Does Spraying of Atrazine on Triazine-Resistant Canola Hybrid Impair Photosynthetic Processes?

Abstract

Canola is an important rotation crop for the winter season and the use of atrazine-resistant hybrids can lead to an increase in yield. This work was aimed at evaluating the effect of atrazine on photochemical and biochemical processes of photosynthesis in triazine-resistant canola. The experiment was conducted in a greenhouse, with triazine-resistant hybrid Hyola® 555TT, in a randomized block design with three replications. The treatments consisted of application or no application of atrazine on canola plants. The plants were assessed at one, three, five, and eight days after application (DAA) for chlorophyll indexes, modulated chlorophyll a fluorescence and gas exchange. Chlorophyll indexes were higher in canola plants treated with atrazine. Application of atrazine caused an increase in fluorescence at steady state and a reduction in quantum efficiency of photosystem II and electron transport rate, at 1 DAA, and a reduction in photochemical quenching, at 1 and 3 DAA. Lower stomatal conductance, at 1 DAA, and higher net carbon assimilation rate, at 8 DAA, were found in plants treated with atrazine. The application of atrazine temporarily reduces electron transport between photosystems and increases chlorophyll indexes in resistant canola plants, raising the net carbon assimilation rate at eight days after application.

Ecological Approach to the Identification of the Degree of Phytophage Damage Based on Chlorophyll Fluorescence Induction in Oilseed Radish (<i>Raphanus sativus</i> L. var. <i>oleiformis</i> Pers.)

“…The EP indicator showed a steady decline with 13.89-22.97% reduction to control in the marginal variants. The obtained results indicate the similarity of the cotyledon reaction, especially in the variant of damage in the range of 50-70% to the action of aggressive active ingredients of herbicides (Durigon et al, 2019). In other words, the system of combined feeding of flea beetles of the prickly-sucking and gnawing type (Heath, 2017) forms the effect of a necrotic tissue reaction, which increases along with damage.…”

Volunteer rapeseed infestation and management in corn

“…Atrazine has been one of the most extensively used herbicides in the US corn production system due to its effective weed control ability against a broad spectrum of weed species and low cost (Arslan et al., 2016). Canola is highly sensitive to atrazine application; therefore, atrazine‐resistant canola varieties have been developed for weed control in canola using atrazine (Durigon et al., 2019).…”

Comparison of Hyperspectral Imagery and Physiological Characteristics of Bentazone-Tolerant and -Susceptible Soybean Cultivars

“…Genetically modified herbicide-tolerant (GMHT) soybeans are not allowed to grow in non-GMO countries. Atrazine-resistant foxtail millet [20], sulfonylurea-resistant lettuce [21], and triazine-resistant canola [22] are examples of non-GMHT crops in herbicide-based weed management systems. The evaluation and identification of herbicide-tolerant genotypes are important steps in developing non-GMHT soybean cultivars for breeding programs [23].…”