Effect of Salinity and Silicon Doses on Onion Post-Harvest Quality and Shelf Life.

Salt stress during pre-harvest limits the shelf life and post-harvest quality of produce; however, silicon nutrition can mitigate salt stress in plants. Thus, we evaluated the effects of salinity and fertilization with Si, in pre-harvest, on the morpho-physiological characteristics of onion bulbs during shelf life. The experiment was set up in randomized complete blocks, with treatments arranged in split-split plots. The plots had four levels of electrical conductivity of irrigation water (0.65, 1.7, 2.8, and 4.1 dS m-1). The subplots had five fertilization levels with Si (0, 41.6, 83.2, 124.8, and 166.4 kg ha-1). The sub-sub plots had four shelf times (0, 20, 40, and 60 days after harvest). Irrigation water salinity and shelf time reduced firmness and increased the mass loss of onion bulbs during shelf life. Salt stress reduced the contents of sugars and total soluble solids of onion bulbs during storage; however, Si supply improved the contents of these variables. Salinity, Si supply, and shelf time increased the concentrations of pyruvic and ascorbic acids in onion bulbs during shelf life. Si doses between 121.8 and 127.0 kg ha-1 attenuated the impacts caused by moderate salinity, increasing the synthesis of metabolites and prolonging the onion bulbs' shelf life.

Effect of Organic Residues as Fertilizer on Postharvest Quality of Cherry Tomatoes

Abstract Composting of domestic residues to replace cattle manure was evaluated as a fertilization option for the cherry tomato crop. Two sources of organic compounds (CO) were used to prepare compost piles: Domestic residues (DR) and bovine manure (BM), used in 5 proportions (CO1 = 15% DR + 15% BM, CO2 = 10% DR + 20% BM, CO3 = 20% DR + 10% BM, CO4 = 30% BM (control) and CO5 = 30% DR). To compost the compost piles, the organic waste (carbon source) was mixed with remnants of tree pruning (filler) from the urban cleaning service in a ratio of 1: 3. After 90 days, the compost from each matured pile was mixed with 1: 1 coconut fiber substrate and filled into 15 L plastic bags where the cherry tomato plants were grown. The experiment was conducted in a greenhouse using the experimental design of randomized blocks with 5 treatments and 5 replicates (6 fruits per sample). The organic fertilization in the proportions of manure and food residue did not provide statistically significant differences in soluble solids, total sugars, lycopene, β-carotene and micronutrients Zn, Fe, N and P in cherry tomato fruits. Fertilization with CO1 and CO2 increased AT, Mn and decreased the SS / AT, K and Ca ratio. There was no nutritional deficiency of tomatoes in any of the proportions of the organic residues studied.

Yield and quality of cherry tomato fruits in hydroponic cultivation / Produção e qualidade de frutos de tomate cereja em cultivo hidroponia

Because of the food and industrial importance of tomato, it holds great significance, and is one of the most produced species using the hydroponic cultivation systems. The objective of this study was to evaluate the effects of different concentrations of nutrient solution on the production and quality of cherry tomatoes (Lycopersicon esculentum 'Samambaia') grown in a hydroponic system in protected conditions. The experiment was conducted in pots filled with coconut fiber substrate using a randomized complete block design with four replications and six plants per plot. Five concentrations of nutrients were evaluated (50, 75, 100, 125, and 150% of the standard nutrient solution); the solutions produced the following electrical conductivities: 1.8, 2.0, 2.6, 3.4, and 3.9 dS m-1, respectively. At 90 days after transplanting, the tomato fruits were harvested, at which time the production variables and post-harvest quality of mature fruits were determined. The best production and post-harvest quality indexes of cherry tomatoes ('Samambaia') were found when using 111% of the standard nutrient solution, corresponding to the concentrations of 9.44, 2.44, 2.22, 6.44, 4.11, 2.44, and 2.78 mmolc L-1, of NO3 - , NH4 + , P, K, Ca, Mg, and S, respectively; and 66.6, 55.5, 14.4, 1.89, 0.56, and 0.44 mmolc L -1, of Fe, B, Mn, Zn, Cu, and Mo, respectively. Nutrient solutions with electrical conductivity above 2.89 dS m-1 severely reduced the fruit yield of cherry tomatoes.

Devido à importância alimentar e industrial do tomateiro, a cultura destaca-se entre as hortaliças, sendo uma das espécies mais produzidas em sistema hidropônico de cultivo. Nosso objetivo foi avaliar os efeitos da aplicação de diferentes concentrações de solução nutritiva na produção e na qualidade dos frutos de tomate cereja (Licopersicon esculentum, cv. Samambaia) em sistema hidropônico sobre condição de ambiente protegido. O experimento foi conduzido em vasos preenchidos com substrato de fibra de coco utilizando o delineamento de blocos casualizados, com quatro repetições e seis plantas por parcela. Foram avaliadas cinco concentrações de nutrientes na solução nutritiva hidropônica (50, 75, 100, 125 e 150% da solução nutritiva padrão) que, após a diluição dos nutrientes em água de torneira, estas produziram as seguintes condutividades elétricas: 1.8, 2.0, 2.6, 3.4 e 3.9 dS m-1, respectivamente. Aos 90 dias após o transplantio, os frutos de tomate foram colhidos, ocasião em que se determinaram as variáveis de produção e qualidade póscolheita de frutos maduros. A análise dos resultados indicou que os melhores índices de produção e qualidade dos frutos de tomate cereja cultivado em sistema hidropônico foram encontrados nas concentrações de macronutrientes da solução nutritiva correspondente a 9,44; 2,44; 2,22; 6,44; 4,11; 2,44 e 2,78 mmolc L-1 de NO3 - , NH4 + , P, K, Ca, Mg e S, respectivamente, e 66,6; 55,5; 14,4; 1,89; 0,56 e 0,44 mmolc L-1, de Fe, B, Mn, Zn, Cu e Mo, respectivamente. As soluções nutritivas com condutividade elétricas acima de 2,89 dS m-1 reduziram severamente o rendimento de frutos de tomate cereja