Very often, novice gardeners, who for the first time decide to grow tomato seedlings on their own, are faced with the phenomenon of the appearance of a purple tint on the bottom of the leaf blades. Under particularly unfavorable circumstances, cyanosis is observed on the stems, as well as on the upper part of the leaves, which curl into a boat and become smaller.
Reasons: lack of phosphorus and low temperature in the seedling room
This situation, as a rule, arises due to a lack of phosphorus, which is responsible for the development of the underground part of seedlings. A deficiency of phosphorus compounds is observed due to the inability of the root system to absorb all nutrients due to low temperatures. If your seedlings are constantly under stress from sharp fluctuations in night and day temperatures, then they stop growing and acquire a purple hue in the internodes, leaves, and veins on them.
How to help seedlings?
The application of any fertilizers, including those rich in bioavailable phosphorus, is impractical in cold weather, since the roots acquire the ability to absorb elements only at soil temperatures above +12°C.And excess substrate moisture only aggravates the situation.
Therefore, first of all, it is worth taking care of insulating the plants. If your seedlings live in a cold greenhouse or on a balcony, then they should be covered with film or agrofibre at night, and sometimes during the day. During frosts, which are so typical for March and April, it is best to install heating devices in the greenhouse and bring balcony seedlings into the house at night.
Otherwise, depletion of seedling vegetables cannot be avoided, and the plants will remain at one point of development until the onset of warming. And only when you normalize the temperature regime, you can begin to save the plants with the help of fertilizing.
Foliar feeding of tomato seedlings with phosphorus
To eliminate phosphorus starvation, use any mineral fertilizers with a high phosphorus content, for example, “Potassium Monophosphate”, “Double Superphosphate”, “Crystalon Yellow”, “Partner 13.40.13”, etc.
Regular ash will also work. The maximum content of phosphorus salts was found in the ash remaining from the burning of birch, pine, as well as tops of wheat, rye, barley, corn and sunflower.
Foliar feeding helps quickly saturate plant tissues with phosphorus and other useful substances. The nutrient solution prepared according to the instructions on the package is used to irrigate the seedlings over the leaves from a room spray bottle.
Liquid ash fertilizer is made by infusing 2 tablespoons of sifted ash in 1.5 liters of water for 3 days (the sediment must be shaken daily). Before use, the solution is carefully filtered.
And the remains of phosphorus fertilizers moisten the soil ball in the planting containers. The procedure is performed twice with an interval of several days.The disappearance of the purple tint occurs after the phosphorus deficiency is eliminated and is usually observed after a week or two.
We wish you to grow strong, healthy and squat seedlings of tomatoes and other vegetables at home!
