Translocação dos herbicidas glyphosate e imazamox em plantas de aguapé

Eichhornia crassipes is one of the main weeds found in aquatic environments, being undesirable for many activities. The aim of this study was to evaluate the translocation of glyphosate and imazamox in E. crassipes. Eight intervals were studied for cutting leaves that received herbicides: 2, 4, 6, 8, 12 and 24 hours after application (HAA), and a treatment with no cutting (untreated). The glyphosate dose was 2,160 g a.e. ha-1 (commercial product - Rodeo) + 0.5% v v-1 Aterbane adhesive spreader and imazamox at 290.4 g i.a. ha-1 (commercial product - Clearcast). The treatments were installed in a completely randomized design with four replications. Glyphosate showed a bad control for all the periods of leaf cutting. The imazamox did not provide control within 12 HAA, while from 24 HAA onward the control was effective. There was not a great mobility of the glyphosate molecule in water hyacinth plants, a period above 24 hours being needed for a satisfactory translocation. For imazamox at least 24 hours were needed after herbicide application for the translocation to occur along with subsequent control.

Evolução de CO2 e atividades enzimáticas em amostras de solo tratado com herbicidas

Effects of bentazon, metolachlor, trifluralin, imazethapyr, imazethapyr+lactofen, haloxyfop-methyl, glyphosate and chlorimuron-ethyl at rates of 2 and 10 times the equivalent commercial dose on soil microbial activity was evaluated in soil samples extracted from a field never treated before. Global soil microbe respiration, estimated by CO2 production at 2, 4, 8, 12, 16, 20, 24 and 28 days of soil incubation and enzymatic activities (dehydrogenase and fluorescein diacetate hydrolysis) at 8 and 28 days were used as bioindicators. Bentazon and mixture imazethapyr+lactofen at the highest rate and haloxyfop-methyl at both rates, inhibited soil respiration although with differences in timing and duration. None of the herbicides affected FDA hydrolysis. Dehydrogenase activity was inhibited at 8 days of incubation with bentazon and imazethapyr at high rates but it was stimulated by metolachlor and imazethapyr at low rate and glyphosate at the highest rate. Herbicide effects on soil microbial activity was detected with higher sensitivity by global soil microbe respiration and dehydrogenase activity than by FDA hydrolysis. Only dehydrogenase activity and soil respiration estimations at 8 days of soil incubation had significant correlation. Results indicated the need of multiple estimations when evaluating herbicides effects on soil microbiota

Épocas de consórcio de alho com cenoura em três sistemas de manejo de plantas daninhas em Jaboticabal-SP

This work was carried out using intercropped cultivation of garlic (Allium sativum) and carrot (Daucus carota) in Jaboticabal, SP - Brazil. Four seeding timings for carrot (0, 15, 30 and 45 days after garlic planting) and three weed management systems (herbicide, frequent manual weed control and no weed control) were tested. The effects of this intercropped system on weed control, efficient land use and productivity were determined. The experimental design was a completely randomized block with split-plots and four replications, with carrot seeding timings being the plots and the weed management systems, the sub-plots. The herbicide oxadiazon at 750 g ha-1 did not cause toxicity in the garlic, nor in the carrot plants. Regandress of the timing for the intercropping establishment the Land Equivalent Ratio (LER) values were greater than one. Garlic-carrot intercropping profitability was greater than that of monocultures of garlic crop, mainly under weed management systems, using the herbicide oxadiazon and frequent manual weeding.

Adjuvantes na deriva de 2,4-D + glyphosate em condições de campo

The aim of the research was to evaluate the effect of adjuvants on the spray drift applications from mixture of 2,4-D + glyphosate. The trial was carried out in field conditions in a completely randomized design. The treatments corresponded to solutions containing mixture of the herbicides 2,4-D + glyphosate (670 and 1068g ha-1, respectively) adding the adjuvants (v v-1): mineral oil (0.5%); anti-drift agent (0.09%); spreader-sticker A (0.1%); liquid fertilizer (0.05%); spreader-sticker B (0.25%); and only herbicides without adjuvantes (control). Nylon strings were used to drift determination outside the application area (1, 5, 10, 20, 50, 100 and 200 m away) with 4 replications and six foam cylinders placed on the boom of the sprayer were used to collect the droplets subject to drift. The applications were performed simultaneously, using a specific salt tracer for each spray solution to quantify the deposits by spectrophotometer. It was not possible to verify effect of the adjuvants on drift at different distances of the application area. Based on droplets collected above the boom spray, it was found that susceptibility to drift was lower with the mineral oil and the anti-drift agent. The drift risk was higher with the liquid fertilizer and the spreader-sticker B.

Soil nitrogen dynamics after Brachiaria desiccation

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

Action of rain on the efficiency of herbicides applied post-emergence in the control of Senna obtusifolia

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

Efeitos da deriva de clomazone, aplicado isoladamente ou em mistura com ametryn, sobre características produtivas de laranjeira 'Hamlin'

This experiment aimed to evaluate the effect of increasing clomazone (sprayed alone or in mixture with ametryn) drift simulation on quantitative and qualitative aspects of orange production when applied at two developmental plant stages: flowering and initial fruit development (fruits 2 cm diameter or smaller). Increasing drifts of clomazone, in two formulations, and clomazone in mixtures with ametryn were tested. Fruit morphological features, fruit color, flower and fruit abortion and leaf chlorophyll content were evaluated. Simulated drift similar to the recommended dose of clomazone and clomazone plus ametryn caused fruit abortion in citrus at the stage of fruits 2 cm diameter or smaller. Lower drift doses did not result in fruit abortion. Fruit diameter reduction was observed with drift off above 25% of clomazone alone recommended rate and 50% when in mixture with ametryn or in microcapsule formulation. Clomazone drift at 50% of the recommended rate (alone or in mixture with ametryn ) caused clorotic and necrotic spots in the fruit peel. Drift did not affect juice quality in any of the treatments tested.

Adubação nitrogenada e aplicação de herbicidas como reguladores de crescimento em grama esmeralda

Pós-graduação em Agronomia - FEIS

Influência da fixação e de métodos de secagem na detecção de alterações proliferativas ultraestruturais induzidas pelo Diuron no urotélio vesical de ratos wistar

Pós-graduação em Patologia - FMB

Desenvolvimento de biossensor baseado em extrato de açaí e sensor biomimético para detecção de hexazinona

Pós-graduação em Química - IQ

Influência da vinhaça e da palhada de cana-de-açúcar na sorção de herbicidas aplicados em diferentes solos

Pós-graduação em Agronomia (Agricultura) - FCA

Intoxicação e alterações metabólicas do algodão sensível e resistente ao amônio glufosinate

Pós-graduação em Agronomia (Agricultura) - FCA

Qualidade de sementes de soja convencional e transgênica em função da dessecação das plantas com glyphosate

Pós-graduação em Agronomia (Agricultura) - FCA

Influência de diferentes misturas em tanque contendo o herbicida 2,4-D no espectro de gotas da aplicação

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

Métodos para identificação de moléculas com atividade herbicida com ênfase na rota de síntese de carotenóides

Pós-graduação em Agronomia (Proteção de Plantas) - FCA