Resumo

DIEZ, Josefina; TONCOVICH, María Elena  e  RODRIGUEZ, Mónica Beatriz. Fecha De Trasplante y Requerimientos De Nutrientes (N-P-K) En Lotes Tabacaleros De Salta (Argentina). Cienc. suelo [online]. 2014, vol.32, n.2, pp.209-218. ISSN 1850-2067.

Virginia tobacco is cultivated in small plots belonging Chicoana farmers (Salta) and it is fertilized with N, P and K depending on the production and quality objectives. The variation in the planting date could influence yield and consequently the nutrient uptake. We hypothesize that a delay in the planting date could reduce the tobacco yield and consequently, decrease nutrient uptake due to less IAF and photosynthetically active radiation (PAR). The objective of this study was to determine the effect of the planting date: Early planting date and Late planting date (EPD and LPD respectively) on the tobacco yields and nutrient uptake (N,P and K) in small plots in Chicoana. Plant biomass was weighed, and tissue samples were analyzed to determine N, P and K absorbed by leaf, steam and roots. Samples were taken in four phenological stages: adaptation (Ad), height to knee (K); Flowering- unflowering (FU) and maduration-harvest (MH),. Degree days (TT) and photosynthetical active ratiation (Ra) were also estimated. The results indicated that an early planting date produced a higher biomass, thus increasing nutrient requirements significantly (N, P and K). In the MH stage, N, K and P absorption levels for EPD resulted higher than the LPD group (109 vs 65 kg N ha^-1; 175 vs 106,07 kg K ha^-1; 8 vs 5 kg P ha^-1 respectively). PAR values resulted 50% higher in EPD than LPD and could be related to the IAF values and biomass production. These results contribute to optimize the fertilizer rates according to the planting dates.

Palavras-chave : Nutrients, planting date, production.

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