Plant resistance inducers are cost-effective and environmentally pleasing strategies of plant protection to mitigate biotic and abiotic agents threatening food safety and energy security. We, accordingly, present jasmonic acid and k-phosphite as low-cost strategies to enhance productive yield and technological quality of sugarcane crop. Exogenously treatment of the sugarcane variety ‘SP81-3250’ consisted of carrying out foliar application of jasmonic acid at 1, 1.5 and 2 ml L-1 and K-phosphite at 2, 4 and 6 ml L-1 before crop flowering. Interestingly, both systemic phytorregulator and foliar fertilizer at the lowest doses significantly improved contents of total soluble solids and sucrose, as well as productive yield of fermentable sugars. Jasmonic acid could promote growth and development by triggering either non-enzymatic or enzymatic mechanisms in the host self-defense system to support of external stresses, including herbivory by sugarcane-borer. K-phosphite could improve crop performance by not only releasing water-soluble inorganic ions like phosphorus and potash, but also by signaling synthesis of phytoalexins. Purity of cane juice and productivity of stalks sharply decreased, as the doses of the plant-resistance inducers increased. Jasmonic acid and k-phosphite at unbalanced endogenous levels could inhibit physiological ripening and specific enzymatical activity of alkaline invertases and sucrose-phosphate synthase, thereby influencing bioavailability of sucrose. The lower the sucrose content, the poorer the technological quality of sugarcane crop. The conclusion is, therefore, jasmonic acid and K-phosphite at lower doses prove to be effective induced resistance techniques to produce richer feedstock, with potential to produce ethanol fuel and refined sugar in sugar-energy plants.

The biggest challenge facing in sugar-energy plants is to move towards the biorefinery concept, without threatening the environment and health. Energy cane is the state-of-the-art of smart energy crops to provide suitable whole-raw material to produce upgraded biofuels, dehydrated alcohol for transportation, refined sugar, yeast-fermented alcoholic beverages, soft drinks, silage and high-quality fodder, as well as to cogenerate heat and bioelectricity from burnt lignocellulose. We, accordingly, present fuzzy c-means (FCM) clustering algorithm interconnected with principal component analysis (PCA) as powerful exploratory data analysis tool to wisely classify hybrids of energy cane for production of first-generation ethanol and cogeneration of heat and bioelectricity. From the orthogonally-rotated factorial map, fuzzy cluster I aggregated the hybrids VX12-0277, VX12-1191, VX12-1356 and VX12-1658 composed of higher contents of soluble solids and sucrose, and larger productive yields of fermentable sugars. These parameters correlated with the X-axis component referring to technological quality of cane juice. Fuzzy cluster III aggregated the hybrids VX12-0180 and VX12-1022 consisted of higher fiber content. This parameter correlated with the Y-axis component referring to physicochemical quality of lignocellulose. From the PCA-FCM methodology, the conclusion is, therefore, hybrids from fuzzy cluster I prove to be type I energy cane (higher sucrose to fiber ratio) and could serve as energy supply pathways to produce bioethanol, while the hybrids from fuzzy cluster III are type II energy cane (lower sucrose to fiber ratio), denoting potential as higher fiber yield biomass sources to feed cogeneration of heat and bioelectricity in high temperature and pressure furnace-boiler system.

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O objetivo deste estudo foi avaliar a renovação do pasto de Urochloa decumbens para a cultivar Urochloa brizantha (Syn. Brachiaria brizantha) cv. Marandu por meio de diferentes processos de semeadura. Os tratamentos foram: semeadura convencional com uma aração e duas gradagens; semeadura direta em linha sobre a palhada; e semeadura mínima com duas gradagens, em dois ciclos produtivos e cinco cortes consecutivos. Foi determinado o número de perfilhos por plantas após a emergência do pasto, a taxa de cobertura do solo e a altura de planta. A produção total de matéria seca foi obtida pelo somatório das produções dos cortes durante o ciclo produtivo do pasto. O delineamento experimental foi em blocos inteiramente casualizados com três repetições. Os resultados foram submetidos à análise da variância, sendo as médias dos tratamentos comparadas pelo teste Tukey a 5 % de significância. Os melhores desempenhos do estabelecimento e os maiores valores de produção de matéria seca do pasto de Urochloa brizantha cv. Marandu foram obtidos nos sistemas de semeadura convencional e mínima, quando comparados com a semeadura direta.