Complexo lixa e queima das folhas em coqueiro-anão : avaliação de germoplasma e estratégias de controle químico por cyproconazole

• Ano de defesa: 2016
• Autor(a) principal: Silva, João Manoel da
• Orientador(a): Fernandes, Marcelo Ferreira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Agricultura e Biodiversidade
• Palavras-chave em Português: Coco; Germoplasma vegetal; Fungicidas; Cocos nucifera; Queima das folhas; Lixa grande; Lixa pequena; Fungicida sistêmico
• Palavras-chave em Inglês: Leaf blight; Germoplasm; Systemic fungicide
• Área do conhecimento CNPq: CIENCIAS AGRARIAS
• Link de acesso: https://ri.ufs.br/handle/riufs/6782

The coconut palm (Cocos nucifera L.) is a perennial fruit with great economic importance in the Brazilian Northeast and is expanding to other regions. However, this culture is susceptible to various diseases, such as “lixagrande”, “lixapequena” and leaf blight. Although they are of great economic importance, are diseases difficult to control, especially for the high size of the plants. Through this study aimed to describe the relationship between the intensity of the complex sanding and leaf blight (CLQ) in dwarf coconut accession and evaluate the cyproconazole fungicide efficiency to control CLQ in green dwarf coconut tree under different modes (axillary and injection) dosages (0.3, 0.6 and 1.0 g a.i.) and frequency of application (bi-monthly and six-monthly). To test the control efficiency of cyproconazole front of the CLQ. Axillary application was made by the application in the axil of the leaf number 9 of the product diluted and injected by opening a hole in the stem to 20 cm from the ground with a mechanical drill and introduction of pure product in the above doses with a syringe. Was evaluated the incidence and severity in addition to the first leaf with leaf blight (PFQ). The temporal variation in the incidence and severity of disease during the study period was determined by the ratio of the values of the last evaluation (225 d) on the first (0 d). For chemical control with cyproconazole, the use of tree regression resulted in a model where a tree four terminal nodes explained 49% of the total variability of the data. This variability was explained by two factors selected for analysis, dose and mode of application, which contributed respectively with 35.5% and 13.5% of the total variability. It was found that there was a difference for all treatments in relation to control. The application modes differ, where injectable application obtained the best controls with lower levels of incidence and severity and higher levels of PFQ. Doses of 0.6 and 1.0 g a.i. were the most efficient independent of the frequency of application to the axillary and injection modes, respectively. There was no significant effect of frequency of application. In the second experiment were evaluated six dwarf coconut accessions conserved in active germplasm bank (BAG) of Embrapa-CPATC being: AAG (Dwarf Yellow-of the-Brazil-of-Gramame), AAM (Dwarf Yellow-of- Malaysia), stroke (Dwarf-Red-of-Cameroon), AVG (Dwarf-Red-of the-Brazil-of-Gramame, AVBJ (Dwarf-Green-of the-Brazil-of-Jiqui), and AVM (Dwarf-Red-of-Malaysia). the design was randomized blocks with six treatments (accessions) and five repetitions. Was carried out 11 monthly evaluationsfrom June 2015 to May 2016. Ofeach disease was evaluated incidence and severity. With the evaluation of BAG accesses a graphical representation expressed 95% of the variability of the data, and of this total, 72% associated with the axis 1 and 23% to the axis 2. the intensity of CLQ damage stroke access and AVBJ presented an intermediate behavior in relation the other accesses. AVG access followed by AVM tended to greater intensity of great sandpaper and the burning of leaves. A group of AAG and AAM tended to greater intensity of small sandpaper. Regarding the environment the intensity of great sandpaper was positively influenced by the temperature and the incidence of leaf burn negatively by rainfall. The small sandpaper was influenced by the relative humidity.