Avaliação das características estruturais e produtivas do capim Tanzânia (Panicum maximum JACQ. CV. Tanzânia) no sertão paraibano.

Abstract

The objective of this work was to evaluate the productivity of the Panicum maximum CV Tanzania grass under the soil and climatic conditions of the Sertão Paraibano, through the structural characteristics, when submitted to the practice of fertilization and irrigation. The treatments corresponded to combinations between two cut intervals (time required for the canopy to reach 90 and 95% interception of light incident during regrowth - IL), two cutting intensities (20 and 30 cm height after cutting) And two nitrogen doses (75 and 150 mg N / dm³ of soil corresponding to 300 and 600 kg N / ha / year, respectively) that were allocated in experimental units according to a factorial arrangement 2 x 2 x 2 complete block design with 10 repetitions. The morphogenic and structural characteristics evaluated were: Number of Profiles per vase, Total Number of Leaves per Profound, Number of Green Leaves per Prof, Growth Elongation Rate (TlAC), Foliar Senescence Rate. It is possible to observe a significant effect of the nitrogen doses, only for the variable Number of Green Leaves Per Perfilho (NFVP), at the level of 1% of probability by the F test, presenting an average value of 4.15, showing that the different doses Of nitrogen used in the research, did not influence the other variables. However, the cutting height had a strong influence on both NFVP and TIAC, both of which had a significant effect, at the 1% probability level by the F test, and did not present any significance on the other variables in question. Tiller number per pot was influenced by the interaction between nitrogen doses and cut heights. The cutting height of 30 cm associated with a higher nitrogen dose (600 kg of N / ha / year), provided a higher number of tillers per plant as well as a greater amount of green leaves per tiller under the conditions of cultivation in the sertão of Paraíba.