Na maioria das pequenas propriedades rurais, especialmente nas de agricultura familiar, a cana-de-açúcar é cultivada para a alimentação de ruminantes, de monogástricos e humana. Nestas pequenas propriedades, o corte, o carregamento e o transporte da cana-de-açúcar demandam grande quantidade de horas de recursos humanos e, estes constituem isoladamente o item de maior percentual de custo e de desgaste físico dos agricultores nessa cultura. Em canaviais mais produtivos, estes custos são proporcionalmente menores, portanto, há necessidade de implementar medidas que assegurem alta produtividade no ciclo de cana-planta e pequenos decréscimos nos ciclos posteriores, para que o rendimento dos fatores de produção “terra, capital e trabalho” sejam elevados, repercutindo em menor custo de produção. A adubação verde com crotalária juncea nas áreas de reforma ou de implantação do canavial pode contribuir para o aumento da produtividade da cana-de-açúcar, principalmente nos dois primeiros cortes. Neste capítulo são apresentados resultados de estudos conduzidos pelos autores, na zona da mata Mineira. Os tópicos são relacionados a fisiologia da crotalária juncea, a correção da acidez do solo, as épocas de semeadura, as taxas de crescimento e a cobertura do solo, ao acúmulo e ciclagem de nutrientes e, ao aumento da produtividade da cana-de-açúcar nas áreas onde houve o cultivo desse adubo verde antecedendo a implantação do canavial. Pelos resultados apresentados concluiu-se que a adubação verde com crotalária juncea nas áreas de reforma ou implantação de canaviais contribui para o aumento da produtividade de cana-de-açúcar e para o uso mais eficiente dos fatores de produção.
Manilkara zapota L., popularly known as sapoti, has commercial relevance both for fruits, with high prices in the regional markets, and for its wood. Thus, the propagation of this species can be done by seed, however, the germination is slow and uneven. The objective of this work was to study the biometry of the seeds and to evaluate pre-germinative treatments to facilitate the propagation of sapoti. The fruits were from the municipality of Brejão-PE and length, width and thickness were determined in millimeters of each seed and submitted to different pre-germination treatments. The seeds were exposed to the following evaluations: biometry, dormancy overrun, germination tests, germination speed index, root length and aerial part of the seedlings and dry mass of the root and shoot of the seedlings. They have variability regarding their biometry and do not require the adoption of treatments for the breakdown of dormancy, which enables and accelerates the production of seedlings. The treatments aimed at overcoming dormancy of sapoti were not efficient to accelerate the germination of the seeds.
Organic fertilization with poultry litter and sugarcane juice quality Adubação orgânica com cama de aviário e qualidade do caldo da cana-deaçúcar
Potencial fisiológico de sementes de milho crioulo submetidas ao estresse hídrico e salinoPhysiological potential of maize seeds under water and salt stress
O objetivo deste estudo foi avaliar o acúmulo e a alocação de matéria seca e de nutrientes pelas braquiárias decumbens e ruziziensis, em três cortes, cultivadas com adequado suprimento de nutrientes no solo. O delineamento experimental utilizado foi o de blocos ao acaso, com cinco repetições, sendo as parcelas constituídas de cinco sulcos de cinco metros de comprimento, com espaçamento de 0,70 m entre si. Os valores médios de acúmulo de Matéria Natural (MN) e de Matéria Seca (MS) nos três cortes, foram, respectivamente, de 41,0 e 6,53 t ha-1 , a cada quatro semanas. Não houve diferença estatística significativa (P≥0,05) entre as braquiárias; entretanto, houve efeito significativo (P≤0,05) da época de corte para a produção de forragem, uma vez que no segundo corte a produção média das duas braquiárias foi de 7,26 t de MS, superando em 11,77% a média dos primeiro e terceiro cortes. Na média dos três cortes, o teor de proteína bruta da braquiária decumbens foi 107,1 g kg-1, estatisticamente maior que o teor de proteína bruta na braquiária ruziziensis (100,2 g kg-1). Nos três cortes, constatou-se alta produtividade das braquiárias decumbens e ruziziensis, nesse sistema intensivo de produção de forragem.
The present study was carried out with the objective of evaluating the ecological and applied aspects of temperature in the germination of Colubrina glandulosa (Rhamnaceae), Chloroleucon dumosum (Fabaceae), Enterolobium contortisiliquum (Fabaceae), Mimosa bimucronata (Fabaceae) and Sapindus saponaria (Sapindaceae). Then we assessed germination, average germination time, germination uniformity and germination activation energy as a function of temperatures. The experiment was conducted at the Plant Propagation Laboratory, on the Engineering and Agricultural Sciences Campus, at the Federal University of Alagoas, Rio Largo, AL, Brazil. The experimental design was completely randomized with four replications of 25 seeds per treatment. The data were subjected to analysis of variance and the means were compared using the Tukey test at 5% probability. The isothermal incubation was performed in Biochemical Oxigen Demand (B.O.D.) germination chamber, at constant temperatures of 5, 10, 15, 20, 25, 30, 35 and 40 ºC and alternating at 20-30 ºC. The seeds of C. glandulosa, C. dumosum, E. contortisiliquum and M. bimucronata germinated in the range of 10 ºC ≤ T ≤ 35 ºC, and S. saponaria germinated in the range of 20 ºC ≤ T ≤ 35 ºC. We found that seeds in the optimal temperature range has unimodal distribution of relative frequency, concentrating germination in the shortest time. The activation energy was positive in the range of 10 ºC ≤ T ≤ 30 ºC, with an inversion of the signal at a temperature of 35 ºC. The studied species had a wide range of temperature tolerance and the speed was curvilinearly dependent on them. The germination process is predominantly endergonic
Agroecology is the science that establishes the basis for construction of sustainable farming styles. The consortium usually to stand out as alternative interesting small for producers with structural and financial limitations, because it is an effective cropping system practiced long ago and found in all parts of the world, with greater diversity in the tropics. The experiment was conducted between August to November 2012 in the municipality of Garanhuns-PE/Brazil It had as objective to observe how the lettuce would behave in consortium with the carrot in an agroecological system of production. The parameters evaluated in the experiment were plant height, total weight of the plant, weight of leaves and number of leaves. The data obtained were submitted to a statistical comparison test between averages of the consortium and non-consortium beds, using Student's t-test at a significance level of 5%. It was observed that the consortium between lettuce and carrot presented a significant difference for most of the studied variables, negatively influencing its growth.
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