Effect of Plastic Mulch Color on Cut Flower Production of Snapdragon and Dianthus in a High Tunnel Production System

Abstract

The objective of these studies was to determine the effects of colored plastic mulch in a high tunnel production system on cut flower production of ‘Potomac Appleblossom’, ‘Potomac Orange’, ‘Potomac Pink’, ‘Potomac Yellow’, and ‘Supreme Gold Yellow’ snapdragons (Antirhinum majus) in 2007 and ‘Cool Bronze’, ‘Cool Rose’, and ‘Cool White’ snapdragons and ‘Amazon Neon Purple’ dianthus (Dianthus barbatus) in 2008. In 2007, snapdragons were evaluated on blue (BM), red (RM), or white plastic mulch (WM) at the Auburn University, E.V. Smith Research Center (Shorter, AL). Over all cultivars, total stem length, inflorescence length, and stem diameter values were highest on BM and lowest on RM, though inflorescence lengths and stem diameters were not different on BM and WM. ‘Potomac Orange’ and ‘Supreme Gold Yellow’ had the longest total stem lengths and ‘Potomac Yellow’ the shortest while ‘Potomac Pink’ and ‘Potomac Yellow’ had the highest stem diameters and ‘Potomac Appleblossom’ had the lowest over all mulch colors. In 2008, ‘Cool Bronze’, ‘Cool Rose’, and ‘Cool White’ snapdragons and ‘Amazon Neon Purple’ dianthus were evaluated on black (BkM), blue, red, or white mulch or bare ground (BG) at the Auburn University, Wiregrass Experiment Station (Headland, AL). Total stem lengths were highest on BkM and lowest on BG over all cultivars, however the second highest total stem length was on BM, which is in agreement with the 2007 study where BkM was not included. Inflorescence lengths and stem diameters were highest on BkM, BM, and RM in 2008, which agrees with results for 2007 for BM, but not for RM. The same pattern of differences was found for stem diameters. ‘Cool Bronze’ had the highest total stem lengths, inflorescence lengths, and stem diameters while ‘Cool Rose’ had the lowest over all mulch colors. For ‘Amazon Neon Purple’ dianthus, BkM and BM resulted in the highest stem numbers and stem lengths. These studies were conducted at two different locations and at two different times of the year. Though there were inconsistencies in response to mulch color, BkM and BM generally resulted in longer and thicker stems in snapdragons and the highest stem numbers and stem lengths in dianthus.