Common fungal infections plaguing sesame crops

“I lost everything growing sesame. My yield was pitiful, barely covering costs. Sesame farming isn’t for me—it’s not profitable. Diseases and fungi have cursed my fields, destroying my crops.” These are the anguished cries of inexperienced farmers, unaware of the science and skill needed to master sesame cultivation. Like all agriculture, sesame farming isn’t a game of chance or a quick scheme—it’s a craft rooted in understanding plant needs and combating their diseases.

In today’s blog post, we explore  and share practical solutions to help farmers safeguard their yields, protect their profits, and avoid devastating losses.

Common Fungal Diseases in Sesame

Alternaria Leaf Spot

Alternaria Leaf Spot

A Small, dark brown to black spots with concentric rings on leaves, often leading to premature leaf drop. Severe infections can affect stems and pods, reducing seed quality.

Impact: Reduced photosynthesis, lower seed yield, and poor oil content.

Cercospora Leaf Spot

Irregular grayish-white spots with dark borders on leaves, which may coalesce, causing large dead areas. Infected leaves may yellow and drop prematurely.

Impact: Decreased leaf area, reduced seed weight, and lower yield.

Powdery Mildew

Symptoms: White to grayish powdery patches on leaves and stems, which may turn yellow or brown over time. Severe cases lead to distorted leaves and stunted growth.

Impact: Reduced photosynthesis and poor seed development.

Fusarium Wilt

Wilting, yellowing, and drooping of leaves, often starting from the lower part of the plant. Vascular tissues may show brown discoloration, and plants may die prematurely.

Impact: Complete plant loss in severe cases, leading to significant yield reduction.

Solutions for Managing Fungal Diseases in Sesame

Effective management of fungal diseases in sesame requires an integrated approach combining cultural, biological, and chemical strategies. Below are practical solutions to prevent and control these diseases:

Cultural Practices
  • Crop Rotation: Rotate sesame with non-host crops like cereals or legumes for 2–3 years to break the disease cycle and reduce soil-borne pathogens like Fusarium
  • Field Sanitation: Remove and destroy crop residues after harvest to eliminate fungal spores. Avoid planting sesame in fields with a history of fungal diseases.
  • Proper Spacing: Use adequate plant spacing to improve air circulation, reducing humidity around plants and minimizing conditions favorable for diseases like powdery mildew.
  • Timely Planting: Plant sesame early in the season to avoid peak disease periods, especially for diseases like charcoal rot, which thrive under high temperatures and drought.
  • Water Management: Avoid waterlogging and ensure proper drainage, as excessive moisture promotes diseases like Fusarium wilt and charcoal rot.
Chemical Control

Chemical control is a very effective way to control fungi in sesame farm which can be done by either effective seed treatment of the use of fungicide

Fungicides: Apply fungicides like Azoxystrobin, Difenoconazole, carbendazim, mancozeb, or copper-based fungicides for foliar diseases such as Alternaria and Cercospora leaf spots. For powdery mildew, sulfur-based fungicides or triazoles may be effective. Always follow local regulations and recommended application rates.

Seed Treatment: Treat seeds with fungicides like thiram or captan before planting to protect against soil-borne pathogens like Fusarium and Macrophomina.

Timing: Apply fungicides at the first sign of disease or as a preventive measure during high-risk periods (e.g., high humidity or warm temperatures).

For Farmer in Nigeria and many African country can use the following Fungicide for fungi treatment in sesame field.

 5Star by Rainbow

Active ingredient: Azoxystrobin 200g/l + Difenoconazole125g/l

Application rate: 500ml/ha (30-40ml per 20lt Knapsack)

Blue Snow by SARO

Active ingredient: Azoxystrobin 200g/l + Difenoconazole125g/l

Application rate: 500ml/ha (30-40ml per 20lt Knapsack)

 

Monitoring and Early Detection
  • Regularly scout fields for early signs of fungal diseases, especially during flowering and pod formation stages when sesame is most vulnerable.
  • Use diagnostic tools or consult local agricultural extension services to confirm the presence of specific pathogens and tailor control measures accordingly

Conclusion

Fungal diseases pose a significant challenge to sesame production, but with proactive management, their impact can be minimized. By adopting resistant varieties, practicing good field hygiene, and using targeted chemical control, farmers can protect their sesame crops and ensure healthy yields. Regular monitoring and adapting to local conditions are key to staying ahead of these diseases.

Happy farming, and may your sesame fields thrive!

Sesame Production in Nigeria

sesame aggregation

Nigeria is a significant player in the global sesame market, particularly as an exporter. In 2023, Nigeria being the second-largest exporter in Africa and the fourth-largest globally, with a value of $459.4 million, according to Tridge. The country’s exports are a key contributor to the non-oil sector, with a substantial portion going to Japan, China, and other Asian markets.

This growth is attributed to a 2% expansion in cultivated land, favorable weather conditions, and a 40% price surge, incentivizing smallholder farmers, who dominate over 90% of production. Nigeria’s sesame sector is export-oriented, with about 80–90% of output shipped to international markets, primarily China, Japan, and Turkey, generating significant foreign exchange (e.g., N89 billion in 2018)

Nigeria is a significant player in the global sesame market, being the second-largest exporter in Africa and the fourth-largest globally. Sesame is a crucial non-oil export for the country, contributing substantially to agricultural GDP and overall economic growth.

Here’s a breakdown of sesame production and market in Nigeria:

Sesame Production in Nigeria

  • Major Growing Regions: Sesame is widely grown as a cash crop in the savanna agro-ecological zones, particularly in the central and northern parts of the country. Key producing states include:
    • Jigawa
    • Niger
    • Nasarawa
    • Benue
    • Taraba
    • Kano
    • Gombe
    • Kogi
    • Plateau
    • Sokoto
    • Borno
    • Federal Capital Territory (FCT)
    • It can also be successfully grown in some parts of the South East and South South, such as Ebonyi and northern Cross River States.

 

  • Types of Sesame:
    • White (Food Grade) Sesame: Generally used in the bakery industry and grown around Keffi, Lafia/Makurdi, Doma, and in Nasarawa, Taraba, and Benue States.
    • Brown/Mixed (Oil Grade) Sesame: Primarily used for oil production and grown in the North, in Kano and Jigawa States (around Hadejia), and somewhat in the Southern part of Katsina State.
  • Production Statistics:
    • Nigeria produced 509,712 metric tons of sesame seeds in 2022, making it the fourth-largest producer globally (FAO).
    • There has been remarkable growth in sesame production since 1960 due to increasing domestic and international demand.
    • Approximately 90% of the sesame produced in Nigeria is exported.
  • Challenges in Production:
    • Low Yield per Hectare: Average output in Nigeria is around 275 kg per hectare, significantly lower than other major producers (e.g., Saudi Arabia at 1,083 kg/ha, Venezuela at 1,960 kg/ha, China at 1.4-1.6 tons/ha). This is attributed to:
      • Lack of adherence to best farm practices.
      • Knowledge gaps and poor crop management by smallholder farmers.
      • Poor processing procedures.
    • Inadequate Finance: Farmers often face limited access to credit and advanced farming tools.
    • Pests and Diseases: Prevalent pest and disease issues, sometimes exacerbated by a lack of proper knowledge and agro-chemicals.
    • Poor Agricultural Extension Services: Limited access to updated methods and information for farmers.
    • Theft: A significant concern for sesame farmers.
    • Inadequate Storage Facilities: Leads to post-harvest losses and limits Nigeria’s ability to capitalize on the crop’s long shelf life.
    • Quality Inconsistencies: Aggregating harvests from various smallholder farmers can lead to varying qualities, resulting in rejections in the export market.
    • Climate Change Impact: Affects agricultural productivity.

Sesame Market in Nigeria

  • Export-Driven Market: The Nigerian sesame market is primarily export-driven, with Europe, Asia, and the Middle East as key destinations.
  • Major Export Destinations: China, Japan, and Turkey are primary markets. Japan alone accounts for about 40% of Nigeria’s sesame exports.
  • Export Value:
    • Sesame seeds led Nigeria’s agricultural exports in Q1 2024, valued at ₦247.75 billion (US$161M), marking a 99% increase from Q4 2023.
    • Exports surged from ₦73.8 billion in 2014 to ₦1 trillion in 2024.
    • In 2023, Nigeria exported sesame seeds worth $463.827 million.
  • Market Trends:
    • Rising Global Demand: The global demand for sesame is expected to continue growing due to increasing preference for organic foods and its health benefits.
    • Price Volatility: Export prices have fluctuated, reflecting ongoing market instability.
    • Focus on Quality and Compliance: There’s a strong emphasis on enhancing export quality and reducing rejection rates, especially concerning pesticide residue levels and sanitary and phytosanitary standards, particularly for markets like Japan.
    • Value Addition: Stakeholders are pushing for processing sesame seeds into higher-value by-products like butter and oil to unlock more revenue and create jobs, as exporting raw seeds leaves significant potential revenue untapped.
    • Traceability: Becoming increasingly important, especially in demanding markets.
  • Market Challenges:
    • Quality Inconsistencies: As mentioned under production, this is a significant barrier to meeting international standards.
    • Limited Processing Plants: Only a few functional processing plants exist, hindering the production of high-quality seeds for export.
    • Inadequate Infrastructure: Affects transportation, storage, and overall logistics.
    • Trade Barriers: Stringent import regulations in major importing countries.
    • Fluctuating Global Prices: Impacts profitability for farmers and exporters.
    • Limited Access to Structured Markets: Many producers struggle to connect directly with international buyers.

The Nigerian government and various organizations are working to address these challenges through initiatives aimed at improving quality, providing training, streamlining regulatory processes, and enhancing infrastructure to strengthen Nigeria’s position in the global sesame market.