Potato Late Blight Warning System in Bangladesh

Md. Rashidul Islam¹, Md. Hasibul Hasan², Md. Irfan Khan³, Md. Mahmudul Hasan², Mr. Eifaz Ahmed², Zhang Jun³, Maxime Bonnave⁴, Francois Serneels^4
1Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh-2202, Bangladesh, ²Apex Agriscience Limited, Bangladesh, ³HSJD, China and ⁴CARAH, Belgium

Background

In Bangladesh, the potato is an important cash crop with annual production over 10 million metric tons from an area of 0.50 million ha (BBS 2023). Potato late blight (PLB), caused by Phytophthora infestans (Mont. de Bary), limits its production. Ongoing changes in populations of P. infestans worldwide have major implications for the epidemiology of late blight and generally make it more difficult to control. One such major change has been the emergence of the aggressive metalaxyl-resistant clonal lineage EU_13_A2 (Blue 13). This was first identified in Europe with the earliest findings being in isolates collected in 2004 from The Netherlands and Germany (Cooke et al. 2012) and subsequently identified in China amongst isolates collected in 2005 (Li et al. 2013b). Genotyping of 124 samples from Bangladesh (2014-2019) by 12-plex SSR showed that the aggressive European lineage (EU_13_A2) is responsible for severe late blight epidemics on potato in the recent years (Islam et al. 2022). Effective management is achieved by integrating a variety of control measures that may differ in efficacy, duration of effectiveness, and cost. This complexity creates an opportunity for a decision support system (DSS) to be used to provide science-based information to assist with this decision making for precise control.

Strategy

Activity 1: Installed weather station at Apex Agriscience Ltd farm.
Activity 2: Validated weather station for retrieving the weather data.
Activity 3: Completed the coding of the CARAH potato late blight forecasting model and include its results in a small-scale producer friendly Smartphone app in English.
Activity 4: Trained the scientific staff, field technicians (both from research organization and seed companies), Sub-assistant Agriculture Officer (SAAO), DAE of the respective upazillas of the concerned districts and farmers.
Activity 5: Field trial was completed for validating the efficacy of the CARAH early warning system using two potato varieties (Sunshine and Santana) compared to the farmer’s conventional practices.
Activity 6: Assessment of the impact of using the CARAH early warning system in reducing PLB severity.
Activity 7: A field day was organized for the demonstration and validation of the field trial results.

Public and Private Partners

Bangladesh Agricultural University (BAU): BAU was established as the nation’s only Agricultural University in session 1961-62 in 1959. The vision of BAU is to produce quality agricultural graduates, scientists and researchers and to establish functional relationships with relevant government, non-government and private organizations that enable BAU to contribute meaningfully to agricultural development of Bangladesh. Professor Dr. Mohammad Rashidul Islam contributed a smooth communication between CARAH and Apex Agriscience Limited and monitored field trials in validation of the CARAH model. The roles of Professor Islam in this project were to guide the staff for timely application of the fungicides according to the message generated through the model and the master’s degree student involved to assess the late blight incidence and severity in the trail plots compared to the farmer’s conventional practices aimed to validate the warning system.

Apex Agriscience Ltd (AAL): AAL’s journey started in 1980 with its first report-oriented manufacturing enterprise “Apex Foods Limited” and has since grown into a sizeable group of companies, under the management of AHL (Apex Holdings Ltd). A wide range of manufacturing and export-oriented enterprises have been established which range from frozen and convenience foods. It specializes in sourcing, supplying and exporting the highest quality fresh vegetables, fruits and other specialty agro-commodities. Overall financial support was provided by this company to validate and ensuring its proper maintenance for the first time in Bangladesh.

Centre for Agronomy and Agro-Food Industry (CARAH): A non-profit organization registered in Belgium, is the applied research center attached to HEPH Condorcet AgriBioSciences Department, the Agricultural University of Hainaut, China. CARAH carried out a mission of approximately 5 days in Bangladesh in October 2023 to Install the weather station in Apex Agriscience Limited Farm, Connect the weather station to a fully automated platform allowing easy consulting of the CARAH model and accurate planning fungicide sprays against PLB and train the team responsible for potato production in Apex Agriscience Limited and BAU staff. The staff of CARAH assigned to this project was Dr. Maxime Bonnave, International Project Manager. Dr. Maxime has developed the automated warning platform against potato late blight in Belgium.

Beijing Huisi Junda technology Co., Ltd (HSJD): It is a high-tech enterprise specialized in the Research and Development (R&D) of monitoring pathogens and forecasting system. On behalf of CARAH, HSJD prepared and delivered one fully equipped weather station. In close collaboration with CARAH, HSJD also provided IT support and is highly flexible in adapting to specific requirements regarding software development that could be necessary to adapt to local conditions. Dr. Zhang Jun, founder and manager of HSJD, has set up and is managing the network of weather stations installed in Bangladesh and is the designer of the software implementing CARAH model.

Results

This pilot project was conducted to validate the CARAH early warning system at the Apex Agriscience Limited farm (Gobindagonj, NW Bangladesh). For 2 varieties, (Sunshine & Santana) three treatments were compared: T1 Untreated control, T2 Farmer’s conventional practices and T3 Spray according to CARAH warning system. In both Farmer’s Conventional Practices (T2) and the CARAH Early Warning System (T3), fungicides were applied in rotation. For T2, the rotation included Acrobat MZ (Dimethomorph + Mancozeb, 0.40%), Antracol (Propineb, 0.40%), and Sundomil (Mancozeb + Metalaxyl, 0.35%). In T3, the rotation consisted of Acrobat MZ (Dimethomorph + Mancozeb, 0.40%), Micra (Cymoxanil + Mancozeb, 0.40%), and Curzate M8 (Cymoxanil + Mancozeb, 0.35%).This comparison aimed to assess the efficacy of the CARAH system in managing late blight while potentially reducing fungicide use. The first infection appeared 40 days after planting (DAP). Farmers’ plots in the surroundings were sprayed up to 10 times, while plots of T3 only 6 times; on 30, 37, 43, 49, 57 and 68 DAP. No progress of infections was noticed in T2 and T3 contrasting to the T1 where PLB severity reached 100% (Sunshine) and 75% (Santana) at 60 DAP, and 90% at 90 DAP (Santana). 43 (Sunshine) and 46 (Santana) t/ha were harvested from T3, higher than the farmer’s conventional practices. Economic analyses showed a benefit cost ratio at least USD 2.99 over the investment of USD 1.00 in these two varieties if PLB is managed according to the warning system. This system replaces about 50-60% of the synthetic fungicides depending on the outbreak of PLB.

Table 1: Effect of CARAH early warning system on the reduction of PLB severity

Table 2: Economic analysis of the treatments (cv. Sunshine)

Table 3: Economic analysis of the treatments (cv. Santana)

Lessons Learned

1. By validating this model for the first time in Bangladesh, use of fungicides effectively when needed reduced total production costs.
2. Reduce the threat on human health linked to the use of synthetic fungicides.
3. Reduce the pollution of environment by avoiding unnecessary spraying of synthetic fungicides due to precision of the warning message.
4. Improved PLB control by warning system results in reducing CO2 emissions/tonne of potatoes produced.
5. The warning system, being based on real time weather data collection, contributes to climate resilience of potato production by adapting the spraying program to current weather based on daily data collected.