ABSTRACT Cattley guava (Psidium catteyanum Sabine) is a widespread native plant species of South America and constitutes important genetic resources for the improvement of guava trees. Fruits of these species are consumed by wild animals and extracted by local human populations. However, the vegetative propagation of adult plants, which is necessary for fixing desired characteristics, has been inefficient. The objective of this work was to evaluate the rescue of adult plants of P. cattleyanum by herbaceous and semi-hardwood cuttings for the establishment of clonal mini-gardens and to evaluate the rooting potential of mini-cuttings of different genotypes. The experimental design was completely randomized in a factorial scheme with the treatments being different propagule or propagation techniques (herbaceous and semi-hardwood cuttings from mother plants cultivated in the field and by mini-cuttings), with five repetitions and six propagules per plot. The potential for multiplication by the mini-cutting technique and plant vigor were evaluated for 20 genotypes of cattley guava during three seasons of the year (autumn, winter and summer). The use of semi-hardwood cuttings is feasible for the rescue of adult plants and the establishment of clonal mini-gardens. The mini-cutting technique provided the highest rooting percentage, and was most efficient in summer. The genotypes evaluated varied in rooting percentage and plant vigor.

RESUMO: Este trabalho teve por objetivo avaliar a resistência de genótipos de P. cattleyanum a M. enterolobii. O experimento foi conduzido em DIC, com seis tratamentos, constituídospor cinco genótipos de P. cattleyanum, pela goiabeira 'Paluma' (testemunha) e oito repetições constituídas por clones desses genótipos. A classificação quanto à resistência foi determinada de acordo com o fator de reprodução (FR), avaliado aos 135 dias após inoculação com o nematoide. Os genótipos de P. cattleyanum avaliados foram resistentes a M. enterolobii com FR iguais ou inferiores a 0,2.

ABSTRACT: This research aimed to evaluate genotypes of P. cattleyanum by resistance to M. enterolobii. The experiment was conducted in a completely randomized design with six treatments, consisting of five genotypes of P. cattleyanum and guava 'Paluma' (control) and eight replicates. Genotypes classification for resistance was determined by the reproduction factor (RF), evaluated at 135 days after inoculation with the nematode. Genotypes of P. cattleyanum were considered as resistant once reproduction factors evaluated had less than or equal to 0.2.

O interesse comercial pela atemoia vem aumentando cada vez mais no Brasil. O aumento da atividade respiratória, acompanhado por modificações rápidas na composição física dos frutos podem inviabilizar sua distribuição a mercados distantes. Neste contexto, objetivou-se com o presente trabalho avaliar os atributos físicos em frutos de atemoia tratados com 1-metilciclopropeno (1-MCP) e atmosfera modificada associados à refrigeração. O experimento foi instalado em delineamento experimental inteiramente casualizado, em esquema fatorial 4x5, sendo quatro concentrações de 1-MCP (0; 200; 400 e 600 ŋL L-¹) e cinco períodos de avaliação após a colheita, em intervalo de cinco dias, com quatro repetições e quatro frutos por unidade experimental. As atemoias foram colhidas em pomar comercial, no município de Matias Cardoso-MG, no estádio de maturação fisiológica, lavadas, sanitizadas e secas ao ar, depois tratadas com as concentrações de 1-MCP por oito horas, em temperatura ambiente. Logo após, quatro frutos foram dispostos em bandejas de poliestireno expandido. Alguns permaneceram sem membrana, enquanto outros foram embalados com membrana plástica de PEBD 16µm. As variáveis avaliadas nos frutos foram: perda de biomassa fresca, firmeza, concentração de CO2, etileno e coloração da casca. O uso da atmosfera modificada e do 1-MCP, associados ou não, foi eficiente no atraso do amadurecimento dos frutos, permitindo a conservação de sua qualidade física. Frutos tratados com 1-MCP apresentaram-se mais firmes, além da preservação da coloração, verificada através da luminosidade, cromaticidade e ângulo Hueº, que se mostraram superiores quando comparados aos frutos não tratados.

The commercial interest by atemoya is increasing more and more in Brazil. The increased respiratory activity accompanied by rapid changes in the physical composition of the fruits may prevent their distribution to distant markets. In this context, the aim of this study was to evaluate the physical attributes in atemoya fruits treated with 1-methylcyclopropene (1-MCP) and modified atmosphere associated with refrigeration. The experiment was carried out in a randomized design, in a factorial 4x5, four concentrations of 1-MCP (0, 200, 400 and 600 nL L-¹), and five evaluation periods after harvest, in the range of five days, with four replications and four fruits per experimental unit. The atemoya were harvested, from a commercial orchard in the municipality of Matias Cardoso, North of Minas Gerais, at the physiological maturity, rinsed, sanitized and air dried, then treated with concentrations of 1-MCP for eight hours at room temperature. Soon after, four fruits were placed in polystyrene trays. Some remained without membrane, while others were packed with plastic film of LDPE 16 µm. The variables evaluated in the fruits were: fresh biomass loss, firmness, concentration of CO2, ethylene and peel color. The use of modified atmosphere and 1-MCP alone or combined, were effective in delaying fruits ripening allowing the preservation of its physical quality. Fruits treated with 1-MCP were firmer, as well as preservation of staining, verified by luminosity, chroma and Hue º angle, which proved to be superior when compared to untreated fruits.