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Sept 1, 2011

By David Njagi

A report published in May warns nut and fruit farmers in Kenya and elsewhere in the world to brace for harsher times, with researchers suggesting a nosedive in farm yields due to the effects of climate change.

The report published in the online journal PLoS ONE, suggests that a weather trend referred to as winter chill and which is crucial for the flowering and maturation of nuts and fruits, is being altered by global warming, and is projected to affect farmers and particularly those growing the relevant crops in Kenya’s highlands.

According to study leader, Eike Luedeling of the World Agroforestry Centre (ICRAF), winter chill is a prolonged period during the winter season that comes with suitable temperatures for fruits and nuts to peak in production.

Referring to evidence collected during the study, Eike says lack of winter chill can delay or prevent flowering, lead to staggered bloom, and cause various forms of mutations.

But the winter chill period is now being shortened due to global warming and could cripple the sector that is projected to generate US$ 93 billion in annual revenues worldwide.

According to the study, Kenya is among four countries that counted the highest losses due to the current winter chill. The others are Morocco, Tunisia, Israel, and the Cape region of South Africa.

“In these regions, climate change is likely to severely challenge current production systems, some of which already rely on cultural measures such as rest-breaking chemicals and artificial defoliation,” says the report.

Among the adaptation measures the report mentions is breeding of tree cultivars, or what experts describe as fast growing varieties, to suit low chilling temperatures, and reduction in greenhouse gas emissions.

Still, the economic cost of climate change incurred by fruit and nut growers could be substantial, warns the report.

“Many businesses may be confronted with the decision to either abandon their production or adapt to altered climatic conditions,” says the report. “Applying adaptation treatments could be economically unviable.”

Even if crops move towards more suitable climatic zones, most small orchard operations lack the capital to move their production to different areas, potentially impacting many livelihoods, adds the report.

The study singles out apples, cherries, and peaches, apricots, walnuts, pistachios, plums and almonds as some of the farm products that will be affected by decreased winter chills. But this could also affect other indigenous varieties such as those grown in Kenya’s highlands.

Experts say the findings paint a gloomy future for nuts and fruit farmers, even as the Kenya Horticulture Competitiveness Project (KHCP) report predicts high growth in Kenya’s fruit juice exports.

Released in August by Fintrac and the United States Agency for International Development (USAID), the report says fresh fruits contributed 16.5 per cent and 1.2 per cent of the volume of exports with a growth rate of 22.5 per cent in value.

While passion fruits comprised 44 per cent of fresh fruits exports, mango exports were at 32.4 per cent, according to the report.

Other fruit and nuts listed by Kenya’s Horticultural Crops Development Authority (HCDA) are avocadoes, pineapples, bananas, melons, strawberries, apples, macadamia nuts and cashew nuts.

Apart from ICRAF, Kenya, other researchers who participated in the winter chill study were drawn from The Nature Conservancy, Seattle, Washington, United States of America, Rothamsted Research, Harpenden, United Kingdom, Department of Plant Sciences, University of California Davis, Davis, California, United States of America.

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