In recent years, there has been much discussion on climate change and differing and often conflicting views have been expressed on the subject. However, we all know that agriculture is very vulnerable to weather conditions, and those involved in agriculture worldwide have been reporting significant effects on crop production caused by extremes in weather conditions and the shifts in seasons being experienced. While excessive rainfall has caused severe flooding in Pakistan, Russia has at the same time experienced extreme drought and heat which have affected agriculture to such an extent that the government there has had to declare a state of emergency in 27 crop producing regions. These extreme conditions, which have driven wheat prices to the highest since 1973, are expected to continue and to threaten more crops and winter-grain sowings, according to the state weather service.According to the International Food Policy Research Institute, the accelerating pace of climate change, combined with global population and income growth, threatens food security everywhere. The report goes on to say that higher temperatures eventually reduce yields of desirable crops while encouraging weed and pest proliferation. Changes in precipitation patterns increase the likelihood of short-run crop failures and long-run production declines. Although there will be gains in some crops in some regions of the world, the overall impact of climate change on agriculture is expected to be negative, threatening global food security. Populations in the developing world, which are already vulnerable and food insecure, are likely to be the most seriously affected (www.ifpri.org/publication/climate-change).Although I have not studied the local weather statistics closely, my experience in the field in the last two years bears this out. In 2009, during what would normally have been expected to be the wet season, extremely dry conditions were experienced in Barbados, and an upsurge of the soil fungus, Pythium was observed by carrot growers. Severe crop losses were experienced which in turn stymied the import substitution programme which these farmers were part of.Earlier that year, before the drought started, the hot, wet conditions were accompanied by an upsurge in the bacterial disease, Erwinia in onion crops before harvest. In the past, Erwinia was experienced as a post harvest disease, normally appearing on bulbs in storage, more often those which had been damaged by insects or mechanical means. In 2010, some measures, including the use of Calcium Nitrate fertiliser, were introduced in an effort to curb the disease. Extremely high rainfall was again experienced, and although the measures did appear to reduce the incidence of the disease, losses were still experienced.Internet research indicated that in Holland, potato farmers in recent years have also been experiencing an upsurge in Erwinia damage on their potato crops. They report that Erwinia seems to have become more aggressive with increased soil temperatures being experienced, and few if any chemicals are available to control the problem. Some crops are more affected by temperature than others, and while greenhouses provide protection from extremes of rainfall, this type of production is even more susceptible to temperature problems than field production. These growers must take this into consideration when designing their greenhouse structures.There is also a product available which can be sprayed on to greenhouse roofs in order to reflect the heat, while allowing the light conditions to be unaffected. This has proved to be very successful.High temperature also has a deleterious effect on livestock production. In a recent report in the Sunday Sun of August 8, Mr Gerald Proverbs, animal scientist, while addressing the Barbados Egg and Poultry Producers’ Association at the Grand Barbados Beach Resort on the topic Understanding Heat Stress In Poultry And What To Do About It, reminded farmers that they must properly orient their pens for good ventilation, maintain their fans and use heat reflecting roof paint in order to help reduce temperatures and create the proper environment for birds to perform optimally. There is in fact new technology in roof paint additives which achieves this reflection of heat.Many poultry farmers have over the years improved their management of heat by introducing fans or the wind tunnel technology.Farmers are encouraged to be observant of changes in weather conditions and introduce measures, if available, to mitigate the effects of these conditions. Researchers, on the other hand need to continually conduct research in an effort to respond to the farmers’ needs in this and other areas.
• The Agro-doc has nearly 40 years’ experience in agriculture in Barbados, operating at different levels of the sector. Send any questions or comments to: The Agrodoc, C/o Nation Publishing Co. Ltd., Fontabelle, St Michael.
