Potato Tuber Production in Response to Reflected Light from Different Colored Mulches

Abstract

Colored mulches can affect the spectral balance (quality) and quantity of canopy light, which influences plant developmental patterns. Field studies were conducted to evaluate the influence of light reflected from different colored mulches on potato (Solanum tuberosum L.) tuber production. Potato plants (‘Atlantic’, ‘Kennebec’, ‘Red Pontiac’, and ‘Superior’) were grown in field plots covered with straw mulch that had been painted white, red, pale blue, or in alternating 5‐cm stripes of blue and orange to provide a range of reflected light spectra. An unpainted straw mulch treatment and a no‐mulch control were also used. Far‐red to red (FR/R) ratio and percentage of photosynthetically active radiation (PAR) reflected from the different colored mulches relative to incoming sunlight ranged from 0.82 to 1.29 and from 12 to 46%, respectively. Plants receiving reflected light from the white, pale blue, and striped straw mulches produced > 15% more marketable tubers than the no‐mulch control plants. Red and unpainted straw mulches produced plants that had yields similar to the so‐much control. Similarities in yield and spectral pattern between the unpainted straw mulch and the no‐mulch control indicated that yield increases associated with painted straw mulches were due to alteration in the quality and/or quantity of light reflected from them. It was concluded that potato tuber production can be influenced by colored straw mulches.