Registration of \u27Manska\u27 Pubescent Intermediate Wheatgrass

\u27MANSKA\u27 pubescent intermediate wheatgrass [Thinopyrum intermedium subsp. barbulatum (Schur) Barkw. & Dewey] (Reg. no. CV-21, PI 562527) was tested as Mandan 12781 and released 16 April 1992 by the USDA-ARS in cooperation with the USDA-SCS; the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska; and the North Agricultural Experiment Station

Chlorophyll Meter as Nitrogen Management Tool in Malting Barley

Variable precipitation in many regions makes it difficult to predict yield goals and nitrogen (N) rates for malting grade barley (Hordeum vulgare L.). During years with below normal growing season precipitation, barley fertilized at the recommended rate often exhibits grain protein concentrations exceeding what is acceptable for malting. A study was conducted to evaluate the chlorophyll meter as a N management tool. Barley was grown under several N rates in the field. Chlorophyll meter readings and N additions were made at the Haun 4 to 5 growth stage, and grain yield and protein concentrations were evaluated at maturity. Chlorophyll meter readings, normalized as meter reading from treatment plot divided by that from a plot receiving a full N treatment at the Haun 4 to 5 growth stage, were correlated with grain yield (r2=0.67). Stands having normalized chlorophyll meter readings below 95% responded to N additions with yields equivalent to the fully fertilized stand and grain protein concentrations acceptable for malting. A N management strategy is proposed whereby 40 to 50% of the N calculated for the yield goal is applied at planting and a fully fertilized reference strip is included for each variety or soil type. At the Haun 4 to 5 growth stage, chlorophyll meter readings are taken in the reference strip and in the field. Normalized chlorophyll meter readings below 95% of the reference strip indicate a need for additional N fertilizer. This strategy will provide producers with additional time (up to a month) to evaluate growing season conditions before investing in additional crop inputs and will improve the likelihood that a barley crop acceptable for malting will be produced

Crop Residue In North Dakota: Measured And Simulated By The Wind Erosion Prediction System

Residue cover is very important for controlling soil erosion by water and wind. Thus, the Wind Erosion Prediction System (WEPS) includes a model for the decomposition of crop residue. It simulates the fall rate of standing residue and the decomposition of standing and flat residue as a function of temperature and moisture. It also calculates residue cover from flat residue mass. Most of the data used to develop and parameterize this model have been collected in the southern U.S. We compared WEPS‐simulated residue cover with that measured in south‐central North Dakota for 50 two‐year cropping sequences from nine crops species that were grown using no‐till management. Measured data included residue mass at the time of harvest and residue cover just after seeding the next spring. Simulated residue cover significantly (P \u3c 0.05) underestimated measured cover for 33 out of the 50 simulated cropping sequences and overestimated measured cover for five cropping sequences. Some of the differences may be explained by the fact that, for many WEPS crops, residue decomposition parameters are not based on measured field data, but on expert judgment. In addition, WEPS did not predict any stem fall for most of the crops during winter, which contradicts observations that storms flatten many residue stalks of crops such as sunflower. In addition to stem fall and residue decay by biological means, which are driven by temperature and moisture, the model needs to explicitly simulate stem fall by mechanical forces, such as wind‐ and snowstorms, which are important in northern climates. Furthermore, WEPS does not model the migration of unanchored residue caused by rain‐ or windstorms, although this does affect residue mass‐to‐cover ratios and susceptibility to erosion. This study will help improve the WEPS decomposition model and its parameterization, but more data on residue decay and stem fall are needed for different climates and crops to ensure the applicability of the model over a wide range of conditions

Spring Wheat Response to Tillage System and Nitrogen Fertilization within a Crop–Fallow System

Spring wheat (Triticum aestivum L.) production in the northern Great Plains generally utilizes conventional tillage systems. A 12-yr study evaluated the effects of tillage system [conventional-till (CT), minimum- till (MT), and no-till (NT)], N fertilizer rate (0, 22, and 45 kg N ha-1), and cultivar (Butte86 and Stoa) on spring wheat grain yields in a dryland spring wheat–fallow rotation (SW–F). Butte86 yields with CT exceeded NT yields in five out of 12 years with 0 and 22 kg N ha-1 applied, and four years with 45 kg N ha-1 applied. Stoa yields with CT exceeded NT yields in three out of 12 years with no N applied, four years with 22 kg N ha-1 applied, and only one year with 45 kg N ha-1 applied. Yields with NT exceeded those with CT in one year. Most years, yields with MT equaled those with CT. Responses to N tended to be greatest in years when spring soil NO3–N was lowest. Positive yield responses to N fertilization with CT occurred in three years with Butte86 and two years with Stoa; with MT, four years with Butte86 and two years with Stoa; and with NT, five years with Butte86 and three years with Stoa. Cultivars were not consistent in their response to tillage and N fertilization. These results indicate that farmers in the northern Great Plains can successfully produce spring wheat in a SW–F system using MT and NT systems, but yields may be slightly reduced when compared with CT systems some years

Spring Wheat Response to Tillage and Nitrogen Fertilization in Rotation with Sunflower and Winter Wheat

Spring wheat (Triticum aestivum L.) is amajor crop in the northern Great Plains that is generally grown following a 21-mo fallow period. A 12-yr study was conducted to determine the effects of tillage system [conventional-till (CT), minimum-till (MT), and no-till (NT)],N fertilizer rate (34, 67, and 101 kg N ha-1), and cultivar (Butte86 and Stoa) on spring wheat yields within a dryland spring wheat (SW)–winter wheat (WW)–sunflower (Helianthus annuus L.) (SF) rotation. Grain yield responses varied with tillage system, N fertilizer rate, cultivar, and year as indicated by significant tillage x N rate x year and N rate x cultivar x year interactions. In years with .260 mm total plant available water (TPAW) but TPAW, NT grain yields were greater than those with CT at the highest N rate, with similar trends at the medium and low N rates. When TPAW exceeded 400 mm, grain yields for CT were generally greater than for NT at the medium N rates. The greatest 12-yr average grain yield (1727 kg ha-1) was obtained with NT and application of 101 kg N ha-1. Grain yields were lowest during years when TPAW was mm, with only small responses to tillage and N treatments. Cultivars responded similarly to N fertilization in years with \u3e300 mm TPAW, with Butte86 yielding more than Stoa in 6 out of the 12 yr. Soil NO3–N levels increased in the root zone following three consecutive drought years, but had declined to initial year levels by the end of the study. These results indicate that farmers in the northern Great Plains can produce SW following SF in annual cropping systems that do not include a fallow period, particularly if NT or MT systems are used with adequate N fertilization

Registration of \u27Manska\u27 Pubescent Intermediate Wheatgrass

\u27MANSKA\u27 pubescent intermediate wheatgrass [Thinopyrum intermedium subsp. barbulatum (Schur) Barkw. & Dewey] (Reg. no. CV-21, PI 562527) was tested as Mandan 12781 and released 16 April 1992 by the USDA-ARS in cooperation with the USDA-SCS; the Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska; and the North Agricultural Experiment Station

Cell wall-degrading enzymes and aggressiveness in Stagonopspora nodorum

Stagonospora nodorum produces cell wall degrading enzymes when grown in culture media containing cell wall components. The pathogen grew as well on minimal agar plates containing cellulose, xylan and pectin as glucose, except having sparser mycelia. Four cell wall-degrading enzymes, cellulase, xylanase, pectinase and b-1,3-glucanase were coordinately induced in culture filtrates growing on xyaln and cellulose as substrates. An aggressive isolate (sn26-1) secreted more cell wall-degrading enzymes than the others. Based on isoelectric focusing profiles, six to seven xylanase isozymes were induced by cellulose and xylan. No difference was found in the high (sn26-1) and low (9074) aggressive isolates. Addition of cell wall-degrading enzyme mixtures, not high xylanase alone, to a spore suspension of a low aggressive isolate (9074) caused a limited increase in tissue necrosis. We conclude that the cell wall degrading enzymes play a role in early penetration of the host by the fungus, but they are not important elicitors for disease development