1. Maize trials in Denmark -from design to result Janne Aalborg Nielsen M.Sc.,Teamleader

2. Maize variety trials in Denmark  In Denmark app. 100 maize varieties for whole silage are tested – why so many?  Denmark is the Northern limit for growing maize for whole silage  There is a large and intensive dairy farming industry  All breeders can register any variety either for official testing or for supplemental testing

3. Size of the trials  2.6 ha

4. Challenges  Experimental design - how to minimize the variation due to large experimental area  Sowing single plots efficiently  Harvest within as short a time span as possible

5. Challenges - continued  Determining dry matter and minimizing the differences in dry matter content between varieties  Eliminating the influence of the harvest time during the day by correct sampling  Efficient and secure handling of data

6. Experimental design  Many treatments – a higher experimental error  Reducing the change of obtaining a significant result  Differences between varieties are small  In this case it is widely recognized to apply an incomplete block design (Williams, 2000)

7. Experimental design - continued  2006: The incomplete block design was implemented for variety testing of maize  The randomization plan is created in “PC- Field Trial (in the “Nordic Field Trial System”)  The algorithm is based on a “dll” from the “CycDesign” program

9. Sowing single plots  Same germination conditions  As short a period as possible  Germination percentage, grain weight  Grains are weight out  Number of plants in every variety is exactly the same  Arranged according to the randomization plan

10. “Baural” single plot sower  400 plots  5-6 hours

12. Growing season

13. Harvest  Not all the varieties reach maturity at the same time  Most correctly to harvest at the time when dry matter content is as desired for each variety  Not possible  The data is not available prior to harvest  Very costly to harvest at different periods

14. Harvest - continued  Whole silage maize is harvested when the dry matter is app. 30 percent  “Champion” maize cutter mounted with a “Haldrup” weighing and sampler unit**  Eliminating inter plot competition****

16. Harvest - continued  Yield is measured on a “Mettler” weight  Data automatically transferred to a computer in the tractor**  “Haldrup Harvest Manager”  Randomization plan is imported from PC-Field Trial****

18. Sampling  Plot sample is drawn from the harvested mass  App. 1 kg is taken**  Perforated plastic bag, bar code label (precise ID)**  The sample is weighed**  Data send to a computer in the tractor****

22. Sampling - continued  Samples placed in a trailer**  Semi heated air**  Starting the drying process of the sample  Dries in the trailer for 24-28 hours  Moved to the drying oven**  Dries for 18 hours at 60 °C****

24. Drying of samples

26. Advantages  1) The determined dry matter will exactly match the measured yield and thereby eliminate fluctuations in dry matter during the day;  2) The quality analysis will be more reliable because this fixes the content of sugar and starch. In air tight bags the sample will start to ensile or rot which can result in useless results from the laboratory.

27. Quality analysis  Plot samples are subdivided  Send to the laboratory for quality analysis

28. Quality analysis  Crude protein, % in dry matter  Wood pulp, % in dry matter  Crude ash, % in dry matter  Sugar, % in dry matter  Starch, % in dry matter  Enzyme digest.OM, %, (cattle)  NDF, % in dry matter, total  iNDF, % in dry mat.

29. Statistics and reporting  Breeder, adviser and farmer: The size of the yield  Very important is also the quality of the yield

30. Statistics and reporting  Quality of the yield  Sugar, starch, digestible parts etc.  Value of the crop  How much milk a kilogram of maize will produce

31. Statistics and reporting  Yield and quality parameters are transformed into yield of feeding units per hectare and net energy value for a high yielding milk cow  SAS Proc mixed  F-test and an LSD value