Abstract The baru (Dipteryx alata Vogel), is fruit tree displaying economic, environmental, industrial and food importance. The objective of this study was to adapt to the tetrazolium test methodology to baru seeds and evaluate the physiological quality of seeds stored for 12 months at 10 and 20 ºC, using X-ray images as a toll for detection damage throughout the storage period while also carrying out germination, emergence and electrical conductivity tests. Baru seeds remained viable for 12 months of storage, albeit with a small decrease in vigor after nine months. The applied tetrazolium test methodology was efficient in determining internal seed damage. The pre-soak time for the tetrazolium test and solution concentration was 24 hours and 0.05%. No changes in seed morphology and radiographic images were observed during the storage periods, regardless of the assessed temperature. The X-ray test enabled a precise visualization of internal baru seed structures.

ABSTRACT The production of quality seedlings coupled with the correct choice of fertilizer doses/sources and the container type are essential in the planting of forest species. Thus, the objective of this study was to evaluate the relationship between morphological, physiological and anatomical characteristics and container volume with different fertilizations on Acrocarpus fraxinifolius seeds seedlings. The experiment was conducted in a 2 x 8 factorial scheme (2 volumes of containers and 8 fertilizations), tested in polypropylene tubes of 50 and 110 cm³ and according to different fertilizations: control without fertilization; 4 increasing doses of Osmocote® Plus: 3, 5, 7, 9 kg.per.m³ of substrate, respectively; and 3 split mineral fertilizers with coverings. It was possible to note that the tube with the greatest volume of 110 cm³ presented the best results regarding the morphological characteristics, however, when analyzing the physiological variables it was clear that the 50 cm³ tubes present similar results to those of larger volume when well fertilized. Split fertilization presented better results than slow-release fertilization, and 50 cm³ tubes were more sensitive to fertilization due to the lower volume. Thus, the use of 50 cm³ tubes with fertilization is recommended for producing A. fraxinifolius seedlings, due to presenting physiological quality and economy of inputs in nursery production, transportation and planting.

ABSTRACT The maturing of drift used in the culture of sugar cane can have harmful effects on other crops grown in the vicinity of sugar cane plantations. Among these, sunflower grown in the off-season can have its growth and productivity affected by drift. The objective of this research was to evaluate whether the drift of trinexapac-ethyl and glyphosate promotes changes in the photosynthetic metabolism of sunflower plants. Two trials were carried out to evaluate the effects of these products on gas exchange, chlorophyll fluorescence, chloroplastid pigments, membrane permeability, sugar content, as well as shikimic acid and malondialdehyde concentration in the treated plants. In the first experiment, we tested glyphosate in doses of 0 (control); 3.6; 7.2; 14.4; 28.8; and 86.4 g a.e.∙ha−1 and in the second, trinexapac-ethyl at doses of 0 (control) 3.12; 6.25; 12.50; 25, and 75 g a.i.∙ha−1. The growth regulator trinexapac-ethyl did not change the photosynthetic metabolism of plants. However, glyphosate caused damage to the photosynthetic apparatus and a reduction in the carbohydrate concentration and chloroplastid pigments, with casual damage to cell membranes; these effect were more intense at increased doses. The effects of glyphosate were evidenced by the increased concentration of shikimic acid, derived from its mechanism of action. Concludes that, the photosynthetic metabolism of sunflower plants is not affected by the growth regulator trinexapac-ethyl, unlike to the evident effects after application of glyphosate.