Global ETD Search

381	Studies on the Biology of Soybean Cyst Nematode Poromarto, Susilo Hambeg January 2011 (has links) Soybean cyst nematode (SCN), Heterodera glycines, is a threat to soybean production in North Dakota. Studies on the biology of SCN were conducted to improve my understanding and management of this plant parasitic nematode. The objectives of the research were to; (1) determine if SCN reproduces on crops commercially grown or being tested for production in North Dakota, (2) evaluate the effects of SCN on growth of dry bean, (3) determine if there could be a shift in the SCN population toward greater ability to reproduce on dry bean, and (4) characterize the spatial distribution of SCN in research size field experiments. Canola, clover, lentil, and sunflower were nonhosts while borage, camelina, chickpea, crambe, cuphea, field pea, nyjer, and safflower were poor hosts for SCN with female indices (FI) less than 8. Lupines were susceptible hosts with FI’s of 42 to 57. FI’s of dry bean cultivars varied from 5 to 117. Kidney beans averaged the highest FI at 110 followed by navy, pinto and black at FI’s 41, 39, and 16, respectively. Pod number (PN), pod weight (PW), seed number (SN), and seed weight (SW) of GTS-900 (pinto bean) were significantly less at 5,000 and 10,000 eggs/100 cm3 soil compared with the control by 44 to 56% averaged over the two years. Significant reduction in growth of Montcalm (kidney bean) and Mayflower (navy bean) was observed at 2,500 and 5,000 eggs/100 cm3 soils in 2009, but not in 2008. There was no evidence that SCN was increasing reproduction during two 11 month periods of continual reproduction on roots of dry bean cultivars Premiere and Cirrus (navy), Buster and Othello (pinto), and Eclipse and Jaguar (black). The spatial distribution of SCN in field plots was aggregated in nine of ten field sites with large differences in egg numbers between plots. Lloyd’s index of patchiness ranged from 1.09 to 3.34. Spatial distribution of SCN can be an important factor affecting the results of field experiments. Heterodera. Soybean. Soybean -- Diseases and pests.
382	The intensity of barley diseases in Quebec caused by Cochliobolus sativus and their effects of different barley cultivars. Pua, Eng-Chong. January 1979 (has links) No description available.
383	The effect of daylength, pathogen isolate and host variety on Verticillium wilt of sunflower. Sedun, Frederick Samuel. January 1981 (has links) No description available. Wilt diseases Sunflowers -- Diseases and pests.
384	Studies of the phylloplane microflora of lettuce and its interactions with pesticides and Sclerotinia sclerotiorum Mercier, Julien. January 1986 (has links) No description available. Lettuce -- Diseases and pests. Sclerotinia sclerotiorum.
385	Seuil économique et programme d'échantillonnage séquentiel pour le thrips de l'oignon (Thrips tabaci Lindeman) sur l'oignon Fournier, François January 1993 (has links) No description available. Onion thrips. Onions -- Diseases and pests.
386	A comparison of the morphology and anatomy of normal Abies balsamea and that infected by Melampsorella cerastii (Pers.) Schroet. Turnau, Edmund Albert Otto. January 1950 (has links) No description available. Balsam fir -- Diseases and pests Botany
387	A study of the stylet-bearing nematodes associated with cranberries in Massachusetts. Coughlin, John W. 01 January 1960 (has links) (PDF) No description available. Cranberries Diseases and pests Plant nematodes.
388	Effect of injected antiviral compounds on apple mosaic and other diseases of apple trees. Cheplick, Susan 01 January 1982 (has links) (PDF) No description available. Antiviral agents Apples Diseases and pests.
389	Time-of-planting treatments and the role of Pratylenchus penetrans in peach decline in Massachusetts. McCouch, Susan R. 01 January 1982 (has links) (PDF) No description available. Peach Diseases and pests Pratylenchus penetrans.
390	Biology and control of the boxwood mite : Eurytetranychus buxi (Garman) on boxwood. Aranda, Rafael Padilla 01 January 1961 (has links) (PDF) No description available. Boxwood Diseases and pests Eurytetranychus buxi.

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