With the weather conditions we have had this year, it is likely some corn fields will start to show "firing" or yellowing on the bottom of corn plants.

Agronomists indicate the two most common nutritional causes of lower leaf firing are nitrogen and potassium deficiencies. While both of these show up on the lower leaves, it is very easy to tell them apart.

Nitrogen deficiency will start as yellowing at the tip of the leaf and then go back the middle of the leaf following the midrib, forming a V.

A potassium deficiency also will start at the tip of the leaf, but the yellowing will go down the outside edge. The symptoms will start at the bottom of the plant and go up as the deficiency becomes worse.

These nutrients are mobile, and the plant will strip them out of the older leaves and move them to the new growth. Thus, the higher up on the plant symptoms are observed, the worse the deficiency. Eventually, the yellowing could cover the entire leaf, causing it to die.

There are several possible causes for these deficiencies. Most obvious is the lack of nitrogen or potassium in the soil.

For nitrogen, either not enough was applied, or a significant amount might have been lost after application by leaching and denitrification because of the wet weather pattern.

For potassium, look at the soil test. If the soil test is low, then this is likely the cause of the deficiency. If the soil test is not very recent and potassium levels were marginal, they could be critically low now, especially following a good crop year like we had last year and/or if high-potassium-consuming crops like hay or soybeans preceded the corn.

Incomplete starter fertilizers might be another factor. There is not much you can do at this point. Just be sure to apply sufficient potassium in the form of fertilizer or manure before the next crop.

However, a potassium deficiency can show up even with optimum or high soil test levels. This is usually because the plant is not being able to take up the potassium in the soil. Anything that limits root growth can cause this: compaction, low pH, root injury by herbicides and root-feeding insects.

Compaction is a very common cause of this problem, especially sidewall compaction resulting from wet conditions at planting. Again, there is not much we can do about this at this time, but you need to plan on minimizing the problem in the future.

For less obvious symptoms, plant analysis is an excellent tool for diagnosing these problems. Be sure to follow the sampling recommendations from the lab. A good way to determine the problem using plant analysis is to take a sample from the problem area and a similar sample from a nearby normal area and compare the results.

County committee election nominations accepted

Nomination petitions are being accepted until Aug. 3 for the Farm Service Agency County Committee.

Interested persons should contact FSA to request a nominating petition.

Butler, Beaver and Allegheny counties are served by a five member county committee. The three county region has been divided into five different Local Administrative Areas.

This year, the election will be held in LAA Number 3, which includes the following Butler County townships: Jackson, Forward, Penn, Jefferson, Winfield, Cranberry, Adams, Middlesex, Clinton and Buffalo.

Elected county committee members serve a three-year term. Committee members are paid to attend meetings, which are held about every six weeks.

Luke Fritz is executive director of the Butler County Farm Service Agency.