Edmar Soares de Vasconcelos

Agrupamento de modelos de regressão da análise de adaptabilidade e estabilidade de genótipos

The objective of this work was to provide evidences of differences among regression models, obtained by the Eberhart & Russell method, for the genotype adaptability and stability analysis, and to propose a methodology for grouping similar models. The test to verify the identity of models was used in the evaluation data of 14 corn genotypes in eight environments. Once the hypothesis of equality of regression models was discarded, model grouping was performed through estimating the mean square of the reduction (MSQRed) between pairs of regression models. After obtaining these values, the smallest one was selected and its significance was verified by the F-test. If this MSQRed is not significant, the model pair related to it comprises the initial group. The models identity verification method can be successfully used for grouping linear regression equations, obtained by the Eberhart & Russell method, in order to study genotype adaptability and stability. The similar models grouping allow the formation of genotype groups with the same statistical behavior

Cultivo do tomateiro sob diferentes espaçamentos entre plantas e diferentes níveis de desfolha das folhas basais

This work aimed to study the influence of plant spacing and level of basal leaves defoliation on yield characteristics of tomato. The experimental design was a randomized complete block design in a factorial 2x4 with five replications. Two spacings (0.30 and 0.50 m) and four levels of defoliation (0, 50% and 100% of basal leaves removed after fruiting the first cluster and 100% of basal leaves removed after harvest of the first cluster). It was evaluated the number of normal, defective and total fruits per cluster, mass of normal, defective and total fruits per cluster, longitudinal and transversal diameter of the normal fruits; and productivity of normal and total fruits per cluster. Removing the basal leaves is favorable for production, when there is a higher plant density, and must be performed before the formation of the first cluster. For more spaced plants the basal leaves influenced these characteristics, not being favorable their removal during the formation of the first cluster, but after sampling this. Defoliation is a practice that can be used to increase aeration, improving the utilization of solar radiation and reduce pest problems.

Desenvolvimento e produtividade de quinoa semeada em diferentes datas no período safrinha

This work was carried out with the aim of evaluating the development and productivity of the BRS-Piabiru variety of quinoa when sown on different dates during the off-season at Campo Mourao, PR. Six sowing dates were evaluated, namely: March 18, 2008; April 2, 2008; April 17, 2008; May 2, 2008; May 17, 2008; and June 10, 2008. The culture indices evaluated were the number of days to flowering, the number of days to maturity, plant height at maturity, and productivity. The experiment was conducted in a complete-block design with random treatments and four replications. The results indicate that the seeding date had an influence on the number of days to flowering, number of days to maturity, plant height at maturity, and productivity. The greatest plant height, together with the highest productivity for quinoa were obtained on March 18.

Tamanho de coleção original, métodos de agrupamento e amostragem para obtenção de coleção nuclear de germoplasma

The objective of this study was to verify the effect of original germplasm collection size on the effectiveness of different clustering methods and sampling, used to obtain core collections, and to compare these methods in the establishment of core collections. Simulations were made for seven sizes of original collections, and seven sampling strategies were used for the establishment of core collections using morpho-agronomic traits. Eight strategies for obtaining core collections were used, six of them by grouping techniques (Tocher and sequential Tocher), and two without grouping (random and Tocher with inverted criteria grouping). For grouping strategies, constant, logarithmic and proportional sampling were used. The explained variance, the value of the determination coefficient, the coincidence coefficient, and the coincidence standard deviation coefficient between the core and the original collections were determined. The constant and logarithmic sampling strategies generate core collections which are representative of the original collections. The sequential Tocher grouping is more efficient in representing the original collection by the core collection than the Tochers. Among the evaluated strategies the sampling by Tochers inversed grouping criterion is the most efficient to generate representative core collections of the original collections