@article{duthie_campbell_1991, title={EFFECTS OF PLANT DEBRIS ON INTENSITY OF LEAF-SPOT DISEASES, INCIDENCE OF PATHOGENS, AND GROWTH OF ALFALFA}, volume={81}, ISSN={["1943-7684"]}, DOI={10.1094/Phyto-81-511}, abstractNote={When leaf spot diseases are severe, early harvest of alfalfa (Medicago sativa) has been recommended to preempt defoliation, preserve yield and quality, and prevent accumulation of pathogen-infested leaf debris. Effects of debris on incidence of all leaf spots taken together (percentage of leaves with lesions caused by species of Leptosphaerulina, Stemphylium, Phoma, and/or Cercospora), frequency of leaf spot pathogens (percentage of diseased leaflets infected by each pathogen), and yield were evaluated during five periods of alfalfa growth in each of 2 yr among untreated plots (10.0×4.1 m) and plots in which naturally infested debris was either removed or added immediately after each harvest (...)}, number={5}, journal={PHYTOPATHOLOGY}, author={DUTHIE, JA and CAMPBELL, CL}, year={1991}, month={May}, pages={511–517} }
 @article{duthie_campbell_nelson_1991, title={EFFICIENCY OF MULTISTAGE SAMPLING FOR ESTIMATION OF INTENSITY OF LEAF-SPOT DISEASES OF ALFALFA IN FIELD EXPERIMENTS}, volume={81}, ISSN={["0031-949X"]}, DOI={10.1094/Phyto-81-959}, abstractNote={In each of two field experiments, efficiency of multistage sampling was evaluated for estimation of intensity of leaf spot diseases during 10 periods of alfalfa growth over 2 yr. Disease was assessed visually on sections of the alfalfa canopy with the aid of descriptive rating scales. In experiment A, severity of disease was assessed every 7 days on four canopy sections (0.5×0.5 m) per replicate plot (3×3 m) with 12 plots per treatment (...)}, number={9}, journal={PHYTOPATHOLOGY}, author={DUTHIE, JA and CAMPBELL, CL and NELSON, LA}, year={1991}, month={Sep}, pages={959–964} }