For pathogens with highly localized inoculum, controlled positioning of susceptible plants can be used to delay exposure to the pathogen. For example, when wheat is direct-drilled in fields where wheat was infected by Gaeumannomyces graminis var. tritici (Ggt) in the previous season, the remaining rows of wheat crowns serve as an inoculum source for the new wheat planting. In order to determine how different seeding patterns of wheat might affect yield loss to Ggt, we constructed a mathematical model in three stages. First, we calculated the probability density function for the distance between a new seed and the nearest old row of crowns for two main planting scenarios: parallel to the previous year's rows or at an angle to them. Second, we used estimates from Kabbage and Bockus [Kabbage, M. and Bockus, W. W. 2002. Plant Disease 86, 298–303] of the yield loss to Ggt as a function of the distance between wheat seed and inoculum source. Third, we combined these two models to estimate the average yield loss for different planting patterns. We estimated that planting parallel to and between the previous year's rows would cut yield loss almost in half for a typical row spacing compared to angled planting, provided there was not an important offset, or bias, in the position of the parallel planting. Planter wobble was relatively unimportant if there was no systematic bias in position.
This is a preview of subscription content, log in to check access.
Buy single article
Instant access to the full article PDF.
Price includes VAT for USA
Subscribe to journal
Immediate online access to all issues from 2019. Subscription will auto renew annually.
This is the net price. Taxes to be calculated in checkout.
Bailey, D. J. and Gilligan, C. A. 1999. Dynamics of primary and secondary infection in take-all epidemics. Phytopathology 89, 84–91.
Bockus, W. W. 1983. Effects of fall infection by Gaeumannomyces graminis var. tritici and triadimenol seed treatment on severity of take-all in winter wheat. Phytopathology 73, 540–543.
Bockus, W. W., Davis, M. A. and Norman, B. L. 1994. Effect of soil shading by surface residues during summer fallow on take-all of winter wheat. Plant Disease 78, 50–54.
Butler, F. C. 1953. Saprophytic behaviour of some cereal root-rot fungi. I. Saprophytic colonization of wheat straw. Annals of Applied Biology 40, 284–297.
Colbach, N., Lucas, P. and Meynard, J.-M. 1997. Influence of crop management on take-all development and disease cycles on winter wheat. Phytopathology 87, 26–32.
Cook, R. J. 1981. The influence of rotation crops on take-all decline phenomenon. Phytopathology 71, 189–192.
Cotterill, P. J and Sivasithamparam, K. 1988. The effect of tillage practices on distribution, size, infectivity and propagule number of the take-all fungus, Gaeumannomyces graminis var. tritici. Soil Tillage Research 11, 183–195.
Evans, M., Hastings, N. and Peacock, B. 1993. Statistical Distributions (Wiley, New York).
Garrett, S. D. 1940. Soil conditions and the take-all disease of wheat. V. Further experiments on the survival of Ophiobolus graminis in infected wheat stubble buried in the soil. Annals of Applied Biology 27, 199–204.
Garrett, S. D. 1948. Soil conditions and the take-all disease of wheat. IX. Interaction between host plant nutrition, disease escape, and disease resistance. Annals of Applied Biology 35, 14–17.
Hornby, D. 1975. Inoculum of the take-all fungus: Nature, measurement, distribution, and survival. EPPO Bulletin 5, 319–333.
Kabbage, M. and Bockus, W. W. 2002. Effect of placement of inoculum of Gaeumannomyces graminis var. tritici on severity of take-all in winter wheat. Plant Disease 86, 298–303.
Madden, L. V., Hughes, G. and Irwin, M. E. 2000. Coupling disease-progress-curve and time-of-infection functions for predicting yield loss of crops. Phytopathology 90, 788–800.
Moore, K. J. and Cook, R. J. 1984. Increased take-all of wheat with direct drilling in the Pacific Northwest. Phytopathology 74, 1044–1049.
Ross, S. M. 1997. A First Course in Probability (Prentice Hall).
Scott, P. R. 1969. Control of Ophiobolus graminis between consecutive crops of winter wheat. Annals of Applied Biology 63, 47–53.
Whelan, B. M. and McBratney, A. B. 2000. The “null hypothesis” of precision agriculture management. Precision Agriculture 2, 265–279.
Wilkinson, H. T., Cook, R. J. and Alldredge, J. R. 1985. Relation of inoculum size and concentration to infection of wheat roots by Gaeumannomyces graminis var. tritici. Phytopathology 75, 98–103.
About this article
Cite this article
Garrett, K.A., Kabbage, M. & Bockus, W.W. Managing for Fine-Scale Differences in Inoculum Load: Seeding Patterns to Minimize Wheat Yield Loss to Take-all. Precision Agriculture 5, 291–301 (2004). https://doi.org/10.1023/B:PRAG.0000032767.59598.fd
- reduced tillage
- spatial variability
- plant disease