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

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

Size of the trials 2.6 ha

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

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

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)

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

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

“Baural” single plot sower 5-6 hours

Growing season

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

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**

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**

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**

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**

Drying of samples

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.

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

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.

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

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

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

Thank You