Submitted to: Journal of Vegetable Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/20/2008
Publication Date: 12/1/2008
Citation: Gordon, G.G., Wheeler, F.G., Reed, S.T., Brown, J.E., Vinson, E.,F.M. Woods, 2008. The effects of Color Plastic Mulches and Row Covers on the growth and production of Summer Squash. International Journal of Vegetable Science. 14(4):322-338. Interpretive Summary: Photomorphogenesis is the ability of light to regulate plant growth and development independent of photosynthesis. Products of photomorphogenesis include but are not limited to flowering, internode elongation, abscission, chlorophyll development, root shoot growth, and lateral bud outgrowth. Phytochrome is the photoreceptor responsible for light-regulated growth responses. It exists within plants in two interconvertible structures: the inactive structure (pr), absorbs only red light, the active structure (pfr) absorbs light in the far-red region of the spectrum. The ratio of far-red to red light a plant absorbed can affect the earliness of fruit production in summer squash. With increased earliness in fruit development, farmers can possibly generate greater revenue depending on marketing opportunities. The color of plastic mulches can influence the far-red to red light ratio reflected to leaves. A study was initiated to determine the effect of different plastic mulch colors on squash. Summer squash was grown on an Orangeburg sandy loam soil in Shorter, AL. Plant grown with either: black, white, red, silver, or blue plastic mulch with and without a spunbonded row cover. The use of colored plastic mulches increased early and total yield of summer squash compared to bare soil with or without row cover. However, there were no yield differences between the different mulch colors. Soil temperatures were higher with row covers than without. Increased soil and air temperatures did not always correlate with increased yield. Mean air temperatures were above 33 °C, high enough to cause yield reduction in many vegetable crops. This may have confounded any mulch/row cover temperature effect on yield. It is possible that the FR:R and blue light reflected from the plastic mulches could have the positive effect on the growth and yield of vegetable crops under more moderate temperatures.
Technical Abstract: Summer squash [Cucurbita pepo (L) ‘Prelude II’] was grown on an Orangeburg sandy loam soil in Shorter, AL. The summer squash was direct seeded in single rows. The experiment consisted of twelve experimental treatments as follows: (1) Black plastic mulch (BPM) + spunbonded row cover (RC), (2) BPM, (3)White plastic mulch (WPM) + RC, (4) WPM, (5) Red plastic mulch (RPM) + RC, (6) RPM, (7) Bare soil (BS) + RC, (8) BS, (9) Silver plastic mulch (SPM) +RC, (10) SPM, (11) Blue plastic mulch (BLUPM) + RC, (12) BLUPM. Soil temperatures were more than five degrees lower than air temperatures in all treatments and air temperatures were 2 to 5 °C higher with row covers than without. Increased soil and air temperatures did not always correlate to an increase in yield. In this study colored plastic mulch with or without row covers did not increase early fruit yield in squash. The lack of a mulch/row cover induced temperature effect on yield was attributed to the relatively high mean air temperatures that may have masked any temperature effect. Further studies need to be performed to have a better understanding of the effects of vegetable crops grown with row covers and various colored plastic mulches. KEYWORDS: Summer squash, plastic mulch, row covers, earliness, soil temperature, air temperature, stem diameter