RESPOSTA DO FEIJÃO-CAUPI À INOCULAÇÃO DE Bradyrhizobium japonicum, ADUBAÇÃO NITROGENADA E NITROGÊNIO DO SOLO

Cowpea bean is an important agricultural crop, which has a high capacity of to associate with bacteria that fixes atmospheric nitrogen, which can reduce costs with fertilizers. The objective of this study was to evaluate the productivity and growth rates of cowpea when submitted to nitrogen-fixing bacteria (Bradyrhizobium japonicum), nitrogen fertilization and soil nitrogen. The experiment took place at the Federal University of the West of Pará, Campus Santarém-Pará, during the months of April to July 2017, under greenhouse, in pots, in a completely randomized design, with nine treatments of five replicates each. The treatments were: inoculant use, nitrogen fertilization and soil nitrogen and three types of cowpea, Manteiguinha, IPA 207 and BRS Tumucumaque, the variables evaluated were stem diameter (DC), plant length (CP), number of grains per pod (NG) and productivity per hectare (PG). There was no significant difference for the variables DC, CP, NG and PG. Manteiguinha showed higher values of CP and PG, which was 1869.5 kg ha-1 when submitted to nitrogen fertilization. The IPA 207 presented lower PG when inoculated and higher PG with the use of nitrogen fertilization, which was 2586.1 kg ha-1. For the BRS Tumucumaque, higher CP were obtained in the treatment that used the nitrogen of the soil, nevertheless in this treatment the PG was the smaller among the treatments, higher productivity was obtained by the inoculation that was of 2499.9 kg ha-1. The inoculation of Bradyrhizobium japonicum is efficient for BRS Tumucumaque and inefficient for IPA 207 in relation to productivity.KEYWORDS: Biological fixation of nitrogen, Fertility, Productivity.El frijol-caupi es una cultura de importancia económica y social, posee la capacidad de asociación con bacterias que fijan el nitrógeno atmosférico pudiendo reducir costos con fertilizantes. Así, el presente trabajo tuvo como objetivo evaluar la productividad y crecimiento de frijol-caupi sometidos a la inoculación de bacterias fijadora de nitrógeno (Bradyrhizobium japonicum), fertilización nitrogenada y nitrógeno del suelo. Instalado en casa de vegetación, en macetas, el experimento con delineamiento completamente casualizado compuesto por cinco repeticiones de cada tratamiento. Los tratamientos fueron constituidos del uso de inoculante, fertilización nitrogenada y nitrógeno del suelo y tres tipos de frijol-caupí, una variedad (Manteiguinha) y dos cultivares comerciales (IPA 207 y BRS Tumucumaque), se obtuvieron datos de diámetro del caule (DC), longitud de planta (CP), número de granos por vaina (NG) y productividad por hectárea (PG). No hubo diferencia significativa en las variables DC, CP, NG y PG. La variedad Manteiguinha presentó mayores valores de CP y PG, que fue 1869,5 kg ha-1 cuando sometido a la fertilización nitrogenada. La cultivar IPA 207 presentó menor PG cuando inoculada y mayor PG con el uso de la fertilización nitrogenada que fue 2586,1 kg ha-1. Para la cultivación BRS Tumucumaque mayor CP fueron obtenidos en el tratamiento que usó el nitrógeno del suelo, sin embargo en ese tratamiento la PG fue la menor entre los tratamientos, mayor productividad fue obtenida por el uso de la inoculación que fue de 2499,9 kg ha-1. La inoculación de Bradyrhizobium japonicum es eficiente en la cultivación BRS Tumucumaque e ineficiente en la cultivación de la IPA 207 en relación a la productividad.PALABRAS CLAVE: Fijación biológica del nitrógeno, Fertilidad, Productividad.O feijão-caupi é uma importante cultura agrícola, apresenta capacidade de associação com bactérias que fixam o nitrogênio atmosférico, podendo reduzir custos com fertilizantes. O objetivo no trabalho foi avaliar a produtividade e crescimento de feijão-caupi submetidos à inoculação de bactérias fixadora de nitrogênio (Bradyrhizobium japonicum), adubação nitrogenada e nitrogênio do solo. O experimento foi desenvolvido na Universidade Federal do Oeste do Pará, campus Santarém-Pará, nos meses de abril a julho de 2017, sob viveiro de mudas, em vasos, em delineamento inteiramente casualizado, com nove tratamentos de cinco repetições cada. Os tratamentos foram: uso de inoculante, adubação nitrogenada e nitrogênio do solo e três tipos de feijão-caupi, Manteiguinha, IPA 207 e BRS Tumucumaque, as variáveis avaliadas foram, diâmetro do caule (DC), comprimento de planta (CP), número de grãos por vagem (NG) e produtividade por hectare (PG). Não houve diferença significativa para as variáveis DC, CP, NG e PG. O Manteiguinha apresentou maiores valores de CP e PG, que foi 1869,5 kg ha-1 quando submetido à adubação nitrogenada. O IPA 207 apresentou menor PG quando inoculada e maior PG com o uso da adubação nitrogenada que foi 2586,1 kg ha-1. Para o BRS Tumucumaque maior CP foram obtidos no tratamento que usou o nitrogênio do solo, no entanto nesse tratamento a PG foi a menor entre os tratamentos, maior produtividade foi obtido pelo uso da inoculação que foi de 2499,9 kg ha-1. A inoculação de Bradyrhizobium japonicum é eficiente para BRS Tumucumaque e ineficiente para IPA 207 em relação à produtividade.  PALAVRAS-CHAVE: Fixação biológica de nitrogênio, Fertilidade, Produtividade

Evaluation of Trichoderma spp. Isolates in Cocoa Seed Treatment and Seedling Production

Isolates of Trichoderma spp., a soil fungus, has been used to control diseases and promote plant growth, reducing the use of chemicals in the production of seedlings of different plant species. We evaluated the effect of some Trichoderma spp. isolates on seed treatment and seedling production of Theobromacacao. Five isolates from the Amazon region were tested. In laboratory, the following variables were evaluated for seed treatments: germination, germination speed index, radicle and hypocotyl lengths, and fungi incidence. In nursery, the following forms of application were tested: via seeds; in the substrate at pre-planting; monthly in post-planting substrate, and also their combination. The following was evaluated: height, diameter, number of leaves, root length, leaf area, and shoot dry mass and root system. Inoculation with Trichoderma increased the length of the radicle and hypocotyl and showed no fungi in the seeds. In seedlings, some treatments increased height and plant root dry mass. The use of Trichoderma was beneficial for seeds and appeared favorable for T. cacao production

Beneficial Soil Fungi and Jabuticaba Growth Promotion

Trichoderma is a genus of fungi widely used in agriculture as a biocontrol agent and more recently as a plant growth promoter. We evaluated five Trichoderma isolates, in different application modes, throughout the development of jabuticaba seedlings. These included three isolates of the species Trichoderma asperellum (Tam01, Tam02, and Tam03) and two isolates of Trichoderma sp. (Tc and Tce) in four modes of application: via seeds; in applications on the pre-planting substrate; in monthly applications in the post-planting substrate; and their combination. The control treatment consisted of plants without the use of Trichoderma. Seedling height, collar diameter, and the number of leaves were evaluated monthly. Statistical analysis was conducted using data collected two, four, seven, and thirteen months after emergence. The application of Trichoderma promoted the growth of jabuticaba seedlings up to four months after emergence. The isolate Tam03 and the application via seeds were the treatments that most influenced the analyzed variables at four months. The use of Trichoderma stimulated the beginning of the development of jabuticaba seedlings