Emergência de plantas daninhas em função da posição da semente e quantidade de palha de cana-de- açúcar

This work was carried out to evaluate the effects of sugarcane straw density and positions of seeds of Euphorbia heterophylla, Mucuna cinereum, Digitaria nuda and Eleusine indica on emergence and initial development of plants. The experiment were arranged in a completely randomized design, with 15 treatments and four replications, in a factorial arrangement 3 x 5 with a additional control; the first factor was constituted by position of seeds related to the straw (under, between and on) and the second by five quantities of straw (1, 2, 4, 8 e 16 t ha -1) with a control without straw. At 15 days after sowing (DAS) it was realized evaluations of height, dry mass and emergence percentage for E. heterophylla and M. cinereum, and at 28 DAS it was analyzed dry mass and emergence percentage for D nuda e E. indica. Data obtained were submitted to F in variance analysis test and means were compared with Tukey at 5% probability. Emergence and initial development of E. heterophylla e M. cinereum were reduced with increasing of straw and were affected by seed position, but it was not inhibited in none of conditions, indicating aggressiveness of these weeds in sugarcane mechanized harvest conditions. D. nuda and E. indica emergence was not affected by seed position and coverage soil with 8 e 16 t ha -1 of sugarcane straw inhibited its emergence.

Taxa de semeadura de Brachiaria brizantha consorciada com milho na incidência de plantas daninhas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influéncia da adubação nitrogenada sobre a interferéncia de plantas daninhas em feijoeiro1

The competition between weeds and bean plants, especially because of nutrients in the environment, is extremely important to minimize potential losses of crop productivity. Thus, the aim of this work was to evaluate the effects of using nitrogen fertilization on the timing and extent of the period before interference (PAI), total period of interference (PTPI) and the critical period of interference control (PCPI) in bean cultivar 'Ruby'. The seeds were sown in the conventional system and the trial was conducted in two areas at the same time, in which the nitrogen fertilization was performed only in one of them. Each area received 14 treatments consisting of two groups: first, the crop was free of interference of weeds from emergence to 10, 20, 30, 40, 50, 60 and 70 days; and the second: the crop remained free of interference from sowing to the same periods described above. The experimental design was randomized blocks with four replications. Raphanus raphanistrum showed greater relative importance in the two areas, mainly due to the accumulation of dry mass, followed by Amaranthus deflexus. There was no difference in diversity and evenness of weed populations in response to the fertilization. In the area without N PAI occurred 18 days after emergence (DAE), and up to 24 DAE PTPI, resulting in PCPI 18 to 24 DAE, this area had 58% of reduction in crop yield. In the area where with nitrogen fertilization, PAI occurred at 38 DAE and PTPI occurred at 19 DAE. In this area there was 56% of reduction in crop yield. The nitrogen fertilization increased crop productivity and favored competitiveness in relation to weeds.

Períodos de interferência de plantas daninhas na cultura do girassol

The interference of weeds in sunflower cultivation can significantly reduce the productivity of achenes. The objective of this study was to determine the period before interference and total period of interference of the weed community on productivity and achene oil of sunflower cultivation. The experiment was conducted under field conditions in the fieldin Botucatu (SP) in the 2007/2008 agricultural year. The experimental design was a randomized complete block with four replications. The treatments were composed of portions represent periods of control and presence of weeds. For control periods, the culture was kept free of weeds by increasing periods of 7, 14, 21, 28, 35, 42, 49 and 110 days after the emergence (DAE) of sunflower. For periods of coexistence, the culture was maintained in the presence of the weed community for the same periods. We assessed the following variables: diameter of chapters, achene yield, oil yield of sunflower, density and dry matter of weeds and phytosociological indices. The period before the interference was 35 DAE culture to the productivity of achenes, and the total period of interference lasted until 24 DAE. For oil yield, the period before the interference was 25 DAE, whereas the total period of interference lasted for 14 DAE.

Eficiência de herbicidas inibidores da ALS e PROTOX sob condições de déficit hídrico no comportamento bioquímico de plantas daninhas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Características da anatomia foliar e da deposição de gotas de pulverização em plantas daninhas aquáticas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da absorção do amicarbazone e intoxicação em cana-de-açúcar e plantas daninhas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Influência do amicarbazone no fotossistema II de plantas daninhas e cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Velocidade de absorção do glufosinate e seus efeitos em plantas daninhas e algodão

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Determinação dos períodos críticos de interferência das plantas daninhas sobre o milho (Zea mays L. cv C333) em função da redução de espaçamento da cultura

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Otimização vetorial e técnicas de mistura de herbicidas aplicadas ao controle de plantas daninhas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Plantas daninhas, atributos biológicos e elementos-traço em latossolo tratado com lodo de esgoto por treze anos consecutivos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Comparação de métodos de mapeamento da distribuição espacial da infestação de plantas daninhas

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

Transmissibilidade da leprose das cercas-vivas, quebra-ventos e plantas daninhas para citros através de Brevipalpus phoenicis (Geijskes, 1939) (Acari: Tenuipalpidae)

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Uso e manejo de plantas alimentares em ambientes agrícolas e florestais em Iporanga, SP

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)