I grew up watching the television show Quincy, M.E. Jack Klugman starred as a Los Angeles County medical examiner in the mystery-thriller, one-hour show as Quincy who had to solve mysterious deaths. I would argue this show set the tone for future shows such as "CSI: Crime Scene Investigation" and "NCIS". These shows lead us to believe we can easily solve crimes and determine the cause of death.
How does this relate to harvest 2017? My extension colleagues and I often joke that we get Quincy M.E. calls during harvest every year. The body is dead (crop maturity) and now the client wants to know what caused the death or in this case the unexpected loss of yield. The crop is harvested, the yield is not as good as the client had anticipated, or the yield varies widely from one end of the field to the other and now the client wants to know why. Farmers often leave us a check strip of the affected “body”, but the “body” or crop is so far gone, it is difficult to always ascertain what might have limited yield.
Was it the dry conditions of the growing season? If so, why was yield so variable across the field. Did the crop experience off-target movement of a herbicide that may have caused yield loss? Well, it may have, but there is no good way to identify that cause in October. Even knowing that some herbicides cause specific ear conditions in corn, other factors can cause similar conditions in corn. Was it compaction? Well, maybe we can tell when we dig roots and see limited root growth, or perhaps we note tomahawk roots indicating sidewall compaction during planting. Was it rootworm damage? Perhaps. At this stage, it may be difficult to distinguish some rootworm feeding from normal root degradation. Was it a foliar disease? Hard to tell now when all the leaves are brown on the corn, or completely dropped in the soybeans. Sometimes we can still see patterns in the field, even with mature crops, that might provide some clue as to what happened, but this clue is harder to recognize with dropped leaves or collapsing corn stalks.
Extension field agronomists and retail agronomists are asked to solve many “murder mysteries” in production crop fields. This is part of the job. However, sometimes agronomists need to be able to see the clues when the clues are fresh. For example, identifying the impact of a foliar disease requires seeing the crop much earlier in the season to determine the actual disease and the severity. Sometimes the “body” dies of natural causes, sometimes the “body” dies from complex plant-soil-climate interactions. Sometimes the “body” is murdered from complications of unintended consequences such planting in wet soils, herbicide drift, weather or other reasons. And sometimes those unintended consequences are aided and abetted by mother nature with too much rain, not enough rain, too much heat, not enough heat.
Take some time to review the growing season conditions to determine what may have impacted that crop. Feel free to call your extension field agronomist yet this fall, but recognize that the clues may be long gone and the mystery may go unsolved. Most importantly, plan now for several scouting trips for 2018, keep good notes and do visual observations throughout the growing season. Feel free to call your extension field agronomist when you are uncertain about the cause of what you are seeing during the growing season.