlorophyll cannot be synthetized, tree body appears etiolating, even seriously effect fruit trees’s growth and yield of.
150 PPM of ferrous in apple trees ‘s leaves is the critical value. And If ferrous in effective content in soil is less than 4.5 PPM, it could be regards as the basis of ferrous deficiencies. The typical symptoms of apple tree ferrous deficiency appear that green blades turns etiolating, that also called chlorosis. The first Symptom is that new tip top of new leaves turn yellow green, then turned white, but leave vein still keep green like a green mesh. The worse will be the top new leaves were dead as withered shape.
Solutions for photinia ferrous deficiency:
1, choose appropriate site to built the garden
Try to avoid to plant the trees in the high PH value, heavy sticky and easy to harden soil where underground water level would not high and slat are low. Create favorable ecological environment for apple trees’ growing. At the mean while, it’s better to choose the root stock (such as hitom, Chinese catalpa child) that can resist yellowing as well.
2, Increasing the amount of organic fertilizer and improving soil physical properties will be good for ferrous activation obviously. How many Organic content directly influence effective ferrous content. Organic fertilizer could also improve the soil structure, prevent soil harden and increase effective ferrous content. Therefore, increasing organic fertilizer is the important improvement of ferrous nutrient and the fundamental method to control the apple tree ferrous deficiency.
3,The application of ferrous fertilizer
There are many fertilizing methods. To apply which method, not only consider the site conditions, but also consider the apple yield the age of the tree. Anyway, No matter in what method, remember no excessive to avoid fat harm.
(1) Ferrous fertilizing: According to autumn basal fertilizers, mix organic fertilizer with 0.15 ~ 0.2 kg ferrous sulfate or integrated iron. This method is better not applied in heavy alkaline orchard to avoid the ferrous curing and cannot be root absorbed.
(2) the branches injection: As to serious lack of ferrous tree, the most common and effective solution is to apply 0.15 ~ 0.1% of ferrous sulfate solution to injection branches.
(3) Foliar spraying ferrous fertilizer: During fruit tree growth period, spraying on leaves with 0.3 ~ 0.5% of ferrous sulfate, citric acid iron or organic integration holmium liquid. Spray once every 10 ~ 15 days, continuous 2 ~ 3 times. Choose organic ferrous fertilizer as possible when foliar spraying in the tree to avoid the fertilizers doing harm and causing fruit face not clean.