Have you estimated your dry bean yields yet?

With dry bean harvest approaching, here’s how to estimate potential harvest yield.

Growers can estimate dry bean yields by determining the average number of plants per acre, the average number of pods per plant and the average number of seeds per pod. If a seed or pod will not mature, it should not be counted.

Start with counting the total plants per 1/1000th acre to determine plant population. Make at least three counts in separate sections of the field, calculate the average of these samples, then multiply this number by 1,000. Use the table below to determine the length of row you’ll need to measure, depending on your row width.

Row width
(inches)
Length of single row to
equal 1/100th of an acre
15 34' 10"
22 23' 9"
30 17' 5"
36 14' 6"

Within a representative and uniform plant stand, randomly select five plants each from at least five randomly selected locations in the field.

Pull and count the pods from each plant and then count the seeds per pod to determine average seeds per pod for all five replications. You may choose to count a randomly selected number of pods, say 25 pods from each location. But, remember, a more complete count will lead to a more accurate estimate. This information is combined with the average number of plants per 1/1000th acre, using the calculations at the end of this article.

The final piece of information you will need is the average number of seeds per pound, depending upon the class of bean grown. You can use the table below, but seeds per pound can vary for different varieties within a bean class. Ideally, you should use reported estimates for seed number per pound for your variety.

Bean class Average number of seeds
per pound
Navy/Black 3,000
Small Red/Pink 1,600-2000
Kidney 900-1,000
Pinto 1,400
Great Northern 1,600-1,800

The accuracy of yield estimate can be improved by counting seeds and pods from at least 10 plants per replication.

Calculations

  1. (Average seeds per pod) x (average pods per plant) equals average seeds per plant.
  2. (Average seeds per plant) x (plants per 1/1000th of an acre) x (1000) divided by seeds per pound of the variety equals yield in pounds per acre.

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