QUALITY OF PROCESSING TOMATO FRUITS IN COMPETITION WITH Solanum americanum

Abstract

-Five experiments were conducted to evaluate the hypothesis that Solanum americanum density and time of coexistence affect the quality of processing tomato fruit. The tomato crop was established using either the direct drilling or the transplanting technique. The factors evaluated consisted of weed density (from 0 up to 6 plants m -2 ) and time of weed interference (early bloom stage, full flowering stage, fruit filling, and harvest time). The effects of competition on tomato fruit quality were analysed using a multiple model. Tomato variables evaluated included industrial fruit types (which depended on ripeness and disease infection) and soluble solids level ( o brix). Tomato fruit quality is dependent on the factors tested. Under low densities (< 6 plants m -2 ) of S. americanum there was a small impact on the quality of the tomato fruits. The percentage of grade A (mature fruit with red color and without pathogen infection) tomato fruits is the variable most affect by the independent variables. The impact of these independent variables on the percentage of grade C (green and/or with more than 15% disease infection) tomato yield was of smaller magnitude and in an inverse trend as the observed for grade A. The level of soluble solids was influenced by the weed interference on only two experiments, but the impact was of small magnitude. The impact of the results on current and future crop management practices is discussed.Keywords: weed competition, critical period, density-dependent processes, threshold. Palavras-chave: interferência, período crítico, processos dependentes da densidade, nível de dano econômico. RESUMO -Cinco experimentos foram conduzidos para avaliar a hipótese de que a densidade de Solanum americanum e o tempo de convivência podem alterar a qualidade dos frutos do tomate para a indústria. O tomate foi cultivado usando-se o plantio direto ou a técnica de transplante. Os fatores avaliados consistiram da densidade de plantas daninhas (de 0 até 6 plantas m -2 ) e do tempo de interferência delas (fases de pré-florada, pleno florescimento, enchimento de frutos e colheita). Os efeitos da interferência sobre a qualidade dos frutos do tomateiro foram analisados utilizando um modelo múltiplo. As variáveis de tomate avaliadas foram tipos de fruta para indústria (em função da maturação e infecção da doença) e teor de sólidos solúveis ( o brix). A qualidade dos frutos de tomate é dependente dos fatores testados. Sob baixa densidade (<6 plantas m -

Dinâmica do banco de sementes de plantas daninhas no solo conduzido sob plantio direto

“…Keywords: Spontaneous plants, no-tillage system, seed viability. variar entre 10 a 80% de acordo com as espécies, período de competição, densidade de plantas, estádio de desenvolvimento da cultura e condições edafoclimáticas (Portugal et al, 2015). Estratégias de controle devem ser utilizadas em conjunto com práticas de manejo do solo, incluindo o banco de sementes, de forma que interfiram negativamente no estabelecimento e competição das plantas daninhas sob as culturas (Colbach et al, 2017).…”

Tomato Components and Quality Parameters. A Review

“…The tomato fruit quality is determined by at least two variables: fruit type and total solid soluble, the total soluble solids (oBrix) are determined using a refractometric index that indicates the percentage of soluble in a solution. The solutes consist of a mixture of several chemicals which predominate sugars (65%), acids (13%), and other compounds (mainly amino acids, ascorbate, minerals, pectins, and phenols) (Portugal et al, 2015). Flavor results from the complex interaction of taste and aroma.…”