Integration of Stalk Destruction Methods for the Glyphosate Herbicide-Resistant Cotton

The increase in geographical areas used for cultivation of transgenic glyphosate herbicide-resistant cotton has hindered the stalk destruction, compromised the phytosanitary break implementation and consequently increased the population of insect pests and cotton plant pathogens. This study evaluated the efficiency of the combining mechanical and chemical methods in the destruction of transgenic cotton stalk resistant to the glyphosate herbicide. Two experiments were carried out in 2015 and 2016 in Primavera do Leste,-Mato Grosso, Brazil and Luís Eduardo Magalhães, Bahia, Brazil, respectively. The study evaluated different mechanical destruction equipment in combination with the chemical methods. In each environment, a randomized block experiment with four replications was employed. The results of the experiments indicated that the mechanical destruction increased the control efficiency by at least 10% when compared to chemical destruction of the cotton stalk. Chemical destruction with herbicides combined with mechanical destruction methods does not increase the control efficiency of cotton stalks destruction. Furthermore, the application of hormonal herbicides following the mechanical shredding of cotton stalks does not increase the control efficiency of glyphosate-resistant cotton stalk.

High-Quality Natural Fibers from Cotton Stalk Bark via Limited Alkali Penetration and Simultaneous Accelerated Temperature Rise

High-quality cotton stalk fibers that are both fine and have a high breakage strength are extracted via limited alkali penetration in the glycerol solvent and simultaneous accelerated temperature rise by means of microwave-assisted heating. Alkali is widely used in the extraction of cotton stalk fibers. However, alkali molecules in the aqueous phase penetrate easily into the fiber bundles, resulting in a simultaneous degumming between the inner and outer layers of the fiber bundles. In previous reports, the fibers treated in the aqueous phase present a coarse fineness (51.0 dtex) under mild conditions or have a poor breakage strength (2.0 cN/dtex) at elevated temperatures. In this study, glycerol is chosen as a solvent to reduce the penetration of alkali. Simultaneously, the microwave-assisted heating form is adopted to increase the temperature to 170 °C within 22 s. The inhibited alkali penetration and accelerated temperature rise limited the delignification to the outer layer, resulting in fibers with both appropriate fineness (23.8 dtex) and high breakage strength (4.4 cN/dtex). Moreover, the fibers also exhibit a clean surface and large contact angle. In this paper, we detail a new strategy to extract high-quality lignocellulosic fibers that will be suitable for potential reinforcing applications.

Co-Pyrolysis of PCB with Cotton Stalk: Product Characterisation

With advancing technology, PCB (Printed circuit board), one of the most important components of e-waste, has become a source of pollution due to an ineffective waste management system. This problem can be solved by converting PCB waste into a valuable product which will emerge to maximize the renewable energy supplies. In this aspect, co-pyrolysis is advantageous in both simple and successful in producing high-quality pyrolysis oil. In this paper, cotton stalk (CS) as biomass was used for co-pyrolysis with PCB. Slow pyrolysis of PCB, CS, and co-pyrolysis of PCB:CS (1:1) have been carried out for temperatures up to 500 \(℃\) in a fixed-bed reactor. The products of pyrolysis: oil was analysed by GC-MS and FTIR and gas had been analysed by GC. The results indicate that there is an increase in oil yield from 19.6% to 27.5 % by weight and phenol and phenolic compounds in oil of co-pyrolysis from 60.94–76.82% than literature available. As per authors knowledge co-pyrolysis of PCB:CS has been attempted first time and the products characterisation were found completely different than any other biomass co-pyrolysis with PCB.