Cotton Links


Crucial Decisions
Producers Must Weigh Energy Costs Against Crop’s Water Needs

By Amanda Huber
Southeast Editor

Although there were a few more rain events this year than last, it appears that many producers across the Southeast will again be hoping for late-season rains to make a respectable yield of their cotton crop.

However, this year, fuel costs that a few years ago would have seemed impossible have producers thinking twice about irrigating to supply the crop with its most essential element – water.

“We are still in a drought situation, but no one is running out of water at this point,” says Glen Ritchie, University of Georgia cotton physiologist. “It may be that growers will have to think about cutting back on irrigation because of the energy costs.”

Ivey Griner, senior agricultural specialist at the University of Georgia’s C.M. Stripling Irrigation Re-search Park, between Camilla and Newton, Ga., says an acre/inch of water for diesel, factoring in everything, is around $18 to $20.

“That may even be a little conservative since the price continues to rise,” he says. “But for an electric motor, it is around $11 dollars per acre inch.”

Electric Favored Over Diesel

Griner says electric motors are preferred, and it is likely that economics may drive producers to converting their motors to electric instead of diesel.

Ritchie agrees that producers face a real challenge to provide what the crop needs and making it pay in the end.

“Producers tend to be pretty efficient with irrigation,” he says. “If anything, they may tend to underwater a little bit, or they may wait a little long to put the water on. It really is a matter of finding a good balance.”

Ritchie says it is obvious the areas where producers planted into a little moisture, but then it turned off dry.

“We are seeing skips in fields, and some areas are really hit and miss,”he says.

Ritchie adds that skips in the field reduce yields, but they also can reduce quality.

“We have found that quality is loosely tied to plant density,” he says. “You don’t usually see quality issues until you see a field that has a lot of skips.”

Quality Dependent On Moisture

According to Ritchie, these things are dependent on plant density, which goes back to emergence and needing moisture to emerge uniformly.

But he, like many others, knows that cotton is good at compensating for a few skips.

“In the past, when we have had significant rain in August and September, the crop has recovered,” Ritchie says. “But eventually, it reaches some level or some point that it won’t matter, when the crop is drought stressed beyond measure.

“The last couple of years we have had crops that looked like they would be failures. Then, they got late rains and recovered pretty well. It makes you nervous to have to depend on that.”

Contact Amanda Huber at (352) 486-7006 or ahuber@onegrower.com.

Value Of Research

With the crop already reaching the mid-point of the season, producers will have to take what comes, hoping a pattern of rain develops soon enough. In the meantime, Ritchie and a team of researchers are pursuing studies with the goal of improving water management and efficiency. Some of those study areas are as follows:

• Relationship between cotton and water. These are studies aimed at increasing the understanding of plant water use, irrigation timing and irrigation efficiency. “Essentially, getting at precisely how much water the crop needs and when it needs it,” Ritchie says.

• Subsurface irrigation. “We’ve been getting a lot of questions from growers about it, and we decided to look into it so that we could provide the information they wanted to know,” Calvin Perry, UGA department of Biological and Agricultural Engineering and interim director of the irrigation park, says.

• Variety trials. “We are also looking closely at varieties, and, specifically, we are looking at ones that will do better when we are limited on water,” Ritchie says.

• Interaction between plant growth regulator and water management by the crop. “We are looking at relationships between plant growth regulator (PGR) applications and water,” Ritchie says. “Are we able to improve efficiency by using more or less of the PGRs?”

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