RESUMOA maioria dos pomares de cajueiro no Brasil está localizada no trópico semiárido, onde a água é escassa e apresenta problemas de salinidade. Desta forma, este trabalho objetivou avaliar o efeito da salinidade na germinação e no desenvolvimento inicial de mudas de cajueiro BRS 274 e BRS 275. Os tratamentos foram dispostos em esquema fatorial 5 x 2 com quatro repetições, referentes a soluções salinas ajustadas para as condutividades elétricas (CEa) (0, 3,0, 6,0, 9,0 e 12 dS m -1), e dois clones de cajueiro (BRS 274 e BRS 275). As variáveis avaliadas foram: porcentagem de emergência (PE), índice de velocidade de emergência (IVE), tempo médio de emergência (TME), altura da plântula (AP), diâmetro da plântula (DP), número de folhas (NF), área foliar (AF), massa seca das folhas (MSF), massa seca do caule (MSC) e massa seca da raiz (MSR) obtidos 30 dias após a emergência. Houve efeito de interação entre os clones e a salinidade da água de irrigação para as variáveis PE e IVE. Por sua vez, todas as variáveis estudadas foram influenciadas pela salinidade da água de irrigação e o clone BRS 275 apresentou resultados superiores para as variáveis PE, IVE, TME, AF e MSF em comparação com o clone BRS 274. Palavras-chave: Anacardium occidentale, condutividade elétrica, salinidadeGermination and seedling establishment of clones of cashew irrigated with saline water ABSTRACT Most cashew orchards in Brazil are located in semi-arid tropics, where water is scarce and has salinity problems. Based on this fact, this study aimed to evaluate the effect of water salinity on initial development of clones of cashew. Treatments were arranged in a 5 x 2 factorial design with four replications, relative to electrical conductivity of water for irrigation (ECw) (0, 3.0, 6.0, 9.0 and 12.0 dS m -1 ), and two clones of cashew (BRS 274 and BRS 275). The variables evaluated were: percentage of emergence (PE), rate of emergence (IVE), mean emergence time (TME), seedling height (AP), diameter of the seedling (DP), leaf area (AF), leaf dry matter (MSF), stem dry matter (MSC) and root dry matter (MSR) obtained 30 days after emergence. There was an interaction between clones and salinity of irrigation water for the variables PE and IVE. All parameters studied were affected by salinity of irrigation water and the clone BRS 275 presented superior results for PE, IVE, TME, AF and MSF variables compared to clone BRS 274.

ABSTRACT. Using commercial cultivars to compose crossing blocks in cotton is a promising strategy, because these materials have desirable agronomic and technological characteristics. The objective of this study was to evaluate the genetic diversity among 16 cotton cultivars cultivated in two environments in the State of Mato Grosso, the largest national producer, using agronomical and technological traits. There was significant effect to cultivars for all traits, while genotype x environment interaction was significant only for average boll weight, short fiber index, and maturity of fibers. Therefore, because of the presence of genotype x environment interaction for three traits, we chose to study genetic diversity among cotton cultivars separately in each environment and investigate the interaction impact on the diversity among genotype pairs. Based on agronomical and technological performance and genetic diversity among cultivars in both environments, the most promising cross involves FM 910 and LD CV 02. We also observed that lint percentage and average boll weight presented a higher discrimination capacity in both environments.

The cashew gummosis caused by the fungus Lasiodiplodia theobromae is one of the most important disease of cashew in the northeast of Brazil. The lack of studies about method of early detection, pathogen dissemination, host predisposition, mechanisms of attack and defence and efficient control measures assures this disease as a limiting factor as to growing of cashew under semi-arid conditions. Therefore, the characterization of spatial patterns of gummosis development under commercial orchards may provide important insights into the mechanisms involving in dissemination and disease progress of this disease, as well as in the understanding of dynamic of host, pathogen and environmental interactions for this pathossystem. This work aimed to characterize gummosis temporal and special dynamics in three commercial orchards of cashew clones of cashew with different levels of susceptibility by studying the special arrangement of diseased plants. Disease incidence and severity, quantified determined by a descriptive scale in clones BRS 226 (resistant), Embrapa 51 (slightly resistant) and Faga 11 (susceptible) in a commercial orchard located in Pio IX district (Piaui state, Brazil), were monitored and mapped. Data were collected within three blocks of 90 plants for each clone. Indices of dispersion were estimated to study the spatial dynamic. The dynamics and structure of gummosis foci were also analysed. As expected, data showed different degrees of gummosis incidence and severity for the three clones. Even under different levels of disease, a random dispersion pattern model of dispersion could be observed at the beginning of epidemic for all clones. However, as disease develops, a clustered model is likely to fit. The increase in disease incidence resulted from the increasing in both focus number and size.

L a s i o d i p l o d i a t h e o b r o ma e, a g en t of gu m m os i s a n d b la c k branch dieback of cashew, is the most important disease of cashew crop in semi-arid regions of northeastern Brazil. This pathogen is a well known fungus in many host plants as capable of colonizing th ei r tis su es wi th out s howin g di sea se s ymp toms. Thi s fea tu re ensures great epidemiologic importance as considering tactics for d i s e a s e a v o i d a n c e . T h e o c c u r r e n c e o f c a s h e w gu m m o s i s i n geographically isolated areas reinforces the seed and scion borne pathogen hypothesis. The objectives of this study were to determine the ability of L. theobromae to survive in cashew tissues without showing symptoms and to evaluate plant propagating materials (seed and scion) as source of primary inoculum. The presence of the fungus at different distances from the canker throughout the stem in both Cardoso, J.E.; Bezerra, M.A.; Viana, F.M.P.; Sousa, T. R. M.; Cysne, A.Q.; Farias, F.C. Endophyte occurrence of Lasiodiplodia theobromae in cashew tissues and its transmission by vegetative propagules. Summa Phytopathologica, v.35, n.4, p.262-266, 2009 Keywords: Gummosis, Anacardium occidentale, grafting, epidemiology.Palavras-chave adicionais: resinose, Anacardium occidentale, propagação, epidemiologia. RESUMOLas iodi plod ia t heob roma e , agen te c ausa l da res inos e e da podridão-preta-da-haste é o principal patógeno do cajueiro no semiárido nordestino. Esse patógeno é reconhecido em outros hospedeiros pela capacidade de colonizar tecidos vegetais sem aparente sintoma. Es sa c arac terísti ca é de gra nde imp ortâ nci a ep idemiológic a, prognosticando medidas de exclusão no manejo da doença. A ocorrência epidêmica da resinose em áreas isoladas reforça a hipótese dos propágulos assintomáticos do hospedeiro servirem como fonte de inoculo primário. Os objetivos deste estudo foram determinar a capacidade de L. theobromae de sobreviver em tecidos de cajueiro sem apresentar sintomas e estimar a transmissão deste patógeno via propágulos. A presença do fungo a diferentes distâncias do cancro e nas duas direções em relação ao mesmo (descendente e ascendente) foi determinada pelo plaqueamento de tecidos de troncos infectados. Na outra parte do trabalho, foram coletados em Cardoso, J.E.; Bezerra, M.A.; Viana, F.M.P.; Sousa, T. R. M.; Cysne, A.Q.; Farias, F.C. Ocorrência endofítica de Lasiodiplodia theobromae em tecidos de cajueiro e sua transmissão por propágulos. Summa Phytopathologica, v.35, n.4, p.262-266, 2009 pomares comerciais sementes de plantas sem sintomas e com sintomas severos de resinose. Estas foram semeadas separadamente e as plântulas obtidas foram enxertadas com garfos provenientes de ramos de plantas sadias e ramos de plantas severamente infectadas, perfazendo-se todas as combinações de origem da semente e garfos. As mudas produzidas conforme os quatro tratamentos foram plantadas sob condições favoráveis à doença. L. theobromae foi isolado até 80 cm, tanto na direção ascendent...

ABSTRACT.Final cotton quality is of great importance, and it depends on intrinsic and extrinsic fiber characteristics. The objective of this study was to estimate general (GCA) and specific (SCA) combining abilities for technological fiber traits among six upland cotton genotypes and their fifteen hybrid combinations, as well as to determine the effective genetic effects in controlling the traits evaluated. Patos, PB, Brazil. The experimental design was a randomized block with three replications. Technological fiber traits evaluated were: length (mm); strength (gf/tex); fineness (Micronaire index); uniformity (%); short fiber index (%), and spinning index. The diallel analysis was carried out according to the methodology proposed by Griffing, using method II and model I. Significant differences were detected between the treatments and combining abilities (GCA and SCA), indicating the variability of the study material. There was a predominance of additive effects for the genetic control of all traits. TAM B 139-17 presented the best GCA estimates for all traits. The best combinations were: FM 993 x TAM B 139-17, CNPA 04-2080 x PSC 355, FM 993 x TAMCOT-CAMD-E, PSC 355 x TAM B 139-17, and TAM B 139-17 x TAMCOT-CAMD-E, by obtaining the best estimates of SCA, with one of the parents having favorable estimates for GCA.