Rates and Methods of Application of Nitrogen and Phosphorus for Commercial Field Production of Head Lettuce in Southcentral Alaska

Head lettuce (Lactuca sativa L.) is one of the major agricultural crops grown in Alaska. In 1992, its wholesale value was approximately $314,000, second only to potatoes among Alaska’s commercially field grown vegetables (Brown et al., 1992). The quality of head lettuce is as important as yield, as lettuce heads that do not meet minimum size and weight standards are unmarketable. Head size and weight are strongly influenced by management practices, dictating a high level of management for successful commercial production. Among manageable cultural variables, rate of fertilizer application and the method of fertilizer placement are two of the most critical. Despite the value of the head lettuce crop to Alaska vegetable growers and the importance of fertilization as a management practice, little research has been published on rates of application and method of applying nitrogen and phosphorus to commercially grown head lettuce

Effects of Potassium Source and Secondary Nutrients on Potato Yield and Quality in Southcentral Alaska.

Calcium (Ca), magnesium (Mg), and sulfur (S) are required for the growth and development of all higher plants. They are commonly referred to as secondary nutrients because they are less often limiting to plant growth than the primary nutrients nitrogen (N), phosphorus (P), and potassium (K), although secondary nutrients are as critical for crop growth and development as the primary nutrients. There is limited information available concerning secondary nutrient requirements of potatoes grown in southcentral Alaska. Laughlin (1966) conducted studies between 1961 and 1963 comparing potassium chloride (KCl) and potassium sulfate (K2SO4) as potassium sources for Green Mountain potatoes, and determined the effects of varying rates of magnesium sulfate (MgSO4) and K2SO4 on Kennebec potatoes. Since these studies were conducted without irrigation and at production levels about one-half those obtained by top producers in the Matanuska Valley today, it was considered appropriate to expand upon the previous work using current production practices. Potassium was supplied as KCl and K2 SO4 to explore the need for additional S under local potato production conditions and to determine the effects of the chloride (Cl) and sulfate (SO4) anions on production and quality of potato tubers. In addition, Mg and Ca were added to determine whether the background levels of these nutrients were adequate for optimum production

No-till Forage Establishment in Alaska

We assessed the effectiveness of no-till forage establishment at six Alaska locations: Anchor Point, Sterling, Point MacKenzie, Palmer, Delta Junction, and Fairbanks. Directly seeding grass into established grass stands generally did not improve forage yields or quality. Seeding rate had little effect on establishment of newly seeded forages in no-till. Grass yields were depressed when companion crop yields were high, and they typically did not recover in subsequent years. Red clover established well, producing high yields of good quality forage under no-till at Point MacKenzie, but established poorly at Anchor Point and Delta Junction. These results indicated that no-till seeding of most forage crops into declining grass stands is not likely to be successful in Alaska with current available technology

AFES Circular 80

To remain competitive, commercial vegetable producers require updated information on the performance of new vegetable varieties under the soil and climatic conditions of southcentral Alaska. Variety trials provide the opportunity to evaluate potentially adapted plant material. Although many varieties are developed in environments considerably different from that of southcentral Alaska, some may prove to be useful to commercial growers in Alaska. The information on new varieties must be collected over several growing seasons to provide sufficient confidence in the observed performance. Additionally, each year of the performance trials, new varieties are grown with traditional or standard varieties which are used to compare the quality of the new varieties. Commercial production of new varieties should be considered after several years of variety trial work with initial plantings on a small production scale.Introduction -- Overview -- Seed Source List -- Weather Summary -- Broccoli -- Cabbage -- Carrots -- Lettuce -- Potatoe

Irrigated alfalfa in southern Idaho

1 sheet; 28 cm

Malting barley

3 p.; 28 cm

Irrigated spring wheat, southern Idaho

3 p.; 28 cm

Research Progress Report, No. 21

Husby and Krieg (1987) reported that average Alaskan forages were deficient in energy for beef cattle and protein levels were marginal for growing animals. Both the energy and protein of Alaskan forages are low for lactating dairy cows (Brundage and Herlugson, 1984). Energy and protein concentrates are imported to Alaska from elsewhere in the U.S. High transportation costs make these imported feedstuffs expensive for Alaskan livestock producers. Brassica crops, such as rape (Brassica riapus L.) and turnips (B. rapa L.) have been widely studied as forage crops because they have the potential to produce high yields of excellent quality forage. Jung et al. (1986) demonstrated this potential when they reported that Brassica spp. yielded 4-7 tons DM/A and the forage was highly digestible (80-90% in vitro dry matter digestibility). Crude protein was relatively low for turnip roots (8-12%), but top growth was high (up to 27%). Lambert et al. (1987) found that the quality of Brassica spp. was too high for optimum performance of growing lambs. They reported that it was necessary to include some coarse feed, such as grass hay, to increase the fiber content in the diets of these animals. The potential of Brassica crops has been investigated in Alaska (Mitchell and Krieg, 1985; Panciera et al., 1990). The yield and quality of these crops in Alaska were similar to the levels observed in the Lower 48 states. Basic agronomic information is needed in order to develop management recommendations for Brassicas in Alaska. Research is underway to define the nitrogen and phosphorus fertilizer requirements (Panciera etal., 1990). This report summarizes the results of a two year study concerning the effects of seeding rates on dry matter yields of two Brassica hybrids

Research Progress Report, No. 39

Early perennial forage performance research was done in Alaska at a number of locations near the turn of the twentieth century, including Copper Center, Kenai, Sitka, and Rampart (Georgeson, 1899; Georgeson, 1901-1904). Resulting yields for native and introduced cool season perennial grasses were fairly positive, however, all sites were rain fed and some seedings were unsuccessful due to dry conditions. Timothy (Phleum pratense L.), smooth bromegrass (Bromus inermis L.), perennial ryegrass (Lolium perenne L.), and orchard grass (Dactyls glomerata L.) dominated the early test plantings

Research Progress Report, No. 15

Nutrient uptake and physiological development in potato plants have been investigated in major potato growing regions, but comparable studies have not been conducted in high latitude areas such as the potato producing sections of southcentral Alaska. Knowledge of plant development and nutrient partitioning among various plant parts is important both in terms of general understanding of the growth habits of potatoes in a unique environment and for improved management of field production of this crop. Nutrient response data provide a basis for fertilizer application recommendations. A field study designed to define potato plant development under various fertility regimes was initiated in 1989. Potato plants were intensively sampled through the growing season to determine the effects of nutrient availability on growth processes, to measure growth rates of various plant parts, and to determine the fate of nutrients absorbed by the plant. The results of the effects of soil fertility on potato plant development are presented in this report. Nutrient uptake and partitioning data will be compiled in later publications when laboratory analyses are complete