André Gustavo Battistus

Chemical control of Pileamicrophylla in cattleya seedlings (Cattleyatenebrosa x Cattleyaleopoldy)

Species of the orchidaceae family are grown for marketing flowers and among them the genus Cattleya stands out. However, due to its slow growth, the substrate is subjected to weed infestation. Therefore, this study aims to evaluate the selectivity and efficiency of herbicides in controlling Pilea microphylla in Cattleya orchid seedlings (Cattleya tenebrosa x Cattleya leopoldy). We used a completely randomized design with four replications. The evaluated herbicides were oxyfluorfen (0, 120, 240 and 480 g ha-1), flumioxazin (0, 12.5, 25 and 40 g ha-1), nicosulfuron (0, 20, 40 and 80 g ha-1) mesotrione (0, 96, 144 and 192 g ha-1), clethodim (0, 60, 84 and 108 g ha-1) and metsulfuron-methyl (0, 1.2, 1.8 and 2.4 g ha-1). At post-emergence applying time, the Cattleya plants had three bulb sand were 10 cm tall, while P. microphylla, where 5 cm tall. Nicosulfuron, mesotrione and clethodim herbicides did not control P. microphylla, while oxyfluorfen and flumioxazin showed over 90% efficiency level sin controlling P. microphyllafrom 14 days after application (DAA). As to metsulfuron-methyl, it showed efficiency superior to 90% from the control dose of 1.8 g ha-1 at 28 DAA. All herbicides were selective plants of Cattleya, however, only oxyfluorfen, flumioxazin and metsulfuron-methyl were effective in controlling P. microphylla.

Alternative management of root-knot nematodes (Meloidogyne incognita) in beans (Phaseolus vulgaris).

The bean diseases have been responsible for major yield losses. The root-knot caused by the nematode Meloidogyne have been highlighted in recent years, especially in the soybean growing regions. Thus the aim of this study was to evaluate the potential of induction of resistance by Trichoderma and plant extracts compared with chemical terbufos and water in controlling nematode galls. Thousand nematode larvae J2 were inoculated in the root system of each plant. The evaluation took place 60 days after inoculation. The use of terbufos was efficient, but with the entire load of environmental impact. Alternative treatments of applying Trichoderma to the soil and incorporation of crotalaria leaves in the ground exerted the greatest effect in reducing the severity of disease and pathogen in greenhouse conditions.