Browse on keywords: disease green manure
Search results on 05/25/13
1540. Davis, J.B.. 1988. Winter rapeseed (Brassica napus) with differential levels of glucosinolates evaluated to suppress Aphanomyces root rot.. M.S. Thesis.
Winter rapeseed (Brassica napus) with differential levels of glucosinolates were evaluated as a green manure crop to suppress Aphanomyces root rot of peas.
7524. White, J.G.H.. undated. Grain legumes in sustainable cropping systems; a review.. unpublished manuscript, Plant Science Dept..
This paper briefly reviews the role that grain legumes can play in sustaining cropping systems. It presents various estimates of N fixation of grain legumes, with lupin and fababean showing the highest rates, followed by peas and lentils, chickpeas, and soybeans. Phaseolus beans are generally poor N fixers. Fababeans are more tolerant of soil mineral N than other species and will still fix large quantities of N when mineral N is present. Under drought stressed conditions, peas and lentils were more efficient in N fixation than fababeans. Only in lupins and fababeans was N fixation normally greater than the N removed in the seed. The roots and nodules of grain legumes are likely to be the greatest source of N for following crops. This N is often quickly mineralized within several weeks after harvest, and strategies are needed to prevent its loss. Grain legumes are also beneficial break crops, particularly for soil-borne diseases, and can help to control certain grassy weeds. Preceding grain legumes with a brassica crop has reduced the incidence of Aphanomyces root rot in peas, due to sulfur containing compounds. Most grain legumes suffer reduced yields if soils are compacted and poorly aerated. The paper contains numerous references and tables on nitrogen relations.
10516. Short, R.. 1991. Common root rot of peas incited by Aphanomyces euteiches.. handout at Crops 510 seminar, WSU.
Aphanomyces euteiches is often the primary and dominant invading species of a pathogen complex that attacks peas, along with Fusarium, Pythium, Rhizoctonia, and Ascochyta. Aphanomyces causes 16-20 million dollars of crop loss annually in the U.S. The oospores may persist in soil for more than 20 years, making it a difficult disease to eliminate. Control of Aphanomyces demands and integrated approach due to its invasive and pervasive nature. Field sampling can help determine inoculum levels, and crop sequences can be altered. In some cases, a break of five or more years between pea crops is needed to lower inoculum levels for minimal damage. Cultural practices which reduce soil compaction and promote drainage are beneficial. Organic amendments such as crucifer green manure crops have reduced inoculum levels in infested soils. Biological control agents, such as Trichoderma and Pseudomonas, show promise. Breeding for multiple disease resistance is another important strategy.