- There is a little information about sweet sorghum crop behavior under chemical ripeners spraying management. Therefore, the aim of this study was to assess the technological profile of sweet sorghum (cv. CMSXS-646) juice under spraying of plant growth regulators and sampling periods. A randomized complete block experimental factorial design was used, with an additional control treatment (arrangement 2x2+1), corresponding to two chemical ripeners with three-doses for each product, glyphosate (0.2, 0.4, and 0.8 l c.p. ha-1) and methyl-sulfumeturon (10, 20, and 30 g c.p. ha-1), two sampling periods (15 and 30-days after spraying - DAS) and one control treatment (water spraying). After crop harvest, stalks were milled using a hydraulic press and the derived juice was assessed for total soluble solids (°Brix), apparent sucrose (POL), purity (PRT), reducing sugars (RS), total reducing sugars (TRS), fibers (FIB) and recoverable theoretical sugars (RTS). The dataset was subjected to the Shapiro-Wilk, Fisher, Tukey, Pearson and multiple linear regression statistical tests (p<0.05). There was an interaction between causes of variation for almost all assessed characteristics except to RTS, only affected by the sampling period. As conclusion, it is possible to grow sweet sorghum (cv. CMSXS-646) till thirty-days after spraying of chemical ripeners, treated by glyphosate 0.4 l c.p. ha-1 or sulfumeturon-methyl 10 g c.p. ha-1, because these doses caused feedstock with high °Brix, POL, total reducing sugars, purity levels.Keywords: Sorghum spp., phytorregulators, plant growth regulators, glyphosate, sulfumeturon-methyl. PERFIL TECNOLÓGICO DE CALDO DE SORGO SACARINO (cv. CMSXS-646) SUBMETIDO À APLICAÇÃO DE MATURADORES QUÍMICOS E ÉPOCAS DE AMOSTRAGEMRESUMO – Há poucas informações sobre o comportamento da cultura do sorgo sacarino sob manejo de aplicação de maturadores químicos. Portanto, o objetivo desta pesquisa foi avaliar o perfil tecnológico de caldo de sorgo sacarino cv. CMSXS-646 submetido à aplicação de maturadores químicos e períodos de amostragem. Aplicou-se o delineamento de blocos inteiramente casualizados, em esquema de fatorial (2x2+1), correspondente a dois maturadores químicos com três dosagens - glifosato (0,2; 0,4 e 0,8 l p.c. ha-1) e sulfumeturon-metil (10, 20 e 30 g p.c. ha-1); dois períodos de amostragem (15 e 30 dias após aplicação - DAA); e um tratamento controle (aplicação de água). Após a colheita, destinaram-se colmos à moagem, realizada em prensa hidráulica, para extração de caldo; avaliaram-se sólidos solúveis totais (°Brix), sacarose aparente (POL), pureza (PRT), açúcares redutores (AR), açúcares redutores totais (ART), fibras (FIB) e açúcares teóricos recuperáveis (ATR). Ao conjunto de dados, aplicaram-se testes estatísticos, Shapiro- Wilk, Fisher, Tukey, Pearson e regressão múltipla, ao nível de 5% de probabilidade. Houve interação entre as causas de variação para quase todas as características, exceto ATR, influenciado, somente, pelo período de amostragem. Concluiu-se que a aplicação dos maturadores químicos glifosato 0,4 l c.p. ha-1 e sulfumeturon-metil 10 g p.c. ha-1 apresentou um incremento na qualidade da matéria-prima com alto teor de °Brix, POL, açúcares redutores totais e níveis de pureza trinta dias após a pulverização dos maturadores.Palavras-chave: Sorghum spp., fitorreguladores, reguladores de crescimento vegetal,

In twenty-first century, free-living endophytic and rhizosphere-competent microbes have become breakthrough strategies to meet global demands for sustainable foods and renewable fuelstocks owing to their great potential to produce stress-tolerant food and energy crops. Here, we investigate how Bacillus aryabhattai could mitigate water stress by drought in sugarcane seedlings. Briefly, the sugarcane genotypes, namely IAC91-1099 and RB85-5156, both exposed to cells-centrifuged B. aryabhattai suspension at 1x10 8 CFU mL-1 and non-treated were developed under irrigation regimes of 0, 7, 14 and 21 days to simulate different degrees of soil moisture content. The osmotolerant bacterium remarkably enhanced development of aboveground structures and root system, mainly in irrigated seedlings of IAC91-1099. Clearly noted that microbial metabolism depends on genotype and soil water potential to promote plant growth. This bacterium probably enabled sugarcane plants in early phenological stages to cope with water deficit by regulation of plant growth hormones along with solubilization of nutrients. Of particular importance, the bacterium exerted more pronounced effects by conferring drought tolerance at 7 and 14 days irrigation interval, irrespective of sugarcane genotype, which also translated into increased biomass of shoots and roots. Microbial degradation of ethylene precursors exuded in rhizosphere could reasonably explain why B. aryabhattai-associated seedlings developed deeper root systems to uptake water and nutrients and, consequently, allocating larger amounts of dry matter to shoots. Collectively, our findings provide relevant insights on the beneficial effects of the cacti-associated B. aryabhattai in alleviating the harmful effects of drought stress in seedlings and contribute to increasing our understanding of the phenotypic outcomes from the interaction between sugarcane genotypes and a beneficial rhizobacterium. Hence, this bacterial inoculant forms a low-cost and ecologically sound strategy to enhancing drought stress tolerance in sugarcane crops planted in water-limited zones in Brazil.

Rev. Virtual Quim. |Vol 10| |No. 5| |1225-1247| 1225 Artigo Parâmetros Tecnológicos e Avaliação de Enzimas Antioxidantes da Cana-de-açúcar (Saccharum spp.) quando Aplicados Maturadores Químicos Moreira, B. R. A.;* Viana, R. S.; Manarelli, F.; Viana, C. R. A.; Nakamune, A. C. M. S.Abstract: The aim of this study was to evaluate juice technological traits and antioxidant enzymes specific activities from sugarcane cultivars following chemical ripeners spraying. The field experiment had a randomized block design (with six replicates) in factorial arrangment (9x2): active ingredients (control 0.00 L ha -1 , ethephon 0.67 L ha -1 , glyphosate 0.35 L ha -1 , MTD 1.00 L ha -1 , trinexapacethyl 0.80 L ha -1 , sulfumeturon-methyl 0.02 kg ha -1 , ethephon 0.34 L ha -1 plus glyphosate 0.15 L ha -1 , MTD 1.00 L ha -1 plus glyphosate 0.15 L ha -1 , and sulfumeturon-methyl 0,02 kg ha -1 plus glyphosate 0.15 L ha -1 ), and sugarcane cultivars (RB86-5156 and RB86-5453), respectively. Subsequent to crop harvest (carried out 60-days after chemical ripeners spraying) stalks and leaf samples were assessed to °Brix, Pol, purity, theoretical sugars recoverable (TSR), fibers, superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and peroxidase (POD) specific activities. There was null hypothesis rejection at interactive level between causes of variation for CAT and POD; while SOD, PAX, and all juice traits were affected only at simple effects level. It was concluded that chemical ripeners management enhanced juice quality and antioxidant enzymatic system reactivity of sugarcane crop. ResumoO objetivo desta pesquisa foi avaliar parâmetros tecnológicos de caldo e atividades específicas de enzimas antioxidantes de cultivares de cana-de-açúcar tratados com maturadores químicos. Aplicou-se o delineamento de blocos casualizados, com seis repetições, em esquema fatorial 9x2: ingredientes ativos (controle 0,00 L ha -1 , etefon 0,67 L ha -1 , glifosato 0,35 L ha -1 , MTD 1,00 L ha -1 , etil-trinexapac 0,80 L ha -1 , sulfumeturon-metil 0,02 kg ha -1 , etefon 0,34 L ha -1 + glifosato 0,15 L ha -1 , MTD 1,00 L ha -1 + glifosato 0,15 L ha -1 e sulfumeturon-metil 0,02 kg ha -1 + glifosato 0,15 L ha -1 ) e cultivares (RB85-5156 e RB85-5453), correspondentemente. Posteriormente à operação de colheita, realizada sessenta dias após a aplicação de maturadores, destinaram-se colmos e folhas ao laboratório, para determinação dos parâmetros tecnológicos de caldo, °Brix, Pol, Pureza, ATR e Fibras, e análise de atividades específicas das enzimas antioxidantes, superóxido dismutase (SOD), catalase (CAT), ascorbato peroxidase (APX) e peroxidase (POD), respectivamente. Houve rejeição de hipótese de nulidade, ao nível de interação entre as causas de variação, para CAT e POD; SOD, APX e todos os atributos de caldo foram influenciados, apenas, ao nível de efeitos isolados. Portanto, concluiu-se que plantas submetidas à aplicação de maturadores químicos exibiram qualidades de caldo superiores e sistemas antioxidantes enzimáticos mais reativos a radi...

Pesticides offer stakeholders cost-effective solutions to control weeds. Nevertheless, such active compounds can manifest as severe environmental pollutants when escaping from agroecosystems into surrounding natural ecosystems, driving the need to remediate them. We, hence, analyzed whether Mucuna pruriens can develop a potential phytoremediator for treating tebuthiuron (TBT) in soil with vinasse. We exposed M. pruriens to microenvironments containing tebuthiuron at 0.5, 1, 1.5, and 2 (standard dose) L ha−1 and vinasse at 75, 150 (industrial recommendation), and 300 m3·ha−1. Experimental units without organic compounds represented controls. We assessed M. pruriens for morphometrical features, such as plant height and stem diameter and shoot/root dry mass, over approximately 60 days. We obtained evidence for M. pruriens not effectively removing tebuthiuron from the terrestrial medium. Such a pesticide developed phytotoxicity, significantly limiting its germination and growth. The higher the dose, the more negatively the tebuthiuron impacted the plant. In addition, introducing vinasse into the system, irrespective of volume, intensified the damage to photosynthetic and non-photosynthetic structures. Equally important, its antagonist action further decreased the production and accumulation of biomass. As M. pruriens could not effectively extract tebuthiuron from the soil, it could allow neither Crotalaria juncea nor Lactuca sativa to grow on synthetic media containing residual pesticide. An atypical performance of such testing (tebuthiuron-sensitive) organisms over independent ecotoxicological bioassays validated inefficient phytoremediation. Hence, M. pruriens could not offer a functional remediative option to treat environmental pollution by tebuthiuron in agroecosystems where vinasse occurs, such as sugarcane-producing areas. Although M. pruriens considered a tebuthiuron phytoremediator as cited in the literature, satisfactory results did not occur in our research due to high concentrations of vinasse in the soil. Therefore, this information requires more specific studies about the influence of high concentrations of organic matter on M. pruriens productivity and phytoremediation performance.

The aim of this study was to evaluate the energetic potential achieved by the application of phyto-regulators to sweet sorghum cultivars. A randomized complete block design was used. Experiments were conducted using two sweet sorghum cultivars (BRS 508 and BRS 509), four phyto-regulators (ethephon, ethyl-trinexapac, glyphosate, and sulfometuron-methyl), and a control; four replicates were performed 70 days after sowing, at the beginning of the flowering phase of the plants, with the aid of a CO2pressurized coastal sprayer. The plants were harvested after 40 days, with the stems being cleared at the height of the apical bud, and were subjected to grinding for the extraction of broth. The following analyses were carried out: chemical (total extractives, lignin, and holocellulose contents), proximate (volatile matter, fixed carbon, and ash contents), and energetic (higher heating value). Multiple comparison (Tukey) and linear correlation (Pearson) analyses were carried out at a 5% significance level. The phyto-regulators positively and significantly influenced the chemical attributes and contents of lignin and fixed carbon. It was concluded that glyphosate, sulfometuron-methyl, and ethephon enhanced the biomass/bioenergy potential of sweet sorghum cultivars.