Impact and Management of Crop Diseases in Agriculture

Crop diseases, particularly those caused by fungi, are a constraint to crop production in all agricultural zones and especially in the agronomically favorable wet tropics. It is estimated that each year fungal diseases alone are responsible for reductions in world production amounting to 10%, with up to 50% losses in severe disease years [1]. During the early agricultural history, the concept of how plants became diseased and the basis of disease resistance were relatively simplistic - originating from a combination of factors that included chance, luck, and superstition [2]. However, it became increasingly obvious that successful crop cultivation required the avoidance of fields that previously grew diseased plants, prompting the rather general realization that disease could be transmitted, and disease resistance breached [3].

During the latter stages of the nineteenth century and the early part of the twentieth century, the nature of the various factors contributing to plant diseases became more clearly defined and the role of environmental conditions, particularly of extremes in moisture, whether too little or too much, in subsequent plant disease [4]. It soon became apparent, too, that diseases were aggravated and yield losses increased when other stresses affecting the plants combined with disease to form a 'multiple impact' situation leading to the 'crop loss. Early work on plant diseases also saw the application of Koch's postulates to the demonstration of the causes of 'exotic' plant diseases in various locations [5]. At the same time, experiments to confirm the effect of diseases on yields were also initiated, providing widely available documentation of the generation-detritus-priming outbreaks that have often been linked with periods of major cosmic disruption. [6] Despite the significance of these locational and experimental conclusions and projections, crop problems continued to occur throughout the major landmasses, and with the successes in science and technology of the twentieth century came the development of new agricultural lands and the increased use of fertilizers, pesticides, and water as inputs. [7]

References:

[1] A. K. Pandey, G. D. Sinniah, A. Babu, and A. Tanti, "How the global tea industry copes with fungal diseases–challenges and opportunities," Plant Disease, 2021. apsnet.org

[2] D. C. He, M. H. He, D. M. Amalin, W. Liu et al., "Biological control of plant diseases: An evolutionary and eco-economic consideration," Pathogens, 2021. mdpi.com

[3] DB Collinge, DF Jensen, M Rabiey, S Sarrocco, "Biological control of plant diseases–What has been achieved and what is the direction?," Plant …, vol. 2022, Wiley Online Library. wiley.com

[4] I. Ul Haq and S. Ijaz, "History and recent trends in plant disease control: An overview," in Plant Disease Management Strategies for Sustainable Agriculture, Springer, 2020. [HTML]

[5] D. T. Teshome, G. E. Zharare, and S. Naidoo, "The threat of the combined effect of biotic and abiotic stress factors in forestry under a changing climate," Frontiers in plant science, 2020. frontiersin.org

[6] L. Fu, Z. Wang, O.P. Dhankher, et al., "Nanotechnology as a new sustainable approach for controlling crop diseases and increasing agricultural production," Journal of Experimental Botany, vol. 2020. academic.oup.com, 2020. [HTML]

[7] M.E. Hossain, S. Shahrukh, and S.A. Hossain, "Chemical fertilizers and pesticides: impacts on soil degradation, groundwater, and human health in Bangladesh," in Soil Degradation: Challenges and Opportunities, Springer, 2022. [HTML]