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News brief
Non-paralysing success with non-toxic legumeResearchers at ICARDA have recently bred and harvested the first lines of a
previously toxic legume that may now be eaten without fear of paralysis.
Grasspea (Lathyrus sativus), also known as chickling pea or Indian
vetch, can withstand weeks, even months, without rain as well as endure long
periods of water-logging. Whilst harmless to humans in small quanities, a
steady diet of grasspea seeds over several months can result in irreversible
paralysis of the leg muscles and, under certain conditions, retardation and
death in young children. Farmers plant grasspea primarily as a forage crop for
livestock, which are unaffected by the toxins and yet, despite the risk,
thousands of people confronting drought and crop failures in Ethiopia, India,
and Pakistan will also use the crop to supplement their meagre diets.
Researchers from national programmes are currently being trained by ICARDA
scientists to develop locally adapted selections of the newly developed
non-toxic hybrids, which remain tolerant to drought and water-logging, and to
begin seed production programmes in countries most in need.
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Leaf miner pest in Malawi
An important pest of legumes in eastern and southern Asia has been reported
for the first time in Malawi. An outbreak of leaf miner (Aproaerema
modicella Deventer) in groundnut was observed in northern Malawi with
affected leaves appearing burnt due to shrivelling and desiccation. Mild
infestation was also observed on pigeonpea grown as a mixed crop in groundnut
fields but was not observed on other legume crops (e.g. bambara groundnut,
common beans and cowpeas) in the area although it is known to affect soybean.
In recent years, leaf miner has caused considerable damage to groundnut crops
in Uganda but scientists at ICRISAT are unaware of any other previous outbreaks
of leaf miner in Malawi and other parts of Africa. Leaf miners are not believed
to migrate any distance and it should be possible to eradicate the pest from
the primary foci of infestation. Monitoring of the pest, using pheromone traps
at all locations where the leaf miner has been observed, has been advised for
coming season. Scientists at ICRISAT are asking for any information on the
occurrence of groundnut leaf miner in other parts of Africa to be reported to
them in order to determine seasonal occurrence, distribution, host range, yield
losses and biology of this pest. Diversity for combating diseaseResearchers working with farmers in China have shown that growing several
rice (Oryzae sativa) varieties as a mixture within a field over two
years has increased yields (89%) and dramatically decreased the incidence of
disease (94%). Monocultures of a single variety of cereal crops are easier to
plant, harvest and market but yields can be severely reduced if these identical
plants are prone to attack by disease. By growing several disease-resistant
rice varieties as a mixture, Zhu Youyong and colleagues have demonstrated in a
trial involving thousands of farmers in the Yunnan province that the level of
fungal rice blast was reduced and spraying with fungicides was not required. By
hand harvesting, a common practice among rice farmers in the Province,
different varieties could still be separated and marketed. Martin Wolfe of
Wakelyns Agroforestry in the UK writes in Nature (Vol 406) that mixtures
of species would provide even greater diversity and further restrict the spread
of diseases, pests and weeds. Threat of silverleaf whitefly in India
The silverleaf whitefly, Bemisia argentifolii, otherwise known
as the 'B' biotype of B. tabaci, has been identified for the first
time in India. Discovered near Bangalore, this whitefly attacks a wider
range of crops, reproduces more rapidly, inflicts more damage, and is
more resistant to insecticides than the indigenous Indian biotype. High
populations of the B biotype recently caused failure of the tomato crop
in an important vegetable production area near Bangalore, through direct
damage to plants, as well from the effects of tomato leaf curl virus disease
(ToLCVD), which is caused by one of the viruses that it transmits. Scientists
at NRI funded by the DFID Crop Protection Programme, working in
collaboration with the University of Bangalore identified the B biotype.
In collaboration with AVRDC, these scientists are working on developing
ToLCVD-resistant tomato lines, which are currently being cleared for release
and could be available at the end of the year. Although local small-scale
farmers have welcomed these resistant tomato varieties, the silverleaf
whitefly could soon spread to affect a wider range of crops, including
many vegetables, tobacco and cotton. New technologies continue to be explored
in the U.S. for combating this whitefly, which has created a multibillion-dollar
dent in U.S. agricultural earnings. Success with seed priming
A new website dedicated to providing more information on seed priming
has been launched by DFID's Plant Sciences Research Programme based at
the Centre for Arid Zone Studies, Bangor, UK. The seed priming project
is currently involving collaboration with farmers in 15 countries in Africa
and Asia and with a variety of different crops (upland rice, wheat, barley,
maize and chickpea) including on saline soils (see also Developments 99-4). On-farm trials, have established
that overnight soaking is sufficient to achieve better germination, faster
and more vigorous growth of seedlings, earlier flowering and maturing
of crops and more resistance to dry periods. In the Barind region of Bangladesh,
recent data analysis has just confirmed that seed priming with chickpea
has resulted in increased crop yields of 50% and 20% in two consecutive
years. The new website will serve to provide updated results and contact
information for anyone interested in using this simple but successful
technology. Pesticides and parasitesPesticides are the suspected cause for the devastating decline in the lobster population off the coast of New York. Preliminary tests on lobsters from Long Island Sound have found traces of pyrethroid and researchers believe that that this may be linked to an outbreak of West Nile virus in New York last year. In an attempt to prevent another outbreak of the virus, which is spread by mosquitoes, several eastern coastal states sprayed large quantities of insecticide. Although the US Environmental Protection Agency restricts spraying to land, scientists have surmised that heavy storms caused by Hurricane Floyd at the time of spraying may have washed large amounts of the pyrethroid chemicals into the sewers which flow into the Sound. Although the pesticides may have been sufficient to cause the fatalities, a Paramoeba parasite has also been found in the nervous system of lobsters studied which may indicate that the insecticide affected the lobsters' immune system, allowing the parasite to overwhelm the population. Beekeeping for rural developmentThe significant role that beekeeping can play in sustainable livelihoods is to be discussed at an International Symposium at the University of Wales Swansea, UK during 18-20 September, 2000. Beekeeping spans many different sectors, including forestry, horticulture, agriculture, animal production and the natural environment. Beekeepers themselves are often categorised as farmers who are recognized for their crop and animal husbandry skills and yet their knowledge and involvement in beekeeping is often not acknowledged. This Symposium intends to address these and other issues that result from the varied nature of this activity by providing a forum for sharing experiences and an opportunity to reflect on how the practice of beekeeping in developing countries is viewed by academic 'experts'. Current development issues, including the appropriateness of technology transfer, training and extension, and the evaluation of beekeeping projects will also be considered. The Symposium is being organized by Bees for Development and The Centre for Development Studies and is to be funded by DFID and the British Academy. Success with silk?
Biotechnology benevolence?The technology to produce genetically engineered vitamin-enriched rice is to be made available to certain regions at no cost. Vitamin A enriched rice or 'golden rice' is being advocated as a means of preventing blindness, which currently affects millions of people due a diet deficient in vitamin A. Monsanto has followed a move by AstraZeneca in May in offering royalty-free licences and seed to researchers in developing countries to use its technology to develop local varieties of 'golden rice'. Rich sources of vitamin A are available in indigenous plants in many countries (e.g. oil palm Elaeis guineensis and drumstick leaves Moringa oleifera) and are being successfully promoted in several regions including West Africa, Asia and Brazil. |
New cucurbit speciesUS Scientists have developed a new cross species, using traditional breeding
techniques, which could give both the parent species more genetic resistance
against diseases and pests. Cucumbers and melons, two Cucurbitaceae
crops of major economic importance, are susceptible to a number of fungal,
bacterial, viral and insect disease that reduce both yield and quality.
However, a new hybrid, Cucumis x hytivus, will allow researchers to
breed improved cucumbers (C. sativus) and melons (C. hystrix) as
the new species will serve as a bridge for transferring useful genes,
especially those for disease resistance, between the two. Mechanized agro-processing in EthiopiaA prototype roller mill is currently being developed for use in Ethiopia. The mill will allow the processing of good textured flour from maize, wheat and barley which, when mixed with QPM (Quality Protein Maize), could make a considerable nutritional impact, particularly in the Ethiopian highlands. Collaboration between IITA, Sasakawa Africa Association and the Ethiopian Agricultural Research Organisation has already resulted in the development of a multicrop thresher, which has helped to reduce postharvest losses due to manual threshing, transport and handling, especially with small grain such as tef, the country's preferred staple. The advantage of the thresher is that is can be used to thresh a range of different crops, without changing any parts. Fifteen multicrop threshers are already in use in Ethiopia and private manufacturers are currently producing a further twenty. Before the failure of this year's Belg (short season) rains, Ethiopia had
achieved a dramatic increase in cereal production during recent years, which
culminated in 1999 with the third largest harvest ever recorded. However,
threshing has traditionally been a time-consuming and labour-intensive process.
Improvements in Egyptian irrigated riceImprovements in rice varieties in Egypt has resulted in higher yields in shorter growing periods whilst also reducing usage of irrigation water. Introduction of these new, improved Japonica varieties has contributed to the recent increase in rice production, particularly in the north of the country where farmers have found it more profitable than cotton seed. In contrast to other cereals, rice is produced in excess of demand in Egypt, and has become one of the country's leading export crops. |
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