How to fight against the weather

An unusually warm autumn and the first half of winter on the European part of Russia has caused winter crops to start growing. Fields with a sowing season of between 25 August to 10 September are particularly affected.

Villi Drevs, Doctor of agricultural science, consultant

The situation was getting worse due to high norms of sowing (more than 5 million germinating seeds per 1 hectare) and the high moisture content (even overmoisture in some places).

Vegetation in individual fields had continued to grow and the number of stems reached 1,500-2,000 per m2 in the middle of January. These crops also showed a staggering number of pests in autumn, for example Hessian fly, frit fly and black fly. Fungus diseases also increased substantially: powdery mildew, snow mould among other types. In other regions of Central Russia the long periods of rain in September delayed the sowing season (after the 20th of September), washed away nitrogen nitrate in the soil and, as a result, the crops grew in winter and were undeveloped, even yellow. Snowfall and frost in February damaged winter crops and raised several problems. However specialists still had many questions – what could they do with the winter crops in spring after snowfall? When could additional fertilizing be started, when could fungicide be used?

Firstly, additional fertilizer ought to be used on undeveloped crops, in order to stimulate growth. In this instance, the amount of nitric fertiliser should consist of 50 to 70 kg of the active ingredient or 150 to 200 kg of ammonium nitrate. This amount would stimulate the maximum number of stems (from 450 to 600 stems per m2, depending on the kind) and the initial forming of generative parts.

The second fertilizer on these fields would be used in the period where nitrates were most frequently used – during the formation of the first internode (EC-31). The amount of nitrogen used here will depend on the species, the largest planned yield and will consist of between 40 and 60 kg of the active ingredient.











 

In the fields where the winter crops have grown in autumn and the number of stems at the start of vegetation numbered higher than 1,000 per m2, fertilizer is used in a different way.

The fertilizer is used considerably later in comparison with normal or weakened crops. Early fertilizing would only bring harm, since it would encourage even more growth. In the later stages of development, there would not be enough nutrients or moisture for such crops and they would wither away.

Using nitrogen fertilizer on crowded and overgrown crops should begin at the start of stem elongation (formation of the first internode). By this time some of the damaged stems will have died. Fertilizing will help the healthy stems and spikelets. The amount of ammonium nitrate should not be less than 150 kg (51 kg of the active ingredient).

The second fertilizer, which is used when leaves are forming – the start of ear formation – will help the nitrogen be distributed evenly in the vegetation period and during the crop, which will give a high protein content.

The use of fungicides on winter crops must also change approach depending on the species, stage of development, weather conditions, nitrogen supply etc.

Early illnesses of stems and leaves, for example Cercospora, early powdery mildew, yellow rust, are treated using a fungicide during the period of stem elongation of wheat. In order to protect the leaves and heads it is necessary to repeat fungicide application at the start of ear formation.

Because of the high cost of fungicides (from 400 to 550 roubles per hectare, depending on the type needed), the majority of farmers can only afford to do one application.

They time the application so it protects against leaf and head disease.

In early spring, the use of fungicides should not be rushed from the start. Fungicides should be used in treating infections of young leaves and stems and not old leaves. Therefore the times that fungicides and herbicides can be used do not coincide. It is advisable to use fungicides in conjunction with the growth regulator CCC. This will have a synergetic effect on the seeds’ components.