Category Archives: Fertility

2015 TN Cotton Variety Trial Results

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PB1742The 2015 TN Cotton Variety Trial Results Publication (PB1742) is now available online. This document contains detailed results from all harvested trails in the 2014 University of Tennessee Cotton Variety Testing program.  This expanded publication follows the recently published summary publication, 2016 TN Cotton Variety Guide (W285), which was released a few weeks ago. Continue reading


Keep soil compaction in mind while harvesting

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September has been warmer and drier than normal but rain is in the forecast over the next few days.  The first report of picking in TN came in late last week and we should be in full-picking-mode after this rain moves through.  Still, there is more to getting back into the field than just waiting for the bolls to dry and ground to ‘hold up’.  With the adoption of the new module-building pickers, the weight of our equipment has increased to record levels.  Continue reading


Last Effective Bloom Date: how is it calculated and what does it mean?

IMG_1876By definition, the last effective bloom date is the day in which the probability of a new flower developing into a boll and making its way into the basket declines to below 50%.  Since it is unlikely (probability less than 50%) that fruiting positions which develop after this date will contribute to yield, end-of-season insecticide termination and defoliation recommendations for our area are based upon protecting/managing  those positions which will be flowering Continue reading


Sulfur Deficiencies in Cotton

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Tyson Raper (Cotton and Small Grains Specialist) and Frank Yin (Systems Agronomist)

Figure 1: Sulfur deficiencies in the upper canopy of blooming cotton during the 2015 season.  Photo courtesy Mr. Bob Sharp.
Figure 1: Sulfur deficiencies in the upper canopy of blooming cotton during the 2015 season. Photo courtesy Mr. Bob Sharp.

Sulfur (S) deficiencies have been becoming more common in cotton fields in recent years.  This is in part due to a reduction in sulfur emissions from manufacturing plants and diesel fuels.  Nitrogen (N) and S deficiencies are commonly confused- particularly late in the season.  Although both cause chlorosis of leaf tissue, the mobile nature of N within the plant results in deficiency symptoms first appearing low in the canopy.  In contrast, S is very immobile in the plant and, as a result, S deficiency symptoms first appear in new growth near the top of the plant.  Continue reading


Cotton Progress/Heat Unit Accumulation for 2015

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A rough start for many of TN’s cotton acres has turned into a decent summer for the majority of our acreage.  This is very evident when looking at accumulated heat units noted at the West Tennessee Research and Education Center in Jackson, TN.  As you can see in the below graph, we are quite a bit ahead of the last two years on accumulated heat units.  Warm temperatures in mid/late June and timely rains have Continue reading