Seed vigor of Piptadenia moniliformis Benth. subjected to thermal stress

The objective of this work is to evaluate the influence of accelerated aging test at 41ºC on the germination and seed vigor of Piptadenia moniliformisBenth. Two experiments were conducted. Experiment 1: seeds were submitted to dormancy overcoming treatments. They were immersed into sulfuric acid for 0 (intact seeds), 5, 10, 15, 20 and 25 minutes. Experiment 2: two methods were evaluated for the accelerated aging test at 41ºC, that is, the traditional method and the saturated NaCl solution method with exposure periods of 0, 24, 48, 72 and 96 hours. After each treatment, the seeds were subjected to electrical conductivity and germination tests. Seeds overcame their dormancy when immersed into concentrated sulfuric acid for 5, 10, 15, 20 or 25 minutes, but thegermination was faster when immersed for 20 minutes. The different methods for the accelerated aging test, decreased the germination potential and seed vigor of P. moniliformisafter 24 hours of exposure. Regarding the method used, the saturated solution provided, in general, the best results since the seed water content was lower, thus reducing the proliferation of fungi. The electrical conductivity test showed that, by increasing the aging period regardless of the method, there is an increase in seed deterioration, corroborating with germination results, which showed that the correlation was moderate and negative and indicated that the higher the conductivity, the lower the percentage and the germination speed index. The immersion of seeds of P. moniliformisinto concentrated sulfuric acid for 20 minutes provides a fast and increased germination. The methods for accelerated agingat 41ºC, traditional and saturated solution, can be used as vigor tests to evaluate the physiological quality of seeds.

Produção hidropônica de coentro e salsa crespa sob concentrações de solução nutritiva e posições das plantas nos perfis hidropônicos / Hydroponic production of coriander and curly parsley under concentrations of nutrient solution and plant positions in hydroponic profiles

O crescimento das plantas e a qualidade do produto final estão diretamente relacionados à solução nutritiva. O objetivo deste trabalho foi avaliar o desempenho do coentro e da salsa, sob concentrações de solução nutritiva e posições das plantas nos canais de cultivo, em sistema de cultivo hidropônico NFT. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema de parcelas subdivididas, sendo dispostas nas parcelas as concentrações da solução nutritiva (50; 75; 100 e 125%) e nas subparcelas as posições das plantas nos perfis hidropônicos (Inicial, Intermediária e Final), totalizando 12 tratamentos e três repetições. Plantas de salsa crespa e coentro apresentaram melhores rendimentos (produção de massa fresca, número de folhas e altura) sob cultivo com 100% da concentração da solução utilizada. Em análise, as posições inicial e intermediária dos perfis hidropônicos refletiram maiores rendimentos nas duas espécies estudadas. Em ambas culturas, o aumento da concentração para 125% é mais prejudicial ao desenvolvimento que a redução para 75%.

Plant growth and final fruit quality, in hydroponics, are directly related to the nutrient solution. This study evaluated the performance of cilantro and parsley, under different nutrient solution concentrations and plant position in the growth profiles, in NFT hydroponics growth system. The experimental design was completely randomized, in split plots, with plots in the nutrient solution concentration (50, 75, 100 or 125%) and the sub plots the plant position in the hydroponics profiles (Initial, Intermediate or Final), in a total of 12treatments and three repetitions. Curly parsley and cilantro presented best yields (production of fresh matter, number of leaves and height) under growth in 100% concentration of the utilized solution. The analysis showed that the initial and intermediate positions in the hydroponics profiles resulted in greater yield for both species studied. Increasing nutrient concentration to 125%, for both cultures, was more harmful for plant development than reducing it to 75%.

Comparação dos sistemas de produção de tomate convencional e orgânico em cultivo protegido / Comparison of conventional and organic tomato growing under protected cultivation

O objetivo deste trabalho foi comparar os aspectos agronômicos e econômicos da produção convencional e orgânica do tomateiro. Realizou-se um levantamento geral dos sistemas de produção convencional e orgânico do tomateiro, abordando os aspectos agronômicos (manejo, preparo do solo, métodos de controle de pragas,doenças e plantas nativas, produtividade, entre outros) e econômicos (custo de produção e lucratividade). O sistema orgânico apresentou-se agronomicamente viável, com um custo de produção 17,1% mais baixo que o convencional e lucratividade até 113,6% maior.

Organic agriculture expansion is a consequence of an increasing global concern about the environment. There is an interest in reducing the adverse effects of chemical use on the ecosystem through the alternate methods, always searching for quality and economic viability of the activities developed. This study compared the agricultural and economical aspects of conventional and organic tomato production, which, besides being a vegetal commonly used "in natura", is a culture of complex management and, therefore, of high economic risk. An overall survey was done about the conventional and organic tomato production systems, analyzing the agricultural aspects (management, soil cultivation, pests, diseases and weed control methods, productivity, among others) and economical (production costs and profitability). The organic system was agriculturally viable, with a production cost 17.1% lower than the conventional and profitability up to 113.6% greater.