Part I of this series showed that having confidence in the results of a plot matters. It’s asking an awful lot of a 5 or 10-acre strip plot to represent hybrid selection across hundreds or thousands of acres. When seed companies use this method they rely on dozens to hundreds of them to understand how different environments impact hybrid performance. This is commonly referred to as GxE, or genetics by environment. But not every grower manages their crops the same so having different locations introduces another factor – management (M). Now we have a GxExM interaction and you can quickly see how the whole picture of product performance can get muddled (e.g. one grower may apply fungicide or late season nitrogen while another doesn’t). That’s why quality data for an individual plot are critical. The data are important to you for your farm but also think of it as a data link in a decision chain.
Are there other ways of evaluating hybrids? Sure. I personally prefer large strips of 5 or more acres for each individual hybrid being tested. But, the yield has to be checked with a weigh wagon or a calibrated yield monitoring system. Using yield maps is fine as long as the data are of good quality. So what are sources of error that can impact plot results? Here are a few:
Harvest ruts can impact next year’s yield but what happens when a plot entry is planted in this affected area while the others are not?
Hybrids planted in the pinch rows (see Plots Suck, Part I).
Plot planted last, long after most acres were planted.
Placing the plot in a part of the field that results in an entry being planted in an undesirable spot that clearly impacts yield (e.g. an entry happens to be planted in a low spot).
Supplied seed has different seed sizes and no adjustments are made resulting in different stands across the plot.
Sprayer runs over or “leans over” some of the rows of a single entry but not the same number across all entries in the plot.
It’s not possible to eliminate every source of error. Remember, the goal is to have each entry in the plot treated equally and to walk away at the end of harvest with a high degree of confidence that the results are correct. When we achieve this we can say, “that plot didn’t suck.”
I am not a farmer. I work with farmers. I am a trained agronomist. (I’m what you call a professional so don’t try this at home.) I have all the answers – most of which are derived driving by fields at 70 mph. I am an “armchair farmer” of sorts, reading articles, published scientific papers, trade magazines and I formulate opinions about the successes and failures of crop production. Of course, I walk fields. Lots of them. My advice is the best advice. I firmly believe that. Do as I say. End of discussion.
I often go out and share my knowledge and wisdom on increasing crop productivity with every grower within listening distance and return back home to the armchair and ponder whether I actually had any impact. In the couple of months after harvest I will have made presentations to over 500 growers. I’ll know shortly of my influence as planting will commence in the next couple of weeks in south Texas.
How will the farm economy affect their decisions? Will they avoid the temptation to plant before the last spring freeze? Will they keep their crop rotation intact to avoid the yield decline associated with monoculture? Will they take the time to eliminate compaction and ruts left after last year’s harvest? Will they plant my hybrids and plant the recommended seed populations or take somebody else’s advice on what to plant?
More importantly, do they realize that when every grower chases the highest price that over-production and depressed prices are the result? Of course they do. They’re independent growers selling into a global market that they virtually have no control over. And that stinks. As the agronomist, I can only give them advice and knowledge about how to increase productivity. But as a farmer, they often can only do what’s needed to survive another year. And in today’s world decisions are often influenced by their bankers or other financial supporters. And I’m pretty sure very few of them have a degree in agronomy. And that stinks, too.
All the training I’ve had. All the years in the business. All the watching and learning from growers all over the Midwest, the Great Plains and throughout Texas. All the reading, studying and driving by countless fields at 70 mph usually lead me to this conclusion – “I told them not to do that.”