Discover best practices to combat common fungal diseases affecting coriander crops, including prevention, identification, and integrated management methods.
A coriander grower notices white powdery spots on leaves during dry weather. Which fungal disease is most likely responsible?
Explanation: Powdery mildew appears as white powdery spots on leaves, especially in dry conditions. Downy mildew, in contrast, produces yellowing and grayish mold under humid conditions. Stem rust shows as reddish pustules mainly on stems, while root rot affects roots and leads to plant wilting rather than powdery growths.
Which practice best helps prevent damping-off, a common fungal disease, during coriander seedling establishment?
Explanation: Well-drained soil prevents excess moisture, limiting the conditions that promote damping-off fungi. Increasing shade can raise humidity, which may worsen fungal issues. Too much nitrogen can make seedlings more susceptible, and planting seeds too deep may inhibit healthy emergence and foster fungal attacks.
When sporadic yellow patches with grayish growth appear beneath coriander leaves, what is a recommended integrated management strategy?
Explanation: Crop rotation and debris removal reduce downy mildew inoculum in soil and on plant remains. Irrigating more often may worsen humidity, sugar sprays are not effective against fungi, and pruning flowers does not impact foliar diseases.
If swollen, tumor-like galls appear on coriander stems, what fungus is likely causing this, and what key symptom distinguishes it?
Explanation: Protomyces macrosporus causes distinctive stem galls in coriander, characterized by swelling. Alternaria alternata usually causes small, dark leaf spots. Fusarium oxysporum typically leads to wilting, and Sclerotinia sclerotiorum produces white, fluffy molds on stems or pods.
What is the recommended approach to using fungicides for managing persistent fungal diseases in coriander crops?
Explanation: Fungicides should be used within an integrated disease management framework, combining cultural, biological, and chemical methods for effectiveness and resistance management. Daily use or excessive application can lead to resistance and environmental harm, while ignoring other measures reduces overall control success.