Hugo César Rodrigues Moreira Catão

Fruit production and classification of four cherry tomato genotypes under an organic cropping system

A field experiment was carried out in the Instituto de Ciencias Agrarias of Universidade Federal de Minas Gerais, Montes Claros, MG, Brazil, during the summer of 2008-2009, to evaluate the productive features of cherry tomato genotypes cultivated under different spacing, in an organic cropping system. The experimental design was randomized blocks in a 3x4 factorial scheme with three replications. The experimental plot was made up of four rows (spaced 1.00 m between rows) with thirty two plants each, utilizing the eight central plants for the analysis. The treatments consisted of three genotypes of cherry tomatoes (CH152, CLN1561-A and Carolina) and four spacings between plants (0.40; 0.60; 0.80; 1.00 m). The fruit percentage in the different diameter classes and the commercial fruits yield per plant and hectare were evaluated. The CH152 genotype produced a greater percentage of noncommercial fruit (with diameter less than 20 mm). The greatest percentage of fruit classified with the largest diameters (above 30 mm) was achieved by the CLN1561A genotype. The highest commercial yields of fruit per plant and per area were found in the CLN1561A genotype, pointing it out as a promising genotype for an organic crop in the summer in the north of Minas Gerais

Fungicides and alternative products in the mycelial growth and germination control of Alternaria tomatophila

Este estudio tuvo como objetivo caracterizar el efecto in vitro de diferentes productos en el crecimiento micelial y en la germinacion de conidios de Alternaria tomatophila, agente etiologico del tizon temprano del tomate. El experimento se establecio mediante un experimento completamente aleatorizado en un esquema factorial 5x4, con cinco concentraciones (0%, 25%, 50%, 75% y 100% de la dosis comercial recomendada) x 4 productos (cimoxanil + mancozeb, oxicloruro cobre, fosfito de potasio 0-28-26 y biofertilizante) con cuatro repeticiones. Los productos se homogeneizaron y anadieron al medio PDA para evaluar la inhibicion del crecimiento micelial y se incorporaron en medio agar-agua para probar la inhibicion de la germinacion de los conidios. El fungicida mancozeb + cimoxanil y el fosfito de potasio 0-28-26 fueron los mejores productos evaluados inhibiendo totalmente el crecimiento micelial, el oxicloruro de cobre demostro tener un efecto intermedio, mientras el biofertilizante fue menos eficaz. La germinacion de conidios tuvo un comportamiento similar frente a los productos evaluados. Elfungicida mancozeb + cycomaxil y el fosfito sobresalieron, seguido de oxicloruro de cobre y del biofertilizante; sin embargo, los productos no inhibieron completamente la germinacion de esporas de A. tomatophila.

Aspectos fisiológicos e bioquímicos da germinação de sementes de alface em diferentes temperaturas

The objective of this work was to evaluate the electrophoretic patterns of heat-tolerant proteins and the activity of the endo-β-mannanase enzyme during lettuce seed germination, at high temperature. Seeds of eight lettuce cultivars were subjected to germination, first count, and emergence tests at two temperatures, 20 and 35oC. The index of germination speed (IVG) and the emergence rate index (IVE) were calculated. The expression of heat-tolerant proteins and of the endo-β-mannanase enzyme was also evaluated for all treatments. The experimental design was completely randomized, in a 2x8 factorial arrangement, with two temperatures and eight cultivars. The highest germination is observed at 35oC in the Everglades cultivar, considered thermotolerant. The patterns of heat-tolerant proteins in lettuce seeds present specific bands in the Everglades cultivar, at 35oC. The activity of the endo-β-mannanase enzyme is higher in the Everglades cultivar, at this temperature. This cultivar has potential for use in lettuce breeding programs aiming for tolerance to high temperatures during germination.

Determinação do ponto de colheita na produção de sementes de pimenta malagueta e alterações bioquímicas durante o armazenamento e a germinação

The harvest point interferes with the quality of the seeds, and in species with fleshy fruits and irregular maturation, there is difficulty in defining it. This study aimed to assess the dormancy of chili in three maturity stages during storage, in order to determine the best point of reaping and sowing and also enzymatic changes during the process of seed germination processed in different stages of maturation during storage. The seeds were manually extracted from fruits at three developmental stages: E1 (fruits with first signs of yellowing), E2 (ripe fruit) and E3 (mature and subjected to seven days of rest Fruits). After drying the seeds with 8% water content were stored in cold storage for 0, 4 and 8 months. After these periods seed quality was evaluated by means of the germination, vigor and enzyme activity tests. For the evaluation of the enzymes during the germination of seeds from each treatment, the seeds of each treatment were sampled for periods of 0, 48, 96 and 144 hours after sowing. We used a randomized block design, factorial trial 3 harvest times x 3 storage periods with Cientifica, Jaboticabal, v.42, n.2, p.187-197, 2014 ISSN: 1984-5529 188 four replications. There dormancy in seeds of chillies especially when newly stored and is surmounted by four months of storage. Chili seeds should be harvested when the E3 stage are sold after processing and at E2 or E3 when stored for periods up to four months. Enzyme changes are evident in the germination process and the different stages of maturation during storage. Additional keywords: Capsicum frutescens; seed maturation; seed quality.

Overcoming strawberry achene dormancy for improved seedling production in breeding programs

espanolLos aquenios de la fresa presentan latencia del tegumento. Este hecho, unido a la baja eficiencia de la polinizacion artificial implica en la realizacion de un mayor numero de cruzamientos para asegurar el numero minimo de aquenios utilizados en la produccion de plantulas en programas de mejoramiento. El objetivo de este estudio fue el de probar soluciones quimicas para superar la latencia en aquenios de la fresa con el fin de aumentar la germinacion y el indice de velocidad de germinacion (IVG). Este estudio consistio en dos experimentos. 1) Inmersion en H2SO4 (98%), HCl (37%) y NaClO (2%) para los tiempos de 0 (control), 10, 20, 35 y 50 minutos. 2) los aquenios se sumergieron en H2SO4 (98%) para los tiempos de 0 (control), 20, 25, 30, 35 y 40 minutos. Se utilizo un diseno completamente al azar (DCA) con cuatro repeticiones. La germinacion y el IVG fueron evaluados todos los dias durante 15 dias. La escarificacion con H2SO4 (98%) durante 40 min aumenta la germinacion de los aquenios de la fresa a 80% y puede ser utilizado como una tecnica para superar la latencia. La escarificacion con HCl y NaClO aumenta la germinacion y el IVG, sin embargo, debe estudiarse junto a otras concentraciones y tiempos de inmersion de esos metodos. EnglishStrawberry achenes present tegument dormancy. This fact, together with the low efficiency of artificial pollination requires a larger number of crossings to ensure the minimum number of achenes used in seedling production in breeding programs. The aim of this study was to test chemical solutions to overcome dormancy in strawberry achenes in order to increase the germination and Germination Speed Index (GSI). The study consisted of two experiments. 1) immersion in H2SO4 (98%), HCl (37%) and NaClO (2%) for 0 (control), 10, 20, 35 and 50 min were evaluated. 2) achenes were immersed in H2SO4 (98%) for 0 (control), 20, 25, 30, 35 and 40 min. A completely randomized design with four replications was used. Germination and GSI were assessed daily for 15 days. Scarification with H2SO4 (98%) for 40 min increased strawberry achene germination to 80% and can be used as a technique to overcome dormancy. Scarification with HCl and NaClO increases germination and the GSI, however, other concentrations and immersion times of those methods should be studied.