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The root-lesion nematode, Pratylenchus brachyurus, is native to the Brazilian Cerrado region. Although soybean is not a natural host of this nematode, its advance on Cerrado areas has made this species become an important pathogen for the crop. This study aimed to assess the spatial distribution of P. brachyurus and its influence on soybean crop productivity in eastern Maranhao. For this, a sampling was conducted in 142 georeferenced points distributed in an area of 180 × 180 m. Plant and soil samples were collected, being the nematodes extracted and counted. Spatial patterns were estimated using geostatistical analysis. Anisotropic exponential models were adjusted for all studied variables with higher ranges in the direction of soil tillage and planting (135°). The increase in nematode population, as well as its spatial pattern, was related to the presence of roots of the host plant in the soil. The direction of soil tillage and planting influenced the distribution of nematodes in the area, being the main controlling factor of their spatial patterns.

Submitted by Guilherme Lemeszenski (guilherme@nead.unesp.br) on 2013-08-22T18:44:44Z No. of bitstreams: 1 S1982-56762012000300009.pdf: 3014271 bytes, checksum: db3bb67342a9ee6bc395b47123acfceb (MD5) Made available in DSpace on 2013-08-22T18:44:44Z (GMT). No. of bitstreams: 1 S1982-56762012000300009.pdf: 3014271 bytes, checksum: db3bb67342a9ee6bc395b47123acfceb (MD5) Previous issue date: 2012-06-01 Made available in DSpace on 2013-09-30T19:33:09Z (GMT). No. of bitstreams: 2 S1982-56762012000300009.pdf: 3014271 bytes, checksum: db3bb67342a9ee6bc395b47123acfceb (MD5) S1982-56762012000300009.pdf.txt: 19326 bytes, checksum: 3daaaa7891a6f603ae6e0ad9473d242b (MD5) Previous issue date: 2012-06-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T13:14:39Z No. of bitstreams: 2 S1982-56762012000300009.pdf: 3014271 bytes, checksum: db3bb67342a9ee6bc395b47123acfceb (MD5) S1982-56762012000300009.pdf.txt: 19326 bytes, checksum: 3daaaa7891a6f603ae6e0ad9473d242b (MD5) Made available in DSpace on 2014-05-20T13:14:39Z (GMT). No. of bitstreams: 2 S1982-56762012000300009.pdf: 3014271 bytes, checksum: db3bb67342a9ee6bc395b47123acfceb (MD5) S1982-56762012000300009.pdf.txt: 19326 bytes, checksum: 3daaaa7891a6f603ae6e0ad9473d242b (MD5) Previous issue date: 2012-06-01 A entrada de agentes fitopatogênicos em novas localidades através de mudas infectadas constitui uma das principais formas de disseminação. Meloidogyne enterolobii é uma espécie de nematoide altamente virulenta que tem causado sérios danos a plantas cultivadas no Brasil. Neste trabalho é relatada a primeira ocorrência de M. enterolobii em mudas de muricizeiro (Byrsonima cydoniifolia), uma planta nativa da Amazônia e em mudas de goiabeira (Psidium guajava), no Estado de Mato Grosso. Com base nos caracteres morfológicos do padrão perineal de fêmeas, região labial dos machos e no fenótipo isoenzimático de esterase, foi confirmado que a espécie encontrada tanto nas mudas de muricizeiro quanto nas de goiabeira é M. enterolobii. Spreading of plant pathogens through seedlings is one of the main ways of introducing pathogens in places free of these agents. Meloidogyne enterolobii is a highly virulent species of nematode responsible for serious damage to plants grown in Brazil. In this study the occurrence of M. enterolobii on young individuals of muricizeiro (Byrsonima cydoniifolia), a native species of the Amazon forest, is made for the first time together with the first report of the occurrence of this nematode on guava (Psidium guajava) in the State of Mato Grosso, Brazil. Based on morphological characters of the perineal pattern of females, lip region of males and the esterase isoenzyme phenotype, we confirmed that the species found in both of B. cydoniifolia and P. guajava is M. enterolobii. Universidade Estadual Paulista Departamento de Fitossanidade Laboratório de Nematologia Universidade Federal de Mato Grosso Universidade Estadual Paulista Departamento de Fitossanidade Laboratório de Nematologia

The incorporation of tools related to the technology of application of pesticides is inevitable for a sustainable agriculture. We tested the efficiency in the control of Ipomoea nil in initial after-emergency with diuron + hexazinone, in two volumes of application (20 ha -1 and 40 L ha -1 ), with or without the addition of adjuvant, using peaks of rotating and hydraulically spraying, comparatively. Other two assays had been carried to compare the volumetric distribution of solution and the diameter of the drops produced for the hydraulical and rotating peaks. The percentage of necrosis in the leaves of I. nil plants increased progressively, in two volumes, with or without the use of adjuvants. The rotating peak did not differ from the hydraulically peak how much to the effectiveness. The use of rotary peak decreased coefficient of uniformity (SPAN) in relation to hydraulic peak, indicating the production of drops with greater uniformity. The distribution of the droplets produced by the rotary nozzle provided uneven distribution pattern in relation to the control peak (TT110.01 a 40 L ha -1 ), due to lower volume of solution used. The peaks spacing was greater with the use of vegetable oil to the volume of 20 L ha -1 . The association of the adjuvants to diuron + hexazinone provided to increase the diameter of the drops, with similar efficiency between the two tested volumes. The lower volume of application of diuron + hexazinone (20 L ha -1 ) in I. nil control can be used, because it provided similar efficacy to the higher volume. The use of adjuvant organ silicone (0.025 % v/v) and vegetable oil (1.0% v/v) may be recommended in the spray system with rotating tip allows for increasing the diameter of the droplets, reducing problems with drift, allowing the use of lower application volume (20 L ha-1), increasing the potential for overlapping droplets on the target.