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Competitive Abilities Of Oat And Barley Varieties, B. D. Mcbratney, K. J. Frey

Journal of the Iowa Academy of Science: JIAS

Competitive ability of a plant genotype reflects its capacity to yield well and compete successfully for light, moisture, and nutrients when grown with similar or dissimilar genotypes. This trait is important to plant breeding because most breeding populations are propagated in mixed or competitive stands. The objective of this study was to assess the competitive abilities of oat and barley genotypes.

Two sets of oat and barley genotypes were evaluated for competitive ability. Set I consisted of five oat varieties, and Set II consisted of two barley and three oat varieties. Neither set, when averaged, showed over- or under-compensation with …

Time To Metamorphosis As A Function Of Larval Size In A Population Of Ambystoma Tigrinum Salamanders Consisting Of Cannibal And Typical Morph Phenotypes, Michael J. Lannoo, Michael P. Sweet, Nancy M. Ladehoff, Edmund S. Fangman, William B. Collins

Journal of the Iowa Academy of Science: JIAS

Salamander larvae of the species Ambystoma tigrinum are dimorphic in northwestern Iowa. In addition to common typical morphs, there exist rare, specialized cannibal morphs, which are induced environmentally by crowding. Cannibal morph phenotypes are characterized morphologically by their large size, proportionately large heads and hypertrophied vomerine teeth, and behaviorally by facultative cannibalism. During metamorphosis amphibians are particularly sensitive to predation. To help understand why cannibal morphs are uncommon, we have raised cannibal and typical morphs in isolation and under crowded conditions to compare the timing and duration of metamorphosis between these morphs. Results show that larger larvae, most of which …