Uniformity at harvest is created at seeding time. Check the number of plants early in the season per yard of row and/or heads per yard at harvest to determine how they compare with ideal populations for the region.
The most profitable producers I work with are the ones who make the most informed decisions. These growers frequently don’t spend any more money per acre on inputs compared with their neighbors; instead, they are able to increase yields and profits by arming themselves with sound technologies. These include soil tests, tissue tests and regular field scouting, all of which can help determine which inputs need to be applied to each field, plus how much and when.
As farm sizes get bigger, finding time to put footsteps in the field becomes more of a challenge, so seeking sound agronomy assistance from a certified crop adviser is money well spent. Such individuals can help scout fields, prepare and gather results from on-farm trials and compare results with other fields and clients to better decide which fertilizer strategies, fungicides and
varieties generate the best return on investment over time.
Even simple strip trials that compare different varieties can help you make better decisions and can make a big difference when it comes to yields and profits. After all, if you don’t compare your varieties to others, how can you be sure you’re planting the best ones?
How do your stands compare? Before you can make wheat management decisions, you need to measure your stands, compare them for consistency and see how they compare to recommendations for your specific region.
Begin early in the season by counting the number of plants per yard of row across different areas of your fields. Next, convert the number of plants per yard of row into plants per square yard by multiplying the average plant population per yard by the value of 36 divided by your row spacing in inches.
For example, if you find an average of 45 wheat plants per yard of row and your row spacing is 6", multiply 45 by 6 (36 divided by 6) to obtain an average of 270 plants per square yard.
Depending on the region’s rainfall and planting date, I generally look for around 200 to 300 emerged plants per square yard. I prefer to see all wheat plant populations per yard of row to
be within 20% of each other, but that rarely happens.
Many factors can decrease plant populations: compaction from tractor wheel tracks, differences in seeding depth, differences in residue distribution and, more frequently, an excessive forward speed at seeding time, which, coupled with adequate down force on each seeder opener, is especially common when no-tilling wheat into heavy residue.
Once you see how well each yard of row compares to the others and the average, you can make better decisions about which improvements need to be implemented.
To be able to make winter wheat nitrogen application decisions, it’s critical to determine how many tillers per plant there are early in the spring.
Depending on moisture, fertility, planting date and other factors, the average number of tillers per plant will usually range from two to four, but fields planted early (especially those with high fertility) can sometimes reach eight to 10 tillers per plant. With good moisture and fertility, most of these tillers can produce heads, so it’s important to apply the appropriate nitrogen rate at just the right time.
Extreme head densities can present huge challenges with regard to lodging and excessive disease pressure. While diseases can be controlled with an effective fungicide program, lodging should not be tolerated, as significant reductions in grain yields and grain quality frequently results.
Most research suggests that maximum wheat yields come from 450 to 600 good heads per square yard, with the top end of this range more suitable for crops with increased rainfall.
Later in the season, when I walk the fields, I sometimes find final head counts (measured after flowering) from about 250 heads per square yard at the low end all the way up to 1,000 heads or more, perhaps within just a few feet of each other.
The result is that some areas are way too thin to generate maximum yields. Other areas may have had additional seed or were overfertilized early, and the result is a crop that gets invaded by diseases and lodges. Either way, the yields will be disappointing. Despite the best intentions with fertilizers and other crop inputs, a poor standard of seeding uniformity may not allow growers to capture the full return on their investment.
Focus on uniformity. Many growers need to upgrade or better maintain their seeding equipment, as irregularities can frequently be traced to that source. Remember that unless you create the potential for high yields at seeding time, you should not expect bin-busting crops at harvest.
The cheapest way to increase yields is to improve the uniformity of the stands. Such improvements may come in the form of adjusting seeding rates based on seed sizes or adjusting seeding rates based on planting dates or crop residue levels. There are almost always opportunities to make simple changes that can boost stand uniformity, increase yields and put more dollars in your pocket.
- March 2011