Produção Nacional
Revisado por pares
Nitrogênio na produção e diagnose foliar do capim-mombaça
2002; INSTITUTO DE ZOOTECNIA IZ/APTA-SAA/SP; Volume: 59; Issue: 2 Linguagem: Inglês
ISSN
1981-4100
AutoresCirlene Aparecida Manarim, Francisco Antônio Monteiro,
Tópico(s)Crop Yield and Soil Fertility
ResumoNitrogen has a great influence on tropical forage grasses productivity. However, information is needed on forage nutrient diagnosis for nitrogen. The objectives of this study were: to evaluate the effects of nitrogen on dry matter yield, on nitrogen concentration in plant parts and on SPAD values; to select a plant part to be sampled for diagnosis and to determine the critical nitrogen level in such selected plant tissue. A greenhouse experiment was carried out with Panicum maximum Jacq. cv. Mombasa grown from January to March in nutrient solution. The experimental design was a complete randomized block design, with four replications. Eight nitrogen rates (0; 14; 42; 126; 210; 294; 378 and 462 mg L-1) were suplied through a ground quartz substrate. Significant effects of nitrogen rates occurred on dry matter yield of plant tops and roots, and on nitrogen concentrations of all plant parts. The two youngest leaf lamina were selected for nitrogen diagnosis and the critical level of nitrogen in such plant tissue was between 16 and 16.5 g kg-1 and the SPAD value associated to this critical level was from 41 to 45 units.
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