Potatoes are a staple crop unique in their high nutrient content and susceptibility to the plant pathogen Phytophtera infestans, also known as the fungal late blight. Blight, made infamous by the Irish potato famine of the 1840s, continues to suppress potato yields globally. Losses to blight are ten times greater in low- than high-income countries, limiting the capacity of potato farming to provide food or economic security. Blight is prevalent wherever potatoes are grown, appearing under cool, wet conditions. The spores of the disease spread quickly through wind and water. Blight first infects the leaves of the potato plant, moving down into the tuber, which will rot and deteriorate in the field. Left untreated, blight can destroy an entire crop within a week of infection. The remedy is simple: an application of a prophylactic fungicide prior to infection. However, average losses are high, estimated at between 25 and 57% of potatoes in Bangladesh. In extreme cases, such as the 2006-2007 season, 50 to 80% of all potato crops in Bangladesh were infected with blight, resulting in severe yield losses across the country.
Farmers in Bangladesh have not been able to effectively contain blight because they face a difficult decision in choosing whether or not to
spray their crops. If farmers spray unnecessarily, they pay a cost for no benefit. If farmers do not spray when necessary, then an uncontrolled outbreak of blight can leave them ruined. Blight imposes costs on farmers twice over: first, in the immediate yield losses to
the disease and the financial deprivation that ensues if farmers fail to spray fungicide when necessary. A ruined harvest is not merely lost
income, but also lost investments in seed, fertilizer, and labor. Second, the risk of blight leads farmers to underinvest in technology and inputs for their farm, or leave their fields fallow. Why invest in high yield seeds, or new practices and technologies when they could all be destroyed?
GEOPOTATO is an information and communication technology that provides farmers in Bangladesh with timely alerts about the risk of
blight. GEOPOTATO was built on decades of research by Wageningen University & Research, and has been field-tested in
Bangladesh over the past three years. GEOPOTATO combines satellite and local weather data with an epidemiological and crop growth model to forecast blight pressure at a high geographic and temporal resolution. GEOPTOATO alerts are calibrated using two parallel models: one tracking the growth of the potato crop and the other tracking the lifecycle of blight. The potato growth model is calibrated using data on local potato varietals and sowing dates, and is updated throughout the season using satellite data. The blight model takes local weather station data as an input to predict the likelihood of a blight outbreak. It is at the intersection of these models, when we predict a blight outbreak concurrent with potatoes that are at a susceptible point in their growth cycle, that GEOPOTATO triggers an alert.
When the GEOPOTATO system detects an elevated risk of blight, it sends an SMS and voice message in the local dialect to farmers with at-risk crops, telling them that they should spray a prophylactic fungicide within the next three days. The alert is designed to be clear, timely, and actionable. Farmers, already aware of the importance of controlling late blight, can go to the village dealer to purchase
fungicide and apply it to their fields. Previously, farmers have lacked information about when and when not to spray. Even experienced
farmers who are familiar with the weather conditions conducive to blight cannot directly observe the presence of the fungal spores, or
how small changes in weather patterns affect the risk their crops face based on their precise stage of growth. GEOPOTATO alerts remove the uncertainty and guesswork over the daily risk presented by blight.