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In order to have a better understanding of the behaviour of several commercial cotton varieties in relation to the main diseases in the cerrado vegetation area, 4 trials were conducted at COODETEC's experimental station in Primavera do Leste, state of Mato Grosso, during the 2003-2004 growing period: EGTRA (Trial on the degree of tolerance to Cotton rust Ramularia); EGTDA (Blue Disease); EGTRO ("Ramubse"), and EGTPC (Boll rot). Two plants were artificially inoculated with "Ramulose". For EGTRO and all other trials, infestation took place naturally. Each trial is composed of the materials to be tested: IPR 96, IPR 94-227, IAC 24, CD 405, DELTAOPAL, IAN 338, CD 408, CD 409, and CD 410, together with a susceptible and a resistant check variety. In the case of EGTDA, the initial stand of IAC 24 was significantly reduced, and IPR 94-227 was the most tolerating variety. For EGTPC, IAN 338 was the material that underwent the most intense rotting process, and CD 409 and IPR 96 were the most tolerant to rotting. For EGTRA, IPR 96 achieved the best mark. In the case of EGTRO, CD 410 was the material most sensitive to "Ramulose" and IPR 96 and CD 407 were the most tolerant varieties after the tolerant check variety BRS Antares.

Cultivar CD 409 derives from a breeding program by Coodetec/Cirad in Palotina, in the state of Paraná, and was obtained through the pedigree selection method. The CD 98-32 line, obtained from an Australian and South American genetic pool, was tested during growing periods 1999-2000, 2003-2004 in the experimental network of the states of Bahia, Goiás, Mato Grosso, and Minas Gerais. Over 40 trials were conducted. CD 409 is tall and growth regulator is consistently used. It has medium, jagged leaves and average pilosity. The fruiting habit of this material is similar to that of CNPA ITA 90; its differential lies in its capacity to retain top bolls, which allows for significant recovery after shedding of first fruiting positions under adverse conditions. It is resistant to bacteriosis and moderately resistant b the Blue Disease. Against "ramulose" and cotton rust ramularia, its resistance is similar to that of all other varieties used in the cerrado area. It has a good tolerance level to nematodes and this was demonstrated in several locations heavily infested with Meloidogyne incógnita. CD 409 is a useful choice for cotton growers with a medium and high level of technical capabilities and skills in his Brazilian cerrado, especially in areas affected by nematodes.

The experiment was conducted in Arasy Orgánica's field located in the District of Guayaibi, San Pedro Department, Paraguay. The purpose of this experiment was to identify commercial varieties of cotton Gossypium hirsutum that were adapted to the system of organic production. The statistical model applied was a block randomized design. The varieties analyzed were REBA P 279, IAN 338, IAN 425, IAN 424, CD 401. The variables analyzed were yield and fiber quality. The phytosanitary treatment of the culture was carried out through different homemade formulations based on leaves of penicillin Aithemantera brasiliana, Carica papaya, "guembe" Philodendrum bipinnatifidum, paradise Mehiia asederach, nettle Urtica dioica, and rust of cow. As for the yield, statistically significant differences between five commercial varieties of cotton under study were not found. This was due to the variability in soil conditions, a severe drought during the time of full flowering and fructification of the crops, besides intense attacks of the boll weevil Anthonomus grandis in the last stage of development of the crops. All varieties under study have good quality fibers and the varieties IAN 424 and IAN 425 have excellent ginning turnout and, for this reason, those two varieties can be usefully grown under the system of organic production.

Visando a atender a exigência do mercado da região centrosul do Brasil e o plantio em áreas com nematóide, a Coodetec/Cirad lançou no mercado na safra 00/01 a variedade CD 405, material obtido no programa de melhoramento genético da Coodetec/Cirad através do método de seleção pedigree. A linha CD 95-621 foi obtida de um cruzamento entre variedades de fundo genético Africano e sul americano, testado primeiramente em Palotina-PR na safra 96/97 e nas safras 97/98, 98/99 e 99/00 na rede experimental multilocal do Paraná e São Paulo. A variedade CD 405 é um material que pode ser classificado na categoria das variedades indeterminadas ("Full season"), tardia, de alta produtividade, pouco exigente em fertilidade, mas muito exigente em regulador de crescimento, sendo tolerante as deficiências hídricas e adaptada a colheita manual. Sua resistência é voltada à bacteriose e doença azul, é moderadamente resistente ao nematóide, fusariose e alternariose, porém é susceptível a ramulariose e ramulose. O rendimento e qualidade da fibra foram classificados como médios.

Obtida do programa de melhoramento genético da Coodetec/Cirad, a linha CD98-225 foi lançada comercialmente em 2002/2003 com a denominação de CD406. Esta variedade foi obtida através do esquema de seleção genealógica a partir de um cruzamento entre variedades de fundo genético Australiano e Sul Americano, e testada pela primeira vez em 1997/98 em Palotina-PR, e nas safras 99/00, 00/01 e 01/02 na rede experimental multilocal da Coodetec nos estados do MT, GO e MG. A variedade CD 406 é um material de ciclo mais determinado que a ITA90, de elevado potencial produtivo, exigente em fertilidade e responsiva, com rendimento de fibra muito elevado (40% comercial) e adaptada à colheita mecânica. Sua resistência é voltada à doença azul e bacteriose com relativa tolerância as doenças foliares. A qualidade de sua fibra fica dentro do padrão produzido atualmente no cerrado, muito parecida com a fibra da ITA90. A CD 406 é uma variedade direcionada para os produtores tecnificados das regiões do cerrado.

Ce rapport est un document de synthèse collective rédigé par les participants du Cirad ou de la Coodetec Il présente des résumés des exposés oraux présentés dans les divers ateliers du IVème congrès cotonnier brésilien, tenu à Goiânia en septembre 2003. Les domaines suivants sont abordés: marchés, politique agricole, économie et agriculture familiale, industrie textile mondiale et ses tendances, analyse des coûts de production, exigences de qualité pour les marchés d'exportation du coton, technologie de la fibre et classification, agronomie, irrigation, variétés, maladies et ravageurs (avec présentation des seuils de traitements actualisés). Les congrès cotonniers brésiliens ont lieu tous les 2 ans, et celui de 2003 a regroupé un très grand nombre de participants. Ce document synthétique très technique constitue la substantifique moelle de l'événement.

Les coopératives de l'Etat du Parana au Brésil constituent un maillon très imprtant de la filière cotonnière de ce pays. Elles ont lancé en 1989 un programme de recherche sur le cotonnier axé principalement sur l'aspect variétal : amélioration des qualités technologiques de la fibre, sélection de variétés tolérantes aux ravageurs et adaptées à la récolte mécanique. Financée par les coopératives cotonnières de cet Etat, cette recherche a donné lieu par la suite à une forme originale de coopération avec le Centre de coopération internationale en recherche agronomique pour le développement (CIRAD, France).

Un total de 184 échantillons de coton ont été recueillis à Trinité-et-Tobago, aux Antilles hollandaises (Curacao, Bonaire et Aruba), à la Jamaïque, à Grand Cayman, en République Dominicaine et aux Etats-Unis d'Amérique (Floride et Porto Rico). Cette mission faisait partie d'un ensemble de mission en plusieurs étapes portant sur le Meso-Amérique et l'Amérique du sud.