updated: 7/5/2007 11:57:45 AM
A Purdue University agronomist says that the next couple of weeks are critical for the state's corn crop. Tony Vyn says another dry period could mean that fewer corn kernels will form on what may be shorter than normal ears. He says a drought now would result in added stress and a higher percentage of barren plants. Purdue says for the average 16-row ear, one kernel per row is equal to about five bushels per acre.
Source: Inside INdiana Business
WEST LAFAYETTE, Ind. - Dry conditions in June may have shortened the length of corn ears. But length isn't all that matters.
Pollination is occurring over the next couple of weeks, and rainfall also will affect how successful that process is, according to Purdue University agronomist Tony Vyn.
Another dry period could mean that fewer corn kernels form on what may be shorter than normal ears. Drought now would also result in added stress and a higher percentage of barren plants in fields that had trouble with variable seedling emergence and early plant growth during dry conditions that prevailed from late April to late May in much of the state.
The weather outlook over the next couple of weeks does indicate normal temperatures and precipitation, according to Ken Scheeringa, assistant to the state climatologist located at Purdue.
"While early stress can be important, severe stress that occurs shortly before to shortly after pollination has a far greater potential to reduce yield per day of stress," said Bob Nielsen, Purdue Extension corn specialist.
The number of kernels per ear is strongly affected by the weather.
"Rain ensures a short interval between tassel emergence and silk emergence," Vyn said. "If it's dry, the silk is delayed, and that lowers the percentage of potential kernels that will be pollinated."
Typically, on each ear shoot, 750 to 1,000 ovules develop, which have the potential to become kernels. Vyn said rain helps pollen shed from the tassel reach receptive silks protruding from the ear. These silks are connected to the ovules, which when pollinated form the kernels.
Corn ears average between 400 and 600 kernels. For the average 16-row ear, one kernel per row is equal to about five bushels per acre. The final potential size of corn ears is determined 10 to 14 days prior to silk emergence, according to Nielsen.
Source: Purdue University