Leaffolder on RICE (Cnaphalocrosis medinalis)

LIFE CYCLE:
Leaf rollers complete a full life cycle in a month.

DAMAGE:
-Scalding the leaf surface and became whitish streaks on leaf blades.
-Fold the leaf tips on the larva stage and feed the leaf tissues.
-Pest outbreak in short time if no action of control taken, infestation the whole field in just few days time.
-Larva stage is actively feeding on the leaves tissues during tillering to booting stage and they will spin the web to make the upper leaves into longitudinally folded.
-Larva is naturally favour to feed on young rice plants, especially those with high Nitrogen fertilized.

Heavily infested by leaffolders during active tillering stage

Infestation of leaffolders on hardening stage

Older leaves is folded like spikes

Larva Stage of leaffolder

Adult of leaffolder

CHEMICAL CONTROL:
-In general, most of the insecticides in the rice market can have good control on leaf rollers. e.g. buprofenzin (Applaud), cartap (Padan), acephate.
-Imidacloprid (Nuprid, Confidor), thiamethoxam (Actara) and dichlorvos (CH dichlorvos 42) have broad-spectrum control on planthopper, leafrollers as well as stem borer.

 Additional info:

http://www.scribd.com/doc/209942573/Integrated-pest-management-of-leaf-folder-Cnaphalocrocis-medinalis-Guen-in-rice
http://www.cropscience.bayer.com/Crop-Compendium/Pests-Diseases-Weeds/Pests/Cnaphalocrocis-medinalis.aspx
http://www.fintrac.com/cpanelx_pu/cambodia/12_13_5906_Technical-Bulletin-44-Rice-Leaffolder-English%20revised.pdf
http://www.knowledgebank.irri.org/decision-tools/rice-doctor/rice-doctor-fact-sheets/item/rice-leaffolder?category_id=345

Tomato Bacterial Wilt

Tomato bacterial wilt is a very destructive disease in green house planting in Cameron Highlands, caused by Ralstonia solanacearum, soil-borne pathogens. Harvesting could be ended after the first harvest, usually 2 months after transplanting. Disease getting severe after first harvest and start spreading from plant to plant, probably because harvesting tools used as the vector transmitting the inoculums. Healthy tomato plants in Cameron commonly can harvest up to 6 months.

 

Bacteria infection causing blockage of the vascular system, preventing water and nutrient transportation, symptoms started with wilting WITHOUT ANY LESIONS, followed with canker stretching over the basal stem, near the soil line. The canker symptom could be confusing with Botrytis cinerea, but its infection can be observed on leaves, fruit peduncle as well as stem. Fruits produced are small and inferior.

 

To differentiate the bacterial from fungal infection, cross cut the basal stem and dip into a glass of water, bacteria ooze will stream out from the stem.

 

Canker symptom appear on the basal stem.
 

Plants died off and fruits awaiting last harvest.

 

Great loss caused by the TBW.



 

 

 

Papaya Dieback Disease

Papaya (Carica papaya) dieback disease WITH NO EFFECTIVE CHEMICAL CONTROL

was discovered firstly in Java Island in 1913. Disease is caused by Erwinia papayae, which can survive in soil for 2 weeks as transient soil inhabitant and believed spread by human activity, birds or insects.

Symptoms:

1. Leaves
Water-soaked necrotic leaves from leaf tips to leaf vein.

Water soaked necrotic lesion
 

2. Shoot
Water-soaked lesions appear at the leaves stalk base and shoot, as well as the crown.

Advanced state of disease infection

3. Fruit
Started with sunken black spots which enlarges gradually.

Circular dark green lesion coalesces.