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The aim of this paper was to describe the histological events that led to somatic embryogenesis in macaw palm (Acrocomia aculeata (Jacq.) Lodd. ex Martius). Zygotic embryos were inoculated on Y 3 medium containing 9 lM 4-amino-3,5,6-trichloropicolonic acid (picloram). Somatic embryos regenerated from nodular callus on induction medium with activated charcoal under photoperiod or without activated charcoal under dark. Many proembryos originated from the fundamental meristem after 10-20 days of culture. When transferred to medium containing activated charcoal, under photoperiod, calli regenerated into somatic embryos of unicellular origin. These embryos had protoderm, plumule and procambial strands and some of them could germinate. After 30-40 days of culture, meristematic masses grew from procambial cells. The masses generated nodular callus, and after transfer to medium without activated charcoal, under dark, they generated somatic embryos of multicellular origin. Those embryos did not regenerate into plants.

Macauba palm stands out for having favorable features to biodiesel production such as the high oil content of its fruit. Considering the great potential of the species and their applicability in the renewable energy field, it becomes indispensable

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The use of quality seedlings is important in establishing a productive coffee crop. However, the most widely used method to produce coffee seedlings is time consuming (6-12 months) and lacks new production technologies. This study aimed to assess the use of fertigation and a growth regulator in the production of coffee seedlings, in order to develop a system faster than the conventional method. For that, Topázio coffee cultivar seeds were pre-germinated and planted in tubes filled with substrate (composted pine bark), in a protected nursery. A randomized block design was used, in a 4 x 2 (fertigation levels x the use or not of growth regulator) factorial scheme, with four replications. Daily fertigation positively influenced all the growth variables evaluated. The foliar spraying of the growth regulator had little effect on seedling growth. When compared to the conventional system described in the literature, the coffee seedling production system described here reduced, by around 60 days, the production time and enables a large-scale production.

Pluchea sagittalis (Asteraceae) is widely distributed in South America and used as a medicinal plant to treat various diseases. The objectives of the work were to evaluate the antioxidant and antifungal activities of the ethanol extract and fractions from the aerial parts of P. sagittalis, as well as to identify the chemical constituents of the most active sample by liquid chromatography coupled to mass spectrometry with electrospray ionization (LC-MS-ESI). The ethanolic extract obtained by maceration of aerial parts showed relevant activity in DPPH free radical scavenging (IC50 = 33.9 µg mL-1) and presented an anti-Candida effect with MIC values of 93.75 µg mL-1 for C. albicans and 187 µg mL-1 for C. glabrata and C. tropicalis. However, the results found for the chloroform fraction prepared from the extract were more significant. This fraction showed the highest antioxidant activity with an IC50 of 12.5 µg mL-1 and inhibited the growth of Candida spp. with MIC values ranging from 46.87 to 93.75 µg mL-1. The qualitative phytochemical screening of this fraction indicated the presence of phenolic compounds and flavonoids. Twenty-three metabolites were identified by LC-MS in the chloroform fraction including caffeoylquinic acids derivatives, flavones and fatty acids, which have recognized antioxidant and antimicrobial effects. The results of the activities, as well as the chemical constituents present in the chloroform fraction, reveal the potential of this fraction as a source of antioxidant and antifungal agents.

While tomatoes can be grown year-round in a greenhouse, the high temperatures of tropical climates are a limitation. As such, cooling the growing environment is key to cultivating tomatoes in controlled environments during summer, but effective cooling systems are expensive and involve high production costs. The use of biostimulants has been reported to increase yield and can mitigate the effects of high temperature on greenhouse-grown tomatoes. Our hypothesis is that biostimulants can improve tomato yield, particularly in the event of stress during cultivation. Our aim was to assess the effects of three biostimulants on greenhouse-grown tomato plants in the summer under a tropical climate. The experiment was conducted in a greenhouse on the Uberaba Campus of the Federal Institute of the Mineiro Triangle (IFTM). We used a completely randomized design consisting of a plot containing five plants, with 1.0 x 0.5 m spacing, an estimated density of 20,000 plants ha-1, and six repetitions. The three biostimulants applied were Alquifishmel®, Booster® and Stimulate®, compared to a control (plants with no biostimulant). Production, fruit quality, yield and plant growth were assessed. All three biostimulants improved yield by more than three metric tons per hectare in relation to the control, primarily due to the larger number of ripe fruits. It is suggested that the biostimulants mitigated heat stress, promoting a larger number of fruits per truss and resulting in higher yield.

Coffee seedling production in cone-shaped containers and substrate results in lower sanitary risk and costs. With the use of small containers and substrates with low fertilizer levels, fertigation is necessary for seedling development. An experiment was carried out with three macronutrient concentrations (electrical conductivities of 1.0, 2.0 and 3.0 dS m -1 ) and a non-fertilized control using Coffea arabica cv. Topázio seedlings in 50 cm 3 cone-shaped containers and composted pine bark-based substrate. The following fertilizers (expressed in g m -3 of water) were used in the nutrient solution with EC of 1.0 dS m -1 : Ca(NO 3 ) 2 (400), KNO 3 (250), MgSO 4 (175), (NH 4 )PO 4 (50) and ConMicros Standard ® (25). In the solutions with 2.0 and 3.0 dS m -1 , macronutrient concentration was doubled and tripled, while micronutrients remained the same. At four months we assessed EC and pH of the solution drained, shoot dry mass, shoot nutrient concentration and accumulation and macronutrient use efficiency. Fertigation with 1.0 and 2.0 dS m -1 produced seedlings with greater mass (+10%) than fertigation with 3.0 dS m -1 , while higher macronutrient supplies increased shoot N, P, K, Mg and S concentration. Fertigation with 2.0 dS m -1 caused greater shoot N, P, K and Ca accumulation and this conductivity also resulted in higher accumulation of B, Fe, Mn and Zn without increasing the micronutrient supply. The response to the increase in Ca in the nutrient solution is evident in the accumulation of this nutrient in the plant but not its concentration, possibly due to the dilution effect. Micronutrient accumulation in this species is also more adequate for determining nutritional status than the concentration in the plant. The least concentrated macronutrient solution increases nutrient use efficiency in C. arabica seedlings as well as being economically and environmentally more sustainable.