Resposta da terceira soqueira da cana-de-açúcar à aplicação de nitrogênio na presença e ausência de silício

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Não preferência para alimentação e antibiose em cultivares de amendoim a Stegasta bosquella (Chambers) (Lepidoptera: Gelechiidae)

This work aimed to evaluate the attractiveness, non-preference for feeding and antibiosis in straight and runner growth habit peanut cultivars to Stegasta bosquella (Chambers). Eight cultivars were evaluated, four of straight growth habit (IAC Tatu, IAC 22, IAC 8112 and IAC 5) and four of runner growth habit (IAC Runner 886, IAC 147, IAC 125 and IAC 503). Free-choice and no-choice feeding tests were performed, using pairs of overlapped leaf discs with 1.0 cm diameter, which were placed in Petri dishes where third instar larvae of S. bosquella were released. The attractiveness to the larvae was assessed in predetermined times, in addition to the dry mass consumed. In the antibiosis assay, the biological parameters were evaluated: period and viability of larvae, pre-pupae, pupae, and total, weight of larvae and pupae, sex ratio and longevity. None of the runner growth habit cultivars exhibited non-preference for feeding-type resistance. Among the straight growth habit cultivars, IAC 5 and IAC 22 were the least attractive and consumed in the free-choice feeding test, and IAC 5 and IAC 8112 were the least attractive in the no-choice test. The runner growth habit cultivars IAC 147 and IAC Runner 886 affected the larval survival of S. bosquella, exhibiting antibiosis-type resistance. For the straight growth habit cultivars, IAC 22 and IAC 8112 affected the larval viability, presenting antibiosis-type resistance. The straight and runner growth habit cultivars did not influence the biological parameters of weight of pupae, sex ratio and longevity of S. bosquella.

Resíduos agrícolas e argila expandida no cultivo da orquídea Oncidium baueri Lindl.

For orchid cultivation in containers is essential to select the right substrate, since this will influence the quality of the final product, it serve as a support for the root system of the plants. This study aimed to evaluate different agricultural residues and expanded clay in Oncidium baueri Lindl. orchid cultivation. The plants were subjected to treatments: pinus husk + carbonized rice husk, pinus husk + coffee husk, pinus husk + fibered coconut, pecan nut husk, expanded clay, fibered coconut, coffee husk, carbonized rice husk, pinus husk. After eleven months of the experiment, the following variables were evaluated: plant height; largest pseudo-bulb diameter; number of buds; shoot fresh dry matter; the longest root length; number of roots; root fresh matter; root dry matter; and electric conductivity; pH and water retention capacity of the substrates. Except the expanded clay, the other substrates showed satisfactory results in one or more traits. Standing out among these substrates pinus husk + coffee husk and pine bark + fibered coconut, which favored the most vegetative and root characteristic of the orchid. The mixture of pinus husk + coffee husk and pinus husk + fibered coconut, provided the best results in vegetative and root growth of the orchid Oncidium baueri and the expanded clay did not show favorable results in the cultivation of this species.

Bactérias promotoras de crescimento e adubação nitrogenada no crescimento inicial de cana-de-açúcar proveniente de mudas pré-brotadas

The objective of this work was to evaluate the effects of the inoculation with plant growth-promoting bacteria on the formation of sugarcane pre-sprouted seedlings, originated from individual buds, and to quantify the initial growth of these seedlings in association with nitrogen application, in a low fertility soil. Two experiments were carried out: one in greenhouse conditions, with a time span of 50 days, and the other in vases under field conditions, with a time span of 180 days. In both experiments, a randomized complete block design was used with a factorial arrangement of 2x3, in the first experiment - with or without inoculation, and with three quantities of bud reserve -, and of 2x2x4, in the second one - with or without inoculation, with or without nitrogen, evaluated in four times: at 45, 90, 135, and 180 days. The inoculant had effect on the initial growth of the pre-sprouted seedlings, increasing sprouting speed and dry matter accumulation on roots and shoots, regardless of the bud reserve amount. In the second experiment, the inoculant increased the initial growth of shoots and root system up to 180 days after transplantation, increasing height, tillering, stalk diameter, dry matter production of stalks and straw, and root length, regardless of nitrogen application. The inoculant has a positive physiological effect on plant growth.

Effects of plant regulators on the growth and flowering of Saint Augustine grass plants

The objective of this work was to evaluate the effects of three plant growth inhibitors on the development and emission of floral rachis of Saint Augustine grass [Stenotaphrum secundatum (Walt.) Kuntzel] plants. The study was carried out in a 15 month old lawn with the experimental plots being distributed in accordance with a complete randomized block design with four replications. The treatments consisted of sole application of trinexapac-ethyl (113, 226, 452, 678, and 904 g ai ha(-1)), prohexadione-calcium (100 and 200 g ai ha(-1)), and bispyribac-sodium (40 and 60 g ai ha(-1)) plus a check treatment in which the plants were not submitted to any of the plant growth inhibitors. The effects of those products were evaluated in terms of visual signs of plant intoxication, plant height, emission and height of floral rachises, and chip total dry matter production. All the plant growth inhibitors resulted in visible injury to the plants but these intoxication signs practically disappeared 28 days after the application. Trinexapac-ethyl at the dose of 904 g ai ha(-1) reduced plant height by 59.7%, the emission of floral rachis by 96.4%, and the amount of chip dry matter production by 87.7%. Plant growth inhibitors may reduce the number of times of lawn plants cutting up to 119 days after their application with no harmful effects on the plants visual aspect.

Subdoses de glyphosate no desenvolvimento de espécies arbóreas nativas

Recovery of degraded areas aims to provide the degraded environment favorable conditions for restructuring in an environment that is unable to regenerate itself and planting of tree seedlings is one of the effective ways to extend this process. However, native tree species have slow growth rate which increases the seedlings production time as well as decreases their competitiveness with weeds in areas of forests deployment. The aim of this study was to evaluate the effects of glyphosate reduced rates application on Psidium cattleyanum (yellow guava), Citharexylum myrianthum (pau-viola) and Cedrela odorata (cedro) seedlings development by analyzing its morphophysiological parameters. The experiment was carried out in greenhouse conditions and the experimental units consisted of one plant were conducted in 2.5L plastic pots and arranged in a completely randomized design with six replications. Treatments consisted of glyphosate application at 0, 7.5, 15, 30 and 60 g ha(-1) using Scout (R) commercial formulation. Treatments application on these species seedlings was realized 120 days after seeds germination. Visual evaluations of plants phytotoxicity were realized at 7, 14 and 21 days after treatments application and plants survival, stomatal conductance, height, stem diameter and dry mass of shoots were evaluated 90 days after treatments application. Different doses of glyphosate did not cause plants phytotoxicity. Already, 30 and 60 g ha(-1) of glyphosate provided greater increases in height, stem diameter and dry mass of shoots for Citharexylum myrianthum and Psidium cattleyanum, respectively.

Relações de interferência entre plantas daninhas e a cultura do grão-de-bico

The grains of chickpea consumed in Brazil are almost entirely imported. Considering that chickpeas presents conditions to be cultivated in some regions of Brazil, this study aimed to study interference of six weed plants (Amaranthus viridis, Bidens pilosa, Raphanus raphanistrum, Cyperus rotundus, Digitaria nuda and Eleusine indica) on the vegetative development of chickpeas. Thus, we evaluated the shoot length, number of leaves, leaf area, chlorophyll content and dry weight of leaves, stem and root of chickpeas. We observed a significant interference on the chickpeas'development in coexistence with weeds. Among the weeds, D. nuda, E. indica and A. viridis were the most aggressive, highlighting the need for early control of weeds when in cultivation of chickpeas in areas with a history of high density of these weeds. The leaf area of chickpeas was the most affected trait by the coexistence with weeds, affecting the development of the crop.

Differential response of clones of eucalypt to glyphosate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Water quality and communities associated with macrophytes in a shallow water-supply reservoir on an aquaculture farm

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Variação morfológica de Poecilia vivipara em um gradiente de predação nop litoral norte fluminense

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação do desgalhador florestal de discos em função de diferentes teores de umidade da madeira de eucalipto

Pós-graduação em Ciência Florestal - FCA

Utilização de pastagem de alfafa e raspa de mandioca na produção de leite de cabras

Pós-graduação em Zootecnia - FMVZ

Quality of wood and pulp from a clone of Eucalyptus grandis planted at three locations

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliações de estratégias de recuperação de pastagens com a introdução de leguminosas

Com o objetivo de avaliar a incidência populacional de plantas daninhas em diferentes manejos de implantação de Stylosanthes guianensis cv. Campo Grande em pastagem de Brachiaria decumbens. Realizou-se um experimento na AgênciaPaulista de Tecnologia dos AgronegóciosExtremo Oeste no município de Andradina/SP emfevereiro de 2011. Utilizou-se o delineamento experimental em blocos ao acaso em esquema de parcelas subdivididas, com quatro repetições e compostos por sete tratamentos (parcelas principais) e duas testemunhas: T1=Plantio direto com dessecação ½ dose de glifosato; T2=Plantio direto sem dessecação; T3=Plantio direto com escarificação do solo; T4=GradagemRome + Plantio direto; T5=Sistema convencional; T6=Brachiaria decumbens e T7= Estilosantes Campo Grande (dessecação com glifosato). Foi avaliado a massa seca de espécies infestantes em diferentes manejos de implantação de Estilosantes Campo Grande, aos 15 dias após semeadura. Os resultados foram submetidos à ANOVA para comparação múltipla de médias, a 5% de significância pelo teste de Tukey. Os T2, T3 e T6 apresentaram uma maior massa seca de espécies infestantes, foram diferentes estatisticamente dos demais (P<0,05), porém não houve diferença significativa entre eles (P>0,05). A massa seca das monocotiledôneas é praticamente toda de Brachiaria decumbens e das dicotiledôneas foi insignificante.

Atributos químicos no solo e produção de Cynodon dactylon cv. Tierra Verde sob doses de biofertilizante orgânico

The concentration of nutrients in plant is related to the soil, fertilization, climate, season, cultivar and cultural practices. Aiming to evaluate the soil chemical properties, the dry matter production of shoots and roots, nutrient content in the plant and the chemical composition of the grass Tierra Verde subjected to levels of organic biofertilizer as nitrogen source, an experiment was conducted in a greenhouse at the Faculty of Veterinary Medicine , UNESP, Araçatuba-SP, January-September 2010. Treatments were arranged in a completely randomized design with six fertilized biofertilizer doses (0, 33, 66, 132, 264, 528 m3 ha-1) and five repetitions for three cuts. We used the model split plot, with doses of biofertilizer considered as main treatments and cuts as sub-plots. We obtained a linear response in the production of dry mass of shoots and roots to the dose of 528 m3 ha-1 of organic biofertilizer. Nitrogen fertilization influenced the soil chemical properties and levels of organic matter, sulfur, boron and manganese, and in foliar levels of phosphorus, potassium and copper. The chemical composition was not altered by the influence of organic biofertilizer doses applied to the soil.