INTRODUÇÃOO algodoeiro é hospedeiro de um complexo de pragas, que podem ocasionar danos às estruturas das plantas. Os níveis populacionais destas pragas sofrem grandes variações, e infestações elevadas provocam sérios prejuízos à cultura, se o efetivo controle não for feito. As medidas de controle das pragas fazem parte dos sistemas de produção do ABSTRACT RESUMO algodoeiro. Para o desenvolvimento sustentado, neste agroecossistema, há necessidade de implementação do Manejo Integrado das Pragas (MIP), que proporciona soluções dos problemas com pragas, a longo prazo. O MIP consiste na integração de práticas e métodos apropriados de controle de pragas, de modo compatível, que possibilita a manutenção das populações dos competidores abaixo do nível de dano econômico. Inclui a com-1. Trabalho recebido em ago./2009 e aceito para publicação em set./2010 (n° registro: PAT 6860/

The increase in cotton plant population by decreasing the spacing between rows cause some changes in phenotypical characteristics of cotton plants, such as decrease in number of leaves per plant, low-development leaves, and great soil shading. Stink bugs of the Pentatomidae family that migrate from soybean crops seem to benefit from the cotton narrow-row planting system. The objective of the present work was to evaluate adult and nymph stink bug populations in cotton plantations under three plant spacing. The experiment was conducted in the 2010/2011 cotton season at the Experimental Farm of the Federal University of Grande Dourados, in Dourados, MS, Brazil. A randomized block experimental design was used, with three cotton growing systems and eight replications, totaling 24 plots. The cotton growing systems were selected based on spacing between planting rows (0.22, 0.45, and 0.90 m). Five evaluations were conducted to survey the stink bug populations, with two samples per plot. The number of nymphs and adults of Euschistus heros and Edessa meditabunda was counted. The spacing between cotton planting rows affects stink bug populations of the species Euschistus heros and Edessa meditabunda. Increases in cotton plant density decrease the occurrence of stink bug in the plantation. The stink bug population is greater in cotton plantations with spacing of 0.90 m between planting rows.

The control of Asian soybean rust depends on fungicide efficacy and the application technology; however, the leaf architecture of soybean cultivars may also interfere in disease control. This study aimed to evaluate Asian rust control and fungicide deposition using spray nozzles in three soybean cultivars. A randomized block design was used, with treatments arranged in a split-plot scheme; the plots were three soybean cultivars (SYN 1561 IPRO, M6410 IPRO, and M6210 IPRO) and the subplots three spray nozzles (11002 BD, AIXR 110015 and TTJ60 11002), in addition to a control with no fungicide application, and four replicates. The volume median diameter, droplet coverage, leaf area index, area under the disease progress curve, 1,000-grain weight and crop yield were evaluated. The 11002BD and AIXR11005 nozzles provided better spray deposition in cultivars with lower leaf area indexes at the R1 phenological stage. Nozzles 11002BD, AIXR110015 and TTJ60 ensured better management of Asian rust than that of the control treatment, regardless of leaf area index. Cultivar SYN1561 obtained the largest grain yield and highest leaf area index in the season with the highest rainfall, regardless of the spray nozzle used.