Introduction

The Klamath Basin has an unique environment characterized by a short growing season and cool night temperatures. Small grain varieties that perform admirably in other parts of the state are often poor yielders in the Klamath Basin. The major emphasis in small grains research at the Klamath Experiment Station has been a cooperative effort with state and regional breeding programs to identify varieties adapted to this unique region. Management parameters, such as fertilization requirements and seeding rates, have also been addressed.

Barley

Spring barley accounts for about 80 percent of cereal crops grown on over 100,000 acres in the Klamath Basin. Both feed and malting types are important in the region. Barley variety trials planted at the Klamath Experiment Station (KES) in 1995 included: entries in the Western Regional Spring Barley trial done in cooperation with western states plant breeders, and a collection of new and promising lines from the Oregon State University (OSU) barley breeding program. The trial, in cooperation with OSU, was planted at KES and at two sites in the Lower Klamath Lake area. Screening of early selections from Idaho, Montana, and Washington breeding programs was also conducted in nonreplicated trials. Barley stripe rust was detected in the Klamath Basin for the first time in 1995. Infestation was wide spread throughout the Klamath Basin but in general was not severe enough to produce large economic losses. Infestation levels at KES were fairly low and did not significantly impact grain yield.

Wheat

Spring wheat is grown on approximately 8,500 acres annually in the Klamath Basin. Soft white (SW) and hard red (HR) selections predominate; however, interest has grown recently in the hard white (HW) class. In 1995, spring wheat variety trials were conducted at the KES in cooperation with Oregon State University and Western Regional plant breeding and evaluation programs. Cold-tolerant, short-season cultivars are needed in the Klamath Basin due to a short growing season with the possibility of frost throughout the growing season. Entries evaluated in these trials included SW, HW, and HR selections. Historically, there has been little disease or insect pressure on small grains in the Klamath Basin. However, the recent introduction of the Russian wheat aphid has altered this situation. Wheat stem maggot is endemic in the area and generally causes only slight damage at the KES. Under mild winter and warm spring conditions in 1992 and 1993, significant damage to cereal crops was experienced, with up to 50 percent of the tillers affected at KES and with serious crop losses in several commercial fields in the Lower Klamath Lake area.

Oats

Oats have been a major crop in the Klamath Basin in the past. Although local oat acreage has declined to about 5,000 acres in Klamath County, it remains an important commodity in the area. Klamath Experiment Station has cooperated in the Uniform Northwestern States Oat Nursery since the 1970's. Over the years, several outstanding varieties have been identified and adopted by the agricultural industry. Such varieties include Cayuse, Appaloosa, Border, and Ogle. Most of these varieties are still in use today; however, there are several experimental lines that appear to have higher yield potentials than the currently grown varieties. Several high yielding lines are also more lodging resistant and have higher test weights than current industry standards. The Uniform Northwestern States Oat Nursery is planted at KES each year to identify promising new oat lines for release by public and private breeding programs.

Companion Cropping

The Klamath Basin has a short growing season with frequent frosts throughout the summer, which limits cropping options in the area to small grains, alfalfa, potatoes, sugar beets, and pasture. Much of the acreage planted to small grains is on soils which are not suitable for potatoes or alfalfa and are maintained in a continuous small grain rotation. Due to greater susceptibility of spring wheat to frost damage, and lower oat yields and price, barley is planted on over 80 percent of the acreage devoted to small grains. Under continuous cropping, diseases and pests such as wheat stem maggot, common root rot, and barley root knot nematode have become serious problems in some areas. Wind erosion is also a problem on some soils.

Much of the cropland in the lower Klamath Basin is reclaimed lake bottom. Some of these soils have very poor structure and poor aggregate strength. The inclusion of legumes and forage grasses in a rotation has been shown to improve soil structure, soil aggregate strength, and other measures of soil health. Interseeding of legumes into small grains has increased grain yield in some locations. Increased yield has been attributed to nitrogen transfer from the legume, weed suppression, and improved soil conditions. The effects of legume interseeding on the subsequent year's crop is attributable to residual nitrogen transfer from decaying plant material and improved soil conditions. It seems that indeterminate legumes with lower seed yield potentials are more beneficial to associated cereals in terms of nitrogen transfer in the current season and as residual nitrogen for subsequent crops.

The production of a second grain crop by interseeding is impossible in the Klamath Basin due to an extremely short growing season; however, it is possible to prolong the growing season past grain harvest date by interseeding a forage species for either hay or pasture. Interseeding a forage legume would enhance nitrogen transfer to the associated cereal and maximize residual nitrogen for the following crop.