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 Plasma-zapping process could yield trans fat-free soybean oil product
02.12.2016 | Purdue University

nachricht New findings about the deformed wing virus, a major factor in honey bee colony mortality
11.11.2016 | Veterinärmedizinische Universität Wien

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: Electron highway inside crystal

Physicists of the University of Würzburg have made an astonishing discovery in a specific type of topological insulators. The effect is due to the structure of the materials used. The researchers have now published their work in the journal Science.

Topological insulators are currently the hot topic in physics according to the newspaper Neue Zürcher Zeitung. Only a few weeks ago, their importance was...

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Researchers identify potentially druggable mutant p53 proteins that promote cancer growth

09.12.2016 | Life Sciences

Scientists produce a new roadmap for guiding development & conservation in the Amazon

09.12.2016 | Ecology, The Environment and Conservation

Satellites, airport visibility readings shed light on troops' exposure to air pollution

09.12.2016 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>