Thinking Globally Acting Locally

It's not quite Shangri-La, but it's close. With majestic Mt. Hood towering over the rolling hills covered with apple, pear and cherry orchards, the Hood River Valley is one of Oregon's most beautiful places and one of the state's most productive agricultural areas.

Valley orchardists produce some of the best apples, pears and cherries in the world. Last year, valley production of these crops brought in more than $58 million. Growers rely on the help of researchers at the Oregon State University Mid-Columbia Agricultural Research and Extension Center (MCAREC) to keep up with the competition.

Located in Hood River, the center is one of 13 OSU facilities carrying on research and extension activities throughout the state. The six researchers on the MCAREC staff serve commercial fruit growers and processors in the region with a broad range of research and extension education activities.

"The center has been a real leader in horticultural practices and integrated management of fruit production," said OSU's Mike Burke, associate dean of the College of Agricultural Sciences. "There has been a lot of focus there on reducing the environmental impacts of agriculture."

In recent years growers and MCAREC researchers have been working toward improving production methods by taking a holistic management approach to all phases of growing commercial tree fruits.

The name given to this new management strategy is Integrated Fruit Production, or IFP. It is the latest in a long list of research initiatives led by MCAREC research staff.

Center superintendent Clark Seavert, who has been at the station for 12 years, said it wasn't a long time ago that most of the attention was devoted to developing ways to increase tree fruit yields.

Jim Phipps (left), Hood River Supply, and Clark Seavert, MCAREC superintendent, look at a soil map on a computer monitor that is part of a computerized fertilizer spreader. Photo: Lynn Ketchum

But that began to change about six years ago when Helmut Riedl, an entomologist at the station, visited southern Italy. While there, he became very impressed with the way the Italians practiced tree fruit growing as one integrated, or holistic, operation.

After returning to Hood River, an enthusiastic Riedl described what he saw in Italy to some local growers. Soon after, the concept of holistic management of tree fruit production began to spread through the valley.

"The move towards holistic management, or IFP, was really a grass roots effort by the local growers who pushed this," Seavert said. Later, most of the fruit packers and growers who at first were doubtful eventually got behind the program.

"Not everyone jumped on the bandwagon at first," he said. "There was a lot of skepticism from other growers and packers the first two years."

Under an integrated management strategy, all aspects of growing tree fruits are seen as relating to each other. These practices include everything from orchard floor management to control of pests and diseases, to fertilization, pruning and thinning practices. Last but not least, how fruit is cared for after it has been picked fits into the picture, too.

A researcher field-tests a new kind of sprayer called a tower sprayer in an experimental orchard at MCAREC. The facility is located on 56 acres of orchard land near Hood River. Photo: Lynn Ketchum

"When we look at production agriculture in the past, the goal has always been to produce more," said Seavert, who was raised on a North Dakota cattle and wheat ranch and holds agriculture degrees from OSU and the University of Idaho. "That was okay at first, but now that we're all part of the global picture we can't fool ourselves anymore," he said. "It's marketing, it's lower inputs, it's the environmental aspects of growing fruit-that's where we've been shifting."

MCAREC has been in the forefront when it comes to finding ways to use fewer pesticides to control insects, disease and weeds. This a top priority, Seavert said.

One example of this trend away from pesticides is the use of predator insects that feed on their destructive cousins. Another example is the way growers are changing their thinking about how much weed control is needed within tree rows.

Any freshman in agriculture can tell you that weeds in an orchard are a problem because they compete with trees for water. In the past, the practice was to spray enough weed control chemicals within the rows so that 35 percent to 40 percent of the orchard floor was weed free.

"We're trying to get that down to 20 percent or 25 percent," Seavert said, "and determine how the reduced weed control affects irrigation, disease and insect management."

MCAREC already has mature pear and cherry demonstration orchards established to evaluate different IFP management practices.

Gene Mielke, a horticulturist at the center, helps growers figure how to reduce costs and improve production by finding ways to make fruit trees more efficient. Mielke's research emphasis is on fertilization, irrigation and tree training.

"We want to use as little fertilizer as we can in orchards," Mielke said. Not only does this lessen the amount of unneeded nitrogen in the soil and save growers money, it also reduces the amount of unwanted growth in trees.

"If we overuse fertilizer we get too much growth in the tree and then it becomes a bigger factory for bugs. Most insects like nice lush, tender growth," he said.

Overfertilization also encourages shoot growth, which lessens the number of fruit buds for next year's crop and produces shading within the tree. Lack of sunlight inside the tree can retard the development of fruit buds lower in the tree.

Horticulturist Roberto Nunez-Elisea is studying pruning and training techniques for cherry tree varieties. He left a research position at the University of Florida to join the MCAREC staff last summer.

"Cherry growers in the Hood River area are interested in new varieties that will bear larger fruit for fresh markets," said Nunez-Elisea. "We will evaluate new cherry tree varieties at the center in the coming year and conduct irrigation management and thinning studies to find ways to increase fruit size."

Researchers at MCAREC are working toward more efficient orchard disease and insect management by experimenting with a relatively new piece of equipment called a tower sprayer.

They hope that the sprayer, which consists of several fans positioned on a vertical bar, will prove to be more effective than conventional sprayers in applying chemicals in traditional orchards while virtually eliminating spray drift.

MCAREC researchers are working with a new orchard sprayer called the tower sprayer. It is designed to apply chemicals to orchard trees more efficiently and eliminate spray drift. Photo: Lynn Ketchum

When to spray a crop is always an important question. Researchers at the center are developing computerized spray models that tell growers when it's best to spray. These models, which cut down on the amount of chemicals applied, are essentially computer programs that correlate weather information with pest levels so that growers will know when insects and fungi have reached threatening levels and need attention.

One of the problems growers encounter because of overuse of pesticides is that more than a few pests have built up resistances to the chemicals, according to Riedl. Also, broad-spectrum pesticides such as organophosphates attack not only a wide range of destructive insects, but friendly insects as well. What's more, excess fertilizer use has led to nitrogen leaching into groundwater in some cases.

"All of these problems can be traced to overuse or inappropriate use of something," Riedl said.

In addition to pest insect problems, growers must also contend with plant diseases that are a constant threat to tree fruit crops.

Bob Spotts is the MCAREC team member charged with finding safer ways to fight diseases with earth-friendly technology. One of his research goals is to find out how to better control diseases in tree fruits using fewer chemicals.

In the past, studies have shown that farmers often apply more fungicides than are necessary to ensure that crops worth hundreds of thousands of dollars won't be destroyed by disease.

According to Spotts, there are two tools orchardists can use to cut down on the amount and frequency of sprays: scouting and computer models.

Scouting is a very time-consuming and thus costly farm practice. It involves walking back and forth in the orchard, checking every tree from top to bottom for the first telltale signs of disease. When diseases such as powdery mildew are first spotted, chemical action can be taken.

Another method makes use of strategically placed weather stations throughout the Hood River area that automatically feed weather and other information, such as leaf moisture, into a computer program that electronically analyzes it.

When conditions reach threshold levels, that is, when disease risk is high, orchard managers are notified through their computers that disease pressure is at a point where protective treatments should be applied.

MCAREC has developed its own model to fight pear scab, a disease that renders pears unmarketable. The model is fed mainly two kinds of information, the temperature and the length of time that tree leaves are wet. The information is sent to the center's main computer every 15 minutes from weather stations throughout the Hood River Valley.

Bob Spotts, MCAREC researcher, is studying the use of weather stations to predict the risk of disease outbreaks in orchards. The weather stations automatically feed weather data and other information, such as leaf moisture, into a computer program that analyzes it. Photo: Lynn Ketchum

Eventually, model-driven data will be available on the Internet, Spotts said.

In some crops, he added, computer models can reduce the number of sprays applied as much as 50 to 75 percent, with no lessening of fruit quality.

"One problem growers face with the newer, safer fungicides," Spotts said, "is that it's easier for diseases to build up a resistance to them." For that reason, growers are advised to put variety into their fungicide program by using different compounds with different modes of action. That way, as one OSU pathologist once put it, "we're always keeping disease off guard."

Managing orchards to produce the best quality fruit possible at an economic cost is the highest priority for growers, but it's only half the battle. Producers and fruit packers also have to be concerned about maintaining product quality after harvest when the fruit is moved into storage. That's where MCAREC researcher Paul Chen enters the picture.

Chen's research emphasis is in studying ways to improve fruit handling and storage. He works with growers and operators of the fruit packing industry in the Hood River area.

Chen is currently involved in a study looking at the various means of prolonging the life of winter pears after they are picked.

MCAREC researcher Paul Chen is working with a process called Low Oxygen Storage (LOS) to prevent spoilage in stored pears. Photo: Lynn Ketchum

In the past, winter pears, which include the Anjou, Bosc and Comice varieties, were subjected to heavy doses of inert nitrogen to prevent them from spoiling while in storage. Fruit packers used the technique called Controlled Atmosphere storage, or simply CA, where nitrogen replaced most of the oxygen, which is the main culprit in fruit spoilage.

Later, several antioxidants that kept the pears from succumbing to physiological diseases such as superficial scald were introduced. The antioxidants consisted of synthetic agricultural compounds such as ethoxyquin and diphenylamine. Pears are treated with the antioxidants by dipping or spraying. Packing tissue impregnated with the antioxidants is also used.

Now, with the drive to lessen the use of chemicals in agriculture, researchers are looking at ways to either eliminate spoilage-deterring chemicals altogether or at least lessen their use.

Chen and others have recently found that even higher doses of nitrogen applied in storage rooms, a process called Low Oxygen Storage (LOS), is effective in protecting fruit from spoilage. "Low" is a good term to describe the method since all but 0.8 percent of the oxygen in storage rooms is replaced by nitrogen.

LOS is only effective in controlling spoilage in stored fruits for several months. From there, the antioxidant compounds are brought in to take over.

Seavert noted that research on fruit storage by MCAREC scientists has been very successful as cold storage operators in Oregon and the rest of the world have adopted MCAREC temperature and atmosphere recommendations for pears.

He added that the top priorities for MCAREC staff in every project are to ensure the research remains relevant to tree fruit industry needs, and to always anticipate new trends and directions likely to affect the industry in the future.

"It's important for all of us at the center to think a few steps ahead," Seavert said. Hood River Valley growers are glad that they do.

If you'd like to learn more about the work that the Mid-Columbia Agricultural Research and Extension Center is doing, log onto the center's website.