Weekly in-season Updates
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INFORMATION |
May 2, 2005 Talkin’ Cotton – May 2, 2005
Primary decisions at planting involve variety and plant population. This week we will address plant population. Back in the days of “cheap” seed, population was not much of an issue, but since technology is delivered on the seed, seed prices have increased dramatically. Seed sizes vary, from about 4,000 to near 6,000 seed per pound. Modern planters are calibrated by seed drop rate instead of number of pounds of seed planted per acre. Irrigated seeding rates are usually about 40,000 to 55,000 seed dropped per acre and dryland rates usually run from about 25,000 to 50,000 seed per acre. I have recently had questions on the proper seeding rate, and cost per acre of the technology. Our research on dryland has indicated that about 32,000 seed per acre provides a yield that is as high as 50,000 seed per acre. We have some excellent dryland farmers that plant 25,000 to 30,000 seed per acre and have good results. High rainfall during late July and August will favor the higher populations, and low rainfall during this period will favor the lowest populations. Shane Osborne worked up some numbers based on 2005 seed costs and if you are planting 40,000 seed or more of a Roundup Ready variety, you can lower your planting rate by 8,000 to 10,000 seeds per acre, and more than pay for the advantages of a stacked gene variety. In our dryland variety tests, most of the Roundup Ready varieties yield less than stacked varieties due to bollworm damage that is, in our opinion, not enough to justify spraying, but evidently results in loss of yield. By reducing planting rates, it’s like getting Bollgard protection at no extra cost, something you might want to consider this year.
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