Yield estimate before harvest

A yield estimate is somewhat possible with the following formula, which requires close examination of the components that contribute to yield.

You need to know:

• Number of pods per plants
• Number of seeds per pod
• Number of plants per square foot
• Seed weight

These will take some time to count, and you would need to do a number of counts across a field to get a somewhat accurate estimate. And if seeds have more time to fill and get larger between counting and harvest, the estimate will be low.

The forumula

Yield estimate (bu/acre) = # pods per plant X # seeds per pod X # plants/sq ft X seed size conversion factor (see below).

Approximately 25 to 50 samples will provide an estimate within +/– 25 per cent. That is a lot of work for an estimate that will not be very accurate. While you don’t have to shell out pods to count seeds (you can hold a pod up to sky) you will need them get a seed weight.

Seed size conversation factor

g/1000 seeds   1bu/acre – seeds/square foot        bu/acre conversion factor

2                                              261                                         0.0038

2.5                                           208                                         0.0048

3                                              174                                         0.0057

3.5                                           149                                         0.0067

4                                              130                                         0.0077

4.5                                           116                                         0.0086

5                                              104                                         0.0096