ABSTRACT
A very limited amount of information is available in relation both to the residual effect of herbicides destinated to the destruction of cotton stalks and to the time interval required to prevent that development and yield of the following crop be affected. This work aimed to identify the residual activity of herbicides intended to eliminate cotton stalks and to estimate the safety interval (SI) of time for the next cotton sowing. Two trails were simultaneously carried out, the first one for a single application and a second one for the two sequential applications of herbicide treatments, in a 15×5 factorial design organized in randomized complete blocks with four replications. Levels of first factor were constituted by herbicide treatments and the levels of the second factor were composed five periods of time for cotton sowing after herbicide application (0, 30, 60, 90, and 120 days). Herbicides were 2,4-D, glyphosate, saflufenacil, [imazapic + imazapyr], dicamba, fluroxypyr and sulfentrazone. Results provided an indication of residual activity of herbicide treatments in soil and indicated that a single application or two sequential applications of glyphosate + dicamba + saflufenacil have a considerable potential to affect cotton and a period exceeding 100 days for a single application and exceeding 120 days for two sequential applications was necessary. Treatments with 2,4-D and 2,4-D + glyphosate provided the shortest safe interval and may be used for cotton stalk destruction with no risks for the crop sowing after the withdrawal period.
Subject(s)
Pest Control/methods , Gossypium , Agricultural Pests , 2,4-Dichlorophenoxyacetic Acid , Herbicides , InsectaABSTRACT
Este trabalho teve como objetivo registrar o ataque de Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, Formicidae) em noni, Morinda citrifolia L. Este registro foi ao acaso. As operárias foram coletadas manualmente em junho de 2015 na região sul de Rondônia, Brasil. O desfolhamento pelas formigas foi registrado em uma planta de noni com quatro anos de idade. No local foi encontrado apenas um sauveiro. A desfolha aconteceu de baixo para cima. O horário de forrageamento concentrava-se no período noturno. Esse é o primeiro registro dessa formiga cortando folhas de noni, no estado de Rondônia e no Brasil.(AU)
This study aimed store cord the attack of Atta sexdens rubropilosa Forel, 1908 (Hymenoptera, Formicidae) in noni, Morinda citrifolia L. This record was random. The workers were collected manually in June 2015 in the southern region of Rondonia, Brazil. The defoliation by ants was recorded in a noniplant four years old. On the site we found only one ant nest. Defoliation happened from the bottom up. The foraging time was concentrated at night. This is the first record of ants cutting leaves of noni in the state of Rondonia and Brazil.(AU)