Effects of Climate Change on Food Crops


Climate change introduces a new variety of challenges to the global agricultural sector (Bharti & Chauhan, 2012). The challenges are mostly phased on the high prevalence of pests and diseases. Food crops are the most affected considering that their field-period is shorter as compared to subsistence crops, which have longer periods, thus, well adapted to withstand adverse climatic and pathological conditions. As Reddy & Hodges, (2000) observe, food crops such as fruits and vegetables are highly susceptible to attacks by crop diseases and pests: climate changes aggravate the prevalence of diseases and pests on food crops. Therefore, it is in the scope of this study to provide an in-depth analysis of the effects of climate change on food crops, with specific emphasis on potato crops.


In this study, the most important materials adopted are research findings and reports from a target region where production of potatoes has been greatly affected due to change in climatic conditions. Potato crops were considered for this study based on considerations that they are classified as the world’s major non-cereal food crops.

According to FAO (2005), potato crops are the fourth largest crops after maize rice with annual production of more than 325 million tones. Nair (2010) further asserts that potato consumption is steadily rising across the world, especially in developing countries, whilst the production is steadily decreasing. Therefore, a study on the predisposing climatic changes on the topic is not only necessary but also much needed to provide a baseline for decision making among agricultural stakeholders. Data for use in the study will be obtained from crop researches on a similar topic carried out in Asia, reflecting on Late blight of potato disease. The choice of Asia is informed by the annual production of approximately 137 million tones, which accounts for more than 80% of the total world production (Haden, 2009).


In this study, the data presented was collected from a series of three workshops that focused on the relationship between climate change and food crop disease prevalence in two different regions. Bangladesh in Asia and Australia were selected for the research, as representation of diverse climatic conditions, through which an inference will be drawn on the effects of climatic changes on crop diseases. Late blight disease was the center of the study, climate projections were made prior to the study, and the impact coupled with the severity of late blight disease on potatoes upon altering the climatic conditions was also put into perspective.

In the course of the study, model potato farms were developed and the climatic conditions monitored periodically. In the nurseries, late blight traps were raised, to aid identification of the onset of late blight symptoms among the crops in different regions. The fog and sunshine hours were captured across Bangladesh in Asia, as well as Australia. Also, the temperature and relative humidity recordings were taken and later analyzed qualitatively, based on the rainfall, leaf wetness and sunshine recordings taken on a daily basis.


After the expiry of the disease initiation period in the two regions, based on climatic conditions and the period of disease onset, the data acquired was qualitatively analyzed. After evaluating the data, it was deduced that the onset of late blight disease in potatoes was identified early in the presence of temperatures of (>10?C) and average Relative Humidity of (>70%). These two weather conditions formed the most critical weather parameters associated with the onset of late blight. This was widely experienced in Asia, whilst in Australia the initiation of late blight was insignificant. Another critical finding from the models was that the occurrence of morning fog was a contributing factor towards the initiation of late blight disease in potatoes. This was more evident on data collected on foggy days, which had minimum temperatures of more than 10.00C.


Late blight disease was not initially experienced in Asian region, owing to the prevailing weather characterized by hot Alpine climatic conditions that discouraged the initiations of late blight disease in crops (Snowdon, 2010). Boyd (2010) further observes that, as a result of climate change and global warming, the Asian region is experiencing increased precipitation resulting from the melting of the icecaps in the Himalayas among other regions. This provides the humid and warm conditions that favor the onset of late blight in potatoes. Due to the prevailing humid conditions in Asia, potato production in Asia is greatly declining as a result of high disease prevalence (Thompson & Cohen, 2012).

On the other hand, in Australia the incidence of late blight disease is relatively low owing to the prevailing climatic conditions. In the past, the disease was a common concern among farmers in the region, but due to change in climatic condition incidences of the diseases are very low in selected regions (Mendelsohn & Dinar, 2012). This is based on the fact that in Australia summer is too hot and this discourages the initiation of late blight.


In the study, potatoes have been used to establish the relationship between climatic changes and their effects on food crops. Based on the research findings, it can be concluded that climate change is a great threat to the global agricultural sector, in that it can greatly eliminate the incidence of the disease in one region, while at the same time, transfer the provide to another, but larger geographical location (McKibben, 2012). It is clear from the study model in as much as climate change helped alleviate the annual problem of potato late blight disease in the small continent of Australia, it transferred the problem to the larger Asian continent. Therefore, it is recommended that all stakeholders in environmental conservation should create awareness among various communities on the effects of climate change resulting from various human activities (Schneider, 2010).


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Boyd, S. (2010). Tomato and potato late blight information for the upcoming growing season. Meine: University of Maine Cooperative Extension.

FAO. (2005). Helping small farmers think about better growing and marketing : case studies on commercialisation of small farmers. Apia: FAO, Sub-Regional Office for the Pacific Island.

Haden, R. (2009). Food culture in the Pacific Islands. California: Greenwood Press.

McKibben, B. (2012). The global warming reader : a century of writing about climate change. New York: Penguin Books.

Mendelsohn, R., & Dinar, A. (2012). Handbook on climate change and agriculture. Cheltenham: Edward Elgar Pub.

Nair, C. (2010). Consumptionomics : Asia’s role in reshaping capitalism and saving the planet. Oxford: Infinite Ideas.

Reddy, K. R., & Hodges, H. F. (2000). Climate change and global crop productivity. New York: CABI Pub.

Schneider, S. H. (2010). Climate change science and policy. Washington DC: Island Press.

Snowdon, A. (2010). Post-harvest diseases and disorders of fruits and vegetables Volume 2. New Jersey: Manson Pub.

Thompson, B., & Cohen, M. J. (2012). The impact of climate change and bioenergy on nutrition. New York: Springer.