May 1997
Resources used in preparing this summary include; 1) interviews and survey responses from growers, researchers, pest control advisors, 2) pesticide use proposals for the Tule Lake and Lower Klamath NWRs, 3) Klamath Experiment Station bulletins, and 4) Service and Reclamation files and interviews. This section describes agricultural practices on the refuges in a general sense; a technical workbook detailing current and proposed pest management on the leased lands is included in later sections of this Plan.
The Lower Klamath and Tule Lake NWRs lie within the Intermountain Region, characterized by hot summers and cool winters. Elevation ranges between 4,100 and 4,300 feet. The growing season is short, usually lasting from May to September. Frosts may occur each month of the year. Annual precipitation averages about 12 inches, but there is considerable variation from year to year.
Crops currently grown on the refuges include potatoes, sugarbeets, alfalfa, onions, and small grains including barley, oats, and wheat. Only grain crops are grown on the Lower Klamath refuge; no row crops are produced. Grain crops are grown on Tule Lake NWR in rotation with row crops.
Soils on the refuges are some of the best in the world. These muck soils are high in organic matter, formed when the land was covered by water. Much of this irreplaceable soil is currently subject to wind (and water) erosion, calling for farming techniques that prevent this loss.
Potatoes in Klamath Basin are planted on about 8,500 acres in Klamath County, Oregon and 10,000 acres in northern Modoc and Siskiyou counties, California. There are generally three markets for Klamath Basin potatoes: seed (1,500 acres), chip processing (2,500 acres), and fresh market sales (14,500 acres). Potatoes are an important cash crop in the Klamath Basin.
About 3,200 acres of potatoes, representing a wide number of varieties, are planted on the Tule Lake leased lands annually. Most of leased-land potatoes, as in the rest of the Basin, are grown for the fresh market. No seed potatoes are grown on the refuge. Fresh market crops are processed in about 20 locally owned packing sheds and sold primarily in California population centers. Growing practices differ somewhat depending on the market.
The short growing season, punctuated with mid-season frosts was a major obstacle to potato production until introduction of solid-set sprinkler irrigation, which can protect against short-duration frosts down to 25 degrees F. Although the short growing season may limit yields, particularly for late-maturing varieties, the leased lands have two distinct advantages over most other potato production areas in the U.S. First is the exceptional soil quality. Second is the absence of two difficult pests, the Colorado potato beetle and the disease, late blight.
Currently, eight insect pest species exist on leased lands of which green peach aphids, loopers, cutworms, potato aphids, grasshoppers, and yellowstriped armyworms are considered priority pests by growers. Root-knot nematode and lesion nematode were also considered priority pests. Twenty diseases are currently associated with potatoes on the refuge. Priority diseases include early blight, white mold, leaf roll virus, potato virus Y, pink rot soft rot, Rhizoctonia silver scurf, blackleg, and Verticillium wilt. Late blight does not exist in the area yet, but is likely to in the future and is a disease of great concern to growers.
Refuge potato growers use a variety of pest control measures. These include preventive practices such as proper fertility and irrigation, sanitation, starting healthy plants, crop rotations, trials with different varieties, seed treatments, and use of certified seed. Pest control practices used during the season include monitoring and treatments with insecticides, herbicides, and fungicides. Nematodes are currently managed by crop rotations and fumigants. End-of-season disease prevention practices include care in handling and storage.
Some growers have minimized the need for chemicals by the use of crop rotations, cover crops and green manures. These practices help to maintain soil fertility, tilth, drainage and water-holding capacity, thus promoting a healthy crop better able to withstand pests.
Roughly 600 acres of alfalfa are currently grown on Tule Lake leased lands. Winter dormant varieties are grown to insure protection of the plants from cold-weather injury. Growers usually obtain 3 cuttings per year between May and September. Total seasonal production in the TID averages 4 to 6 tons per acre and stand life is long; 6 to 8 years is common. Forage quality is high, attributable to the short growing season and cool night temperatures.
There are three distinct markets for Klamath Basin (including refuge grown) alfalfa: export or "press" dairy hay, dairy hay for the domestic market (especially for California) and cattle feed hay. Production practices may differ significantly, depending on the market demand.
Pests that may attack alfalfa on leased lands include seven insects, six diseases and vertebrate pests (primarily voles or mice). Alfalfa weevils, aphids, and variegated cutworms are priority insect pests.
Currently a variety of pest controls are used including monitoring, timing of spring cuttings, proper irrigation and fertility management, early cutting and pesticide applications. Resistant varieties prevent most diseases from being severe. Fungicides are not used. Nematode-resistant varieties (now being developed) are identified by growers as a future method for limiting nematode losses.
Onions are grown on roughly 200 acres of the Tule Lake NWR, and are rotated with grains and other row crops. Total production of onions in Klamath Basin is roughly 3,000 acres. Both dehydrating and fresh market onions are grown, while dehydrating onions are grown on contract. Onions are planted on less acreage than other refuge-grown row crops, but their net return per acre is high.
Onions have three important insect pests, two of which, the onion maggot and thrips are of greatest concern to growers. Most onion fields are treated with insecticides every year to control onion maggots and thrips. Priority diseases include downy mildew, damping-off, white rot and neck rot. White rot is a limiting factor in onion production, and soils infested with this fungus are avoided for growing onions. White rot is slowly spreading in the leased lands and also around Klamath Basin. Onions do not compete well with weeds, so tillage and herbicide applications are currently used to control weeds.
Sugarbeet production in the Klamath Basin has expanded from approximately 1,000 acres in 1990 to 11,000 acres in 1995. Production on Tule Lake NWR is roughly 600 acres. Modest beet yields (18 to 23 tons/acre) are offset by the high sugar content of Basin-grown beets. The high quality of these sugarbeets combined with the relative lack of pests that plague other sugarbeet growing areas explain the rapid expansion of this crop in recent years. All beets are grown on contract.
Local production costs for sugarbeets have been kept to a minimum because control measures have not been necessary for pests such as curley top virus, yellow viruses, sugarbeet cyst nematodes, and Rhizomania.
Like all the other crops grown in this very changeable climate, planting sugarbeets is something of a roll of the dice. On average, 10 to 20 percent of the acreage requires replanting due to frost damage and injury from blowing soils. If the sugarbeets survive the early challenges, then weed and flea beetle control are the second and third most important factors determining yield and profitability. Both weeds and flea beetles are controlled with chemical treatments.
Sugarbeet growers use a variety of preventive measures against pests including resistant varieties, seed treatments for diseases, crop rotations, and sanitation (by keeping equipment clean) to prevent introduction of Rhizomania and cyst nematodes. Disease control treatments are rarely needed. Elemental sulfur is sometimes used as a fungicide for mildew control.
Small grains are planted on roughly 100,000 acres in Klamath Basin. Barley is the predominant crop, making up roughly 80 percent of small grain acreage, with spring wheat and oats a distant second and third, respectively. A similar situation exists on the leased lands, where 10,200 acres of barley, 3,400 acres of oats, and 1,700 acres of wheat are grown. Much of this acreage is grown on the Lower Klamath Refuge. Grains are grown in the Tule Lake Refuge in rotation with row crops. On Lower Klamath, grains are planted every year after a period of flooding in the winter. Each spring, the stubble from the previous year is burned prior to working the soil in preparation for planting.
Aside from the climate, the main constraints to grain production are the Russian wheat aphid, the wheat stem maggot, common root rot (a fungal disease) and the barley root-knot nematode. Most other diseases of small grains are unimportant due to the use of resistant varieties and certified seed. However a new race of barley strip rust was found in the Basin in 1995. To date its economic impact has been relatively minor.
Small grain growers use a variety of pest control measures. These include preventive practices such as crop rotations, varietal rotation, seed treatment, seed testing, removing pest host plants, and planting resistant varieties. Growers monitor and use pesticides to control damaging pests during the production season. Tillage is used for weed control, along with herbicides.
Numerous weed species have been documented on the refuges. Growers indicate there are 12 priority weeds on refuge lands: five-hook bassia, netseed lambsquarter, pigweed, redroot pigweed, wild mustard, kochia, common purslane, hairy nightshade, wild oats, Canada thistle, perennial pepperweed, and black nightshade. These weeds were listed as affecting all crops grown on leased land to a greater or lesser degree, with five-hook bassia being the greatest pest species.
Pesticide use proposals (PUPs) indicate that several additional weeds may reach economically damaging levels, depending on the field history and crop grown. These include poison hemlock, purple loosestrife, western waterhemlock, quackgrass, field bindweed, and Russian thistle.
Treatments to control weeds include aerial and ground applications of herbicides, cultivation, crop rotation, and biological controls. Banded herbicide applications combined with between-row cultivation are the primary methods of weed control for onions, sugarbeets and potatoes. Spring tillage prior to seed-bed preparation controls some weeds. Post-plant applications of herbicides are typically used for broad-leaved and grass weed control. Minimal hand-hoeing occurs.
Vertebrate pests are more or less of a problem, depending both on the animal and the crop involved. For instance, mice and voles are of particular concern on alfalfa, potatoes, and sugarbeets, but less so for onions and grains. Blackbirds, on the other hand, are an economic pest for grain crops, but are of little concern to growers of other crops. Mice (voles), gophers, blackbirds, coyotes, squirrels, and marmots were listed as vertebrate pest species by some growers.
The montane vole is known by leased-land farmers to be a pest of economic significance. It has done considerable damage to potato crops, and lesser damage to alfalfa and grains. The economic damage to potatoes is significant as all potatoes with bite marks are considered "culls". Damage to number 1 potatoes varies annually from field to field and from year to year but has reached 30 percent (Brian O'Conner, leased-land grower, personal communication, September 26, 1996). In 1995, 30 percent damage amounted to $630 per acre.
Return to the IPM Plan Table of Contents or continue on to C. Current Economic Information for Leased Lands