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

400 plots

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