methods have indirectly led to improving molecular diffusion of fumigants and their persistence in soils ( López-Fernández et al., 2016 ). It has been reported that the efficacy of Met-Na was improved when applied with the soil surfactant Integrate
Feras Almasri, Husein A. Ajwa, Sanjai J. Parikh and Kassim Al-Khatib
Michael W. Olszewski, Samara J. Danan and Thomas J. Boerth
Surfactants increase wettability of pine bark and may be required in coarse substrates to enhance lateral movement of water and reduce infiltration rate through a container ( Bilderback, 1993 ). Cid-Ballarin et al. (1998) hypothesized that
Robert A. Saftner, J. George Buta, William S. Conway and Carl E. Sams
ICI Surfactants, Wilmington, Del., for samples of Atlox 8916TF, Brij 93 and 98 and Renex 30 and 36; OSi Specialties, Inc., Tarrytown, N.Y., for samples of Silwet L-77 and L-7604; Union Carbide Corp., Danbury, Conn., for samples of Tergitol 15-S-3
John Sloan* and Wayne Mackay
Soils exhibit a degree of hydrophobicity and can repel water rather than absorb it. Surfactants lower the surface tension of water which may increase its infiltration into the soil and adsorption to soil solids. The objective of this study was to determine if water treated with a surfactant would increase conserve soil moisture and decrease the amount of water needed to sustain healthy plant growth. Clay and sandy loam soils were placed in 15-cm greenhouse pots. Impatiens seedlings were transplanted into each pot. All pots were fertilized equally and the Impatiens flowers were allowed to grow for 8 weeks. Then the pots were treated with tap water or tap water mixed with a commercial surfactant at one times (1×) or two times (2×) the recommended rate. After applying the water treatments, pots received no additional water. Each pot was weighed twice per day and the plants were observed for signs of wilting. Upon initial signs of wilting, each plant was rated on a scale of 1 to 3 with 1 = no wilting, 2 = leaves starting to droop, and 3 = wilting leaves and stems. Addition of the surfactant at the 1× and 2× rates slowed the loss of water from both the sandy loam and the clay soils. The effects of the surfactant were apparent within 3 to 5 days in the sandy loam soil and 6 to 10 days in the clay soil. The benefits of reduced water loss from soil were manifested by reduced wilting in Impatiens plants in soils treated with 1× and 2× the recommended rate of surfactant. In the clay soil, use of the surfactant increased the amount of time before Impatiens plants began to wilt. It appears that adding a surfactant to irrigation water can conserve soil moisture and extend the time between water applications.
Matthew D. Madsen, Michael A. Fidanza, Nicholas S. Barney, Stanley J. Kostka, Turmandakh Badrakh and Mica F. McMillan
–oxirane copolymers was effective at improving seedling emergence and plant growth in water repellent soils. This surfactant chemistry was patented by Kostka and Schuermann (2008) and is distributed under the trade name SET-4001 (Aquatrols Corporation of America
Daniel K. MacKinnon, Dale Shaner, Scott Nissen and Phil Westra
it to a crop by a conventional sprayer presents many challenges. The effectiveness of 1-MCP in field applications will be influenced by many factors, including spray volume, surfactants, and spray nozzle types, perhaps more so than with other
K. Wignarajah, David Bubenheim, Theodore Wydeven Jr., Wade Berry and Greg Schlick
Anionic surfactants are the major class of surfactants used in detergent, laundry and related industries. Hence, they are a major contaminate of both domestic and industrial waste streams. Lettuce (Lactuca sativa cv Waldemann's Green) was grown in nutrient solutions with the addition of the anionic surfactant, Igepon TC-42. The toxic response of lettuce to Igepon was that the roots turned brown and became necrotic within 24 h following exposure. Growth was supressed for approximately 4 days following exposure to concentration greater than 0.35 mM; new roots formed rapidly and growth resumed. When fresh plants were transferred to the solutions containing Igepon 48 h following introduction of the surfactant no signs of toxicity were observed. This would indicate that either the first series of plants absorbed the toxic material or the Igepon was decayed or degraded in the nutrient solution. The rapid recovery of plants from this stress suggests the potential of a wide range of strategies that could be developed for utilizing waste streams containing anionic surfactants.
Megh Singh, Shiv D. Sharma, Analiza H.M. Ramirez and Amit J. Jhala
speculated that the plasma membrane is a barrier to the foliar uptake of glyphosate and biologically active surfactants contribute to glyphosate flux across the plasma membrane ( Riechers et al., 1994 ). On the other hand, it was reported that removing the
R.C. Ebel, D.G. Himelrick, A. Caylor and J. Pitts
The surfactant “Surfactant WK” (dodecyl ether of polyethylene glycol) was applied to peach trees [Prunus persica (L.) Batsch] at full bloom over 3 years. Blossoms died rapidly so that within 2 days dead blossoms could be distinguished easily from live blossoms or set fruit. There were strong (R 2 > 0.87), linear correlations between concentration of “Surfactant WK” applied and percent blossoms removed and fruit set, which were similar over the 3 years. Trees were hand-thinned according to commercial practices after treatment. There was similar cropload, fruit weight, and yield across treatments at harvest indicating no negative effects by the chemical on productivity. There was only slight limb damage at the highest concentrations of “Surfactant WK,” which overthinned blossoms. We recommend that based on the effectiveness, consistency, and lack of significant phytotoxicity, “Surfactant WK” be reevaluated as a thinning chemical for peach trees.
Peter D. Petracek, Moritz Knoche and Martin J. Bukovac
Despite the widespread use of surfactants to enhance the performance of foliar applied chemicals, the mechanisms for this enhancement are poorly understood. The penetration of surfactant per se through the cuticular membrane (CM) may play a pivotal role. Thus, we examined CM penetration by octylphenoxy surfactants (Triton X series) using a finite dose (Franz) diffusion cell. The effect of hydrophile length was studied using 14C surfactant (15.9 mm in 20 mm citrate buffer: pH 3.2) with 3, 9.5, 12, 16, and 40 ethylene oxide units per molecule (EO). One 5-μl droplet of surfactant solution was applied to the outer morphological surface of CM enzymatically isolated from mature tomato fruit. The inner CM surface remained in contact with stirred buffer at 25°C. The buffer was sampled periodically through a side portal over 648 h. Penetration curves (time vs. % penetrated) for all surfactants were characterized by three phases: lag, linear, and asymptotic. Lag: There was no effect of EO on the length of the lag phase (average 5 h) Linear: Steady state penetration (0.6 to 1.1% / h) was inversely related to log EO content. Asymptotic: About 70% of applied short EO (3 to 16) surfactants penetrated while 25% of the 40 EO penetrated in 648 h.