Most of the curling and wrinkling of leaves is usually due to viral infection, however it is usually good to show the sample or photo of the diseased leaf
SAULOSI KACHITSA
June 9, 2017 - 20:09
Curling of leaves in water melons is mainly casued by Downy mildew (Pseudoperonospora cubensis).
The symptoms of the disease include small, irregular, chlorotic spots on upper leaf surface becoming brown and necrotic; entire leaf may become blighted; infected leaves tend to curl upward from the margins. Gray to purple downy growth may be visible on underside of lesions
The disease survives only on living cucurbits; introduced into area by wind; spreads by air movement, rain-splashing and mechanically on equipment, etc.
The disease can be controlled by application of fungicides such as Mancozeb (Dithane M-45) at the rate of 2g/litre. This can be used as a protective application at an internal of 5-7 days.
Culturally the disease can be controlled by proper crop management through promotion of air movement and reduction humidity levels inside the crop canopy. Avoid excess overhead irrigation. Consider irrigating during the late morning to facilitate rapid leaf drying. Maintain good weed control in the field. Control alternate weed hosts (wild cucumber, golden creeper and volunteer cucumbers) in neighbouring fence rows and field edges. Ensure field workers wash their hands before moving from one field to another and, if possible, wear freshly laundered clothing each day. If possible, work in diseased fields at the end of the day
Answers
Most of the curling and wrinkling of leaves is usually due to viral infection, however it is usually good to show the sample or photo of the diseased leaf
Curling of leaves in water melons is mainly casued by Downy mildew (Pseudoperonospora cubensis).
The symptoms of the disease include small, irregular, chlorotic spots on upper leaf surface becoming brown and necrotic; entire leaf may become blighted; infected leaves tend to curl upward from the margins. Gray to purple downy growth may be visible on underside of lesions
The disease survives only on living cucurbits; introduced into area by wind; spreads by air movement, rain-splashing and mechanically on equipment, etc.
The disease can be controlled by application of fungicides such as Mancozeb (Dithane M-45) at the rate of 2g/litre. This can be used as a protective application at an internal of 5-7 days.
Culturally the disease can be controlled by proper crop management through promotion of air movement and reduction humidity levels inside the crop canopy. Avoid excess overhead irrigation. Consider irrigating during the late morning to facilitate rapid leaf drying. Maintain good weed control in the field. Control alternate weed hosts (wild cucumber, golden creeper and volunteer cucumbers) in neighbouring fence rows and field edges. Ensure field workers wash their hands before moving from one field to another and, if possible, wear freshly laundered clothing each day. If possible, work in diseased fields at the end of the day