Spray volumes, adjuvant and rainless intervals in weed control with sulfentrazone

O herbicida sulfentrazone, utilizado na cultura canavieira, é recomendado para o controle de eudicotiledôneas e monocotiledôneas em pré-emergência, sendo também indicado para o controle de Panicum maximum e Ipomea hederifolia. A pesquisa foi realizada com o objetivo de verificar a influência das aplicações do herbicida sulfentrazone com e sem adjuvante em solo desprovido de cobertura por palha, sob diferentes períodos sem precipitação pluviométrica, associado a diferentes volumes de aplicação, para o controle de P. maximum e I. hederifolia. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições, no arranjo fatorial 2x2x6 + 1, ou seja, dois tratamentos de herbicida, dois volumes de calda (60 e 120 L ha-1), seis períodos sem chuva antes da aplicação e mais uma testemunha, que não recebeu aplicação de herbicida. Foram realizadas avaliações de contagem de plantas-daninhas a 15 e 33 dias após a chuva. Foi avaliada também a matéria seca da parte aérea das plantas. Os resultados indicam que a aplicação de sulfentrazone com todos os tratamentos foi eficaz no controle I. hedrifolia, independente do volume de calda, período sem chuva ou presença de adjuvante. Mesmo havendo escape de plantas de P. maximum (emergência de plantas) em todos os períodos sem chuva, os tratamentos são eficazes para o controle da espécie. A presença do óleo mineral na calda com o herbicida sulfentrazone não incrementa o controle de P. maximum e I. hederifolia.The herbicide sulfentrazone, used in sugarcane cultivation, is recommended for the control of eudicots and monocotyledons in pre-emergence and is also indicated for the control of Panicum maximum and Ipomea hederifolia. The research was carried out with the objective of verify the influence of the sulfrentazone herbicide with and without adjuvant on soil without straw cover under different periods without rainfall, associated to different application volumes, for the control of P. maximum and I. Hederifolia. The experimental design was a completely randomized, with four replications, in the 2x2x6+1 factorial arrangement, that is, two treatments of herbicide, two volumes of spray liquid (60 and 120 L ha-1), six periods without rain before application another witness, who received no application. Weed counts were evaluated at 15 and 33 days after rainfall. The dry matter of the aerial part of the plants was also evaluated. The results indicated that the application of sulfentrazone with all treatments was effective in the control I. hedrifolia, independent of the volume of syrup, period without rainfall or presence of adjuvant. Even if P. maximum plants escape (emergence of plants) in all periods without rainfall, the treatments are effective for the control of the species. The presence of the mineral oil in the syrup with the herbicide sulfentrazone does not increase the control of P. maximum and I. hederifolia

Selectivity of the plant growth regulators trinexapac-ethyl and sulfometuron-methyl to cultivated species

The aerial spraying of plant ripeners on sugar cane (Saccharum officinarum L.) crops causes often the contamination of neighboring areas, which subsidizes formal complaints from the neighbors. These contaminations are due to spraying taking place during inadequate environmental conditions or from technical mistakes during the application. One of the most important causes of this contamination is the susceptibility of the species being cultivated surrounding sugar cane. In order to evaluate the effects of sugar cane plant ripeners trinexapac-ethyl and sulfometuron-methyl on peanuts, cotton, potato, coffee, citrus, beans, sunflower, cassava, rubber, soybean, and grapes, eleven experiments - one for each species - were carried out from May 2009 to Jan. 2010. The field experiment was set according to a completely random design with five treatments and four replications. Just before or during flowering, a single treatment of trinexapac-ethyl at 100 or 200 g ha-1 and sulfometuron-methyl at 7.5 or 15 g ha-1 was applied to plants. A control treatment (plants not treated) for each species was part of each experiment. Trinexapac, at the doses of 100 and 200 g ha-1, showed selectivity to peanuts, cotton, potato, coffee, citrus, sunflower, cassava, rubber, soybean, and grape. At the lowest dose (100 g ha-1), it was selective for bean. Sulfometuron, at the dose of 7.5 g ha-1, was selective for peanuts and, at the two studied doses (7.5 and 15 g ha-1), it was selective for coffee, citrus, cassava, and rubber

Selectivity of the plant growth regulators trinexapac-ethyl and sulfometuron-methyl to cultivated species

The aerial spraying of plant ripeners on sugar cane (Saccharum officinarum L.) crops causes often the contamination of neighboring areas, which subsidizes formal complaints from the neighbors. These contaminations are due to spraying taking place during inadequate environmental conditions or from technical mistakes during the application. One of the most important causes of this contamination is the susceptibility of the species being cultivated surrounding sugar cane. In order to evaluate the effects of sugar cane plant ripeners trinexapac-ethyl and sulfometuron-methyl on peanuts, cotton, potato, coffee, citrus, beans, sunflower, cassava, rubber, soybean, and grapes, eleven experiments - one for each species - were carried out from May 2009 to Jan. 2010. The field experiment was set according to a completely random design with five treatments and four replications. Just before or during flowering, a single treatment of trinexapac-ethyl at 100 or 200 g ha-1 and sulfometuron-methyl at 7.5 or 15 g ha-1 was applied to plants. A control treatment (plants not treated) for each species was part of each experiment. Trinexapac, at the doses of 100 and 200 g ha-1, showed selectivity to peanuts, cotton, potato, coffee, citrus, sunflower, cassava, rubber, soybean, and grape. At the lowest dose (100 g ha-1), it was selective for bean. Sulfometuron, at the dose of 7.5 g ha-1, was selective for peanuts and, at the two studied doses (7.5 and 15 g ha-1), it was selective for coffee, citrus, cassava, and rubber