The high value of cotton has driven up the cost of seed and the accompanying technology. Last year the cost of a bag of 250,000 seed-count cotton cost more than $300 a bag. So the natural thing to do is to try and stretch that $300 plus bag of seed over as many acres as possible.

“With our growers, we try to plant for 2-4 plants per foot of row, hoping to average three plants per foot. If the grower can average three plants per foot of row, typically you see one vegetative branch on the bottom of the plant, and it will have a few bolls on it.

“Most of the bolls are produced on fruiting branches, which develop every three days up the main stem and every six days out each fruiting branch. Over the course of a year there are lots of places on the plants to put on bolls and compensate for any kind of stress the plant faces early in the growing season,” Jones says.

Under a normal situation, all the bolls and lint produced on cotton are produced on fruiting branches. The ‘money bolls’ are produced closest to the main stem in the first position fruiting branch. When low plant populations occur, cotton plants under good growing conditions will shift those money bolls higher on the main stem and further out on the fruiting branches.

In low plant populations, growers are likely to see a large increase in number of vegetative branches and a high percentage of bolls under these conditions will come from these vegetative branches.

Like the main stem, vegetative branches take a long time to develop, so there will be late maturity when this occurs, Jones says.

Exactly how widely spaced cotton plants can be and still produce a high yielding crop depends on many environmental factors and on variety.

In his testing program over more than a decade at Clemson University’s Pee Dee Agricultural Research and Extension Center, Jones says cotton plants continue to amaze with their ability to compensate for a skippy stand.

In one series of tests, he grew two Deltapine varieties (50 and 90) back in the 1990s and hand thinned plants to produce side by side comparisons of cotton at 0.6 plants per foot of row in a 38-inch row, compared to 3.7 plants per foot of row.

What he found was no statistical difference in yield between the two plant populations.

Under higher plant population there was peak bloom earlier in the year — approximately three weeks earlier. There also will be significantly delayed boll set — usually about two weeks.

The delays in plant development carried over to about a 2-3 week delay in harvest, which could be significant in some years, Jones notes.