BACKGROUND: Stimulation of plant growth by low doses of a toxic compound is defined as a hormetic effect. Exposure of plants to low doses of glyphosate can cause stimulatory effects on growth or other variables. Sugarcane is the major biofuel and sugarproduction crop cultivated in Brazil, but its expansion to new areas is limited; therefore, there is a demand for new technologies to improve sugarcane production per unit area. The use of pesticides to stimulate growth through the hormetic effect might be a suitable strategy to increase sugarcane yields. The purpose of this research was to investigate the effect of a low dose of glyphosate on metabolic compound accumulation, leaf phosphorus (P) concentration, and morphological variables across a one-year sugarcane cycle, as well as to determine whether the glyphosate effect was sustained and effective in improving the yield and technological quality of the sugarcane at harvest. RESULTS:The application of a low dose of glyphosate led to higher concentrations of shikimic acid and quinic acid, higher leaf P concentrations, and improved plant growth, yield, and technological quality of the sugarcane, by increasing the Brix% juice, pol% cane, total recoverable sugar, tons of culms per hectare, and tons of pol per hectare, relative to the results for an untreated control.CONCLUSIONS: The increased growth stimuli, observed through several variables, promoted an improvement in sugarcane yield. Therefore, the application of a low dose of glyphosate to sugarcane is a promising practice for crop management.

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The micropropagation of hybrid hazelnut (Corylus americana × Corylus avellana) has been limited in its agricultural application due to the lack of efficient procedures for tissue culture and root organogenesis. We established an efficient sterilization protocol for hazelnut micropropagation suitable for in vitro root induction that permitted us to approach the poor root organogenesis experienced with the micropropagation of hazelnut hybrids in vitro. Typically, with standard protocols, root organogenesis had yields of well under 20%. We found that cuttings grown in vitro to the four-leaf stage can be successfully rooted using a combination of indole-3-butyric acid (IBA) pretreatment, followed by a one-week growth period in absolute darkness. The dark period was then followed by a transition to continuous light. In many cases, prolific visible roots formed between 12 and 14 days.