ABSTRACT. Ex vitro strawberry plantlets from micropropagation and coinoculated with arbuscular mycorrhizal fungi (AMF) and biochar can provide beneficial health effects. In the present study, we evaluated the effects of different proportions of biochar in the presence and absence of AMF on the production of secondary metabolites in the leaves and roots of strawberry plantlets during ex vitro acclimatization. Additionally, the enzymatic activity of the substrate enriched with AMF and biochar was analyzed. The experiment consisted of the control (absence of the mycorrhizal community) and four biochar proportions (0, 3, 6, and 9% of the volume of the container) coinoculated with AMF. Plantlets produced on substrates enriched with AMF showed higher levels of polyphenols, flavonoids, phenolic acids, and tannins in the tissues analyzed than control plantlets. The combination of AMF and 9% biochar increased the content of total flavonoids in the leaves of strawberry plantlets and increased the activity of phosphatase. The substrate with up to 6% biochar and mycorrhizae showed increased β-glucosidase activity. In conclusion, mycorrhizae are excellent tools to improve the phytochemical quality of strawberry plantlets acclimatized ex vitro. The association between host plants, mycorrhizal symbionts, and bioactivators of these fungi potentiates properties beneficial to health, which can be exploited efficiently in sustainable agriculture.

ABSTRACT: Even though oats (Avena spp.) have the capacity to produce numerous compounds with the potential to act antagonistically against plant pathogens, studies on the genotypic effect of this crop focusing on their nematicidal activity are limited. The objective of this study was to verify the effect of the aqueous extracts prepared with the biomass of oat genotypes, on the hatching of second-stage juveniles of root-knot nematodes (Meloidogyne javanica and Meloidogyne incognita). The bioassays were carried out in a completely randomized design with four replications. Eighteen extracts were evaluated, consisting of a combination of six oat genotypes Agro Quaraí, Agro Esteio, Embrapa 139, AF 12202, UPFPS Farroupilha, and AF 1345 Ucraniana, and three extract concentrations (5 %, 10 %, and 20 % w/v). Three additional treatments were added to the study (distilled water, chemical nematicides abamectin, and imidacloprid + thiodicarb). The treatments and the suspension containing nematode eggs were placed in Petri dishes and incubated in a growth chamber for ten days. At the 5 % and 10 % w/v concentration levels, a genotype effect was observed in the hatching of juveniles for both nematode species. For the control of M. javanica the extracts of Embrapa 139 had a better performance, while the extracts of Agro Quaraí and AF1345 Ucraniana performed better when under the control of M. incognita. Thus, oat biomass formation might have the ability to suppress the nematode population in the soil, and could therefore, be used for the management of root-knot nematodes.

ABSTRACT. The adaptability of the strawberry is known; however, little is known about the morphological and agronomic performance of these runner plants when transplanted in the Southern Hemisphere. The objective of this study was to evaluate whether strawberry cultivars classified according to their flowering differ in morpho-phenology and agronomic performance. Six cultivars of strawberry were used, two of which were Short Day (SD), Camarosa and Camino Real, and four of which were Neutral Day (ND), Aromas, Albion, Monterey, and San Andreas. The cultivars were arranged in a randomized complete block design with four blocks. The research developed in two parts: one part as descriptive research (morphological performance and phenology) and the other part as explanatory research (morphology of the root system and the agronomic performance). In the descriptive research, the data about the strawberry cultivars were presented in a descriptive way. The data on morpho-agronomic performance (explanatory research) were submitted to analysis of variance and Tukey’s test at a 5% probability of error. It is inferred that there is variability among cultivars regardless of their classification in terms of flowering. In all cultivars, we observed a botanical structure called a hypsophyll that is not included in the morphological descriptors of the species.

RESUMO Ao longo dos anos, o cultivo do morangueiro tem apresentado alterações em sua fenologia, envolvendo, principalmente, o início de floração e frutificação. O objetivo do trabalho foi verificar se os anos de cultivo interferem na duração das fases vegetativa e reprodutiva do morangueiro, em ambiente protegido. Foi observado entre os anos de 2007 a 2014, o desenvolvimento da cultivar de morangueiro Camarosa. O ambiente no qual se estabeleceram os cultivos foi uma estufa agrícola no Setor de Horticultura da Universidade de Passo Fundo, RS. Registraram-se dados como data de transplante, início e final de colheita dos frutos; dados de temperaturas (máximas, médias e mínimas) registradas no ambiente de cultivo. Esses dados foram utilizados para cálculo da soma térmica (diária, acumulada). A análise de dados foi realizada de forma descritiva, relacionando os dados de temperatura com os estádios fenológicos em cada ano. A soma térmica acumulada necessária para iniciar a colheita foi variável nos anos, ficando entre 383 e 438 graus dias-1 para plantas com intervalo entre transplante e colheita de 73 dias (anos de 2008 e 2009) a 816 graus dias-1, em intervalo de 111 dias (em 2014). No primeiro caso, acumulou-se 5,2 ºC/dia, em 2008 e 6 ºC/dia, em 2009. No segundo, foi de 7,3 ºC/dia, em 2014. Mudas transplantadas na primeira quinzena de maio iniciaram a frutificação no início de agosto e setembro. Mudas transplantadas em julho de 2011 e 2012 iniciaram em período semelhante, primeira e segunda quinzena de setembro. Constatou-se que, em função das temperaturas registradas nos diferentes anos de cultivo e épocas de transplante, há alteração principalmente na fase vegetativa do morangueiro.

ABSTRACT Over the years, strawberry growth has shown alterations in its phenology, involving mainly the beginning of flowering and fruiting. The aim of this study was to verify whether the growth years influence the duration of strawberry vegetative and reproductive stages in protected environment. The development of the Camarosa strawberry cultivar was observed between 2007 and 2014. The crops were settled in a greenhouse in the Horticulture Sector at the University of Passo Fundo, RS. Data like transplant date, in the beginning and end of the fruits harvest; temperature data (maximum, average and minimum) were recorded in the growth environment. These data were used for the thermal sum calculation (daily, accumulated). The data analyses were carried out in a descriptive manner, relating the temperature data with the phenological stage of each year. The accumulated thermal sum that is necessary to begin the harvest was variable throughout the years, where it was between 383 and 438 degrees days-1 for plants with interval between transplant and harvest of 73 days (2008 and 2009) at 816 degrees days-1, where the interval was 111 days (in 2014). In the first case, it accumulated 5.2 ºC/day, in 2008 and 6 ºC/day, in 2009. In the second case, it was 7.3 ºC/day, in 2014. Seedlings which were transplanted in the first fortnight of May began fruiting in the beginning of August and September. Seedlings transplanted in July 2011 and 2012 began fruiting in similar periods, that is, in the first and second fortnight of September. It was found that, because of the temperatures recorded in different periods of growth and transplant time, there is alteration mainly in the strawberry vegetative stage.