Citrus anthracnose is a destructive disease that can wreak havoc on citrus crops. It’s characterized by dark, sunken lesions on leaves, stems, and fruit, which can reduce crop yields and lower the quality of the fruit. But with proper identification and control measures, citrus growers can keep this disease at bay. In this blog post, we’ll dive into the causes, symptoms, and methods of controlling citrus anthracnose, so that you can protect your citrus trees and ensure a healthy, bountiful harvest.

What are the Symptoms of Citrus Anthracnose Disease? 

1. 1. The old leaf or the leaf that has become a little old will first have green spots. The color of these spots soon turns brown.
      
      

      Citrus Anthracnose Diseases infected leaf. Image Source: Collected

   2. A kind of fungal structure is produced like a black dot in the parts affected by humid weather. These points are called acervuli.
   3. Anthracnose disease is more on the front and edges of the leaf. Affected branches begin to dry from the top downwards. This is why many people call this disease Die-back disease. (Figure 1).
      
      

      Die-back Diseases (Figure 1).

   4. The leaf falls off as soon as the stalk dries and sometimes the stalk dries up before the leaf is shed. Due to this, numerous dead, half-dead, or rotten branches without leaves are found in the affected plants. If the incidence of the disease is high, the larger branches also become infected and turn yellow. Gradually the leaf of the affected branches drop off and wither. Dead branches also have a lot of black spots (Esarvuli). If the tree has fruit in this condition, the fruit drop can also be infected with this disease. If bota is infected, the fruit becomes weak and the fruit drops.
      
      

      Citrus Anthracnose Disease-infected Fruit. Image source: Collected

   5. Hard wrinkled brown spots appear on the affected fruits. All these fruits rot if stored in the warehouse.

What Cause of Anthracnose disease?

Anthracnose is a fungal infection that affects citrus plants, including oranges, lemons, limes, grapefruits, mandarins, and tangerines. The disease can rapidly spread throughout the tree limbs via wind-blown fragments.

The cause of anthracnose disease is two types of fungus: Gloeosporium limiticolumus and Colletotrichum gloeosporides. 

Anthracnose disease caused by the fungus Colletotrichum gloeosporides is called die-back disease.

Colletotrichun produces black cut-like setae on acervuli. Cita is divided by the cell wall and has a sharp groove-like cut in the anterior direction. Gloeosporium fungi do not produce setae in acervuli. Both fungi are colorless. Produces unicellular conidium.

How do the Origin and spread of The disease?

Anthracnose disease spores reside in the soil and on abandoned parts of infected plants. Sowing or planting seedlings in disease-contaminated seedbeds causes infection. From affected trees by water splash and wind Conidium spreads on large trees. The black dots on the affected parts burst with rain in spring and the conidia are released comes and attack all the plants of the season. Anthracnose disease especially early blight attacks the plant at a vulnerable moment. That is if there is a lack of sufficient water and necessary nutrients in the soil if there are substances harmful to the plants in the soil, and when the plants are weakened due to excessive heat, wind, etc, the germs of this disease easily attack the plants.

How To Control Citrus Anthracnose Disease?

1. 1. Seedlings should be produced in disease-free seedbeds and then planted in disease-free gardens. 
   2. When the seedlings are growing up, they should be sprayed with resin bird mixture in the ratio of 4: 4: 50 once in January and again in September to keep them disease free. 
   3. The application of suitable fertilizers and regular irrigation around the roots is necessary to ensure that the plant does not become weak due to a lack of necessary nutrients. 
   4. Due to excessive hot air blowing, the tree becomes weak. So, if possible, the direction from which the hot air comes should be fenced by planting other trees. 
   5. It is very important to keep watering the plant every week during the hot season. 
   6. High alkalinity in the soil disrupts the plant’s food supply and weakens the plant. Therefore, if the soil is more alkaline, 4.5 kg of gypsum should be applied to each plant. 
   7. Affected parts should be pruned every year after harvesting. While pruning the affected part, 10 cm below the scar should also be pruned the healthy part. Because the mycelium of the fungus stays up to several centimeters through the part that looks healthy under the scar. 
   8. Trimmed parts should be carefully collected and buried or burned. 
   9. Copper fungicide should be sprayed immediately after pruning. Otherwise, the spores can enter the plant body through the cut wound and cause disease.

Conclusion

Anthracnose is a significant threat to citrus crops, causing dark, sunken lesions on leaves, stems, and fruit. However, with proper identification and control measures, citrus growers can effectively combat this disease and protect their crops. By understanding the causes and symptoms of anthracnose and exploring various methods of control, we can work towards ensuring a healthy, abundant harvest of one of the world’s most important and beloved fruits. Let’s continue to prioritize research and development in this area so that we can effectively address the challenges posed by anthracnose disease and safeguard our citrus crops for years to come.

Contact us if you have any questions about citrus anthracnose after reading the article. You can send samples of any crop problem to our expert team, which will be resolved within 24 hours.