ANDRE RICARDO MACHI

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Agora exibindo 1 - 5 de 5
  • Artigo IPEN-doc 26924
    Ionizing radiation and the influence of package to control of Sitophilus oryzae in rice
    2017 - MACHI, ANDRE R.; HARDER, MARCIA N.C.; ARTHUR, PAULA B.; FRANCO, SUELY S.H.; ARTHUR, VALTER
    Objective: This study aimed to use the gamma radiation from Cobalt-60 to control of Sitophilus oryzae in package with previously infested rice and artificial reinfestation. Material and Methods: In the research, 3 types of sample were used: 2 commercial rice packages and 1 in crystal sugar packages. The samples were irradiated with a dose of 1.0kGy to promote disinfestations under a dose rate of 0.560 Gy/h. After 60 days were counted the number of live and dead insects in each package. Results: We concluded that the package containing holes for gases exchange from inside to outside of the package showed easily penetration of insects, while the two packages without holes prevented the reinfestation of insects. Conclusion: The dose of 1.0 kGy was sufficient to do the disinfestations of rice.
  • Tese IPEN-doc 26491
    Efeitos da radiação ionizante nas fases do ciclo evolutivo de Aedes aegypti L. visando o seu controle através da técnica do inseto estéril
    2019 - MACHI, ANDRE R.
    Aedes aegypti L. é um dos principais insetos causadores de doenças no mundo, sendo assim, é importante trabalhos envolvendo o seu manejo. O objetivo do projeto foi avaliar os efeitos da radiação gama do Cobalto-60 nas fases do ciclo evolutivo de A. aegypti, visando a aplicação da TIE. O trabalho foi realizado no Laboratório de Radiobiologia e Ambiente do Centro de Energia Nuclear na Agricultura (CENA/USP) em Piracicaba- SP. A criação do A. aegypti foi mantida nas instalações do laboratório, sob condições de 25±2°C, UR 50-70% e fotofase de 12 horas. A irradiação de todas as fases do ciclo foi realizada em uma fonte de Cobalto-60 tipo Gammacell-220, instalada no CENA/USP, nas seguintes doses: 0 (controle) até 70 Gy sob uma taxa de dose de 0,356 kGy/hora. Quando ovos foram irradiados, avaliou-se viabilidade contando o número médio de larvas L4, pupas e adultos fêmeas e machos emergidos. Foi também avaliado a porcentagem de eclosão em larvas L1 da geração F1. Para larvas irradiadas, avaliaram-se a o número médio de larvas L4, pupas, adultos fêmeas e machos emergidos, porcentagem de eclosão em larvas L1 e larvas L4 F1. Das pupas irradiadas, avaliaram-se a média de eclosão de larvas F1, de larvas L4 F1, porcentagem de pupas F1 e média de adultos machos e fêmeas F1. Em adultos irradiados, avaliaram-se a média de eclosão de larvas F1, larvas L4 F1, pupas F1 e adultos machos e fêmeas F1. Avaliaram-se parâmetros de competitividade e longevidade de machos F1. Os resultados mostraram que as doses esterilizantes para as fases irradiadas: ovo, larva e pupa foram de 15 Gy, 20 Gy e 60 Gy, respectivamente. Já para adultos da geração F,1 as doses de 45 Gy e 50 Gy para macho e fêmea. Para a fase adulta, doses de 40 Gy e 45 Gy foram esterilizantes para machos e fêmeas. No teste de competitividade, a proporção de 10 machos estéreis: 1 macho não irradiado: 1 fêmea não irradiada causou 92,2% de ovos inviáveis, na dose de 50 Gy. A longevidade dos machos foi reduzida em pupas e adultos irradiados com a dose de 40 Gy.
  • Artigo IPEN-doc 25721
    Efficacy of irradiated glyphosate against Brachiaria plantaginea L.
    2018 - MACHI, ANDRE R.; FERRARI, LUIZ S.; ARTHUR, VALTER
    Glyphosate irradiated with cobalt-60 type Gammacell 220 at different rates was sprayed on seedlings of Brachiaria plantaginea L., a common weed, grown in pots (one seedling with 3-4 leaves in each pot), at different concentrations equivalent to 1 L h-1 or 3 L h-1. Each sample containing 40 ml of the product (glyphosate) taken to a source of Cobalt-60 type Gammacell 220, under a dose rate of 0.312 kGy/hour in doses of: T0, control (water instead of glyphosate); T1, glyphosate at 1.0 L h-1; T2, glyphosate at 3.0 L h-1; T3, glyphosate irradiated at 250 Gy at 1.0 L h-1; T4, glyphosate irradiated at 500 Gy at 1.0 L h-1; T5, glyphosate irradiated at 750 Gy at 1.0 L h-1; and T6, glyphosate irradiated at 1000 Gy at 1.0 L h-1. The effects were assessed in terms of the extent of injury, where scale of 0% (no visible injury) to 100% (plant dead), number of tillers, weed survival and dry biomass produced by the plants. The most effective treatment was glyphosate irradiated at 250 Gy h-1 and applied at 1.0 L h-1. It is important to know that gamma radiation in glyphosate herbicide can be used without antagonistic interactions without cause resistance.
  • Artigo IPEN-doc 23556
    Milbemectin and etoxazol acaricide resistant and susceptible strains of Tetranychus urticae (Trombidiformes: Tetranychidae) are equally radiosusceptible and unable to reproduce when irradiated with 400 Gy
    2016 - ARTHUR, VALTER; NICASTRO, ROBERTO L.; SATO, MARIO E.; MACHI, ANDRE R.
    The twospotted spider mite, Tetranychus urticae Koch (Trombidiformes: Tetranychidae), is considered one of the most important phytophagous mites causing considerable damage in several agricultural crops. The aim of this study was to evaluate the susceptibility to gamma irradiation of strains of T. urticae resistant (R) and susceptible (S) to the acaricides, milbemectin and etoxazol. The R and S strains for milbemectin and etoxazol were irradiated with 200 and 400 Gy of gamma radiation in a Gammacell 220 source to evaluate the effects of gamma radiation on the growth rate of the mites. A dose of 400 Gy totally eliminated populations of both R and S strains of T. urticae within 10 d. A dose of 200 Gy was not sufficient to totally eliminate both T. urticae strains, but it significantly reduced egg viability of both strains. In the most likely measure of efficacy for phytosanitary irradiation of mites—i.e., prevention of F1 egg hatch when parent adults are irradiated—no differences were found in response to irradiation among the 4 strains.
  • Artigo IPEN-doc 23517
    Development of phytosanitary irradiation against Aceria litchii (Trombidiformes: Eriophyidae) on lychee
    2016 - ARTHUR, VALTER; MACHI, ANDRE R.
    The lychee erinose mite, Aceria litchii (Keifer) (Trombidiformes: Eriophyidae), is the most important pest of lychee (Litchi chinensis Sonn. (Sapindales: Sapindaceae) in parts of China, India, Southeast Asia, South Africa and Brazil. This study sought to develop the basis for phytosanitary irradiation of lychee to provide quarantine security against this pest. New methodology had to be devised for this purpose because the adult, the largest life stage—about 200 μ long—cannot be seen without magnification, and because this species does not survive more than a few d even on detached young lychee leaves, or under other artificial conditions. Initially we adapted a method devised by Azevedo et al. (2013) for keeping the adults alive long enough to evaluate the lethal effects of candidate acaricides for at 48 h post treatment. We collected infested leaves from a lychee orchard and irradiated then with doses increasing by increments of 200 Gy in the range 0–2,000 Gy. Each infested leaf had 30 to 40 adult mites. Each of 3 replicates involved ~816 adult mites and ~2,450 adult mites per treatment. Because of the presence of predators hidden within the erinea, we collected 30 adult mites per replicate immediately after irradiation, and placed them in a 14-cm-diam petri dish with a new young lychee leaf and moist cotton. We covered each petri dish with parafilm® to prevent escape of mites and loss humidity. At 24, 36, and 48 h post irradiation, we counted the numbers of live and dead mites. At 24 h post irradiation mortality occurred only in 1,800 and 2,000 Gy treatments, and it was only 1.7% in both treatments. At 36 h mortality had increased to 11.1 and 24.4% in the 1,600 and 2,000 Gy treatments, respectively. At 48 h statistically significant mortality occurred with all doses in the 200–2,000 Gy range; and it was 73.3% and 100.0% in the 1,800 and 2,000 Gy treatments, respectively. Since 2,000 Gy is unacceptable for phytosanitary irradiation, a dose had to be identified that prevents reproduction, i.e., a F1 generation. To prolong the survival of irradiated mites for at least 13 d, which appears to be the generation time of Aceria spp., we cut infested fragments of leaf blades, examined the under a microscope to remove adults and immature forms of predators mites, placed them in petri dishes, irradiated them with doses increasing by increments of 100 Gy in the range 0–500 Gy, and glued each irradiated leaf fragment onto a newly flushed leaf of a potted lychee tree in a screened greenhouse. Each treatment had 4 replications, and each consisted of ~10 adult mites for a total of ~40 adult mites per treatment in the first trial and 18 adults per replicate for a total of ~72 mites in the second trial. By 72 h post irradiation the mortality rate was considerably greater with all doses in the range 200–500 Gy than at 48 h in the earlier experiment, and the percent mortality with 100 Gy was significantly greater than in the control (0 Gy). Therefore, 72 h post irradiation seems to be the minimum time required for the lethal symptoms of irradiation to develop within the dose-range that is relevant to phytosanitary irradiation of fresh plant materials. In both the first and the second trials, moderate symptoms of erinose developed during 18 d post irradiation in the treatments with 0–300 Gy, but no erinose symptoms developed in the 400 and 500 Gy treatments. All symptomatic leaves displayed the patchy growth of erinea, i.e., abnormal felt-like hairs on the abaxial leaf epidermis. In addition by d 18 some galls had been formed on the upper sides of some of the leaves with erinea. These data show that irradiation of A. litchii with ≥ 400 Gy prevented it from reproducing, which is a critically important criterion of phytosanitary irradiation. Additional experiments are needed in the 300–400 Gy range to find the minimum dose required for phytosanitary irradiation.