Date: 03.07.2020
Why spreading risk?
Because of the climate change, more and more weather extremes appear during the year. Distinct spring drought is disturbing the tillering of the plants. Early heat periods in the summertime lead to quick ripening. Years with delayed harvest due to rain falls, require varieties with stable hagberg falling number. The mild winters of the last years are interrupted once in a while by extreme frost events in spring time which are not predictable. In the same time more and more farmers are making early delivery contracts for their harvest but have to deliver then in time a certain amount and quality. Also the capacity of machinery and workforce in modern big farm structures, has to be used optimal. The challenge in farm management, is the minimization of the above mentioned risks and optimization of the available resources on the farm. In that matter, the variety choice is one important key for success. In diagram 1 you can see which attributes are most important in variety choice.
Agronomic attributes
In the field, the good lodging resistance of the varieties has a big priority. By intensive selection of the breeders, nearly all modern wheat varieties are equipped with a good lodging resistance today. Varieties with a high risk of lodging are almost not available anymore. That is the reason why lodging fields disappeared almost totally from the countryside and only after heavy rainfalls it can be found sometimes. On locations where a very strong lodging resistance is needed, varieties like ETANA, ASPEKT and ARCHITEKT are very suitable. But also varieties with a normal lodging resistance like PATRAS and ARKTIS can be grown comfortable with an locally adapted quantity of growth regulator.
After some years with mild winters, the very important attribute of frost resistance of winter wheat varieties was sometimes forgotten. As a kind of insurance, the frost resistance has a high priority in regions where late frost events without snow coverage can happen. The financial loss for the farmer can be very high due to missing frost resistance.
Harvest timing with different maturity
The maturity of north European varieties is spreading about over one week. Especially in bigger farms, it can be interesting to plant earlier and later varieties on the different fields, to time the harvest and flatten the peaks of parallel ripening fields. Additionally this topic can also lead to a reduction of risk, caused by different weather conditions. In years with late rainfall, this rain can be used better by later varieties. On the other hand, when heat and drought are speeding up ripening already in June, earlier varieties have often a benefit. This kind of earlier varieties are for example ASPEKT and EMBLEM.
Resistance characteristics
Regarding the resistance characteristics, a completed profile is most important. That means, the varieties should have a low to medium susceptibility to all leaf diseases. This is more important than outstanding resistance notes at a single specific disease in connection with bad notes at other diseases. A high susceptibility means, that the disease is building up very quickly under suitable weather conditions and needs a quick reaction with fungicide. It is monitored in official trials, that in some varieties for example DTR is damaging already end of June 10% of the leaf surface. In resistant varieties it could take up to two more weeks to reach that level of infection. Good resistance is providing more time for the fungicide application. If you are missing the right time for application at susceptible varieties, that can cause a certain damage and reduce the yield significantly.
Quality characteristics
For farmers, a high safety in quality parameters is very important. Especially in the marketing relevant characteristics, when to fulfill contracts. In the past there have been sometimes problems with the falling number due to delayed harvest. This was caused by periods of rainfalls in harvest time. So it is not surprising that varieties with a good falling number stability are preferred by farmers. Regarding protein content, varieties like PATRAS have a higher protein content and bring more safety for the growers to reach the requested level also on critical locations.
Outcome
Modern varieties are offering a broad range of different attributes to choose from. In most cases it make sense to take a deeper look to the individual profile and to split the risk by choosing different types of varieties. The yield has no longer the highest priority because we are faced with climate change, weather extremes and more limitations in the use of chemicals and fertilizer. In the end, varieties with a completed resistance package, good winter hardiness and stable quality and yield characteristics, are the preferred choice.