@article{lehman_blum_1999, title={Evaluation of ferulic acid uptake as a measurement of allelochemical dose: Effective concentration}, volume={25}, number={11}, journal={Journal of Chemical Ecology}, author={Lehman, M. E. and Blum, U.}, year={1999}, pages={2589–2600} }
 @article{blum_shafer_lehman_1999, title={Evidence for inhibitory allelopathic interactions involving phenolic acids in field soils: Concepts vs. an experimental model}, volume={18}, DOI={10.1080/07352689991309441}, abstractNote={The accepted criteria for identifying allelopathic interactions in the field that have been proposed in the literature offer heuristic function, but to date have failed as a framework for research and diagnostics. If the present criteria are to be modified to make them useful empirically, their shortcomings must be identified. For this review, data from the literature and from defined model systems consisting of plants, soil, and/or microbes are used to evaluate the applicability of the accepted criteria to defined systems in which plants are responding to known allelochemicals. Based on this evaluation, modified criteria are proposed. In many respects, however, the modified criteria are as difficult to satisfy in the field as those proposed previously. The new criteria have value as a research framework because they clearly suggest that a shift in research focus to the soil environment, specifically the barrier of the rhizosphere through which allelochemicals must pass, is essential if the role of allelopathic interactions in the field is to be established.}, number={5}, journal={Critical Reviews in Plant Sciences}, author={Blum, Udo and Shafer, S. R. and Lehman, M. E.}, year={1999}, pages={673–693} }
 @article{lehman_blum_1999, title={Influence of pretreatment stresses on inhibitory effects of ferulic acid, an allelopathic phenolic acid}, volume={25}, ISSN={["1573-1561"]}, DOI={10.1023/A:1020828630638}, number={7}, journal={JOURNAL OF CHEMICAL ECOLOGY}, author={Lehman, ME and Blum, U}, year={1999}, month={Jul}, pages={1517–1529} }
 @article{lehman_blum_1997, title={Cover crop debris effects on weed emergence as modified by environmental factors}, volume={4}, number={1997}, journal={Allelopathy Journal}, author={Lehman, M. E. and Blum, U.}, year={1997}, pages={69–88} }
 @article{blum_king_gerig_lehman_worsham_1997, title={Effects of clover and small grain cover crops and tillage techniques on seedling emergence of dicotyledonous weed species}, volume={12}, DOI={10.1017/s0889189300007487}, abstractNote={AbstractWe monitored emergence of morning-glory, pigweed, and prickly sida from seeded populations in no-till plots with no debris (reference plots) or with crimson clover, subterranean clover, rye, or wheat debris. Cover crops were either desiccated by glyphosate or mowed and tilled into the soil. Debris levels, soil temperature, moisture, pH, nitrate, total phenolic acid and compaction were monitored during May to August in both 1992 and 1993. Seedling emergence for all three weed species ranged from <1 to 16% of seeds sown. Surface debris treatments delayed weed seedling emergence compared with the reference plots. Rye and wheat debris consistently suppressed weed emergence; in contrast, the effects of clover debris on weed emergence ranged from suppression to stimulation. Gfyphosate application resulted in a longer delay and greater suppression of seedling emergence in May than in April. In 1993, plots in which living biomass was tilled into the soil were also included and monitored. Weed seedling emergence was stimulated when living biomass was incorporated into the soil. Covariate, correlation and principle component analyses did not identify significant relationships between weed seedling emergence and soil physical and chemical characteristics (e.g., total phenolic acid, nitrate, moisture, temperature). We hypothesize that the observed initial delay of the weed seedling emergence for all three species was likely due to low initial soil moisture. The subsequent rapid recovery of seedling emergence of morning-glory and pigweed but notprickfy sida in the clover compared with the small grain debris plots was likely due to variation in soil allelopathic agents or nitrate-N levels. The stimulation of weed seedling emergence when living biomass was incorporated into the soil was likely caused by an increase in “safe” germination sites coupled with the absence of a zone of inhibition resulting from tillage.}, number={4}, journal={American Journal of Alternative Agriculture}, author={Blum, Udo and King, L. D. and Gerig, T. M. and Lehman, M. E. and Worsham, A. D.}, year={1997}, pages={146–161} }
 @article{lehman_blum_gerig_1994, title={SIMULTANEOUS EFFECTS OF FERULIC AND P-COUMARIC ACIDS ON CUCUMBER LEAF EXPANSION IN SPLIT-ROOT EXPERIMENTS}, volume={20}, ISSN={["1573-1561"]}, DOI={10.1007/BF02059898}, abstractNote={Experiments were conducted to determine how plant responses to mixtures of allelochemicals may change as the proportion of roots in contact with allelochemicals is modified. Thirteen-day-old cucumber seedlings were treated with ferulic and/orp-coumaric acid in a split-root nutrient culture system. Leaf areas were determined just prior to treatment and at harvest, 24 hr after treatment. Ferulic acid was more inhibitory to cucumber leaf expansion thanp-coumaric acid. The effects of ferulic andp-coumaric acids on leaf expansion were additive. For individual acids, mixtures of ferulic andp-coumaric acids in the same container and combinations of ferulic andp-coumaric acids in separate containers, the inhibition of leaf expansion was directly related to the product of the concentration of the acid(s) and the proportion of roots treated with the acid(s). Pretreatment with 0.2 or 0.4 mM ferulic acid and subsequent treatment with 0.5 mM ferulic acid failed to show evidence of acclimation by cucumber seedlings.}, number={7}, journal={JOURNAL OF CHEMICAL ECOLOGY}, author={LEHMAN, ME and BLUM, U and GERIG, TM}, year={1994}, month={Jul}, pages={1773–1782} }