CS273655B1 - Method of nitrate content reduction in plants - Google Patents

Abstract

The solution consists in application of saccharose solution on plants, mainly on lettuce, approximately 6 days before crop. This brings about a decrease in contents of nitrates by 600 to 1000 ppm NaNO3.

Description

The invention relates to the cultivation of vegetables, in particular quick lettuce, with a low nitrate content.

Fast salad due to low light intensity accumulates nitrate to an increased extent. If treated 4 to 6 days prior to harvest with a 1% sucrose solution, depending on the light intensity, the NaNO4 content is reduced by 600 to 1,000 ppm relative to untreated plants.

Around the contemporary cultivation of fast vegetables is to achieve a high yield of high-quality fast salad. Existing technology produces salads largely with nitrates above the norm. The standards setting the maximum permissible nitrate content in vegetables are very much exceeded in our Sasto conditions, especially for fast vegetables.

Based on a large number of scientific works, it appears that, especially in fast vegetables, the cause is not only the increased use of industrial nitrogen fertilizers that negatively affect nitrates, but also a number of other internal and external factors.

Reduction of nitrates to nmonica is closely associated with b photosynthesis. Even between the rate of photosynthesis and the utilization of nitrate nitrogen, there are direct relationships that are amplified by the length and intensity of sunlight. Under optimal illumination the intensity of photosynthesis increases and thus also the carbohydrate content. In the presence of macroergic compounds, the nitrates are then converted to ammonia which binds the oxoacids. If these conditions are not met, nitrate accumulates in plant organs.

In fast vegetables, the intensity of photosynthesis is very low due to low light intensity. As a result, the plant suffers from a lack of essential metabolites necessary for the enzymatic reduction of nitrates, resulting in a high to very high nitrate content which achieves up to twice the hygiene standard under extreme conditions.

The object of the invention was to select a suitable solution which, after foliar application, would stimulate the enzymatic conversion processes of nitrates and significantly reduce their content. This would create conditions for higher nitrate reductase activity in plants and provide sufficient carbon skeletons to assimilate ammonia nitrogen.

The undesirable high nitrate content can be largely eliminated by introducing the process according to the invention, which is based on a foliar application of a sucrose solution in the optimum period of 6 days before harvest (maximum range 4 to 8 days). The sucrose solution used for this purpose has an optimal concentration of 1% and is always prepared fresh.

This cultivation method according to the invention has solved the substantial reduction of nitrates which are commonly found in plants under unfavorable lighting conditions and has the following advantages:

- sucrose does not adversely affect plants

- an easy way to apply the solution to plants

- the substance used is affordable

- the application makes it possible to reduce the nitrate content by 600 to 1000 ppm NaNO4

Example:

The stabilizing solution is a 1% aqueous sucrose solution. To 1000 m ^J , apply 100 l of this solution with a sprayer. Spraying must be fine (preferably aerosol) to reach the surface of the whole plant. The application is carried out with the lettuce cover fully engaged at the time of 4 to 8 days (optimum 6) before the expected harvest date. To ensure foliar nutrition of plants, it is not recommended to apply watering to the leaves 2 days after spraying.

It has been found that the utilization solution according to the invention reduces the NaNO 2 content by 600 to 1000 ppm, depending on the light regime. By way of example, specific NaNO 2 contents after the treatment of the lettuce according to the invention show a marked decrease (see Table I).

Said utilizing solution is affordable compared to growth substances (gibberellins,

CS 273655 B1 (cytokinins), which stimulate plant growth and thereby reduce the nitrate content and achieve the same effect. At the same time, significant savings in foreign exchange funds used to purchase these substances, which affect the morphology of lettuce head, can be achieved.

TABLE I RESULTS OF THE TESTS

Variety Marcia Kozmanův Aperture at harvest 8 500 lux 7 500 lux Nitrate content in NaNO4 control 3 986 ppm 3 575 ppm utilizing solution 2 613 ppm 2 657 ppm -

Claims (2)

SUBJECT OF THE INVENTION Process for reducing the nitrate content of plants, in particular vegetables, characterized in that the plants are treated with a sucrose solution 4 to 8 days before harvesting. 2. The method of claim 1, wherein a 1% sucrose solution is used.