Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Coconut lethal yellowing in Ghana: a new hybrid is being tested

04.09.2006
Coconut is a major source of income for farmers along the Ghanaian coast. However, it has been hit by the devastating effects of a small wall-less bacterium, a phytoplasma, which causes coconut lethal yellowing disease.

The disease has already destroyed coconut plantations in several world regions: East Africa, the Caribbean and Central America. Like all known phytoplasma diseases, it is probably transmitted by an as yet unidentified insect. Attacks result in fruit fall and in frond yellowing and then frond fall. The palms die within a few months, leaving a field of bare stems.

In western and central Ghana, lethal yellowing disease has been wreaking havoc since 1964. Within around twenty years, more than 6 500 hectares were devastated. To date, just one variety, the "Sri Lanka Green Dwarf" seems to be resistant, but trials have shown that it does not adapt easily to the growing conditions in Ghana. The "Malayan Yellow Dwarf", however, has proved to adapt well in the past. Lastly, the "Vanuatu Tall" is less severely affected than the local "Tall" variety. There are thus plans to replant with hybrids between "Dwarf" and "Tall" varieties.

Based on observations made in the 1980s-90s, researchers began testing a hybrid in 1999, obtained by crossing the "Malayan Yellow Dwarf" variety with the "Vanuatu Tall". The trials were launched under a programme conducted by CIRAD in Ghana, from 1999 to 2004, as part of an operation to support the commodity chain, funded by the Agence française de développement. In all, almost 210 000 plants were distributed to more than a thousand growers, who replanted 1 300 hectares of coconut plantings.

Unfortunately, the results were not convincing. In zones where the disease is very active, the hybrid was affected as soon as the second year. Moreover, the "Vanuatu Tall" has no longer been resistant to the disease since 2003. In the centre of the country, one-hectare plots have already suffered substantial losses: between 19 and 80% in less than five years. Although a large number of plots are still unaffected today, once the disease occurs, there is very little chance for smallholders.

Moreover, the trees need to grow correctly from the outset. Again, the results have been mixed: two thirds of the farms observed during the project obtained growth rates similar to those of reference plantations, or showed only a slight delay. However, the remainder fell well short of the standard growth models. There are many reasons for this variability (soil fertility, water stress, cropping practices, pressure from insect pests, etc).

The strategy in future will consist in only distributing the hybrid to areas with low parasite pressure. In central Ghana, where that pressure is high, a new variety is due to be tested: a cross between the "Sri Lanka Green Dwarf" and the "Vanuatu Tall". Moreover, a project financed by the Fonds de solidarité prioritaire (FSP) has just been luanched. It is managed by the Cooperation and Cultural Aid Service at the French Embassy in Ghana, and in particular includes a study of the pathogen, its variability and its diagnosis, a "vector determination" component and another component on "agro-socioeconomics", which includes a study of farmers' strategies and practices in response to the disease.

Helen Burford | alfa
Further information:
http://www.cirad.fr/en/actualite/communique.php?id=513

More articles from Agricultural and Forestry Science:

nachricht Researchers discover a new link to fight billion-dollar threat to soybean production
14.02.2017 | University of Missouri-Columbia

nachricht Important to maintain a diversity of habitats in the sea
14.02.2017 | University of Gothenburg

All articles from Agricultural and Forestry Science >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

From rocks in Colorado, evidence of a 'chaotic solar system'

23.02.2017 | Physics and Astronomy

'Quartz' crystals at the Earth's core power its magnetic field

23.02.2017 | Earth Sciences

Antimicrobial substances identified in Komodo dragon blood

23.02.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>