Agronomy Talk

Agronomy Update

Corn Tip Loss, NCLB Persists, and Japanese Beetle Damage

Published on Monday, August 10, 2015

This week, central Indiana sales intern Christy Kettler provides an update on crop condition and insect pressure she has been seeing while scouting area fields. 


Corn showing tip loss, NCLB persisting, and Japanese Beetles damage 

Christy Kettler | Sales Intern | Central Indiana
August 3-7, 2015

Kernels are plump and leaves are green, corn has reached its prime time. Most ears around northern Indiana are showing R3 development, the milking stage. At this stage, it is very apparent what percentage of kernels did not get pollinated.

Genetics and breeding selections in corn play a key role in the crop’s ability to produce kernels through the tip of the ear. Other factors affecting the completeness of fertilization include insect damage to silks, chemical damage during pollination stages, and offset flowering dates between plants. Determining the average number of fertilized kernels on each ear can lead to a yield estimate for a field. Keep in mind that brown silks cannot fertilize kernels, so damage at the green silk stage will limit yield while damaged brown silks will not. 

Silks were damaged by Japanese Beetles, blocking the transport of pollen to kernels.

Some soybeans throughout the area have been affected by sudden death syndrome (SDS). This is mainly due to the high moisture levels this year, which have created ideal environments for the growth of the fungus. The disease appears at first in smaller areas, usually compacted or more water logged areas. The upper leaves will look yellow, turn to brown, shrivel, and eventually die. This is not a preventable disease, but certain varieties can be selected that are less likely to result in major losses. Talk to your local seed advisor or dealer if you suspect SDS in your fields.

Japanese Beetles have infested soybean fields in the state also. Leaves will show ragged holes in the top canopy, usually leaving behind larger veins with minimal tissue and small veins left. The yield damage for soybeans is usually not quantifiable and usually does not call for any treatment. Sweep the soybeans 20 times, in five areas of a field to determine if their presence is approaching economics threshold. Refer to Purdue University Extension for thresholds and information on insects. 

The insect traps in north central Indiana had seven ECB moths this week. 

Look for my findings next week!


If you have any questions on these findings or want to learn more, please contact your local seed advisor or dealer.

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Denny Cobb

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