ABSTRACT The cultivation of Cotton (Gossypium hirsutum) is trending in an upward expansion at Minas Gerais state, Brazil. Due this growth, the breeding program has been demanded for the knowledge about the genetic diversity and correlation between morpho-agronomic traits, to start interesting crosses. The objective of this work was to study the genetic diversity and the correlation network between morpho-agronomic traits of cotton genotypes. Two cotton accessions and five commercial cultivars: FM993, FMT701, FM910, DP604 and DP604BG were evaluated for 16 traits. The results revealed divergence between the genotypes. Unweighted pair-group method arithmetic average (UPGMA) analysis allocated the genotypes in three clusters, with DP604 and Accession 2 being the most divergent. The correlation network helped to visualize the association between traits, presenting a negative correlation between anthracnose with plant height (-0.465), plant vigor (-0.486) and main root length (-0.437). Also, even with some genotypes presenting a higher number of reproductive branches, the correlation for this trait with number of bolls showed a high significant value (0.68). Thus, the genotypes showed wide genetic diversity for the composition of future crosses in cotton breeding programs. The correlation network allowed the visualization of a medium to high correlation pattern for the morpho-agronomic traits.

Abstract Brazilian coffee cultivation was boosted over the last few decades by the mechanization of various field operations. Considering the influence of genetic factors on coffee harvesting efficiency, we aimed to evaluate the use of mechanized harvesting characteristics as a criterion to select progenies derived from ‘Icatu’ germplasm, previously evaluated for agronomic characteristics, resistance to rust and cercosporiosis. We also investigated genotypic and phenotypic correlations between semi-mechanized harvesting characteristics. Ten progenies of Coffea arabica L. were analyzed in two experimental farms during two consecutive harvests. Genetic parameters were evaluated to trace selection strategies. Four progenies that were suitable for mechanization were selected, supporting our hypothesis of the use of harvest characteristics as selection criteria.

RESUMO Objetivou-se avaliar o uso do polímero hidro retentor no crescimento inicial de cafeeiros em diferentes níveis de irrigação e tipos de mudas. O experimento foi instalado em vasos com solo argiloso, em casa de vegetação do Setor de Cafeicultura, Universidade Federal de Lavras. O experimento foi conduzido em delineamento de blocos ao acaso com parcelas sub-subdivididas e três repetições, totalizando 48 unidades experimentais. Quatro níveis de irrigação (25%; 50%; 75% e 100% de água disponível) foram aleatorizados às parcelas; os tipos de mudas (formadas em saquinho e tubete) foram aleatorizadas às sub-parcelas; e a ausência ou presença do polímero hidro retentor foram aleatorizados nas sub-subparcelas. Nos tratamentos com uso do polímero hidro retentor utilizou-se a diluição de 1,5 kg de polímero em 400 litros d'água, para utilização da dose de 1,5 litros da solução por planta. Em intervalos de 60 dias durante a condução do experimento (360 dias a partir da implantação), avaliou-se o diâmetro de caule, altura de planta, área foliar, número de folhas e número de ramos plagiotrópicos dos cafeeiros. O polímero hidro retentor hidratado beneficiou o crescimento do cafeeiro em sistema irrigado. A irrigação promoveu maior crescimento das plantas, sendo que as mudas formadas em saquinhos apresentam maior crescimento que mudas em tubetes.

ABSTRACT The aim of this work was to evaluate the use of a water-retaining polymer on the initial growth of coffee plants for different levels of irrigation and types of seedling. The experiment was set up in pots with a clayey soil, in a greenhouse of the Sector for Coffee Production of the Federal University of Lavras, Brazil. The experiment was arranged in a randomised block design into sub-lots with three replications, giving a total of 48 experimental units. Four levels of irrigation (25%, 50%, 75% and 100% of the available water) were randomly assigned to the lots; the type of seedling (grown in bags or tubes) were randomly assigned to the sub-lots, and the use or not of the water-retaining polymer randomly assigned to the sub-sub-lots. In the treatments with water-retaining polymer, a dilution of 1.5 Kg of polymer to 400 litres of water was used at a dose of 1.5 litres of solution per plant. The following were evaluated at intervals of 60 days during the experiment (360 days from planting): stem diameter, plant height, leaf area, number of leaves and number of plagiotropic branches on the coffee plants. Hydrated water-retaining polymer favoured the growth of coffee plants under an irrigated system. Irrigation resulted in greater plant growth, with the seedlings grown in bags showing more growth than those grown in tubes.