Nitrogen topdressing is essential for forage production, but the high cost of fertilizers stimulates the search for new technologies, such as the use of diazotrophic bacteria, which can fix the atmospheric nitrogen. To evaluate the potential of this technology in providing the amount of nitrogen requested by xaraés grass as topdressing, plants were fertilized at planting with an N rate of 100 kg ha-1, inoculated with strains of diazotrophic bacteria and Azospirillum brasilense, and compared with plants that received 100 kg ha-1 of N at planting and as topdressing during two periods of shoot growth (58 days in the first period and 26 days in the second period) in 20-dm3 pots. The data were subjected to analysis of variance and means compared by the Scott-Knott test at 5% significance. The leaf area of xaraés grass inoculated with strain UN42 was similar to that of plants that received nitrogen topdressing. However, grass biomass production was higher when nitrogen topdressing was applied. Plant inoculation with Azospirillum brasilense and strains UN16, UN17, UN21, UN33, UN49, and UN78 increased crude protein contents of xaraés grass when compared to nitrogen fertilization at planting without inoculation. However, grass inoculation with diazotrophic bacteria does not replace nitrogen topdressing completely.

A cafeicultura tem grande importância econômica no território nacional, entretanto, enfrenta algumas limitações no seu manejo, principalmente na sua implantação, pelo fato de comprometer todo o processo produtivo. A utilização de bioativadores de microrganismos no solo na instalação de lavouras cafeeiras gera um impacto de reciclagem de nutrientes auxiliando no aproveitamento, desenvolvimento e absorção da lavoura cafeeira. Os bioestimulantes à base de algas marinhas, enzimas e microrganismo solo, vêm sendo utilizados como uma alternativa para nutrição de plantas, pelo fato da intensa demanda de nutrientes no sistema atual de agricultura. Neste estudo, objetivou-se verificar o efeito de diferentes dosagens de bioativador de solo (Vitasoil®) na implantação de lavoura cafeeira (Catuai 144 vermelho). Foram testados uma aplicação via solo em 5 doses de 4, 6, 8,10 e 12 gramas por planta, somada a 3 aplicações de 3 gramas via foliar na mesma, para fazer a utilização da mesma ocorreu a hidratação com 100 ml de água para cada grama de produto. Aos 120 dias foram realizadas avaliações no experimento, medições da parte aérea e radicular, contagem de folhas, espessura do caule, pesagem da fração aérea e radicular verde e seca, área foliar e relação parte aérea /raiz. O delineamento experimental foi em blocos ao acaso. Entre os dados analisados observou que o uso do bioativador se mostrou superior estatisticamente quando comparado à testemunha, não diferindo entre si em dosagens. O ativador de microbiota de solo (Vitasoil®) aplicado via solo e foliar em mudas de café, promoveu um melhor desenvolvimento inicial do cafeeiro sendo observado em diâmetro, peso verde e seco, número de folhas por muda, área foliar, altura de planta, comprimento de raiz e relação parte aérea/raiz.

<p>One of the alternatives to increase productivity and without harming the environment is the use of green cover associated with soil bioactivators. However, there are still incipient studies reporting the association influence of these two techniques on soil quality. In this sense, the objective in this work was to evaluate the Penergetic^® bioactivator effect associated to different cover plants on the physical and biological characteristics of the soil cultivated with coffee tree. The experiment was carried out in a coffee field with <em>Catuaí Vermelho</em> cultivar IAC 144, in a randomized block design in a factorial scheme 4 (soil cover) x 2 (use or not of the Penergetic^® bioactivator), consisting of control (without plant cover); oats (<em>Avena strigosa</em>) + forage turnip (<em>Raphanus sativus</em>); oats (<em>Avena strigosa</em>) + forage turnip (<em>Raphanus sativus</em>) + lupine (<em>Lupinus albus</em>) + rye (<em>Secale cereale</em>) + vetch (<em>Vicia sativa</em>) (RLSV); <em>Brachiaria brizantha</em> (<em>Urochloa brizantha</em>), associated or not with the Penergetic® bioactivator use. The experiment was conducted for 6 months and after that period physical and biological soil characteristics were analyzed. Data were analyzed by the Scott Knott test at 5% probability. The treatments containing cover plants had lower temperature and greater water retention.  The bioactivator use reduced the nematodes population from the <em>Meloidogyne</em> genus and when associated to the cover plants increased the density of diazotrophic bacteria and solubilizers of phosphorus and potassium.</p>

A aplicação de herbicidas com adjuvantes pode melhorar a eficiência de controlede plantas daninhas como a Digitaria insularis L., que ocasiona prejuízos emdiversas culturas agrícolas devido a sua alta competitividade e dificuldade decontrole. Assim, este estudo teve como objetivo avaliar o sinergismo do adjuvanteSinerMax® associado aos herbicidas cletodim, glifosato e haloxifop-P-metílico nocontrole do capim-amargoso (Digitaria insularis L). O experimento foi conduzidoentre setembro e outubro de 2018. O delineamento experimental utilizado foi o emblocos casualizados em esquema fatorial 3x2+1 com 5 repetições, sendo ostratamentos com cletodim 240 g L-1 de i.a. (0,45 l ha-1), glifosato 480 g L-1 de i.a.(4 L ha-1) e haloxifop-P-metílico 124,7 g L-1 de i.a. (0,5 L ha-1) associados ou nãoao adjuvante SinerMax® (0,5 L ha-1) e o tratamento controle sem uso de herbicida,sendo avaliado a ausência de dano aparente, a morte completa da planta e matériaseca das plantas. Os dados obtidos foram submetidos a análise de variância e asmédias comparadas pelo teste de Scott-Knott à 5% probabilidade. Os herbicidashaloxifop-P-metílico e glifosato apresentam os melhores níveis de controle deDigitaria insularis L., com maior fitotoxidade (entre 60 e 90%) e menor acúmulode matéria seca em relação ao tratamento controle. O adjuvante (SinerMax®)associado aos herbicidas glifosato, haloxifop-P-metílico e cletodim não resultouem maior eficiência de controle de D. insularis L.

Aims:The objective of this research was to investigate the effect of calcium silicate on gaseous exchanges and production factors in the sweet pepper, cultivated under conditions of soil salinity induced by potassium fertilization, in protected cultivation. Study Design: The experiment was arranged in a randomized complete block design in a 2 × 5 factorial scheme with five replications. Place and Duration of Study: The experiment was conducted in the sector of Olericultura and Experimentation of the course of Agronomy from October 12, 2018 to February 2019. Methodology: The experiment was arranged in a randomized complete block design in a 2 × 5 factorial scheme (two sources of correction: calcareous and silicon and five increasing rates of KCl equivalent to 150, 300, 450, 600 and 700 kg ha -1 of K 2 O). Ten treatments with five replicates where each experimental unit consisted of a polyethylene pot, with a volume of 19 dm 3 . The electrical conductivity, the determination and quantification of silicon in soil and plant, liquid photosynthesis, stomatal conductance, intercellular CO 2 concentration, transpiration, water use efficiency and instantaneous carboxylation efficiency were analyzed. Dias et al.; JEAI, 40(2): 1-12, 2019; Article no.JEAI.50539 2 Results: With the increase of K 2 O in the soil there was a tendency of reduction in liquid photosynthesis, transpiration, stomatal conductance, intercellular CO 2 concentration, water use efficiency and instantaneous carboxylation efficiency in the presence and absence of calcium silicate. Higher rates of K 2 O (300, 450 and 600 kg ha -1 ) reduced the length and yield of sweet pepper fruits in the presence and absence of calcium silicate. The rate of 150 Kg K 2 O favored the growth of sweet pepper plants in the presence of calcium silicate. Conclusion: It is concluded from the research that the dose of 300 kg ha -1 of K 2 O, in the presence of calcium silicate, provided the best results for the electrical conductivity of 2.76 dS m -1 , silicon content in the soil of 5.70 mg kg -1 , 14% silicon leaf content, improving photosynthetic rates, transpiration, water use efficiency and fruit production. The increase in salinity reduced fruit yield, in the presence and absence of Si. Original Research Article

Cover crops between rows of coffee contributes to the promotion of a sustainable production. The objective of this work was to evaluate the improvement of the chemical and physical attributes of the soil and coffee production using cover crops between the coffee lines. This study was at Boa Esperança Farm, Serrania – MG. The experimental design consisted of randomized blocks, with 7 treatments and 4 replications: control, no cover plant, with traditional farm management (chemical and mechanical weed control); crotalaria (Crotalária spectablis); cuandu (Cajanus cajan); cowpea (Vigna unguiculata L. Walp.); mix of crotalaria + cuandu + cowpea; Brachiaria brizanta (Urochloa brizantha) and Brachiaria ruzizienses (Urochloa ruzizienses) as cover plants. The data were submitted to analysis of variance by the Scott-Knott test at 5% probability. Results confirm that cover crops promote cycling and nutrient accumulation in the soil, maintain a mild temperature and promoted better moisture maintenance. It also demonstrated that although the population dynamics of weeds have a positive result, only the use of cover crops is not enough for 100% weed control in the coffee crop. Besides, they have a contribution to the development and production of coffee and to reduce the phytonematoid population.

The development of production technologies, such as greenhouses, was highlighted in the growth of horticultural crops. However, these products are often offered without basic instructions to farmers who can generate financial losses. One outstanding production technology is substrate cultivation, which would be very useful in the cultivation of protected plants. Like this, in order to evaluate the effects of different doses of phosphorus on the production of tomato groups grown in substrate under greenhouse conditions, a randomized complete block design was used in a 2 x 5 factorial scheme, with two tomato groups: Santa Cruz "Debora Max" and Cherry "Coco" x five rates of P 2 O 5 (0; 33; 66; 99 and 132 g; 10 L of nutrient solution) with four replicates. The results showed that the electrical conductivity inside the Slabs is not homogeneous, being recommended to wet the substrate inside the slabs, before the planting to reduce the electrical conductivity. In relation to phosphorus efficiency, the highest tomato yield was for the 6.6 g L -1 phosphorus dose for the two Santa Cruz and Cherry groups. The main advantage of using slabs in tomatoes is the efficiency of the phosphorus used in the first planting.Key words: Lycopersicon esculentum, substrate, slabs, phosphorus, fertilization. INTRODUCTIONThe tomato Lycopersicon esculentum Mill is one of the main vegetables produced in Brazil, arriving at the market in an in natura or processed way. The tomato production chain reached more than 37 million tons in 2010, for global parameters, consolidating the chain as one of the main agribusiness. By 2016, according to estimates by the World Tomato Processing Council, the amount should reach more than 39.3 million tonnes. Most of the production, near 97%, is concentrated in the 10 largest producers, which accumulate around 34.1 million tons. Brazil is in eighth place with 1.25 million tons produced (Carvalho et al., 2016). In order to improve tomato yield and meet increasing demand, new technologies have been adopted, among which the production in a protected environment stands out (Cararo and Duarte, 2002). The cultivation in a protected environment provides better accommodation of the plants against undesirable climatic factors, reducing the risks of tomato cultivation, besides allowing the production of fruits in times not favorable to the conduction of planting in the open field (Alvarenga, 2004). The technique of cultivation in protected environment using substrate has been generalized to allow better nutrient absorption, higher productivity, better product quality and facilitation of the implementation of cultural practices (Gul et al., 2005). Gualberto et al. (2002) comments that this system has many advantages that include the high quality and yield of the crop, lower fertilizer losses and the better use of water, besides the reduction in environmental pollution and greater control and efficiency in the process productive. Riviere and Caron (2001) report that substrate cultivation is effective in protecting crop path...

This work proposes OCLAS (Organic ChemistryLanguage