According to literature sources, winter rapeseed with a yield of 3.5 t/ha in autumn needs 50-60 kg/ha of nitrogen (N), 18-20 kg/ha of phosphorus (P 2 O 5 ), 60 kg/ha of potassium (K 2 O), 56-60 kg/ha of calcium (CaO), 5-10 kg/ha of magnesium (MgO), 23 kg/ha of sulfur (S), 100-150 g/ha of boron (B), 10-40 g/ha copper (Cu), 100-120 g/ha of manganese (Mn), 60-150 g/ha of zinc (Zn) and 2-3 g/ha of molybdenum (Mo). However, due to various circumstances, which usually occur in the fall, it is impossible to fully provide the needs of the culture at the expense of root nutrition. Therefore, specialists of UKRAVIT SCIENCE PARK  recommend foliar feeding of rapeseed with readily available fertilizers in critical phenophases, writes   agronews.ua.

Advantages of foliar feeding

The importance of foliar fertilization of winter rapeseed in the fall cannot be underestimated or neglected. First, such feeding quickly eliminates the lack of mineral nutrition elements and contributes to the establishment of a high future yield. Foliar feeding eliminates physiological diseases caused by unbalanced mineral nutrition or micronutrient deficiency (B, Mn, Zn, Cu, Mo) in the soil.

Secondly, feeding with readily available elements of mineral nutrition, amino acids and growth stimulants contained in TM "Avangard" fertilizers activate physiological and biochemical processes and quickly eliminate stress on winter rapeseed.

Thirdly, foliar feeding increases the resistance of winter rapeseed to diseases. Thus, sulfur increases resistance to gray rot, alternariosis, cylindrosporiosis, and boron compounds - to gray rot, phomosis, sclerotiniosis, false powdery mildew, root neck rot and cabbage hernia

It is important that the biological efficiency of foliar fertilizing with microfertilizers is quite high, because the microelements contained in the fertilizer are represented by easily available complexonates, which have a high rate of assimilation by the leaf surface. They quickly penetrate into plant cells, within one or two days. Due to autumn foliar fertilizing with TM "Avangard" fertilizers, 40-50% of the needs of winter rapeseed in microelements (B, Mn, Zn, Cu, Mo) are provided, which are critically needed by young plants when their root system is still weakly functioning.

Scientific and production tests proved that foliar fertilizing of winter rape with TM "Avangard" fertilizers during critical phenophases provides a high return on 1 hryvnia spent on fertilizers - at the level of 5-6 hryvnias.  

Autumn nutrition

When planning foliar fertilization of winter rapeseed in the autumn period, it is recommended to maintain a fine balance with regard to its physiological needs, experts of UKRAVIT SCIENCE PARK warn. On the one hand, the culture must receive enough nutrition to form 8-10 true leaves, a taproot 10 cm long, a root neck thickness of 10 mm, accumulate enough nutrients, assimilants in the root system to ensure optimal overwintering. On the other hand, rapeseed must not overgrow, so that its winter hardiness does not decrease or dangerous diseases do not appear: root bacteriosis, snow mold, downy mildew in the spring.

So what kind of nutrition does winter rapeseed need in the fall? First of all, this is optimal provision of the main elements of mineral nutrition - compounds of nitrogen ( N ) , phosphorus ( P ), potassium ( K ) and ), as well as mesoelements - compounds of sulfur ( S ), calcium ( Ca ), magnesium ( Mg ) , which are indispensable in production processes.  

Winter rapeseed is the leader in takeawaysulfur compounds (S) – 40-60 kg/ha, which depends on the size of the crop. The monitoring of the "Institute of Plant Health" established that 80-90% of soils have a low or very low content of mobile sulfur, at the level of 1.5-3.0 mg/kg. Without sufficient supply of rapeseed with sulfur compounds, it is impossible to obtain high efficiency from nitrogen fertilizers, since sulfur compounds are part of enzymes that improve metabolism, participate in the reduction of nitrate nitrogen (N-NO 3 ) to amide nitrogen (NH 2 and NH 4), in the formation of chlorophyll chloroplasts. The optimal ratio between nitrogen and sulfur in rapeseed plants should be 10:1. Sulfur compounds increase by 20-25% the coefficients of consumption of nitrogen compounds by rapeseed and stabilize the oil content in the seeds. Sulfur compounds have a strong influence on the quality of rapeseed: they increase the content of fat, the content of unsaturated fatty acids.  

In the fall, winter rape is also recommended to be fedmagnesium (Mg). It is a structural element of chlorophyll and an activator of many enzymes. This element contributes to the transport of carbohydrates from the leaves to the roots, the formation of a well-developed root system and successful overwintering. Almost 80% of domestic soils have a high, elevated, medium or high content of exchangeable magnesium (Mg), at the level of 200-500 mg/kg of soil. However, due to unfavorable conditions in autumn, rapeseed cannot always fully provide itself with this element through root nutrition.

Trace elements are equally important for the successful overwintering of winter rapeseed -B, Mn, Zn, Cu, Mo. In the conditions of Ukraine, there is a biophilic reaction of culture to foliar fertilization with trace elements in the following order:B > Mn>Mo > With >Zn.

Research by the Institute of Plant Health has shown that most domestic soils have a very low, low or medium content of mobile trace elements. As a result, winter rapeseed cannot fully meet its needs with trace elements only through root nutrition. Therefore, foliar fertilizing of crops with fertilizers enriched with microelements is of great importance for the formation of high yields.

Emphasis on boron

Winter rapeseed is typicalborophil. His need forfight (AT)5 times higher than that of grain crops. However, at least 40% of domestic soils have a very low or low content of mobile boron (B) compounds, at the level of 0.3-0.5 mg/kg of soil.

Boron compounds are involved: in the differentiation of meristem (generative) tissues of the root system and vegetative organs, in the formation of cellular structures (they give them strength and elasticity). They contribute to the assimilation of calcium (Ca), nitrogen (N), phosphorus (P) and optimize the synthesis of amino acids and proteins. Boron compounds stimulate the synthesis of carbohydrates and ensure their transportation from vegetative organs to the root system and generative organs. Boron compounds also have a positive effect on the formation of an optimal relationship between vegetative organs and the root system of winter rape, which is valuable in autumn. Subsequently, boron compounds ensure the germination of pollen tubes, improve the fertilization of flowers, and as a result, increase the seed productivity of rapeseed. In general,

The optimal pH of the soil for assimilation of boron compounds by crops is 5.5-6.0. Deficiency of boron compounds on winter rapeseed is most often observed at neutral or slightly alkaline soil pH, on calcified or carbonated soils, under water shortage, cool weather, which negatively affects overwintering and yield.

With a deficiency of boron (B), the content of the phytohormone auxin decreases, the growth points of the root system and stems die, the stems crack and the root system becomes hollow. Boron (B) compounds in the plant body are not reused, that is, they cannot be reused from the lower leaves.

Therefore, as the winter rapeseed grows and develops, it needs at least 2-3 foliar feedings with readily available boron fertilizers, because physiological diseases that cannot be controlled by fungicides will appear with boron deficiency.

Fertilizing in the fall to lay the foundation for the future yield

In order to ensure as fully as possible the needs of winter rapeseed with balanced nutrition in the fall, specialists of the UKRAVIT SCIENCE company recommend foliar feeding in the phase 4-6 and in the phase 8-10 leaves with an easily digestible fertilizerVanguard Ripak. Due to the balanced composition of top dressing, they will meet the needs of rapeseed in the elements of mineral nutrition in the early phenophases, and increase the assimilation coefficients of nitrogen, phosphorus, sulfur, potassium compounds from fertilizers and soil by 10-15%. The exchange processes of the culture at the cellular level will be activated, which will contribute to the growth and development of the root system, the laying of flower buds, an anti-stress and stimulating effect will be manifested, which will contribute to successful overwintering and the formation of high productivity of rapeseed.  

Also together with fertilizerAvangard Ripak - 2.0 l/hain one solution, it is recommended to feed winter rapeseed with fertilizer in autumnVanguard Boron (B - 150 g/l, N - 65 g/l)the norm is 1.0-1.5 l/ha: because the root system of the crop is still poorly developed and has a low absorption capacity. And even if farm soils have an average or high content of mobile boron compounds, at the level of 0.3-0.5 mg/kg of soil, the coefficient of their consumption by culture is 3-6%, which is not enough to fully meet the needs of rapeseed in the fall.

Such feeding will stimulate the growth and development of the root system and vegetative organs, promote the outflow of photosynthesis products from the vegetative organs into the root system, eliminate the hollowness of the root system, strengthen immunity to diseases and resistance to adverse environmental conditions, and improve the agrochemical efficiency of traditional mineral fertilizers.

Improving the effectiveness of foliar fertilization

In order to maximize the absorption of nutrients by the leaf apparatus of winter rapeseed, UKRAVIT SCIENCE PARK experts recommend paying attention to: the recommended pH of the working solution and to adjust it, if necessary, use an acidifier-conditioner. It is also recommended to add an adhesive or adjuvant to the working solution to improve the processes of wetting, spreading and penetration of the working solution through the cuticle and epidermis of the leaves.

In addition, it is necessary to adjust the sprayer accordingly - choose the optimal pump pressure, the size of the nozzle tips, as well as pay attention to weather conditions (air temperature, wind speed, etc.) and carry out foliar feeding at a favorable time of day. It is important to feed at critical developmental phenophases to get the most out of the treatment.

In the complex, this will allow to optimally adjust the mineral nutrition program of winter rapeseed, to provide it with a successful wintering and active growth and development in the spring.