Browse on keywords: crop rotation wheat disease
Search results on 10/16/18
1466. Coventry, D.R. and J.F. Kollmorgen. 1987. An association between lime application and the incidence of take-all disease in wheat.. Aust. J. Exp. Agric., 27:695-699.
The effects of lime, deep ripping and fertilizer treatments on the occurrence of take-all symptoms in wheat. Although liming the soil increased damage by Gaeumanomyces graminis var. tritici, and perhaps other pathogens, the overall grain yields were not reduced because of the countering effect of lime promoting yield. Lime also altered the composition of grasses in pasture plots, resulting in more brome grass and barley grass. The control of take-all by crop rotations and controlling grassy weeds in pasture could be a necessary adjunct to liming if maximum yield benifits are to be obtained. Liming severely acid soils benifits the host more than the pathogen, whereas in moderately acid soils the reverse was true. The traditional rotation is a long-term clover ley pasture (5-8 yrs) with a significant component of annual grasses that host G. graminis var. tritici, followed by 2-4 years of consecutive cereal crops. This system therefore favours a build-up of inoculum of the take-all fungus and liming may therefore increase grain yield losses.
5114. Pesik, J.. 1976. The influence of various proportions of cereals in crop rotation. Rostlina Vyroba, 22(XLIX).
Experiments demonstrated that grain yield was affected mostly by the forecrop. Clovers and barley, after a fertilized root crop, provided good forecrops. Neither increased N-rates nor organic fertilizing alone could compensate for the negative effect of less favorable forecrops. In the years with the incidence of leaf-diseases, the strongest attack was observed at the highest N-rates. The interaction of higher N-rates with organic matter compensated for the effect of unfavourable forecrops and resulted in high yields.
5981. Rovira, A.D.. 1986. Influence of crop rotation and tillage on Rhizoctonia bare patch of wheat.. Phytopathology, 76(7):669-673.
Rhizoctonia bare patch was more severe in direct drilled wheat than in wheat sown into cultivated soil. The area of affected crop was consistently larger when wheat followed a mixed annual pasture of grasses and Medicago spp. than when wheat followed wheat, peas, or grass-free pasture of Medicago spp. All isolates of R. solani were pathogenic on wheat, barley, peas, Medicago spp., annual ryegrass, and barley grass.
6359. Smiley, R., D. Wilkins, W. Uddin, S. Ott, K. Rhinhart, and S. Case. 1989. Rhizoctonia root rot of wheat and barley.. OR Agr. Expt. Sta. Special Report 840, p. 68-79..
Rhizoctonia root rot is now considered the most severe root disease of barley in the PNW. It is more important than take-all and Pythium on wheat produced in drier areas (<16" precip.). Based on long-term plots at Pendleton, different management systems are unlikely to greatly influence the biological resistance of soils to Rhizoctonia. Rotational crops susceptible to Rhizoctonia include wheat, barley, peas, chickpeas, lentils, and rapeseed. The disease is less apparent on small grains after legumes than after cereals. Rhizoctonia damage is always highest on no-till systems, but yields may not suffer due to improved water relations under conservation tillage. Australian research indicates that applications of N and P fertilizers can reduce the disease. There appear to be detrimental herbicide interactions with Rhizoctonia, particularly Glean on high pH soils. Also, the use of glyphosate increased disease incidence, perhaps by signalling the pathogens to move from the dying plants to newly seeded ones. A delay of at least 2 weeks is suggested between chem kill and planting of a new crop.
10098. Reeves, T.G., A. Ellington and H.D. Brooke. 1984. Effects of lupin-wheat rotations on soil fertility, crop disease and crop yields.. Austral. J. Expt. Animal Husb. 24:595-600..
Three experiments were conducted between 1974 and 1979 in northeastern Victoria to investigate the effects of rotating wheat and sweet lupins on crop yields, soil fertility and crop diseases. The grain yield of continuous wheat was 2.58 t/ha and of continuous lupins 0.66 t/ha. Wheat, grown after a lupin crop, yielded 750 kg/ha more than wheat after wheat, and a second wheat crop, after lupins, yielded 420 kg/ha more than a third successive wheat crop. Lupins, grown after wheat, yielded 50-165% more than lupins after lupins. Grain N of wheat was significantly increased after lupins. Differences in soil mineral N were apparent ten weeks after sowing, with mean N levels of 37 and 55 kg/ha under wheat and lupins, respectively. Soil mineral N was consistently greater after lupins than after wheat. Overall, mean accretion of mineral N under lupins was 41 kg/ha/year. Lupins after lupins suffered severly from brown leaf spot, up to 63% of plants being infected compared with only 18% after wheat. Disease incidence in wheat (mainly G. graminis) increased from less than 1% in the first year of cropping, to 36% infection in year 3 of continuous wheat. When wheat was grown after lupins, disease incidence was negligible.
10988. Cook, R.J.. 1981. The influence of rotation crops on Take-all decline phenomenon.. Phytopathology 71:189-192.
Five rotation crops (potatoes, oats, alfalfa, beans, grass) were tested for their ability to promote take-all decline in continuous wheat. Take-all from natural inoculum was common on wheat plants in plots previously planted to wheat, grass, or soybeans, but was mild or nonexistent on wheat after oats, potatoes, or alfalfa. When inoculum was introduced, take-all was severe in plots previously planted to potatoes, oats, alfalfa, or beans, whether or not the soil had been fumigated. In contrast, soil in plots previously planted to wheat or the grass mixture had to be fumigated before disease of such severity could develop in response to introduced inoculum. Soils cropped continuously to wheat or wheat in rotation with grass were suppresive to take-all; the other crops resulted in soil becoming highly conducive to take-all.
11184. Cook, R.J. and R.J. Veseth. 1991. Wheat Health Management.. Amer. Phytopathol. Soc. Press, St. Paul, MN..
Wheat Health Management was written as a thorough guide to wheat production for growers as well as researchers. It is applicable throughout most of North America and many other wheat producing areas. The book is technically complete but easy to read, and is illustrated with many excellent photos and figures. Wheat health management is discussed before planting, at planting, postplant, and postharvest. The final chapter presents the idea of holistic health for wheat.