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Factor T.L.,Sao Paulo Agency for Agribusiness and Technology | Junior S.L.,Sao Paulo Agency for Agribusiness and Technology | Filho H.S.M.,Sao Paulo Agency for Agribusiness and Technology | De Araujo J.A.C.,Sao Paulo State University
Acta Horticulturae | Year: 2012

In tropical conditions such as Brazil, depending on the local altitude, potatoes can be planted and harvested in every month of the year successively, which favors pest and disease incidence, especially aphids transmission viruses. Therefore, obtaining good yield depends on constant pest and disease control and quality potato seed acquisition. One of the main strategies to increase a healthier seed potato multiplication rate and production is the use of hydroponic systems, with or without substrates, in channels, pots or boxes. In 2005 and 2008, researches investigated several hydroponic systems with and without the use of substrates. In the hydroponic systems without substrate, the aeroponic system resulted in the highest multiplication rate, with 47 tubers plant-1 compared to NFT and DFT, 35 and 37 tubers plant-1, respectively. With the use of substrates, the pot system obtained better results, reaching 12 tubers plant-1, followed by the capillary system and boxes, with 8 and 7 tubers plant-1, respectively. Potato seed production was influenced by hydroponics systems. Among hydroponic systems with substrate, the pots were shown as the best option. However, higher yields were obtained in the hydroponics systems without substrate, with the aeroponic system that provided the best results. Source

Factor T.L.,Sao Paulo Agency for Agribusiness and Technology | Junior S.L.,Sao Paulo Agency for Agribusiness and Technology | Purquerio L.F.V.,Sao Paulo Agency for Agribusiness and Technology | Calori A.H.,Technology College
Acta Horticulturae | Year: 2011

Several factors affect tomatoes production since their sowing until harvest. Seedlings production is considered one of the most important steps in the growing process. High quality seedling production requires use of high technology. Among it is worth to mention trays, substrates, automation controls, fertigation, and especially pest control established with the use of high efficiency pesticides and fungicides. Until recently, fungicides were mainly focused on pathogens control. Some, however, such as pyraclostrobin, a fungicide of strobilurine group, have shown advantages, because of its positive physiological benefits on plants. Several studies have shown that the main purposes of pyraclostrobin are related to the reduced production of ethylene, increased activity of the nitrate reductase enzyme, the greatest resistance of the water stress and the increased chlorophyll content. The objective of this study was to evaluate the effect of pyraclostrobin+metiram (50 g a.i. and 550 g a.i. kg-1) and boscalid (500 g a.i. -1) at different doses and times of application on substrate in the growth and development of tomato seedlings. Tomato seedlings answered positively to pyraclostrobin+metiram and boscalid, with maximal responses achieved in the dose range from 2.2 to 4.4 g L-1 and 0.37 to 0.41 g L-1 for pyraclostrobin+metiram and Boscalid, respectively. The application of pyraclostrobin+metiram and boscalid on substrate soon after the period in germination chambers is not recommended. The application after planting and before germination chamber is the most promising. Source

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