|Direct harvest beans not for everyone|
|September 23, 2016 Jerry Purvis|
A field that’s ideal for growing direct harvested beans will be flat and irrigated by pivots. During harvest, a flex combine head is needed to keep yield losses to a minimum. Courtesy University of Nebraska
While direct harvested dry edible beans may be appealing to local bean growers, it’s not a practice that needs to be adopted by all producers. For some growers, direct harvesting might not even be recommended.
Beans strains that are bred for direct harvesting have stronger stems that can stand upright, as opposed to traditional beans that usually lie closer to the ground. Pods on these strains not only have an upright structure, but also set their pods higher on the plant. That allows for fewer losses at harvest time as fewer pods are on the ground.
Bean breeders are farther along with developing upright standing pinto beans than with the Great Northern variety. However, both varieties are available for growers who would like to try them.
These strains have been widely grown for several years in northern states such as Minnesota and North Dakota. Now they’re becoming more popular in Nebraska.
“In the last five to 10 years the practice has been increasing,” said John Thomas, Cropping System Extension Educator in Box Butte County with the University of Nebraska.
“Direct harvesting doesn’t work for every variety of bean, but people are attracted to it because the beans can be harvested in one pass through the fields.”
Originally, bean harvesting traditionally required one pass to cut the beans, another pass to windrow the beans, and a third to combine the beans. Today, cutting and windrowing are completed in one pass.
Thomas said a drawback to traditional harvesting is the beans lying in windrows are vulnerable to wind that can scatter the beans, and they can get soaked by rain during the drying process. Plus, wet beans are more susceptible to disease, such as the commonly occurring white mold.
While producers should have better yields with direct harvest, that isn’t always the case. As the combine moves through the fields, some pods are shattered if they’re low-lying. Those beans fall on the ground and are lost.
A grower who wants to try direct harvesting will need a level field surface, a good variety of bean, and the correct combine header (such as a flex head) to do a good job while keeping yield losses to an acceptable level.
Thomas said an acceptable loss for direct harvesting would be two to four bushels per acre. He’s seen losses of eight to 11 bushels per acre with direct harvested beans.
Any amount over five bushels should be a concern. He’s also seen them harvested with as little as one bushel per acre lost.
“With traditional harvesting, growers will lose about 1˝ bushels an acre,” Thomas said. “It’s not like the traditional method loses none. Plus, with wind loss and diseases, that loss can go up significantly.”
For successful direct harvested beans, all of the growers’ field practices, such as tilling and planting, need to leave a flat surface on the field. Gentle rises in the field aren’t a problem, but ridges and ditches are.
“Most growers won’t attempt to direct harvest when they’re using furrow irrigation,” Thomas said. “However, there are certain ways to bed the field to make it possible. It’s tricky and I don’t recommend it.”
He added that direct harvesting involves more than just getting a new combine header and going out into the field. The grower has to use the entire direct harvesting system, from a level field, having a good upright bean variety, good weed control, plus the correct combine header with a knowledgeable combine operator.
“The direct harvesting method has been increasing locally over the last five years, from about five percent up to maybe 20 percent now,” Thomas said. “There are more operators who want to try direct harvesting to grow their beans.”
As for the near future, researchers say they’re ultimately looking for a dry bean variety that has good yields, even maturity across different soil types, and carries the pods higher in the pla