Yield is king for spring wheat performance
The old farming adage says that yield is king, and this is no more so than when analysing the performance of spring wheat.
Yield results from this year’s AHDB variety trials highlight the yield gap between varieties. From this we can see that the impact on financial performance is considerable and with the available price premiums for spring-sown Group 1 varieties far below what is needed to make these types competitive it further highlights the importance of yield in delivering attractive gross margins.
- Across five trials spanning Lincolnshire, Cambridgeshire, Hampshire and Suffolk, the Group 2 variety, KWS Cochise has out-performed all others in 2018. In the case of the Group 1 control, Mulika, the yield gap ranges from 7% in Friesthorpe in Lincolnshire to almost 30% in Norton, Hampshire. KWS Chilham and KWS Kilburn also put in above-average performances.
- As shown in Table 1, across five years of trials between 2014 and 2018, KWS Cochise is 12% higher yielding than Mulika with KWS Chilham 8% and Group 4, KWS Kilburn 9% higher yielding.
- As shown in table 2, at a base price of £150/t Mulika needs a premium of £20/t to achieve gross margin parity with KWS Cochise (even after assuming equal variable costs between varieties). This increases to £28/t if KWS Cochise is not grown to Group 1 protein specification due to a 40kg/ha saving in ammonium nitrogen.
The higher yield potential of KWS Chilham and KWS Cochise is evident in Chart 1 below which shows that these varieties still deliver better financial returns than Group 1 varieties receiving a premium of £15/t over feed values. Chart 1 is based on true gross margins with fertiliser rates adjusted according to protein target: 220kg N/ha for 13% protein and 160kg N/ha for 11.5% protein (nitrogen priced at £1/kg for comparison).
- KWS Cochise produced to the lower-protein specification of 11.5% represents the best possible gross margin based on AHDB 2014-18 mean yields and available premiums delivering £141/ha more than a Group 1 variety grown to 13% specification.
- KWS Chilham produced to the same specification lower-protein target is the next best financial option.
- The higher yield potential of KWS Chilham and KWS Cochise means that even when grown to a feed protocol these varieties deliver gross margin returns in excess of the sole Group 1 variety produced to 13% protein and achieving a £15/t premium over feed.
There is far more to variety choice than just yield potential; disease resistance is becoming increasingly important as growers look for varieties that are lower risk. The resistance of the main spring wheats are displayed in table 3 below.
- Of the popular spring wheat varieties for which seed is widely available for 2019, KWS Chilham has the best combination of resistance to Septoria tritici and yellow rust.
- KWS Kilburn offers good all-round disease resistance but lacks midge resistance.