Plant growth analysis describing the soybean plants response on dryland field to seed co-inoculation / Análise de crescimento de plantas descrevendo a resposta do cultivo de soja no campo à coinoculação de sementes

ABSTRACT: Plant growth analysis can be used for soybean plants evaluation to identify morphologic changes caused by soil microbes after seed inoculation. The objective was to measure changes of inoculated soybean plants grown under regular field Brazilian production conditions. The experiment was carried out to compare 5 inoculation treatments: T1 (Bradyrhizobium japonicum and B. diazoefficiens), T2 (T1 and Azospirillum brasilense), T3 (T1 and Trichoderma asperellum), T4 (T1 and T. virens, and Bacillus amyloliquefaciens) and T5 (T1 and Penicillum bilaiae). Leaf area, shoot and root dry matter were measured at vegetative and reproductive growth stages. Results of this study validate the contribution of plant growth analysis of soybeans plants for identifying their responses promoted by the combined inoculation of their seeds with selected microbes. Also, the microbial effects on plant growth vary not only between microbes but also between parts of the plants and through the plant development stages. The introduction of different microbes in soybean rhizosphere combined with Bradyrhizobium sp. strains can contribute to increase crop dry matter productivity during its growing cycle.

RESUMO: Análise de crescimento de plantas pode ser utilizada para avaliação de plantas e identificação de mudanças causadas por microrganismos de solo, depois de serem inoculados nas sementes. O objetivo deste estudo foi medir as mudanças no crescimento de plantas de soja inoculadas em condição de cultivos extensivos de campo no Brasil. O experimento foi conduzido para comparar cinco tratamentos inoculados: T1 (Bradyrhizobium japonicum e B. diazoefficiens), T2 (T1 e Azospirillum brasilense), T3 (T1 e Trichoderma asperellum), T4 (T1 and T. virens, e Bacillus amyloliquefaciens) e T5 (T1 e Penicillum bilaiae). A área foliar e a massa seca da parte aérea e de raízes foram medidas nos estádios vegetativos e reprodutivos. Os resultados validam a contribuição da análise de crescimento de plantas de soja para identificar as respostas causadas pela inoculação de sementes com combinação de microrganismos selecionados. Os efeitos dos microrganismos no crescimento das plantas não variam apenas entre os microrganismos, mas também entre as partes das plantas e ao longo do seu desenvolvimento. A introdução de diferentes micróbios na rizosfera de soja, combinados com cepas de Bradyrhizobium sp. pode aumentar a produtividade de massa seca das culturas durante o seu ciclo de crescimento.

Prácticas agrícolas para el cultivo de Xanthium strumarium L (guizazo de caballo) con fines terapéuticos / Agricultural practices for the culture of Xanthium strumanium L (guizazo de caballo) with therapeutic aims

Xanthium strumarium (guizazo de caballo) se encuentra entre las plantas con antividad antimitótica. OBJETIVOS: determinar en esta especie los aspectos agrícolas que garanticen el adecuado material vegetal. MÉTODOS: se realizaron estudios durante 2007-2009, donde se evaluaron dos fechas de siembra: junio y julio; dos distancias de siembra 90 x 30 cm y 90 x 50 cm y dos momentos de cosecha: 3 meses de edad (parte aérea y raíces) en plantas que presentaban estado de floración-fructificación y 4 meses de edad (solo raíces) en plantas en fructificación. Las semillas, obtenidas de areales silvestres, se sembraron en parcelas, 3 repeticiones en cada caso. Se evaluó la altura de las plantas en el momento de la cosecha, se seleccionaron 10 plantas/parcelas y se cosecharon 39 plantas/parcelas en la distancia de 90 x 30 cm y 24 plantas en la distancia de 90 x 50 cm, en el caso del follaje se evaluaron los rendimientos de 10 plantas/parcelas en cada caso. RESULTADOS: se observó que bajo cultivo la altura de las plantas fueron mayores en las que se sembraron en junio, con distancia de 90 x 30 cm, en tanto que en las de julio se comportaron de forma similar, independientemente a las distancias de siembra empleadas y en correspondencia con ello los rendimientos resultaron iguales; sin embargo, cuando se quieren cosechar también las raíces, es preferible hacer la cosecha a los 3 meses de edad y, en este caso, los mayores valores se presentaron en las siembras de julio, con distancia de 90 x 30 cm. CONCLUSIÓN: para el aprovechamiento de la planta con doble propósito: parte aérea y raíces, pues en ambas se ha encontrado la actividad antimitótica, la siembra se debe realizar entre junio y julio a la distancia de 90 x 30 cm y recolectarse el material a la edad de 3 meses

Xanthium strumarium (guizazo de caballo) is among the plants with antimitotic activity. OBJECTIVES: to determine in this species the agricultural features to guarantee the appropriate plant material. METHODS: during 2007-2009 studies were conducted to assess to sow dates: June and July; two sow distances 90 x 30 cm and 90 x 50 cm at two sow periods: three months of age (aerial parts and roots) in plants with a flowering-fructification states and four months of age (only roots) in plants in fructification process. Seeds obtained from wild aerial plants were sowed in plots, three repetitions in each case. The plants height was assessed at the harvest moment, choosing 10 plants/lots and 39 plants/lots were growed at a 90 x 30 cm distance and 24 plants at the 90 x 50 cm distance, in the case of foliage the yields of 10 plants/lots were assessed in each case. RESULTS: there was that at culture the plants heights were higher in those sowed in June at a 90 x 30 cm distance while those sowed in July behaved in a similar way independently of the sow distances used and in correspondence with it, the yields were similar; however, when we desire to grow also the roots, it is preferable to grow at three months of age, and in this case, the higher values were in sows of July at a 90 x 30 cm distance. CONCLUSION: for the plant exploitation with a double aim: aerial parts and roots, since in both there is antimitotic activity, sow must to be performed between June and July at a 90 x 30 cm distance and to harvest the material at three months age

Adubação nitrogenada e partição de massa em plantas de Brachiaria brizantha cv. xaraés e Panicum maximum x Panicum infestum cv. massai / Nitrogen fertilization and dry matter partition in xaraes grass and massai grass

Objetivou-se, com o presente trabalho, avaliar a partição de massa seca em plantas de capim-xaraés (Brachiaria brizantha) e capim-massai (Panicum maximum x Panicum infestum), submetidas a quatro doses de nitrogênio (0, 40, 80 e 120 mg/dm³). O experimento foi realizado em delineamento inteiramente casualizado, com 4 repetições. A semeadura de ambas as forrageiras foi feita em bandejas contendo substrato agrícola comercial e 15 dias após a emergência cinco plantas foram transferidas para os vasos, com volume de 5,8 dm³. Dezoito dias após a transplantação realizou-se o desbaste, deixando-se três plantas/vaso. Quando as plantas atingiram altura média de 35 cm foram submetidas a um corte de uniformização a 5 cm do solo. A adubação nitrogenada foi fracionada em 4 aplicações, e após quarenta e cinco dias em crescimento livre, as plantas foram colhidas e avaliadas quanto aos teores de MS da lâmina, colmo, material morto e raiz. Avaliaram-se também as razões parte aérea:raiz e lâmina:colmo. O nitrogênio exerce efeito na partição de MS de plantas de capim-xaraés, favorecendo o desenvolvimento da parte aérea, sem efeito no sistema radicular. Observou-se também que o nitrogênio favorece a relação lâmina:colmo, além de acelerar o processo de senescência nessas plantas, com conseqüente aumento na deposição de material morto.

The experiment was carried out in a greenhouse with the objective of evaluating the dry matter partition of capim-xaraés (Brachiaria brizantha) and capim-massai (Panicum maximum x Panicum infestum) submitted to four treatments of nitrogen (0, 40, 80, and 120 mg/dm3). A randomized design with four replications was applied. Both species were sowed in trays containing commercial agricultural substratum and 15 days after the emergence of five plants they were transferred to 5.8-dm3 vases. When the plants reached an average height of 35 cm, they were cut 5 cm from the soil to achieve a uniform cut. The nitrogen was applied four times. After forty-five days of free development the plants were cut and evaluated for dry matter of the leaf, stem, dead material, and root. The shoot to root and lamina to stem ratios were also evaluated. It was observed, according to the results that the nitrogen affected the dry matter partition of capim-xaraés, favoring the development of the shoot, but without effect on the roots. The total dry matter production of xaraes and massai shoot, as well as the lamina to stem ratio increased linearly with the doses of N, without affecting the root dry matter. It was also observed that nitrogen favors the lamina to stem relation and increases the dead material deposit in xaraes grass and massai grass.