A.C.P. Rodrigues

Levantamento da infestação de plantas aquáticas em Porto Primavera antes do enchimento final do reservatório

The objective of this work was to identify the aquatic plants and their infestation levels in Porto Primavera Reservoir in the state of Sao Paulo, Brazil, before the reservoir was filled. The aquatic vegetation in the dam (72 sites) were evaluated and marked with GPS equipment. The species were identified and a visual estimate (site size) of the proportional distribution of the plants in the infestation foci was carried out. After plant identification, eighteen macrophyte species were found in the dam and their frequency and distribution were determined as follows: Eichhornia crassipes, Eichhornia azurea, Pistia stratiotes, Paspalum repens, Cyperus brevifolius, Paspalum conspersum, Echinochloa polystachya, Egeria densa, Egeria najas, Polygonum hidropiperoides, Polygonum lapathifolium, Alternanthera philoxeroides, Eleocharis sellowiana, Nymphaea ampla, Pontederia cordata, Salvinia auriculataa, Salvinia rotundifolia, Typha angustifolia. The highest relative frequencies were observed in: E. azurea (36.11%), E. crassipes (16.67%), P. stratiotes (13.89%), S. auriculata (13.89%), C. brevifolius (11.11%), and P. lapathifolium (6.94%).

Características morfológicas de gramas em resposta à aplicação de trinexapac-ethyl

The aim of this research was to evaluate the effects of the sequential application of two rates of trinexapac-ethyl on the morphology of the following turf grass species: Broadleaf Carpetgrass (Axonopus compressus), Bahiagrass (Paspalum notatum), St. Augustinegrass (Stenotaphrum secundatum) and Korean Lawngrass (Zoysia japonica). The treatments used were trinexapac-ethyl with two sprays applied at 20 day interval at two different rates (56.5 + 56.5 and 113.0 + 113.0 g ha-1) and a control without spraying, for each species. The turf grasses were cut at the height of 3 cm, and sprayed after the treatments. Twenty days after the first treatment application, the plots were cut again and the second treatment application was carried out. The experiment was arranged in a completely randomized block design with four replications. Growth reduction was evaluated based on the height of the plants. Inflorescence number and height were weekly evaluated by sampling, carried out in 0.25 m2 in the center of the plots. Total dry matter was evaluated at the end of the experiment. Ttrinexapac-ethyl application delayed growth and inflorescence emission and did not cause any visual damage to the turf grasses. Trinexapac-ethyl application can reduce the need of cuts for a period up to 55 days after the second application.

Avaliação qualitativa e quantitativa na deposição de calda de pulverização em Commelina benghalensis

O objetivo deste estudo foi o de avaliar a quantidade e qualidade da deposicao da calda de pulverizacao em plantas de Commelina benghalensis, considerando os volumes de aplicacao, as pontas de pulverizacao e o ângulo dos bicos na barra de pulverizacao. Foram utilizadas cinco hastes de plantas por vaso. O delineamento experimental adotado foi o inteiramente casualizado, com 20 repeticoes. O experimento foi conduzido em casa de vegetacao e a aplicacao da calda foi efetuada apos 40 dias do transplantio das hastes, quando estavam com 30 a 40 cm de comprimento. Os tratamentos foram constituidos por cinco pontas de pulverizacao (TX-VK 6, TX-VK 8, XR 11001 VS, XR 11002 VS e TJ60 11002 VS), sendo testadas com dois ângulos de aplicacao (0o e +30o), exceto a TJ60 11002 VS, e todas com dois volumes de calda distintos (100 e 200 L ha-1). Foi utilizado como tracador o corante Azul Brilhante FDC-1 na concentracao de 500 ppm, para determinar a deposicao da calda de pulverizacao. Apos a aplicacao, 20 hastes no total foram imediatamente coletadas e, em seguida, lavadas em 100 mL de agua destilada, para posterior quantificacao do tracador em espectrofotometro. Os dados foram transformados em valores de depositos por grama de massa seca e ajustados a curva de regressao pelo modelo de Gompertz. Os resultados evidenciaram que, independentemente da ponta utilizada, o volume de 200 L ha-1 proporcionou os maiores depositos medios e pontuais nas plantas. Quanto a uniformidade do deposito de calda sobre as plantas, a ponta XR 11001 VS no volume de 100 L ha-1 proporcionou a melhor uniformidade. Contudo, quando se utilizou o ângulo de +30o, ocorreram acrescimos dos depositos ao se utilizar o volume de 100 L ha-1, e, nesse caso, houve melhor uniformidade para o volume de 200 L ha-1.

Seletividade do herbicida saflufenacil a Eucalyptus urograndis

Forest plantation areas are constantly expanding. However, weed interference affects the growth and development of eucalyptus plants, as they compete for water, nutrients, space, and light. The objective of this study was to evaluate the selectivity of the herbicide saflufenacil, applied with or without the mineral oil Dash, on Eucalyptus urograndis at different application sites (plant, soil and soil + plant). The experimental design was completely randomized, with four replications, consisting of a 3 x 11 factorial, with three sites for herbicide application on the plant and eleven saflufenacil doses combined or not with the adjuvant Dash. Each plot consisted of a vase with a plant. Treatments were 0, 25, 25 + Dash (0.5% v/v), 50, 50 + Dash (0.5% v/v), 75, 100, 125, 150, 175 and 200 g a.i. ha-1. Visual evaluations of plant intoxication were carried out for 56 days after application (DAA). Height, stem diameter, and dry biomass of the plants were also evaluated. The saflufenacil doses tested without adjuvant proved to be selective for the plants of E. urograndis, independent of the application site. The addition of Dash to the treatments caused severe injuries to the plants at the initial assessments, when applied on the plants, with full recovery at the end of the test at 56 DAA. Herbicide application combined with the adjuvant only in the soil did not cause plant toxicity to the eucalyptus plants.

Variáveis qualitativas da pulverização em feijão, Bidens pilosa E Brachiaria plantaginea

Conduziu-se este trabalho, com o objetivo de avaliar a qualidade da deposicao da calda de pulverizacao em plantas de feijao (Phaseolus vulgaris L.), Bidens pilosa L. e de Brachiaria plantaginea (Link) Hitchc. presentes na linha e entrelinha da cultura. Foi utilizado como tracador o corante Azul Brilhante FDC-1 (500 ppm). Utilizaram-se cinco pontas de pulverizacao: jato plano (XR 110015 VS e XR 11002 VS), jato plano duplo (TJ60 11002 VS) e jato conico (TX-6 VS e TX-8 VS) e dois volumes de aplicacao 150 e 200 L ha-1. O delineamento utilizado foi de blocos ao acaso, com 4 repeticoes. Foram amostradas 25 plantas em cada parcela/repeticao, de plantas de feijao e plantas daninhas presentes na linha e na entrelinha da cultura. Apos a aplicacao, as plantas foram coletadas e lavadas em agua destilada para quantificacao do tracador em espectrofotometro. Os dados ajustaram-se a curva de regressao pelo modelo de Gompertz. Os resultados evidenciaram que: para as plantas de feijao as pontas XR 110015 e TJ60 proporcionaram as deposicoes mais uniformes, nos volumes de 150 e 200 L ha-1, respectivamente; a ponta TX-6 no volume de 150 L ha-1 apresentou melhor uniformidade de distribuicao para ambas as especies de plantas daninhas presentes na linha da cultura; para as plantas daninhas presentes na entrelinha, no volume de 150 L ha-1, destacaram-se as pontas XR 110015 e TJ60 11002 para B. pilosa e B. plantaginea, respectivamente, no volume de 200 L ha-1 destacou-se a ponta TX-8 para ambas as especies.

Seletividade de herbicidas aplicados na grama Batatais e na grama São Carlos

The objective of this study was to evaluate the selectivity of herbicides applied on Bahiagrass (Paspalum notatum) and Broadleaf Carpetgrass (Axonopus compressus) turfgrasses under field conditions. The experiment was arranged in a randomized block design, with four replications. The turfgrasses were cut to the height of 3 cm, followed by herbicide application.. The treatments were: control, fluazifop-p-butyl (125 g ha-1), sethoxydim+mineral oil (276 g ha-1 + 0.5% v v-1 of Assist), bispyribac-sodium (25 g ha-1), chlorimuron-ethyl (15 g ha-1), ethoxysulfuron (150 g ha-1), halosulfuron (112.5 g ha-1), iodosulfuron-methyl (10 g ha-1), metsulfuron-methyl (2,4 g ha-1), nicosulfuron (125 g ha-1), pyrithiobac-sodium (140 g ha-1), trifloxysulfuron-sodium (22.5 g ha-1), 2,4-D (720 g ha-1), quinclorac (375 g ha-1), atrazine (1,250 g ha-1), bentazon (600 g ha-1), linuron (1,350 g ha-1), fomesafen (187.5 g ha-1), lactofen (120 g ha-1), oxadiazon (600 g ha-1) and oxyfluorfen (720 g ha-1). The herbicides with selectivity potential for P. notatum were chlorimuron-ethyl, ethoxysulfuron, pyrithiobac-sodium, 2.4-D, bentazon and fomesafem and those with selectivity potential for A. compressus were chlorimuron-ethyl, ethoxysulfuron, halosulfuron, iodosulfuron-methyl, metsulfuron-methyl, pyrithiobac-sodium, 2.4-D, quinclorac, atrazine and bentazon, besides fomesafen.