Application of rape pod sealants to reduce adverse environmental impacts

Abstract

The results indicate that treatment with PS4 exerts a beneficial effect in reducing rape seed yield loss (68-104 kg ha in 2014 and 194-305 kg ha in 2015) compared to other investigated PS. © 2017 Society of Chemical Industry.

Evaluation of the Effectiveness of Pod Sealants in Increasing Pod Shattering Resistance in Oilseed Rape (Brassica napus L.)

“…The chemical compositions of the pod sealants were based on di-1-p-menthene (555.4 g L −1 ) and alcohol ethoxylate (90.0 g L −1 ) for PS1 (commercial product); carboxylated styrene butadiene copolymer (450.0 g L −1 ) and aliphatic oxyalkylated alcohol (100.0 g L −1 ) for PS2 (commercial product); and pine resin (960 g L −1 ) and nonaethylene glycol (25 g L −1 ) for PS3 (commercial product). PS4 was produced in a laboratory reactor by homogenizing polyalkyleneoxide-modified heptamethyltrisiloxane (250 g L −1 ) with an acrylic dispersion (350 g L −1 ) by adding polyethylene glycol (200 g L −1 ) and water (rest) [38]. The dosages applied to the field trials were 1.25 L ha −1 (6.25 g kg −1 concentration) PS1, 1.0 L ha −1 (5.00 g kg −1 ) PS2, 1.3 L ha −1 (6.50 g kg −1 ) PS3, and 0.4 L ha −1 (2.00 g kg −1 ) PS4, with each sealant sprayed on two lines (12-m width) of the field (Figure 1).…”

“…The strength of PS4-treated pods increased most likely due to the presence of the acrylic dispersion, a component of PS4 that covers the pod with a resilient film. However, this material does not ensure good solution coverage over the pod surface [69], so a second component (trisiloxane) that lowers the dynamical surface tension of spray solutions was added [38], ensuring quick spreading of the solution across the pod surface. Rapid spreading was achieved by the formation of extremely thick wetting films and partly by long-range electrostatic forces [70].…”

“…Trials on the application of commercial pod sealants to OSR crops have generated variable results, particularly under field conditions [21,23,27,36,38,39]. Currently, the most promising method of controlling pod shattering in OSR is the application of a recently developed acrylic-and trisiloxane-based pod sealant, these substances work by physically preventing valve separation by gluing them together and altering the pod moisture regime.…”

“…Currently, the most promising method of controlling pod shattering in OSR is the application of a recently developed acrylic-and trisiloxane-based pod sealant, these substances work by physically preventing valve separation by gluing them together and altering the pod moisture regime. The sealant allows moisture to leave the pod but prevents from getting into it, thus decreasing pod expansion and contraction resulting from watering and drying cycles [38]. Previous studies have suggested that this acrylic-and trisiloxane-based pod sealant (PS4) is environmentally friendly, does not penetrate seeds in the treated pods, and does not reduce oil content [38].…”

“…The sealant allows moisture to leave the pod but prevents from getting into it, thus decreasing pod expansion and contraction resulting from watering and drying cycles [38]. Previous studies have suggested that this acrylic-and trisiloxane-based pod sealant (PS4) is environmentally friendly, does not penetrate seeds in the treated pods, and does not reduce oil content [38]. However, no study has evaluated the influence of different weather conditions on OSR pods treated with this sealant in terms of their pod strength or moisture content and subsequent losses prior to and during harvesting.…”