Update: New Pest & Disease Records (06 Aug 14)

A mixed infection of Papaya ringspot virus and phytoplasma has been detected in India © Scot Nelson  (CC BY-SA)
A mixed infection of Papaya ringspot virus and phytoplasma has been detected in India © Scot Nelson (CC BY-SA)

We’ve selected a few of the latest new geographic, host and species records for plant pests and diseases from CAB Abstracts. Records this fortnight include the first report of Diaporthe pseudomangiferae causing inflorescence rot, rachis, canker, and flower abortion of mango,  the first report of mixed infection of Papaya ringspot virus and phytoplasma in papaya in India and fig fly occurrence in Rio Grande do Sul State.

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Update: Plant Health News (21 May 14)

Scientists have discovered the mechanism for pink bollworm resistance to Bt cotton (David Nance, USDA)
Scientists have discovered the mechanism for pink bollworm resistance to Bt cotton (David Nance, USDA)

Here’s a taste of some of the latest stories about plant health, including the discovery of how pests develop resistance to biotech cotton, the intensification of the battle against coffee rust, and a biodiversity assessment of over 10,000 Ghanaian cocoa farms.

Click on the link to read more of the latest plant health news!
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Cotton Topping Reduces Pests

Cotton topping has been reported to reduce bollworm infestations without negatively affecting cotton yields. Scientists in Mali looked at three bollworm species, which are responsible for the majority of cotton yield losses in sub-Saharan areas of Africa, where topping is no longer employed.

Cotton Bollworm by Ombrosoparacloucycle (Flickr)

Cotton topping is an agricultural technique in which the shoot tips of cotton plants are cut off by farmers. It has been used in some sub-Saharan Africa regions to increase crop yields, but has not previously been studied in the context of reducing crop pests.

One species of concern is the cotton bollworm, Helicoverpa armigera, which is a pest of major importance in most areas where it occurs, damaging a wide variety of crops including cotton. The distribution map on Plantwise.org includes nearly 600 distribution points. The presence of two to three larvae on a cotton plant is enough to destroy all the bolls (the protective capsule that cotton grows in) within 15 days. It can be controlled  with pesticides as long as they are applied in the early stages of their growth.

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