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http://www.seedquest.com/news.php?type=news&id_article=54725

A ProMED-mail post    <http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>

Date: September 2014

Source: European Plant Protection Organisation (EPPO) Reporting Service 9/2014/164 [edited] <http://archives.eppo.org/EPPOReporting/2014/Rse-1409.pdf>

 

A systematic survey for the presence of potato cyst nematodes (_Globodera rostochiensis_ and _G. pallida_ — both EPPO A2 List) was initiated in Bosnia and Herzegovina in 2011. Until 2012, only _G. rostochiensis_ had been detected in Bosnia and Herzegovina.

In autumn 2012, viable cysts were found in 2 soil samples originating from 1 field located 70 km [about 43 miles] east of Sarajevo.

Morphological and molecular analysis confirmed the occurrence of _G. pallida_ in these samples. More samples were collected from the other fields of the grower concerned, as well as from their surroundings, but no cysts were found in these additional samples.

A more intensive sampling regime was implemented in the infested field (1.1 ha [2.7 acres]) and revealed a high infestation of 1 cyst per gram of soil in the infestation focus. The high infestation level and the use of farm-saved seed potatoes by the grower suggest that the introduction of _G. pallida_ probably took place several years before via imports of infected seed potatoes.

Phytosanitary measures were taken on the infested field (prohibition to grow potatoes for the next 6 years, continuing sampling).

communicated by: ProMED-mail <promed@promedmail.org>

[Both golden (_Globodera rostochiensis_, with at least 5 races) and pale (_G. pallida_) potato cyst nematodes (PCNs) cause serious crop losses in potato. Other solanaceous crops (such as tomato) and weeds may serve as pathogen reservoirs. PCN symptoms on potato include stunting, yellowing, and wilting of leaves as well as a reduced root system. PCNs may lead to complete crop failure. Diseased plants first occur in isolated patches and these become larger with each new crop.

The nematodes can survive in soil for up to 20 years as cysts. Spread occurs via infected soil, water, wind, or on plant material (such as the seed potatoes suspected above). Disease management includes exclusion, long crop rotation with non-host species, use of crop cultivars resistant to specific PCN races and nematicides. These control measures can be combined to keep nematode levels below economic thresholds. Both PCNs have been included on the quarantine lists of the European Plant Protection Organisation (EPPO).

In the Eurasian area, golden PCN is widespread but pale PCN has a more restricted distribution and its detection in specific areas is considered of significance to the respective region. It would be important to ascertain the original source of the infection in Bosnia and Herzegovina, as that location would also require appropriate measures to improve the health of local solanaceous crops.

Maps

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PUBLIC RELEASE DATE: 3-Jul-2014

Contact: Caroline Wood
cwood4@sheffield.ac.uk
44-7771-765335
Society for Experimental Biology

http://www.eurekalert.org/pub_releases/2014-07/sfeb-owh062714.php

 

Many modern crops have high productivity, but have lost their ability to produce certain defence chemicals, making them vulnerable to attack by insects and pathogens. Swiss scientists are exploring ways to help protect 21st century maize by re-arming it with its ancestral chemical weapons.

The researchers, led by Dr Ted Turlings (University of Neuchâtel, Switzerland), found that many varieties of modern maize have lost their ability to produce a chemical called E-β-caryophyllene. This chemical is normally produced by traditional ancestors of modern maize roots when the plant is under attack from invading corn rootworms. The chemical attracts ‘friendly’ nematode worms from the surrounding soil which, in turn, kill the corn rootworm larvae within a few days.

The scientists used genetic transformation to investigate if restoring E-β-caryophyllene emission would protect maize plants against corn rootworms. After introducing a gene from oregano, the transformed maize plants released E- β-caryophyllene constantly. As a result, these plants attracted more nematodes and suffered less damage from an infestation of Western Corn Rootworms.

“Plant defences can be direct, such as the production of toxins, or indirect, using volatile substances that attract the natural enemies of the herbivores” says lead scientist, Dr Ted Turlings (University of Neuchâtel, Switzerland). One of the types of toxins that maize plants produce against their enemies is a class of chemicals called benzoxazinoids. These protect maize against a range of insects, bacteria and fungi pests, yet some species have developed resistance against these toxins and may even exploit them to identify the most nutritious plant tissues.

These results show how knowledge of natural plant defences can be practically applied in agricultural systems. “We are studying the wild ancestor of maize (teosinte) to find out which other chemical defences may have been lost during domestication of maize” Dr Turlings added. “These lost defences might then be reintroduced into modern cultivars”.

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Book Review: Rice Pests of Bangladesh- Their Ecology and Management
Authors: Zahirul Islam and David Catling

The University Press Limited
Red Crescent House, 6th Floor
61 Montijheel C/A
GPO Box 2611, Dhaka 1000
Bangladesh
Website: http://www.uplbooks.com.bdo
e-mail: upl@bangla.net

2012, 422 pages
ISBN: 978 984 506 048 6
2003, 512 pages
Price: Tk. 1600.00
Hard cover

Rice Pests of Bangladesh provides a comprehensive coverage of all of the abiotic constraints to rice production in the field and of pests in storage. The quality of this publication is enhanced by the fact that it brings together the accumulated data and experience of the two authors over the last 30 years. The 14 chapters and 422 pages cover all aspects of rice pest management including pests, yield loss, major control strategies and rice IPM.

Chapter 1 is entitled “Bangladesh and Rice.” Chapter 2 discusses the concepts of rice growth and pest status. Chapters 3-7 cover the early vegetative insect pests, general defoliators, stem borers, sap feeders and minor invertebrate pests. Chapter 8 discusses the vertebrate pests; rodents and birds. Chapter 9 provides a comprehensive coverage of the rice diseases; fungal, viral, bacterial and nematodes. The major weed species, their ecology severity and management are covered in Chapter 10. Chapter 11 explains the concepts of yield loss including mechanisms, plant compensation and yield loss assessment methods. Pests of rice in storage including insects, fungi and rodents are explained in Chaptger 12. Provides a detailed coverage of the major control strategies including cultural control, plant resistance, biological control and chemical control and pesticides. Chapter 14 covers the IPM of rice pests; concepts, principles, current management systems and new concepts for IPM in Bangladesh rice production.

This profusely illustrated book with an underlying IPM and ecological approach takes a fresh look at yield losses from insects and diseases and contains a wealth of information for rice plant protection specialists. It is specifically targeted to students, teachers, researchers, extension officers and agricultural development workers. The value of this book is enhanced as the information therein is not only relevant to Bangladesh but also applies to the Indian states of West Bengal, Assam and Bihar.

Prof. E. A. “Short” Heinrichs
Associate Director Emeritus
University of Nebraska
Lincoln, NE 68583-0748 USA

Research Professor, UNL Department of Entomology
Secretary General, International Association for the Plant Protection Sciences (IAPPS)
Email: eheinrichs2@unl.edu

 

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