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Fertilizers supply in the appropriate period and dose is important to obtain satisfactory production. In this research we studied the effect of different split applications and doses of nitrogen in top dressing on the production of the carrot and the physicochemical characteristics of the roots. Nine treatments, resulting from a factorial of 4x2+1 (control without nitrogen fertilization), were evaluated in the randomized blocks experimental design, with four replications. The first factor were four nitrogen (N) doses in top dressing (60, 90, 120 and 150 kg ha-1) and the second were two forms of splitting [three equal applications (1/3+1/3+1/3 of the dose) and one with increasing proportions (1/6+2/6+3/6 of the dose) applied 15, 30 and 50 days after emergence]. We evaluated shoot height, fresh and dry shoot weight, fresh and dry root weight, root diameter and length, yield and some physicochemical characteristics of roots (soluble solids, titratable acidity, maturation index, pH, carotenoid content and reducing sugars). For most of the studied characteristics were observed quadratic effects for N dose, with an estimated maximum yield of 117.7 t ha-1 for the dose of 138 kg N ha-1. The splitting 1/6+2/6+3/6 resulted in higher values for fresh weight of shoot and root, root diameter, yield and carotenoid content, compared to the splitting 1/3+1/3+1/3.

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-The objective of this work was to evaluate the effect of fungicide application on the concentration of Tomato severe rugose virus (ToSRV, Begomovirus) in the 'Mariana' hybrid tomato coinfected with ToSRV and Tomato chlorosis virus (ToCV, Crinivirus) and the progression of viral concentration by qPCR, as well as to quantify fruit yield and quality. Experiment I consisted in the application of fungicides after sowing (pretreatment): pyraclostrobin+metiram (P+M) (at 3 g L ); in experiment II, there was no application at sowing (control treatment), only 4 g L -1 P+M biweekly. ToSRV and ToCV transmissions were performed using sweetpotato whiteflies (Bemisia tabaci, biotype B), at 15, 30, 45, 60, and 70 days after transplanting (DAT). There was an increase in yield, better fruit quality, and a reduction in the ToSRV concentration in the plants, when the viruses were transmitted late and pretreatment was performed. Tray pretreatment in sowing with P+M (3 g L ), aumenta a produção e a qualidade dos frutos, em tomateiro híbrido 'Mariana' coinfectado aos 45, 60 e 75 DAT por ToSRV e ToCV, e há redução da concentração de ToSRV.Termos para indexação: Solanum lycopersicum, boscalida, metiram, piraclostrobina, ToCV, ToSRV.

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