Spray Deposition at Two Growth Stages of Cattail

Abstract

Surfactant use in spray solutions has a major advantage of reducing droplet surface tension and increasing deposition. We aimed to evaluate droplet deposition on cattail plants (Typha subulata) using food coloring (Brilliant Blue -FD & C-1) as marker added to spray solution at two different growth stages: vegetative (4 leaves) and flowering (5 leaves). The treatments were arranged in a completely randomized design with four replications and five plants per plot (16.2-L tanks). Treatments consisted of adding into spray solutions Brilliant Blue alone (control), Brilliant Blue + 0.5% v/v Aterbane and Brilliant Blue + 0.01% v/v Silwet. Spraying was performed by a pressurized CO 2 sprayer at 220 kPa using two Teejet XR 8002 nozzles at a spray volume of 200 L ha -1 . We observed that surfactant addition provided uniform deposition of spray solution on T. subulata plants at both growth stages compared to treatments without surfactant. However, this product has not increased spray deposits on cattail leaves at both stages. A aplicação dos tratamentos foi realizada com um pulverizador pressurizado com CO 2 a 220 kPa, utilizando duas pontas Teejet XR 8002, a um volume de 200 L ha -1 . A adição dos surfactantes proporcionou deposição uniforme da calda de pulverização nos dois estádios de crescimento das plantas de T. subulata estudados, em relação à calda sem surfactante, porém seu uso não aumentou os depósitos nas folhas da taboa, em ambos os estádios de desenvolvimento. KEYWORDS:

Simulated herbicide spray retention of commonly managed invasive emergent aquatic macrophytes

“…It is additionally possible that the adjuvant type could increase spray retention for grass-like species (Huet et al 2020). Previous laboratory-based research (Harbour 1997;Silva et al 2016) reported the addition of a nonionic surfactant, such as that used in the present study, significantly improved spray retention and uniformity of spray droplet distribution on cattail leaves, whereas the use of a drift control agent did not significantly improve spray retention. In a mesocosm study, Sperry et al (2022) also observed an improvement in spray retention for free-floating species with the addition Figure 1.…”

“…Spray retention by weed species has been shown to improve through the manipulation of abiotic factors such as the addition of surfactants, and the use of lower carrier volumes, smaller droplet sizes, lower droplet velocities, and finer spray qualities (e.g., Harbour 1997; Massinon and Lebeau 2013;Dorr et al 2014Dorr et al , 2015Silva et al 2016). Similarly, biotic factors including increased leaf surface area, canopy density and height, as well as a more prostrate growth habit and more wettable leaf surface, could lead to an increase in spray capture (e.g., Dorr et al 2015;Ennis et al 1952;Massinon and Lebeau 2013;Massinon et al 2014).…”