Nitrogen and K deficiency are among the most yield limiting factors in Brazilian pastures. The lack of these nutrients can hamper the chlorophyll biosynthesis and N content in plant tissues. A greenhouse experiment was carried out to evaluate the relationship among N and K concentrations, the indirect determination of chlorophyll content (SPAD readings), nitrate reductase activity (RNO3–) in newly expanded leaf lamina (NL) and the dry matter yield for plant tops of Mombaça grass (Panicum maximum Jacq.). A fractionated 52 […]

Citurs rootstocks are dependent of the growdcover management systems. This study aimed to identify the divergences of seven rootstocks for ‘Folha Murcha’ sweet orange trees in two groundcover management systems on a Paleudult. The study was performed at the IAPAR research station, in Paranavai, northwestern Paraná, Brazil. The experiment was in a complete random block design with threer replications for the bahiagrass (Paspalum notatum Flügge) groundcover treatment and one replication for the perennial groundnut legume (Arachis pintoi Krap. & Greg.). […]

Several studies pointed out the promising use of nutritional diagnosis methods for the determination of optimum nutrient contents and critical levels in plant tissues. Thus, the objective of this study was to compare the optimum nutrient content for soybean, estimated by the Mathematical Chance (ChM), Diagnosis and Recommendation Integrated System (DRIS) and Compositional Nutrient Diagnosis (CND) methods. The optimum nutrient contents estimated by DRIS and CND where identical to the mean content in the reference population. Apart from the nutrients […]