Colletotrichum leaf fall disease

In the rubber plantations are deciduous term illness . Colletotrichum leaf fall disease is a disease that is relatively new on the rubber in Indonesia . In addition to attacking the leaves , the disease can occur in the green parts of plants such as fruit and twigs rubber . Heavy attack on the young leaves of the newly formed deciduous leaf after leaf drop can cause a lot of young secondary is called deciduous . This is especially true if the development of the young leaves takes place in wet weather . While the weather is relatively dry , secondary leaf fall by the caused by iodine . This disease can also occur in nurseries and budwood gardens .

Cause of leaf fall disease is by the caused by the fungus Colletotrichum gloeosporioides . In addition to the rubber , this fungus can also cause disease on cocoa , coffee , citrus , avocado , and so on .

Symptoms of deciduous attacks are as follows :
- The leaves of susceptible young for approximately 15 days after the buds open . After that time the leaves are fully open , the color has changed from green to pale bronze color , the leaves are relatively more resistant . Therefore if the infection Occurs in the early part of the 15 days , the leaves will wither and fall off , but if infection Occurs after that time the leaves are relatively more resistant so even attacked but not killed .
- Attacks on young leaves causing blackish brown splotches in the middle and then Followed wrinkled leaf blade , wet rot incidence in the affected area, and eventually fall .
- In older leaves ( aged more than 10 days ) Causing brown blotches with halo ( ring - shaped boundary) and yellow leaf Becomes rough surface . Further attacks cause the patches to be perforated .
- Attacks on young twigs are still green cause rot symptoms , dry and eventually die back .

The factors that influence the spread of this disease are :
- The development of the disease is greatly aided by moisture . Therefore if there is a lot of rain at the time of the formation of new leaves after the autumn leaves ( deciduous ) will usually severe attack .
- The gardens are located rather high in general more Heavily attacked .
- Vulnerability Affect clones disease progression . Each clone has a different susceptibility to this disease .

This disease can spread through spores occur mainly by the caused by wind , dew or rain water .

To control leaf fall disease is done by combining some suitable control measures. The control measures are :
- Technical culture
Control of the technical culture more and more indirect preventive , for example :

• To Prevent the planting system , roomates is the recommended planting resistant clones 3-4 in the planting area of ​​the types of clones with resistance properties .
• Improve the condition of plants , among others :

1. Fertilization in accordance with the recommended dosage . Plants need to be fertilized with a dose sufficient to reduce the influence of spur defoliation and plant growth . For this purpose fertilizer with a low dose performed several times better than fertilizing at the same time with high doses .
2. Field sanitation , weed control on a regular basis especially around ( disc ) plants .
3. Garden drainage to avoid ponding of water in the garden .
4. Reducing the frequency of tapping

- Chemical
The use of fungicides is recommended to protect the plant from attack Colletotrichum .