Historically, many herbicides have been tested for control of purple and yellow nutsedge, (Cyperus rotundusL. # CYPRO and (C. esculentusL. # CYPES). However, most chemicals provide only poor or temporary control. Reasons for failure include marginal translocation of herbicides to sites of action, temporary inhibition of tuber sprouting, and control of new tuber formation or inconsistent control when applied at different stages of growth and under various environmental conditions. Evaluation criteria that emphasize control of new plants and foliage rather than inhibition of tuber sprouting or new tuber production also contribute to erratic results. Progress toward solving these research problems is evident in studies of the influence of herbicides relative to nutsedge growth stages, new tuber development, and tuber recovery following treatment. In this review, nutsedge response to herbicides grouped by their mode of action within plants will be summarized.

Para se alcançar eficiência no manejo cultural, é muito importante determinar o período crítico de interferência (PCI) das plantas daninhas no cultivo das hortaliças. Avaliou-se neste trabalho a interferência das plantas daninhas na cultura do tomate para processamento, pelo transplantio de mudas, na Embrapa Hortaliças, em delineamento de blocos ao acaso com 3 repetições. Os tratamentos foram divididos em dois grupos, com períodos iniciais crescentes, denominados sem a interferência (no limpo) e com interferência (no mato) das plantas daninhas. No primeiro, a cultura de tomate permaneceu livre da interferência das plantas daninhas desde o transplantio das mudas até os seguintes períodos (dias) do ciclo de desenvolvimento do tomate: 1-28, 1-35, 1-49, 1-63, 1-77, 1-91 (todo ciclo, colheita). Após estes períodos, as plantas daninhas cresceram livremente até o final do ciclo da cultura. No segundo grupo a cultura permaneceu com a interferência das plantas daninhas desde o preparo final do solo e transplantio das mudas até os mesmos períodos descritos para o primeiro grupo. Após estes períodos as plantas daninhas foram removidas manualmente até a colheita. De um total de 24, as espécies mais freqüentes e/ou de maior acúmulo de matéria seca foram: Bidens pilosa, Brachiaria plantaginea, Nicandra physaloides e Oxalis latifolia. As plantas daninhas causaram reduções na produção de tomate de até 75,5%, sendo que o PCI ocorreu no período do 33º ao 76º dia após a implantação da cultura.

The potential for yellow nutsedge (Cyperus esculentusL. var.leptostachyusBoeck. # CYPES) regrowth was reduced by increasing plant age and by glyphosate [N-(phosphonomethyl)glycine] and oxyfluorfen [2-chloro-1-(3-ethoxy-4-nitrophenoxy)-4-(trifluoromethyl)benzene]. Of the amount of glyphosate transported to underground parts, most was found in the tubers, with immature rhizomes, roots, and tubers having 2 to 3 times higher concentrations than comparable mature tissues. Addition of unlabeled oxyfluorfen as a tank mixture with glyphosate increased absorption and translocation, mainly into leaves and new tubers, of radioactivity from14C-glyphosate in 30-day-old plants. In contrast to the younger plants, the addition of oxyfluorfen decreased14C-glyphosate detected in 60-day-old plants. The greater effectiveness of glyphosate when applied with oxyfluorfen on yellow nutsedge at the early growth stage has important implications in the field because the tuberization process must be stopped early in the development of the plant for successful control.

Alambra' was more responsive to treatments than 'Duradoro'. Methyl bromide fumigation and solarization reduced the number and survival of weed seeds in the soil. Solarization increased levels of P and Cu, and reduced levels of Zn in the soil.

A s doenças causadas por organismos presentes no solo causam sérios problemas no cultivo de hortaliças e podem levar a perdas elevadas, em alguns casos chegando a 100% da produção. Em pequenas propriedades, cuja área disponível para produção é restrita, o problema causado pela presença de patógenos de solo pode levar à necessidade de abandono da área inviabilizando a propriedade para produção de determinadas culturas. A murcha bacteriana do tomateiro, causada por Ralstonia solanacearum está associada a solos encharcados e altas temperaturas, sendo mais problemática, e até limitante, no verão e em regiões de clima quente (Lopes et al., 2000). R. solanacearum infecta espécies de plantas pertencentes a mais de 50 famílias botânicas (Hayward, 1994), provocando maiores perdas nas solanáceas. Infecta ainda BAPTISTA MJ; SOUZA RB; PEREIRA W; LOPES CA; CARRIJO OA. 2006. Efeito da solarização e biofumigação na incidência da murcha bacteriana em tomateiro no campo. Horticultura Brasileira 24: 161-165.

O Cerrado brasileiro possui grande potencial devido suas condições edafoclimáticas. Objetivou-se avaliar, o comportamento de genótipos de café, quanto ao desenvolvimento fenológico nas condições climáticas de Ceres-GO. O experimento foi implantado no IF

Genetic dissimilarity can be used to identify promising genotypes for cultivation in specific conditions. Thus, the objective of this work is to study the genetic dissimilarity among 35 genotypes of Coffea arabica in the Cerrado, under irrigation, using phenological data and multivariate statistics. Plant height, stem diameter, canopy diameter, number of orthotropic branch nodes, length of orthotropic branch internodes, length of primary plagiotropic branches, and average plagiotropic branch internode length were evaluated at 6, 12, 18 and 24 months after planting. Data were analyzed using Hierarchical Agglomerative Cluster Analysis and Principal Component Analysis. Three clusters were formed for each evaluation (6, 12, 18 and 24 months). At 6 months, the most distant group consisted of Yellow

Breeding programs and later indication of rust resistant cultivars for different environments and crops systems, in the concept of diseases integrated control, reach out for productivity raising and reduced production costs. The aim of this work was to evaluate the agronomic performance and adaptability of new <em> Coffea arabica </em> cultivars and progenies resistant to leaf rust in Central Brazilian Savanna. The experiment has been conducted since 2008 in an experimental area of Embrapa Hortaliças. Twenty three resistant cultivars, four progenies and three susceptible cultivars as controls, were assessed in a complete randomized block design with four replicates. The following traits were analyzed: plant height, stem diameter, canopy projection, number of plagiotropic branches, yield, grains percentage retained in sieves above 17, grain ripening and diseases resistance. Catucaí 2SL, Sacramento and Araponga stood out in vegetative growth. The highest yields are observed for IPR 103, Obatã 1669-20, Palma II, Sabiá 398 and Acauã, with values higher than 60 sacks per hectare. Among all these cultivars is observed high resistance to rust leaf and greater susceptibility to brown eye spot in the cultivar Acauã, for the place and period of evaluation.