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Articles 1 - 9 of 9
Full-Text Articles in Plant Pathology
Direct Polymerase Chain Reaction-Based Detection Of Cercospora Beticola In Field Soils, R. T. Lartey, T.C. Caesar-Tonthat, Andrew W. Lenssen, J. Eckhoff, S. L. Hanson, R. G. Evans
Direct Polymerase Chain Reaction-Based Detection Of Cercospora Beticola In Field Soils, R. T. Lartey, T.C. Caesar-Tonthat, Andrew W. Lenssen, J. Eckhoff, S. L. Hanson, R. G. Evans
Andrew W. Lenssen
Cercospora beticola, the causal agent of Cercospora leaf spot of sugar beet, survives as pseudostromata in infected sugar beet residues in the soil. Under optimal conditions, overwintering propagules germinate and produce conidia that are dispersed as primary inoculum to initiate infection in sugar beet. We developed a polymerase chain reaction (PCR) technique for rapid detection of C. beticola in field soils. Total DNA was first isolated from soil amended with C. beticola culture using the PowerSoil DNA Kit. The purified DNA was subjected to PCR in Extract-N-Amp PCR mix with CBACTIN primers over 35 cycles. The amplified products were resolved …
Management Strategies To Improve Yield And Nitrogen Use Of Spring Wheat And Field Pea In The Semi-Arid Northern Great Plains Usa, Andrew W. Lenssen, Brett Allen, Upendra Sainju, Thecan Caesar, Robert Lartey, Robert Evans
Management Strategies To Improve Yield And Nitrogen Use Of Spring Wheat And Field Pea In The Semi-Arid Northern Great Plains Usa, Andrew W. Lenssen, Brett Allen, Upendra Sainju, Thecan Caesar, Robert Lartey, Robert Evans
Andrew W. Lenssen
Available water and N fertility are primary constraints to crop production in the northern Great Plains of the USA. A field trial was initiated in 2004 to compare four crop rotations in a complete factorial of two tillage and two management systems. Rotations were continuous spring wheat (SW), pea-SW, barley hay-pea-SW, and barley hay-corn-pea-SW. Tillage systems were no till and field cultivator tillage, while management systems were conventional and ecological. Conventional management included broadcast nitrogen fertilizer, standard seeding rates, and short stubble height. Ecological management practices varied by crop, and included banded nitrogen fertilizer for cereals, increased seeding rate, delayed …
Incorporating Sheep Into Dryland Grain Production Systems Iii. Impact On Changes In Soil Bulk Density And Soil Nutrient Profiles, P. G. Hatfield, H. B. Goosey, T. M. Spezzano, Sue L. Blodgett, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Incorporating Sheep Into Dryland Grain Production Systems Iii. Impact On Changes In Soil Bulk Density And Soil Nutrient Profiles, P. G. Hatfield, H. B. Goosey, T. M. Spezzano, Sue L. Blodgett, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Andrew W. Lenssen
Changes in soil bulk density and soil nutrient profiles are a major concern of dryland grain producers considering grazing sheep on cereal stubble fields. Our objective was to compare burned, grazed, tilled, trampled and clipped wheat stubble fields on changes in soil bulk density and soil nutrient profiles. Treatments were evaluated in a series of three experiments using a randomized complete block design and four replications at each site. Contrast statements were used to make pre-planned comparisons among treatments. For Experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined (Fall/Spr) grazed, and an untreated control. …
Incorporating Sheep Into Dryland Grain Production Systems Ii. Impact On Changes In Biomass And Weed Density, P. G. Hatfield, Andrew W. Lenssen, T. M. Spezzano, Sue L. Blodgett, H. B. Goosey, R. W. Kott, C. B. Marlow
Incorporating Sheep Into Dryland Grain Production Systems Ii. Impact On Changes In Biomass And Weed Density, P. G. Hatfield, Andrew W. Lenssen, T. M. Spezzano, Sue L. Blodgett, H. B. Goosey, R. W. Kott, C. B. Marlow
Andrew W. Lenssen
Weed control in fallow management to conserve soil moisture and nutrients is the largest variable cost to dryland grain production. Our objective was to compare burning, grazing, tilling, trampling and clipping wheat stubble fields on changes in total above ground biomass and weed density. Treatments were evaluated in three experiments using a randomized complete block design for each experiment with four replications at each site. Contrasts statements were used to make pre-planned comparisons. For experiment 1, treatments were fall tilled, fall grazed, spring grazed, fall and spring combined (Fall/Spr) grazed, and an untreated control. For grazing treatments, five mature ewes …
Comparative Structural Study Of Leaf Spot Disease Of Safflower And Sugar Beet By Cercospora Beticola, Robert T. Lartey, Andrew W. Lenssen, Robert G. Evans, Soumitra Ghoshroy
Comparative Structural Study Of Leaf Spot Disease Of Safflower And Sugar Beet By Cercospora Beticola, Robert T. Lartey, Andrew W. Lenssen, Robert G. Evans, Soumitra Ghoshroy
Andrew W. Lenssen
Sugar beet and safflower are sometimes rotated or grown side by side in the Sidney, MT region of the Lower Yellowstone River Basin (LYRB). Cercospora beticola and C. carthami infect sugar beet (Beta vulgaris) and safflower (Carthamus tinctorius) respectively. C. beticola is ubiquitous in sugar beet, but C. carthami has not been reported in LYRB. Observations of unusual leaf spots on safflower in Sidney led to investigation and subsequent identification of safflower as a host of C. beticola. We describe a comparative structural study of progression of C. beticola infection and disease development in both sugar beet and safflower. The …
Incorporating Sheep Into Dryland Grain Production Systems I. Impact On Over-Wintering Larva Populations Of Wheat Stem Sawfly, Cephus Cinctus Norton (Hymenoptera: Cephidae), P. G. Hatfield, Sue L. Blodgett, T. M. Spezzano, H. B. Goosey, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Incorporating Sheep Into Dryland Grain Production Systems I. Impact On Over-Wintering Larva Populations Of Wheat Stem Sawfly, Cephus Cinctus Norton (Hymenoptera: Cephidae), P. G. Hatfield, Sue L. Blodgett, T. M. Spezzano, H. B. Goosey, Andrew W. Lenssen, R. W. Kott, C. B. Marlow
Andrew W. Lenssen
Wheat stem sawfly (WSS), Cephus cinctus Norton (Hymenoptera: Cephidae) is the most damaging insect pest to Montana’s $1 billion dollar per year grain industry. Current WSS control methods are either expensive, reduce wheat yields, or are not effective. Our objective was to compare burning, grazing, tilling, trampling and clipping wheat stubble fields on over-wintering WSS larval populations. Treatments were evaluated in three experiments using a randomized complete block design and four replications at each site. Eight, six, and two sites were used for Experiments 1, 2, and 3, respectively. Contrast statements were used to make pre-planned comparisons among treatments. For …
Cropping Sequence And Tillage System Influences Annual Crop Production And Water Use In Semiarid Montana, Usa, Andrew W. Lenssen, G. D. Johnson, G. R. Carlson
Cropping Sequence And Tillage System Influences Annual Crop Production And Water Use In Semiarid Montana, Usa, Andrew W. Lenssen, G. D. Johnson, G. R. Carlson
Andrew W. Lenssen
Available water is typically the biggest constraint to spring wheat production in the northern Great Plains of the USA. The most common rotation for spring wheat is with summer fallow, which is used to accrue additional soil moisture. Tillage during fallow periods controls weeds, which otherwise would use substantial amounts of water, decreasing the efficiency of fallow. Chemical fallow and zero tillage systems improve soil water conservation, allowing for increased cropping intensity. We conducted a field trial from 1998 through 2003 comparing productivity and water use of crops in nine rotations under two tillage systems, conventional and no-till. All rotations …
The Potential Role Of Sheep In Dryland Grain Production Systems, H. B. Goosey, P. G. Hatfield, Andrew W. Lenssen, Sue L. Blodgett, R. W. Kott
The Potential Role Of Sheep In Dryland Grain Production Systems, H. B. Goosey, P. G. Hatfield, Andrew W. Lenssen, Sue L. Blodgett, R. W. Kott
Andrew W. Lenssen
In dryland farming areas of Montana, annual precipitation is not sufficient for annual planting of cereal grains. Instead, a crop-summer fallow farming system is used to conserve soil moisture and increase available nitrogen for subsequent crop growth. Managing this summer fallow, either by mechanical means or with herbicides, is the highest variable cost associated with dryland grain production in Montana. Wheat stem sawfly, Cephus cinctus (Hymenoptera: Cephidae) is the most damaging insect pest to Montana’s US$ 1 billion per year grain industry. Weed management is the largest variable cost associated with dryland grain production and summer fallow management. Six fields, …
Forage Quality Of Alfalfa Protected By Resistance To Bacterial Leaf Spot, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, D. L. Stuteville
Forage Quality Of Alfalfa Protected By Resistance To Bacterial Leaf Spot, Andrew W. Lenssen, E. L. Sorensen, G. L. Posler, D. L. Stuteville
Andrew W. Lenssen
Bacterial leaf spot (BLS), caused by Xanthomonas campestris pv. arfalfae Dye (Xca ), can prevent stand establishment and decrease the yield and persistence of alfalfa (Medicago sativa L.) in the central USA. Previous studies have shown that BLS inoculation may affect concentrations of monophenolic compounds and thus alter the forage quality of alfalfa. In a controlled environment, comparisons were made of forage quality, including phenolic monomers, of alfalfa cv. Kanza (susceptible) and KS76 germplasm (derived from Kanza, resistant) with and without inoculation with Xca. The cultivarx inoculation interactions were non-significant (P> 0.05 ) for all parameters determined for leaves and …