Physiological response of cotton seeds treated with thiamethoxam under heat stress

Abstract

-This study aimed to verify the effect of seeds treated with thiamethoxam on the emergence, growth and chlorophyll content of seedlings of two cotton cultivars subjected to abiotic stress. The seeds used were from the DeltaOpal and NuOpal cultivars, each one represented by three lots, previously subjected to determination of moisture content, germination and vigor (low temperature germination). Then, the seeds from each lot, treated with thiamethoxam at a dose of 600 mL of product per 100 kg -1 seed or not, were exposed to temperature (18, 25 and 35 °C) and water availability (40, 60 and 80%) stress conditions. The emergence percentage, the root and shoot length, and the chlorophyll content were evaluated. The growth of cotton seedlings from the DeltaOpal and NuOpal cultivars, subjected to low temperature conditions and water availability of 40 to 60%, is favored by seed treatment with thiamethoxam. Seed treatment with thiamethoxam increases chlorophyll content during the development of cotton plants.Index terms: bioactivator, chlorophyll, Gossypium hirsutum L., stress. Termos para indexação: bioativador, clorofila, estresse, Gossypium hirsutum L.

Temperature Extremes in Cotton Production and Mitigation Strategies

“…High night temperatures also reduce the fiber micronaire value along with shorter fibers, whereas low night temperatures cause reductions in total cellulose synthesis and hampered boll development [59,60]. Recently Lauxen et al [61] observed a critical reductions in seedlings germination potential, growth and the chlorophyll contents under low (18 C) and high (35 C) temperature stress along with different levels of water availability stress.…”

Sublethal and transgenerational effects of thiamethoxam applied to cotton seed on Chrysoperla externa and Harmonia axyridis

“…cotton seed treated with thiamethoxam is effective against whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) biotype B for up to 45 days under laboratory and greenhouse conditions, and for up to ∼ 2 months under field conditions. Furthermore, thiamethoxam seed treatment can enhance the growth of cotton seedlings under heat stress …”

Synergistic action of Azospirillum brasilense combined with thiamethoxam on the physiological quality of maize seedlings

“…For the other doses, no difference was found for inoculation. Several studies have highlighted the positive effect of thiamethoxam on physiological quality in seed germination of several crops (Almeida et al, 2009;Almeida et al, 2012;Lauxen et al, 2010), demonstrating increased rooting and development of shoots. Thus, higher values of stem diameter are also possible due to the stimulation of seedling growth.…”