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Monquero P.A.,Anhanguera | Milan B.,Anhanguera | Silva P.V.,Anhanguera | Hirata A.C.S.,APTA Polo Regional da Alta Sorocabana
Planta Daninha | Year: 2010

The objective of this work was to evaluate the effect of desiccation timings (2, 7, 14, 21 and 28 days) before soybean sowing - DBS) of the following cover crops (Brachiaria ruziziensis, Pennisetum americanum and Brachiaria brizantha) on initial crop development, nutritional soybean content and weed management. The experiment was arranged in a complete randomized block design with four replicates. At soybean sowing, the desiccated species were controlled above 90% at 21 and 28 DBS while desiccation at 2, 7 and 14 2 DBS presented lower control, differing between the species. In desiccation at 2 and 7 DBS, soybean emergence occurred under a large amount of green biomass, showing a lower stand. However, in desiccation at 2 DAS, straw remained for a longer time on the soil, reducing new weed emergence flows. Increased intervals between P. americanum desiccation and soybean sowing led to a pronounced increase in soybean phosphorus content. The highest potassium contents in soybean were observed in B. ruziziensis and B. brizantha straw. The highest Nitrogen content was observed when B. brizantha and P. americanum were desiccated at 21 DBS.

Monquero P.A.,Anhanguera | Silva P.V.,Federal University of Santa Catarina | Hirata A.C.S.,APTA Polo Regional da Alta Sorocabana | Martins F.R.A.,AGROEXATA
Planta Daninha | Year: 2011

The objective of this work was to identify the differences between the seedbank of area cultivated with sugarcane picked mechanically by six years and for one year, being used techniques of agriculture of precision. The soil sampling for seedbank determination were performed using a 1,6 ha regular sampling grid. The weed infestation maps were obtained by the kriging interpolation technique. The green sugarcane field presented lower weed infestation potential compared to the burnt sugarcane field, specially the monocotyledonous species like Cyperus rotundus and Brachiaria decumbens. However, some dicotyledonous species can be selected, such as the Ipomoea and Euphorbia and that sugarcane straw can be used as a suppression/selection factor for various species.

Monquero P.A.,Anhanguera | Correa M.C.,Federal University of Santa Catarina | Barbosa L.N.,Federal University of Santa Catarina | Gutierrez A.,Federal University of Santa Catarina | And 2 more authors.
Planta Daninha | Year: 2013

The tolerance of green manure species to diclosulam can be used in crop rotation schemes aiming to reduce the subsequent phytotoxic effect of this herbicide on sensitive plants, such as sunflower or corn plants. This study evaluated the tolerance of green manure to diclosulan and the capacity of these plants in reducing the phytotoxic effect of this herbicide on Helianthus annuus (sunflower). Three rates of diclosulam (0; 0.035, and 0.070 kg a.i. ha-1) were evaluated under greenhouse conditions in pre-emergence of the following green manures: Dolichos lablab, Cajanus cajan, Canavalis ensiformis, Crotalaria juncea, C. breviflora, C. spectabilis, Mucuna deeringiana, M. cinerea, M. aterrima, Lupinus albus, Helianthus annuus, Pennisetum glaucum, Avena strigosa, Raphanus sativus and Calopogonium muconoides. C. cajan, C. ensiformis, M. cinerea, and M. aterrima were selected as the most tolerant ones, being evaluated in the field with diclosulan at the rates of 0, 0.035, and 0.070 kg a.i. ha-1 in a 4 × 3 factorial scheme, with four repetitions. The shoots of these plants were collected 60 days after emergence, and H. annuus was sown as bio indicator of diclosulam. The results showed that C. cajan was the most promising species to reduce the phytotoxic effect of diclosulam on susceptible cultures.

Orzari I.,Anhanguera | Monquero P.A.,Federal University of Santa Catarina | Reis F.C.,Federal University of Santa Catarina | Sabbag R.S.,Federal University of Santa Catarina | Hirata A.C.S.,APTA Polo Regional da Alta Sorocabana
Planta Daninha | Year: 2013

Ipomoea grandifolia, I. nil, and Merremia aegyptia have been important weeds to different crops, causing problems mainly in culture systems. The objective of this work was to evaluate the germinative behaviour of these species under different conditions of temperature (15, 20, 25, 30, and 35 ° C), light (presence and absence) and sowing depth (0; 0,5; 1; 5; 10; 12; 15; and 20 cm) in soils with different textures. The results showed that species incubated at 20 up to 25 °C presented optimal germination. The species presented better germination capacity under no light condition. In relation to soil texture, the results showed that I. grandifolia presented better capacity of germination at greater depths in sandy-clay soil. Both Ipomoea species presented better germination on heavy-clay soil surface. M. aegyptia presented better germination on sandy-clay surface compared to heavy-clay soil. However, germination at greater depths was better in heavy-clay soil.

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