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Comparative Pollination Biology Of Sympatric And Allopatric Andean Iochroma (Solanaceae)1, Steven J. Hall, Stacy Dewitt Smith, Pablo R. Izquierdo, David A. Baum
Comparative Pollination Biology Of Sympatric And Allopatric Andean Iochroma (Solanaceae)1, Steven J. Hall, Stacy Dewitt Smith, Pablo R. Izquierdo, David A. Baum
Steven J. Hall
Field studies were conducted for 15 species of Iochroma Benth. and the nested genus Acnistus Schott to quantify the diversity of pollination systems and to assess the potential contribution of pollinator behavior to the persistence of closely related species in sympatry. We combined measures of pollinator visitation and pollen deposition to estimate the importance of major groups of pollinators for each species, and we calculated proportional similarity in the pollinator assemblage among species. We found that 12 species of Iochroma, encompassing a range of flower colors and sizes, were principally pollinated by hummingbirds and, in many cases, by the same …
No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
No Evidence That Bacillus Thuringiensis Genes And Their Products Influence The Susceptibility Of Corn Residue To Decomposition, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
Kurt A. Rosentrater
The possibility that Bacillus thuringiensis (Bt) corn (Zea mays L.) residues resist decomposition compared to non-Bt residues would present direct (soil carbon turnover times) and indirect (changes in tillage practices) effects on carbon budgets in agricultural systems. We evaluated the relative decomposition of residue from two pairs of Bt and non-Bt corn hybrids from different seed manufacturers buried in the root zone of adjacent Bt and non-Bt corn plots over a period of 384 d. We found no persistent differences in residue decomposition among the different hybrids regardless of the seed manufacturer or the presence of the Bt genes (both …
Long-Term Tillage Frequency Effects On Dryland Soil Physical And Hydraulic Properties, Andrew W. Lenssen, J. D. Jabro, U. M. Sainju, W. B. Stevens, R. G. Evans
Long-Term Tillage Frequency Effects On Dryland Soil Physical And Hydraulic Properties, Andrew W. Lenssen, J. D. Jabro, U. M. Sainju, W. B. Stevens, R. G. Evans
Andrew W. Lenssen
Soil tillage is considered one of most important practices in agricultural production due to its influence on physical, chemical, and biological properties of the soil environment. The effect of a long-term tillage [no-till (NT), spring till (ST), and fall and spring till (FST)] was investigated on soil penetration resistance (PR), bulk density (BD), gravimetric water content (GWC) and saturated hydraulic conductivity (Ks) under dryland conditions. Tillage effects on these physical properties were tested after 22 years on a Dooley sandy loam (fine-loamy, mixed Typic Argiborolls) derived from glacial till parent material. The statistical design used was a randomized complete block …
Evaluation Of Winter Cereals For Pasture In Montana, Andrew W. Lenssen, A. N. Hafla, S. D. Cash, L. M. M. Surber, J. A. Paterson, A. L. Todd, M. S. Huffman
Evaluation Of Winter Cereals For Pasture In Montana, Andrew W. Lenssen, A. N. Hafla, S. D. Cash, L. M. M. Surber, J. A. Paterson, A. L. Todd, M. S. Huffman
Andrew W. Lenssen
In the southern Great Plains, it is common to graze winter wheat pastures prior to grain harvest to take advantage of economic returns from the grain crop and value added to livestock. In Montana, a similar management practice could provide complementary pasture for livestock in the late spring to relieve pressure on cool season native rangelands. A two year study was conducted to evaluate the forage yield and quality of winter cereals, when grazed at three growth stages, vegetative (V), boot stage (B), and at heading (H), prior to hay and grain harvest. Western white faced ewes were used to …
No Differences In Decomposition Rates Observed Between Bacillus Thuringiensis And Non-Bacillus Thuringiensis Corn Residue Incubated In The Field, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
No Differences In Decomposition Rates Observed Between Bacillus Thuringiensis And Non-Bacillus Thuringiensis Corn Residue Incubated In The Field, R. Michael Lehman, Shannon L. Osborne, Kurt A. Rosentrater
Kurt A. Rosentrater
Recent speculation of slower residue decomposition for Bacillus thuringiensis (Bt) corn (Zea mays L.) hybrids compared with non-Bt corn hybrids has prompted investigative study. We evaluated the residue decomposition rates of Bt and non-Bt corn hybrids over a period of 22 mo under field conditions using the litter bag technique. The four corn hybrids used were (i) DKC60–16 (Bt+, Cry1Ab protein active against the leptidopteran European corn borer, event MON810), (ii) DKC60–12 (Bt+, Cry3Bb1 protein active against the coleopteran corn rootworm, event MON863), (iii) DKC60–14 (stacked Bt++, Cry1Ab and Cry3Bb1 proteins) and, (iv) DKC60–15 (Bt−, base genetics). The biochemical and …