The beginning is in the article Growing eggplants in a greenhouse.
Eggplants are grown less and less in the open field, more and more often preferring greenhouses to it, where eggplants ripen much faster, get sick less often and have a much more harmonious taste (do not taste bitter). However, if you want to get high yields, you must definitely provide the plants with the necessary elements for good nutrition. Eggplants especially need phosphorus and potassium (which means phosphorus and potassium fertilizers), but if you fertilize the soil with only these elements, then you may not get the expected large harvest. In order for the eggplants to fully absorb potassium and phosphorus from the soil, it is also necessary to provide for the introduction of nitrogen. At the same time, it is important not to introduce large doses of nitrogen fertilizers into the soil. In general, you need to know that excessive doses of any fertilizers may not improve the situation, but, on the contrary, worsen it.
For better digestibility of fertilizers, it is advisable to loosen the soil, water it, and after application, mulch the soil surface with humus or at least sprinkle it with dry soil so that the fertilizers do not evaporate under the influence of heat and high humidity, which is especially often observed with nitrogen fertilizers.
The most first fertilization for eggplants, you can spend a couple of days after planting the seedlings in the greenhouse. This period is usually enough for the root system of plants to "settle down" in a new place and can fully absorb nutrients from the soil. During this period, you can feed the plants with nitrogen fertilizers and phosphorus fertilizers, it is better to apply them in the form of azophoska. It usually needs about 3 tablespoons per 10 liters of water, always at room temperature (not cold, because it dissolves poorly in cold azophoska). The consumption rate of the resulting solution should be about 500 g per bush, but if the seedlings look weakened, then it can be increased to 600 g.
Second feeding it is appropriate to carry out when ovaries appear. During this period, potash fertilizers (potassium sulfate, but not potassium chloride) and phosphoric (superphosphate) fertilizers are especially important for eggplant plants; it is even better to use potassium monophosphate as a source of both elements. In addition, it is permissible to use a variety of infusions (onion peel (200 g per liter), herbal infusion, etc.). Most often, during the second top dressing, the soil is fertilized with ammonium nitrate, potassium sulfate and superphosphate. It is advisable not to mix these fertilizers, but to apply them separately, in different compositions. The amount of ammonium nitrate is usually equal to two teaspoons per 10 liters of water. This is the norm for 3-4 square meters. m greenhouses. The amount of potassium sulfate is a tablespoon per 10 liters of water, this is the norm for 2-3 square meters. m of soil in the greenhouse, and the amount of superphosphate should be equal to two tablespoons per 10 liters of water, this is also the norm for 2-3 square meters. m greenhouse occupied by eggplants.
Third feeding can be carried out when the first fruits appear. During this period, you can add urea in the amount of 5-7 g per sq. m and potassium sulfate (3-4 g per sq. m). If the plants do not show signs of potassium starvation, then potassium sulfate can be replaced with wood ash - 50-70 g for each plant.
In the event that your eggplants are watered using a drip irrigation system, then it is quite possible to add these fertilizers to the water flowing out of the droppers. The doses are the same.
In addition to mineral fertilizers, eggplants can also be used organic... To do this, use bird droppings diluted 15 times, mullein diluted 10 times, or infusion of fermented weeds, diluted 3 times. To obtain an infusion from weeds, it is necessary to pour about 3-4 kg of vegetative mass without roots and testes with three buckets of water and place the container in a warm place, stirring occasionally. After a week, the fertilizer will be ready. Before adding any of these fertilizers to the solution, it is advisable to add 250-300 g of wood ash.
Read also Herbal starter cultures for plant nutrition.
For a greater effect, it is advisable to introduce organic matter under the eggplant only after the appearance of the ovaries.
I would like to say a few words about foliar dressing eggplants in the greenhouse, that is, the processing of plants on the leaf. In the case of eggplants, it is quite possible to combine them, say, with treatments against diseases and pests. In addition, foliar feeding will be appropriate, if there are signs of a shortage of one or another element, then they will quickly restore balance. The concentration of fertilizers in the solution should not exceed 5 g per 10 liters of water. And don't forget about trace elements. It is noteworthy that in the case of eggplants, the effect of the use of foliar dressings will be noticeable already 12-15 hours after the treatment of the plants with the composition.
In general, eggplant feeding is necessary, the main thing is to do them on time and in moderate doses.