Submitted to: HortTechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/24/2009
Publication Date: 2/1/2010
Citation: Gordon, G.G., Foshee, W.B., Reed, S.T., Brown, J.E., Vinson, E. 2010. The effects of color plastic mulches and row covers on the growth and yield of okra. HortTechnology. 20(1):224-233.
Interpretive Summary: Okra [Abelmoschus esculentus (L.) Moench‘Clemson Spineless’] was grown on an Orangeburg sandy loam soil in Shorter, AL. Okra was direct seeded in single rows. The study consisted of twelve experimental treatments including five plastic mulch colors (black, white, red, blue and silver) plus a bare soil control use both with and without a spunbonded row cover. Soil temperatures were five to seven degrees lower than air temperatures. The dark mulch colors, black, blue and red, resulted in higher soil temperatures than silver or white colored mulches. In general, plots with row cover had higher air temperatures than plots without row cover. Plants grown in soil under a row cover were taller and generally more robust than plants grown without row covers. Early yields were reduced by the presence of row cover. This was attributed to the high air temperature in early June associated with row covers. At times air temperature surpassed 40 °C in plots containing a row cover. In contrast to early yield, by the end of harvest overall yields were greater with the use of a row cover. Also, early yields were generally greatest with dark mulch colors and overall yields greatest with black and blue plastic mulch.
Technical Abstract: Okra [Abelmoschus esculentus (l.) Moench'Clemson Spineless'] was grown on an Orangeburg sandy loam soil in shorter, AL. Okra 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) WM, (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 five to seven degrees Fahrenheit lower than air temperatures in all treatments. The use of darker colored plastic mulches increased early and total yield of okra compared to bare soil with and without row cover. Increased soil and air temperatures did not always correlate to an increase in yield. Because of these findings it is believed that the plant's phytochrome and blue light responses were activated by the colored mulches. Further studies are needed to have a better understanding of the effects of okra grown with row covers and various colored plastic mulches.