Submitted to: Agronomy Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 7/15/2000
Publication Date: N/A
Technical Abstract: Yield and quality of field-grown crop plants can be influenced by the natural phytochrome system that exists within each growing plant. Developing parts of many crop plants are responsive to far-red light (FR) reflected from nearby green plants because the reflected FR affects the FR/R photon ratio which can act through the phytochrome system. We hypothesized that desired FR/R photon ratios could also be reflected from the soil surface to regulate allocation of more photosynthate to desired plant parts, without interfering with incoming photosynthetic light. To field test the hypothesis, high value crop plants were grown over plastic mulches with a range of surface colors in trickle-irrigated field plots. An upwardly reflected FR/R greater than ratio in incoming sunlight favored above ground growth. A new red mulch that reflected a high FR/R resulted in greater early crop tomato yields. However, the reflecting surface had to be large enough to reflect to the developing fruit and to remain intact and clean during the entire season. Strawberry yields were even more responsive than tomato to the new red versus standard black plastic mulch. Now that yield responsiveness to color of reflected light has been established, we are concentrating on colors that influence components of quality.