Tastier strawberries from coloured mulches
The colour of plastic mulches surrounding food crops can enhance the size and taste of strawberries, tomatoes, carrots and basil, scientists have found.
Mulches are often used to cover the earth around plants to reduce moisture loss from evaporation and suppress weeds, cutting down on water consumption and care.
Previous work by the Agricultural Research Service, which is part of the US Department of Agriculture, has shown red plastic mulch produces larger tomatoes and sweeter-smelling, more delicious strawberries.
Studies have also been undertaken on how colour affects the roots, stems, leaves and seeds of cotton, carrots and basil.
But now the researchers, led by plant physiologist Michael Kasperbauer has discovered why the plants respond so positively to certain colours.
The plastics influence the quality of the light reaching the leaves of the plant by absorbing differing amounts of various parts of the spectrum of light, altering the amount of blue light and the ratio of far-red (FR) to red light that plants receive.
Reflecting the right wave lengths of colour onto the developing leaves of the herb basil, for example, influences the size, aroma, and concentration of phenolics in the plant. Phenolics are natural compounds that result in the plant’s characteristic colour, flavour and health promoting antioxidant content.
The use of red mulches also boosted yield of basil plants, improving succulence and fresh weight, as well as surface area of leaves, compared to plants grown above black mulch.
