Macro category are: Nitrogen (N), phosphorus (P), Potasiul (K), Calcium (As), Magnesium (Mg) and sulfur (S).
Macro plays a crucial role in the development of African Violet. Deficiency or excess of these elements usually takes its toll on the health of the older leaves and the soil acidity.
Normal values of Ph indicator violetelor African development beneficial fits within the 3.6-4.3 (neutral or a low acidity). At the slightest change in Ph values there is a ' lock ' to assimilate and decomposition of these elements in the soil substrate.
So, first thing to do is to establish a diagnosis of mixed soil pH measurement.
Effects of deficiency or excess plant macro on the question:
Nitrogen deficiency, first stage, is known by the yellow halo on the older leaves, in the second stage, old leaves turn a lemon yellow as bottom-up. Nitrogen deficiency can be removed by the administration of urea ( leaf with a sprinkling of urea solution with a concentration of 0.05-0.1% or 0.5 g per 1 l water).
Excess nitrogen do more harm Flower - inhibit flowering, observed an increase in abundance of leaf size, flower stalk visibly thickens and develops a conical, flowering is detrimental to plant growth. Favor the occurrence of fungal infections.
Phosphorus deficiency - purple coloring of the lower leaves of the species who may not specify the color, inhibition of flowering, very poor flower development and root. It can alleviate through the administration of chemical fertilizers based on phosphorus ( for example, introducing the mix superphosphate of land for planting flower). For the development of the root system can use designers Ferticare ingrasamnatul 10-5-26 produced by company Kemira. Excess phosphorus contributes to blocking iron uptake by plant, a rapidly aging rosette. Dwarfed plant, Iron deficiency is observed if the leaves appear chlorotic, yellow.
Potasiul : With potassium plant better assimilate nutrients from soil. You can manage potassium fertilizers, But it is dangerous to purple if the soil nitrogen is very small. Potassium deficiency is observed if the first stage is chlorosis (leaves and buds of the plant turn yellow), stage two - the leaves are burned edges, stage three- marginal necrosis occurs (dry leaf edge).
Calcium: PH variation is responsible for. Excess calcium is alkaline earth, Calcium deficiency makes acid which prevents assimilation by the plant other minerals. To maintain the pH in the normal oxalic acid is added to water, acid ascorbic ( 1 ml concentrate or ascorbic acid oxalic acid 10 liters of water for the big Ph value with a.
Magnesium: Deficit-1 stage- chlorosis, stage 2-spotted necrosis (part of the leaf dries and dies). The plant rarely suffer because of excess magnesium.
Sulfur: Sulphur deficiency can be seen only at the plant rooting and planting, for example, in a mixture of perlite. In case the land is organic matter how little, There certainly sulfur. Excess sulfur can see if power plant with chemical fertilizer. Sulfur persist virtually every chemical fertilizer. If the growing point of the plant has thickened and turgid first leaf shrinks, when the plant was supercharged. Substrate must be washed down or change it.