It’s been mentioned on this blog before, but BBC2’s excellent series ‘A New Year at Kew’ is really producing some great horticultural talking points. http://www.bbc.co.uk/gardening/tv_and_radio/yearatkew_index.shtml

The latest edition, screened on Friday 26th February, featured one of the scientists from Kew visiting maize farmers in Ghana in the hope of developing a more practical and cost effective method of protecting their crop.

Pest-free storage of the maize grain is essential, giving the farmers viable seed for the next year’s crop and more importantly, making the difference – quite literally – between life and death for the villagers.

Many insect pests – the Maize Weevil is one – lay eggs on stored grain, rendering it unfit for consumption and planting, so the farmers have been storing the crop together with the crushed root of a native tree which has proven protective qualities.

But this method was both labour and tree intensive, and supplies of the tree – and root – were rapidly decreasing. Thanks to the scientific help from Kew, the active ingredient in the root was found to be water soluble so a lot less root was required to treat the maize.

Fascinating stuff, and it puts me in mind of derris; the natural insecticide which takes it's name from the derris plant, a climbing member of the legume family from south east Asia. The roots of the derris plant contain rotenone, a strong - and natural - insecticide which is now available in various forms for pest control worldwide! http://www.harrodhorticultural.com/HarrodSite/search/product/Pest+Control%5FInsect+and+Pest+traps+and+barriers/GPC-675.htm

‘A New Year at Kew’ - Friday evenings, 8pm, BBC2.