Timely Surge of Moisture / Western Kansas Grower Craig Sloan’s Surge Valve System Boosts Watering Efficacy on Surface-Irrigated ’Flowers and Corn / By Don Lilleboe — “Mile after mile of sage-pocked rangeland testify to Mother Nature’s typical stinginess when it comes to providing rainfall for western Wallace County, Kan. Be that as it may, Craig Sloan’s sunflower crop can count on at least things in a dry year: (1) a ‘surge’ of moisture during the bud stage and (2) another ‘surge around the time of petal drop.
“Sloan, who farms along the Kansas/Colorado border near Weskan, produces most of his sunflower on ridges under surface (furrow) irrigation employing a surge valve system. Surge irrigation is a method whereby water is applied to fields in alternate, automatically timed sets, as opposed to conventional continuous flow application. A butterfly valve located in the center of two wings of gated pipe directs water to one side of center for a programmed period; then automatically switches over to water those rows on the other side for another programmed length of time. This back-and-forth process continues throughout the predetermined irrigation cycle.
“Alternating the flow of water down field rows has several advantages, according to Sloan — all of them centered around improving watering efficiency. . . .
“With a surge system, watering cycles can be tailored to a particular field’s length, slope, shape and soils. Though he has the capacity to program for irrigation sets of up to 48 hours, a typical set for Sloan would be 12 hours. That set would encompass nine hours of ‘push’ time (four and a half on each side of the valve) and three hours of ‘soak.’ During the first cycle, water would likely flow for 40 minutes on each side; during the second, 55 minutes; and during the third cycle, for 75 minutes per side. . . .
“While water is flowing down rows on one side of the valve, the soil surface in watered row portions on the other side becomes somewhat sealed. So later, when water is again flowing down those furrows, it flows faster over the already-watered portions, arrives more quickly at where it’s still dry — and then slows from that point onward.
“By applying water more consistently across the field, Sloan simultaneously achieves a substantial reduction in the amount of tail water coming off the bottom of the field. He says the surge system also allows water to soak more effectively into the sides of the furrows — a particularly important consideration for Sloan, since he waters only every other furrow.”
’Flowers Hold Their Own — “The outcome of this year’s U.S. sunflower growing season didn’t quite match its exceptional 1994 counterpart. But in terms of both yield and quality, the ’95 crop’s performance still graded out at above average.
“USDA’s preliminary estimate of this year’s U.S. sunflower crop. . . placed total production (oil and confection combined) at nearly 4.6 million tons, down slightly more than five percent from the 1994 production level. Though harvested acreage was slightly higher in ’95, the difference came in the average projected yield: 1,313 pounds per acre this year versus 1,410 in 1994 . . . .
“Wet weather throughout much of the northern area was the single most severe production challenge, and it contributed to weed problems and the outbreak of the disease Phomopsis. Insects were almost nonexistent across the entire sunflower belt, from Texas up through Canada.
“Preliminary figures from the National Sunflower Association’s annual crop quality survey of oil-type sunflower suggest an average test weight of 30.14 pounds per bushel in 1995, with a range extending from 35 down to 23 pounds. . . . Oil content of this year’s 1,200 samples (drawn mainly from the Northern Plains region) averaged 43.6 percent, down from 1994’s 44.8-percent average.”
Global Oilseeds ’95 / By Larry Kleingartner — “In what has been an excellent year, sunflower came to represent about 10 percent of world oilseed production in 1995. The biggest news came from the republics of the former Soviet Union (FSU), where a 23-percent increase was recorded. That total — 5.8-5.9 million metric tons — resulted from higher planted acreage (13.6 million this year compared to 12.4 million acres in 1994) and better yields (an average of 928 pounds per acre this year, compared to 794 in 1994. Oilseed production in the FSU has been placed on a world market structure, and private farmers have responded to market forces.
“Argentina’s 1995 sunflower crop was exceptionally large. At 5.6 million metric tons, it represents a 30-percent increase over 1994. The growth was due to expanded acreage and excellent yields (averaging over 1,800 pounds per acre). . . .
“The only country with a serious sunflower production shortfall in 1995 was Spain. Production there was slashed by more than half due to drought (less acreage, poor yields).
“As reported elsewhere in this issue of The Sunflower, the U.S. crop is down about five percent from 1994. At slightly over 1,300 pounds per acre, average U.S. sunflower yield is off about 100 pounds from 1994’s excellent level.”
Phomopsis Rears Its Head in 1995 / By Tom Gulya — “A wet summer helped Phomopsis develop an unwelcome and apparently unprecedented presence in many Northern Plains sunflower fields during 1995.
“Teams of plant pathologists covered nearly 3,000 miles during a mid-September survey of Minnesota and Dakota sunflower areas, investigating the incidence and severity of several diseases. They found Phomopsis . . . in eight out of 10 fields surveyed (though not always in economic proportions — and on one out of every six plants examined. That’s a higher ratio than rust, downy mildew, Sclerotinia wilt and head rot combined in this years survey — and much higher than the incidence of Phomopsis found during a 1991 survey.
“Northwestern Minnesota — particularly the Crookston/ Thief River Falls area — appeared to be impacted most severely by Phomopsis in 1995. However, no county in the survey region (which encompassed much of northwestern Minnesota, the eastern half of North Dakota and the northeastern quadrant of South Dakota) was immune to the problem this year.”