What Drives Pod Count?

Soybeans yield are increasing over half a bushel per year now. Some of that increase is from genetic gain and the rest is from better management. Soybeans have the uncanny ability to produce hundreds of pods per plant, but most never make it past flower or early pod stage.

If you want to increase your soybean yields, track what is happening to pod counts during the season and see if you can do something about it. As soybean flowering wanes and pod fill commences fully over the next 30 days it will be a good time to check pod counts. While counting soybean pods or other yield components can’t be used to estimate field yield, counting pods on a plant can tell you something about how well your management is working.

Many of you remember when Kip Cullers from Southwest Missouri shattered soybean yield records and showed that soybeans could produce more than 100 bu/A. I visited Kip Cullers yield plots during the years he hit 139 in 2006 and 156 in 2007 and counted pods. His average pod count ranged between 100 and 200 pods per plant, probably quadruple that of the average soybean grower. So why were his pod counts so high? It was a combination of early planting, fertility, plant protection, judicious use of biostimulants and irrigating frequently to reduce stress.

I have thought since then growers and agronomists could use pod count to measure changes from management. At the end of the day, soybean growers are literally pod producers because the more pods at harvest means higher yield.

So how do we drive pod count per plant? One way is to plant earlier to increase the number of nodes per plant, either on the main stem or branches. Increasing node count will increase flower set and eventual pod count.

While we don’t know the exact keys to keeping more pods, it lies with reducing stress and feeding the plant routinely during pod fill. Some recommend foliar application of biostimulants, micronutrients, nitrogen and potassium one or more times through the season. And this seems to be the key—feeding the plant at the right time and right diet. But what the right diet and routine is, is still open to interpretation. And many of us have differing opinions in that regard.

Adding one more pod per plant with two to three seeds per pod is equal to an extra TWO bushels per acre. When soybeans have the potential to produce hundreds of pods per plant, saving another four or five pods per plant should give another 10 bushels. Seems simple enough on paper, but it takes a systems approach to set up a high potential number of pods then feed them to keep them.

If your soybean yields are steady at 50, 60 or even 70 bu/A and you want to move to the next level, go out and count pods per plant in a field. Count pods on plants that are spaced an equal distance apart. Do three plants in an area and repeat three or four times in the field. With your baseline pod count today, you can begin to track pods to see what technologies are adding or keeping more pods.