ABSTRACT Kale plants are usually sold “in natura” in street markets and malls. Kale leaves can have their appearance compromised by dehydration and discoloration due to increased post-harvest time exposure. We aimed to analyze the Global Stability Index (GSI) in kale accessions by means of repeated measurement analysis and curve grouping as a complementary form of superior sample identification with regard to post-harvest preservation. Thirty kale accessions were evaluated using a randomized block design with four blocks and five plants per plot. Two commercial leaves per plant were collected, and kept on workbenches in the shade at a temperature of 18 ± 1 °C. Subsequently, the degrees of discoloration and dehydration, total chlorophyll content, and accumulated fresh mass loss were evaluated over a 15-day period. From these data, the GSI was calculated for each day of evaluation. In addition, using mixed models, thirteen co-variance structures were tested. For graphical analysis, thirteen linear and non-linear models were assessed followed by curve grouping using multivariate analysis. The GSI was efficient for differentiating accessions, which became an important tool in post-harvest studies. GSI values were not equally correlated, therefore the use of mixed models became an important approach. The unstructured matrix was the best fit to model the dependence of error. The Melow I model was the best fit for studying the GSI. The accessions UFVJM-10, UFLA-1, COM-1, UFVJM-32, COM-3, UFVJM-8, UFVJM-36 and UFVJM-24, belonging to 3 and 5 clusters, are recommended for crop cultivation and as parental material in breeding programs.

The efficiency of artificial neural networks (ANN) to model complex problems may enable the prediction of characteristics that are hard to measure, providing better results than the traditional indirect selection. Thus, this study aimed to investigate the potential of using artificial neural networks (ANN) for indirect selection against early flowering in lettuce, identify the influence of genotype by environment interaction in this strategy and compare your results with the traditional indirect selection. The number of days to anthesis were used as the desired output and the information of six characteristics (fresh weight of shoots, mass of marketable fresh matter of shoots, commercial dry matter of shoots, average diameter of the head, head circumference and leaf number) as input file for the training of the ANN-MLP (Perceptron Multi-Layer). The use of ANN has great potential adjustment for indirect selection for genetic improvement of lettuce against early flowering. The selection based on the predicted values by network provided estimates of gain selection largest that traditional indirect selection. The ANN trained with data from an experiment have low power extrapolation to another experiment, due to effect of interaction genotype by environment. The ANNs trained simultaneously with data from different experiments presented greater predictive power and extrapolation.

O objetivo deste trabalho foi avaliar os parâmetros genéticos das características agronômicas e de tolerância ao florescimento precoce de onze cultivares de alface, bem como verificar a existência de associação entre as características. O experimento foi realizado em ambiente protegido, em delineamento de blocos ao acaso, com quatro repetições e doze plantas por parcela. Quarenta e cinco dias após o transplantio das mudas, foram mensuradas as seguintes características: massa de matéria fresca total e "comercial" da parte aérea, massa de matéria seca "comercial" da parte aérea, massa de matéria fresca e seca da raiz, diâmetro e circunferência da cabeça, altura de planta, número de folhas por planta e número de dias até a antese. Há variabilidade genética entre as cultivares, em todas as variáveis, exceto quanto à circunferência de planta e matéria fresca da raiz. As cultivares Regina 500, Lívia e Atração foram superiores quanto ao número de dias para o florescimento e também para as demais características avaliadas. A seleção contra o florescimento precoce ocasionou ganho em todas as características; porém, não interferiu na matéria seca da raiz. A matéria fresca da parte aérea e o diâmetro de cabeça são indicadas para a seleção indireta contra o florescimento precoce.

The objective of this study was to evaluate the genetic parameters of agronomic traits and of tolerance to early flowering of eleven cultivars of lettuce, as well as to verify the existence of an association between the characteristics. The experiment was carried out in a protected environment, in a randomized complete block design, with four replicates, and twelve plants per plot. Forty-five days after seedling transplanting, the following traits were measured: total shoot fresh mass, marketable shoot fresh mass, marketable dry shoot weight, fresh and dry weight of roots, diameter and circumference of head, plant height, number of leaves per plant, and number of days until anthesis. There was genetic variability between cultivars for all variables, except for circumference of plant and fresh weight of root. The cultivars Regina 500, Lívia and Atração were superior for number of days to flowering and also for the other characteristics. The selection against early flowering caused gain of all the characteristics, but did not affect root dry matter. Fresh matter of shoots and head diameter are indicated for indirect selection against early flowering.

O objetivo deste trabalho foi avaliar o desempenho agronômico de acessos de couve e estimar os parâmetros genéticos e a correlação entre características de interesse para o melhoramento. O experimento foi realizado em delineamento de blocos ao acaso, com 30 genótipos de couve, entre os quais, três cultivares comerciais, de diferentes empresas. Foram utilizadas quatro repetições, com cinco indivíduos por parcela. Verificou-se variabilidade genética entre os genótipos, com predominância dos efeitos genéticos sobre os ambientais, o que indica a possibilidade de se obterem ganhos genéticos representativos com o melhoramento. As características importantes para o melhoramento da espécie foram: comprimento e largura de folha, diâmetro de pecíolo, área foliar, altura de planta, número de brotações e massa de folhas secas. Os genótipos comerciais apresentaram menor área foliar, massa de matéria seca de folhas, altura de planta, comprimento e largura de folha, comprimento de pecíolo, e número de brotações e de folhas comerciais.

The objective of this work was to evaluate the agronomic performance of kale genotypes and to estimate the genetic parameters and the correlation between traits of interest for breeding. The experiment was carried out in a randomized block design, with 30 kale genotypes, with three commercial cultivars, from three different companies. It was used four replicates, with five individuals per plot. Variability was significant among genotypes, with predominance of genetic effects over environmental ones, indicating the possibility of obtaining expressive genetic gains in breeding. The most important traits for breeding purposes were: leaf length and width, stem diameter, leaf area, plant height, number of shoots, and leaf dry weight. Commercial genotypes showed smaller leaf area, dry leaf mass, plant height, leaf length and width, petiole length, and number of sprouts and commercial leaves.

Objetivou-se avaliar o potencial de silagens de ramas de diferentes clones de batata-doce para alimentação animal. O trabalho foi realizado na Fazenda Forquilha localizada no Distrito de Batatal, município de Diamantina MG, no período de 23/12/2007 a 23/06/2008. O experimento foi conduzido no esquema de parcelas subdivididas em delineamento de blocos completos casualizados. Foram avaliadas a produtividade de matéria verde e matéria seca das ramas e a composição químico-bromatológica, além do perfil fermentativo de suas silagens, em três idades de colheita (120, 150 e 180 dias), em oito clones de batata doce. A produtividade de matéria seca não variou com a época de colheita das ramas, obtendo-se média de 6,01t ha-1. Os teores de matéria seca nas ramas aumentaram com o ciclo da cultura, verificando-se teores médios de 11,94; 12,16 e 19,62%, aos 120, 150 e 180 dias após o corte, respectivamente. As silagens das ramas de batata-doce apresentaram altos teores protéicos e energéticos e adequado perfil fermentativo, portanto, apresentam potencial para utilização na alimentação animal, independentemente dos clones.

The objective was to evaluate the potential of silage derived from different clones of sweet potato for animal feed. The study was conducted at Forquilha Farm located in Batatal district, MG Diamantina in the period from 23/12/2007 to 23/06/2008. The experiment was conducted in split plot design in a randomized complete block. It was evaluated the green and dry matter yield, the chemical composition and the fermentative profile of silage harvested on three dates (days 120, 150 and 180), of eight clones of sweet potato. The dry matter yield did not vary according to the harvest time of the branches, resulting in an average of 6.01t ha-1. The dry matter content in the stems increased with the growth cycle, and there are average levels of 11.94, 12.16 and 19.62% on days 120, 150 and 180 after cutting, respectively. The raw potato silage showed high protein content and adequate energy fermentation and therefore, potential for use in animal feed, regardless of clones.