canopy. The objective of this study was to document the influence of polyethylene mulch surface color on leaf area distribution as measured at two sampling periods: an early sampling period with relatively young plants that had been in the mulch treatment
Margarita Velandia, Karen L. DeLong, Annette Wszelaki, Susan Schexnayder, Christopher Clark and Kimberly Jensen
Polyethylene mulch is traditionally used in the production of some fruits and vegetables to maintain soil moisture and increase soil temperature, control weeds, improve crop quality, and increase yield ( Emmert, 1957 ). In the United States, 1
Bielinski M. Santos, James P. Gilreath and Myriam N. Siham
Polyethylene-mulched vegetables are planted on ≈70,000 acres in Florida ( Olson, 2004 ). One of the main problems in plasticulture is nutsedge control, because of its ability to penetrate through mulch films and to reduce crop yields severely
Jessica R. Goldberger, Lisa W. DeVetter and Katherine E. Dentzman
et al., 2017 ; Rodríguez-Seijo and Pereira, 2019 ). Of particular concern are the environmental impacts associated with the use and disposal of low-density polyethylene plastic mulch films for crop production ( He et al., 2015 ; Kasirajan and
Sanjeev K. Bangarwa, Jason K. Norsworthy and Edward E. Gbur
, has been widely used under polyethylene mulch for effective weed control in vegetable production, including bell pepper ( Duniway, 2002 ). However, because of its ozone-depleting potential, methyl bromide is being phased out from the U.S. agricultural
Heeock Boo, Honggi Kim and Hyunhwa Lee
by sucrose. This study, therefore, was carried out to clarify the distribution of sugars and related sucrose enzymes at four developmental stages of the eggplant fruit cultured on different polyethylene mulches. Materials and Methods Plant
Bielinski M. Santos, James P. Gilreath and Timothy N. Motis
Field trials were conducted from 1999 to 2003 to determine whether chloropicrin (Pic) stimulates nutsedge (Cyperus spp.) emergence through polyethylene mulch, and to examine at which Pic rate the stimulatory effect is maximized. Shank-injected Pic rates were 0, 50, 100, 150, 200, and 250 lb/acre. Application rates between 107 and 184 lb/acre of Pic stimulated nutsedge sprouting through polyethylene mulch by 60%, 400%, 58%, and 120% more than the nontreated control during four of the seasons. Rates above 250 lb/acre eliminated the stimulatory effect on nutsedge, reducing densities to the same levels as the nontreated control. The exact physiological mechanism of this stimulation is still unknown.
Mathieu Ngouajio and Jeremy Ernest
Weed control is one of the benefits associated with the use of plastic mulches used for vegetable production. The mulches decrease light transmission and prevent development of most weed species. Plastics chemistry has developed films varying in their ability to reflect, absorb, and transmit light. Laboratory and field experiments were conducted to 1) measure light transmitted through colored mulches, 2) evaluate weed populations under each mulch type, and 3) determine if light transmission could be used as an indicator for weed populations in the field. The polyethylene mulches were black, gray, infrared transmitting brown (IRT-brown), IRT-green, white, and white-on-black (co-extruded white/black). On average, 1%, 2%, 17%, 26%, 42%, and 45% light in the 400 to 1100 nm range was transmitted through the black, white/black, gray, IRT-brown, IRT-green, and white mulches, respectively. In field experiments, density and dry biomass of weeds growing under the mulches were evaluated. The white mulch had the highest weed density with an average of 39.6 and 155.9 plants/m2 in 2001 and 2002, respectively. This was followed by the gray mulch, with 10.4 and 44.1 weed seedlings/m2 in 2001 and 2002, respectively. Weed density was <25 plants/m2 with the other mulches in both years. Weed infestation was correlated with average light transmission for white, black, white/black, and gray mulches. However, both light quantity and quality were necessary to predict weed infestations with the IRT mulches. Weed infestation under the IRT mulches was better estimated when only wave lengths in the photosynthetically active radiation range (PAR; 400 to 700 nm) were considered. Low weed pressure and high light transmission with the IRT mulches would make them appropriate for use in areas where both weed control and soil warming are important factors.
In 1999, `Sweet Banana' pepper plants were grown under clean cultivation or SMR—red, silver, or black polyethylene mulches. Plants in each of three replications per treatment were field-set on 15 June. On 22 Sept., plants were excavated, and their root systems were examined. The total number of roots per plant at 5-, 10-, 15-, 20-, and 25-cm depths and 10-, 20-, 30-, 40-, 50-, and 60-cm distances from plant stems were recorded. Distribution and architecture of the root systems also were examined. Plants grown under clean cultivation developed 50 to 60 adventitious roots each, while those grown under red mulch developed about 20, and those under black and silver mulch about nine adventitious roots each. In all treatments, the adventitious roots radiated from the stem at an oblique, downward 35° angle. No plants had vertical roots. Root system architecture was similar among treatments, with 40% of the roots in the upper 5 cm of soil and 70% in the upper 10 cm. Thirty percent of roots were within 10 cm of the plant stem, and 50% were within 20 cm. Nearly 100% of the roots were located within 40 cm of the plant stem. Root count decreased with increasing depth and distance from the plant stem. Plants grown beneath the silver mulch produced the greatest number of lateral roots, followed by plants grown in clean cultivation and under black mulch. Plants grown under red mulch produced the fewest roots. Differences among treatments were significant. Colored mulches influence the total number of adventitious and lateral roots but not the root system architecture of pepper plants.
Lynn Brandenberger and Bob Wiedenfeld
acknowledge the assistance of Juan Bernal, Carlos Rodriguez, Venancio Gonzalez and Eden Hinojosa for assistance in all aspects of this study and to Marvin Baker for help in measuring mulch strengths; we would like to clarify that they are co-authors in as much