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Get An Accurate Plant Count

Get An Accurate Plant Count
Remember the compensation factor for soybeans.

Working soils under less than ideal conditions and catching pounding, heavy thunderstorms may have some of you who planted soybeans in the past two weeks wondering if the stand will be good enough to leave. Base your decision on actual plant counts, and on science, not an attitude that it 'looks bad' or 'what will the neighbor think.' While some of you might make a case for leaving a thin stand won't look good to he landlord, it might be an opportunity to convince him that times have changed, and you don't need as many plants out there per acre as most people once thought you did.

The secret will likely turn out to be consistency of stand, length of gaps, lack of canopy, the ability to control weeds and the like. If your stand is still fairly uniform and you have a good shot at good weed control, even though there are fewer plants than you typically see, you might have a shot at pulling off a good yield with the stand you have, rather than replanting at this late date.

Grab the hula-hoop and the Purdue University Corn & Soybean Field Guide and head to the field. Walk the field, rolling the hoop and letting it fall in many random spots. Use averages to decide final population. Recognize that some areas of the field may be better than others in terms of plants existing per acre.

Here are a few examples.

Suppose your hula-hoop, or wire coil if you make it out of #9 wire, measures 30 inches in diameter. That magic multiplication factor is 8, 878, according to the Guide. If you find an average of 12 plants inside the hoop, your total population would be: 106, 53

Is that enough to do the job? Shawn Casteel, Purdue University soybean Extension specialist, believes it should be, especially if conditions about distribution and weed control are met. Ideally, he's shooting more toward 120,000 plants. However, he's a strong believer that stands don't need to be as thick as people have been planting them.

He has a plot out this year to see if he can prove his theory. Since it is at the Throckmorton farm and took a strong hit with rain last week, he may have his own decisions to make about what's good enough to leave and what's not. Stay tuned, and look for a report on his findings here this fall. 

TAGS: Soybeans
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