Submitted to: American Society of Agronomy Branch Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 11/30/2001
Publication Date: N/A
Technical Abstract: High value and specialty crops are frequently grown in drip-irrigated raised-beds that are covered with plastic to conserve water and control weeds with less herbicides. Black is the most common color of plastic mulch. We hypothesized that by using other colors of mulch we could reflect wavelength combinations that act through phytochrome and other components of the natural growth regulating system in plants to alter allocation and use of photosynthate to further improve yield and quality of plant products, while keeping the water conservation and weed control benefits of plastic mulch. A specially formulated red plastic that reflects a high far-red to red photon ratio was developed to favor above ground crops such as tomato, strawberry, and leaf crops. In addition to increased yield of these crops, strawberries grown over the new red versus standard black mulch were sweeter, had higher sugar to organic acid ratio, emitted higher concentrations of favorable aroma compounds, and had higher concentrations of anthocyanins (which are antioxidants important to human health). Colors that reflect a lower far-red to red photon ratio result in shorter stems and larger roots. A wide range of leaf, small fruit, seed and root crops have been, or are now being, evaluated over a range of colors to affect different synthetic pathways to alter yield and quality of plant products used as food.