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The Strength Of Seeds And Their Destruction By Granivorous Insects, Jonathan G. Lundgren, Kurt A. Rosentrater Jun 2007

The Strength Of Seeds And Their Destruction By Granivorous Insects, Jonathan G. Lundgren, Kurt A. Rosentrater

Kurt A. Rosentrater

The influence of seed structure and strength on their destruction by granivores is central to understanding the dynamics of granivore-plant interactions. For up to nine seed species, the effects of seed size (cm3), mass (mg), density (mg/cm3) and coat strength (MPa) on the damage inflicted by three post-dispersal granivores (Harpalus pensylvanicus, Anisodactylus sanctaecrucis, and Gryllus pennsylvanicus) were evaluated. Seed destruction rates by G. pennsylvanicus were statistically unrelated to the size and toughness of the seeds. Seed densities significantly affected their destruction by A. sanctaecrucis and H. pensylvanicus, as did seed size, mass, and strength in H. pensylvanicus under choice conditions. …


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 Jan 2007

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 Jan 2007

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 Jan 2007

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 Jan 2007

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 …