What questions should be asked about yield monitor use for hybrid and variety choice

November 2002

What questions should be asked about yield monitor use for hybrid and variety choice?

Hernan Urcola and J. Lowenberg-DeBoer

Introduction

Manufacturers, agribusinesses and researchers have made many suggestions on how farmers should use their yield monitors and the resulting data, but there is very little information on what farmers actually do with this technology. A series of ten case studies that we recently completed sheds some light on this question. These case studies focus on how farmers in west-central Indiana make hybrid and variety choices, and especially how yield monitor data is used in those decisions.

Because of the lack of information on farmer use of yield monitors, we chose to do in depth case studies based on semi-structured interviews with ten farmers, instead of a broader mail or telephone survey. This allows farmers to raise the issues important to them, instead of responding to our predetermined list of responses. The downside of the case study approach is that the results are difficult to generalize. This was not a random sample of farmers and it is not large enough to be representative. Case studies are often useful in defining research agendas and in identifying which questions should be asked in future surveys. This article focuses on the yield monitor related questions identified in the case studies that we did.

Is yield data from on-farm or other trials useful when many farmers are pressured by seed companies to choose hybrids and varieties before harvest?

Several of the case study farmers ordered most of their seed, especially corn, in August. This gives them top priority in obtaining hybrids that are in short supply. In that case they must depend mainly on their dealer’s recommendation, especially when it comes to new hybrids. Yield monitor data may be useful for diagnosing drainage, pest, soil fertility and other agronomic problems, but it is not of much use for hybrid and variety choice in Indiana in August. Given the rapid turn over of genetics, the previous season’s on-farm trial results may be largely irrelevant.

Do universities and other organizations who conduct hybrid and variety yield trials make that information available in time to be useful for ordering seed for next year?

Case study farmers order the majority of their seed before December 31. Many order in November. The economic motivation for this is clear because seed companies provide discounts for early orders and the purchase becomes a tax deduction for the current year. University and other trial information is often not available until November and some university websites do not post yield trial results until January. Does yield monitor data have additional value because it is available to the farmer immediately after harvest, when many seed decisions are made?

If farmers mainly look at the rankings of average yields, what is the advantage of yield monitor use for hybrid and variety choice?

Average yields could be obtained with a weigh wagon or scales. This is especially true when comparing average yields from relatively large areas. Is the yield monitor’s main advantage in this case convenience? Harvest is a busy time and any disruption of activities can be costly. Farmers often complain of having to wait for a weigh wagon provided by an agribusiness.

How do farmers use their yield maps?

[NS1] Of the farmers with yield monitors, only two out of the five expressed satisfactions with their yield maps. Farmers complained of difficulties in interpreting them. Visual interpretation may be useful for identifying underperforming areas, but for hybrid and variety choice, visual interpretation is of limited use. It is heavily influenced by the color coding. Are the color code increments small enough to pick up yield differences, which are often only a few bushels per acre? Most yield mapping software allows users to identify polygons and calculate average yield and moisture for that area. How many farmers trouble to do such calculations?

What is the plot area and geometry assigned to a hybrid or variety being tested?

Many farmers prefer substantial blocks, often over 10 acres. They complain that the strip trials often recommended by researchers take too much time to plant and harvest.

How do farmers assess yield and return stability?

All of the case study farmers made subjective assessments of variability. The most quantitative among them looked for hybrids and varieties that were in the upper part of the ranking in trials at several sites.

What weight do producers put on yield information from their farms?

All the case study farmers said that yield information from their own farms had the heaviest weight in their decision making. Some went so far as to say that if a hybrid or variety failed to produce on their farm the first year planted, they would drop it, regardless of how well it yielded elsewhere.

Implications for Research Agendas[NS2] :

The case studies do not allow for generalizable conclusions, but they do suggest some areas that researchers might consider for future work, including:

Easy-to-use methods for assessing yield and return stability for alternative hybrids and varieties.
On-farm experimental designs based on larger blocks, instead of equipment width strips. [NS3]
Use of remote sensing to provide a hybrid and variety “early warning system” with yield estimates in August for those producers who order seed at that time.

References:

Urcola, Hernan, “Economic Value Added by Yield Monitor Data From the Producer’s Own Farm in Choosing Hybrids and Varieties,” M.S. Thesis, Department of Agricultural Economics, Purdue University, West Lafayette, IN, 2003.