Browse on keywords: disease CA
Search results on 03/25/19
10338. Morrow, L.. 1992. Chloride fertilizers.. Growers Guide, Feb. 1992, p.A6.
Chloride is provided when KCl fertilizers are used. It affects photosynthesis, enzyme activation, cation transport, stomatal activities and other processes. In soil, Cl inhibits the conversion of ammonium to nitrate. This maintains a lower pH near the root. Cl increases the number of non-pathogenic organisms in the rhizosphere. Cl competes with nitrate for plant uptake, and reduces plant nitrate levels, which can also reduce certain plant diseases. Take-all, tanspot, stripe rust, septoria, leaf rust, and common root rot have all bee suppressed by chloride.
10606. Wohld, M.. 1991. Pest control with green manure crops.. Washington Farmer Stockman, March 1991, p. 20.
Natural fumigation by rapeseed and sudan grass has shown promise in controlling diseases, nematodes, and weeds at Prosser, WA. The decomposign residues release compounds toxic to various pests.
154. Alberta Agriculture, Crop Protection Branch. 1989. Guide to crop protection in Alberta. 1988. Part II - Non-chemical control of weeds, insects, diseases for maximum economic yield.. Print Media Branch, Alberta Agriculture, 7000 - 113 St.,.
Alberta Agriculture's non-chemical guide to crop protection contains 28 pages of general advice on how to control weeds, insects, and disease in crops without chemical pesticides. This includes crop rotation, sanitation, crop competition, physical control, biocontrol, and field scouting. The rest of the book looks at specific pests and considers their life cycles, emergence, reproduction, management strategies, and control. Where available, tables of economic thresholds are included. This is an excellent reference for assessing potential alternatives to chemical pesticides for a large number of pests.
2434. Hanson, J.. 1989. researchers track possible wheat protecting bacteria.. Daily Evergreen, WSU, Pullman, WA; Sept. 8, p.1..
Research by UDSA scientists with a genetically altered bacteria to control take-all in wheat, were able to track the movement of the organism in the soil. An unexpected infection with rhizoctonia occurred and obscured results.
3200. Strand, L.L (ed.). 1990. Integrated pest management for small grains.. Univ. Calif. ANR Publ. 3333, Oakland, CA. 126 pp..
This publication is part of a series on major crops in California. It is a well-written volume with a wealth of information. There are many figures and pictures included to help in diagnosing pest problems. Cultural, biological, mechanical, and chemical controls are included.
4585. Morrow, L.. 1990. Meaningful relationships.. Growers Guide, May 1990 A6.
Calcium is an important nutrient to consider. It gives strength to plant cell walls, making them more resistant to disease. It also interacts with nitrogen and helps the latter enter the plant through the leaves when foliar fed. It also reduces N volatility. Foliar applications of N have been shown to be twice as effective as soil applications. Calcium by itself is best applied at seeding time.
5799. Reider, G.. 1981. Calcium cyanamide - fertilizer or pesticide?. World Crops, Jan., p.17.
Commercial production of calcium cyanamide was the first opportunity man had to fix nitrogen from the air for the production of nitrogen fertilizer. Calcium cyanamide's market potential is based on its herbicidal, fungicidal and other properties and on the fact that the product itself and its metabolites do not cause any environmental concern. Emphasis is laid on those biological properties which provide some answers to problems associated with crop production systems of today.
8858. Chan, M.K. and R.C. Close. 1987. Aphanomyces root rot of peas. 3. Control by the use of cruciferous amendments.. New Zealand J. Agr. Res. 30:225-233.
Growing Brassica napus in Aphanomyces euteiches infested soils for four months reduced the disease severity index (DSI) from 25-50% in three soils tested. There was no reduction in control soils with no plants, wheat, or red clover. Incorporation of dry leaves and stems of five cruciferous species also reduced DSI and oospore numbers. Reductions were greater after 6 weeks than after 3 weeks. Some species were more effective than others - Brassica napus was particularly good.
8783. Marschner, H.. 1986. Relationship between mineral nutrition and plant diseases and pests. Chpt. 11. p. 369-390.. IN: Mineral Nutrition of Higher Plants. Academci Press, Orlando. 674 pp..
Although plant resistance to diseases is genetically controlled, it is considerably influenced by environmental factors, including level of plant nutrition from the soil. Excees N appears to lower disease resistance while potassium sufficiency increases resistance. Calcium makes cell walls more resitant to fungal parasite attack. Deficiencies of nutrients which lead to an accumulation of low molecular weight organic substances lower plant resistance. Boron-deficient wheat has a higher infection with powdery mildew. The severity of take-all on wheat is greatly inhibited by lower soil pH, beginning at 6.8. Ammonium-based fertilizers which acidify the rhizosphere can inhibit take-all severity, while nitrate N increases pH and disease problems. Ammonia is toxic to certain Fusarium species and nitrite is toxic to Pythium and Phytophthora. There is often a positive correlation between nitrogen application and pest attack, as young or rapidly growing plants are more susceptible. A large potassium supply often decreases pest attack. If a fertilizer increases the content of soluble organic nitrogen in plants, sucking insects tend to become more of a problem. The physical surface of leaves can be made less attractive to insects by some foliar sprays containing sodium silicate. One experiment with wheat found that without chemcial disease control, rust infection reduced grain yield in all fertilizer N treatments, but the zero N plots yielded the greatest. With fungicide, split N application led to highest yields.
9865. Simon, A.. 1989. Biological control of take-all of wheat by Trichoderma koningii under controlled environmental conditions.. Soil Biol. Biochem. 21:323-326..
An experiment was conducted to test the effectiveness of Trichoderma koningii as a biological control for take-all disease of wheat. Take-all reduced the length of lateral roots of wheat by 45% in the absence of Trichoderma. When Trichoderma was present, take-all reduced lateral roots of wheat by only 19%. When Trichoderma was added to the soil two weeks before planting, it consistently showed greater reduction in take-all disease than when added at planting time.