4 research outputs found
Cobre via foliar na nutrição e na produção de mudas de cafeeiro
No full textThe objective of this study was to evaluate the effect of different sources and doses of copper (Cu) applied to leaves on growth and nutrition of coffee seedlings. The treatments consisted of combinations of two Cu sources (Cupric Sulfate Ammonium - CSA and Copper Sulfate - CS) and four Cu doses (0, 250, 500 and 1000 g ha-1). The sources of Cu in different doses were dissolved in water, calculated for the application volume of 400 L ha-1. The doses were divided in 3 applications at 20 days. The Cu content and concentration in the leaf, stem, and root in were measured. The dry matter of the leaf, stem, root and total and the utilization, absorption and translocation efficiency, in coffee seedlings were evaluated. In general the Cu content and concentration were obtained for the CS at doses of 250, 500 and 1000 g ha-1 Cu. The maximum increase of total dry matter was 48 and 51 g to CSA and CS, when applied 534 and 668 g ha-1, respectively. The highest utilization and absorption efficiency was found to CSA and CS, respectively. The translocation efficiency was similar for both sources. Objetivou-se com este estudo avaliar o efeito de diferentes fontes e doses de cobre (Cu) aplicado via foliar sobre o crescimento, eficiência e teores nutricionais em mudas de cafeeiro. Os tratamentos consistiram de combinações de duas fontes de Cu (Sulfato Cúprico Amoniacal - SCA e Sulfato de Cobre - SC) e quatro doses (0, 250, 500 e 1000 gha-1) de Cu. As fontes de Cu nas diferentes doses foram dissolvidas em água, e calculadas para o volume de aplicação de 400 L ha-1. As adubações foram feitas via foliar utilizando-se pulverizador manual de 5 L, as doses foram parceladas em 3 aplicações espaçadas de 20 dias. Avaliaram-se os teores e o conteúdo de Cu na folha, no caule, na raiz e total das plantas; a matéria seca da folha, caule, raiz e total; a eficiência de utilização, a eficiência de absorção e a eficiência de translocação em mudas de cafeeiro. De modo geral os teores e acúmulos de Cu são obtidos para a fonte SC em comparação ao SCA nas doses de 250, 500 e 1000 g ha-1 de Cu. Os incrementos máximos de matéria seca total de 48 g para o SCA e de 51 g para o SC, ocorreram quando são aplicadas doses de 534 e 668 g ha-1, de SCA e SC, respectivamente. A maior eficiência de utilização é constatada para o SCA, enquanto que a maior eficiência de absorção é para o SC. A eficiência de translocação apresenta-se semelhante para as duas fontes
Nutrition in bean plants and anthracnose intensity in function of silicon and copper application.
No full textNutrition in bean plants and anthracnose intensity in function of silicon and copper application. The objective of this work was to evaluate the effect of calcium silicate and copper sulfate on anthracnose intensity and nutrition of bean plants. The experiment was conducted using an experimental design in randomized blocks following a 4 x 4 factorial arrangement , (four levels of calcium silicate and four levels of copper sulfate) and two additional treatments (plants without inoculation and plants sprinkled with Benomyl). Four evaluations of the incidence and severity of anthracnose were done, in addition to measuring, total leaf area. At the end of the evaluations, incidence: and data were integrated over time, obtaining the area under disease progress curve (AUDPC). Contents of N, P, K, Ca, Mg, B, Cu, Fe, Mn, Zn, Si and lignin were determined in the aerial Part. A linear decrease of the intensity AUDPC was observed with the increase of the doses of calcium silicate. The severity AUDPC was influenced by the doses of copper, obtaining a reduction of 35% on the higher dosage. The supply of silicon and copper altered the content of the K, mg, S, Zn, Ca and Si in the aerial part of the bean plants
Spatial distribution of Yellow Sigatoka Leaf Spot correlated with soil fertility and plant nutrition
No full textThis study analyzed the spatial distribution of Yellow Sigatoka Leaf Spot relative to soil fertility and plant nutritional status using geostatistics. The experimental area comprised 1.2 ha, where 27 points were georeferenced and spaced on a regular grid 18 × 18 m. The severity of Yellow Sigatoka, soil fertility and plant nutritional status were evaluated at each point. The spherical model was adjusted for all variables using restricted maximum likelihood. Kriging maps showed the highest infection rate of Sigatoka occurred in high areas of the field which had the highest concentration of sand, while the lowest disease was found in lower areas with lower silt, organic matter, total exchangeable bases, effective cation exchange capacity, base saturation, Ca and Mg in soil, and foliar sulfur (S). These results may help farmers manage Yellow Sigatoka disease more effectively, with balanced fertilization and reduced fungicide application. This practice minimizes the environmental impact and cost of production while contributing to production sustainability
Formulações de cobre no controle da mancha aureolada e efeitos fitotóxicos em mudas de cafeeiro
No full textBacterial blight of coffee (Pseudomonas syringae pv. garcae) is an important coffee disease and can be controlled using antibiotics and copper-based compounds. However, copper-based compounds raise doubts among coffee growers regarding bacterial blight control efficiency and phytotoxic potential. In this work, coffee plants were sprayed with different copper molecules in order to study their efficiency on bacterial blight control and the phytotoxic potential. Seven copper formulations, cuprous oxide, copper oxychloride, copper nitrate, copper hydroxide 1 (water-dispersible granules) and 2 (concentrated suspension), copper sulfate 1 (complexed with gluconic acid) and 2 (Bordeaux mixture) were studied. The copper formulations efficiency was compared with the antibiotic kasugamycin, saline solution, and control. In controlled environmental conditions of temperature, relative humidity, and photoperiod, coffee seedlings were sprayed with the treatments and after 24 hours they were inoculated with Pseudomonas syringae pv. garcae suspension. Disease incidence and severity assessments were performed in a 2-day interval during a 16-day period. Phytotoxicity incidence and severity, mapping, and quantification of copper on the leaf tissue surface, dried leaves weight, and total copper leaf content were assessed 16 days after pathogen inoculation. Data were submitted to the Scott-Knott test (p < 0.05). Cuprous oxide and copper sulfate 2 proved most efficient to bacterial blight control, causing lower phytotoxicity effect, best covering, and persistence on leaf tissues. Copper nitrate and copper sulfate complexed with gluconic acid were more phytotoxicity compared to other copper formulations.A mancha aureolada (Pseudomonas syringae pv. garcae) é uma importante doença do cafeiro e pode ser controlada com antibióticos e compostos à base de cobre. Entretanto, compostos à base de cobre levantam dúvidas entre os cafeicultores em relação à sua eficiência de controle e ao seu potencial fitotóxico. Neste trabalho, mudas de café foram pulverizadas com diferentes moléculas de cobre a fim de estudar sua eficiência no controle da mancha aureolada e seu potencial fitotóxico. Foram utilizadas sete formulações de cobre, óxido cuproso, oxicloreto de cobre, nitrato de cobre, hidróxido de cobre 1 (grânulos dispersáveis em água) e 2 (suspensão concentrada), sulfato de cobre 1 (complexado com ácido glucônico) e 2 (mistura de bordeaux). A eficiência das formulações de cobre foi comparada com o antibiótico Kasugamicina, solução salina e controle. Em condições ambientais controladas, as mudas de café foram pulverizadas com os tratamentos e após 24 horas foram inoculadas com a suspensão de Pseudomonas syringae pv. garcae. As avaliações de incidência e severidade da doença foram realizadas em um intervalo de dois dias durante o período de 16 dias. A incidência e a severidade da fitotoxicidade, o mapeamento e a quantificação de cobre na superfície do tecido foliar, o peso das folhas secas e o teor total de cobre nas folhas foram avaliados 16 dias após a inoculação do patógeno. Os dados foram submetidos ao teste de Scott-Knott (p> 0,5). O óxido cuproso e o sulfato de cobre 2 mostraram-se mais eficientes no controle da mancha aureolada, causando menor efeito fitotóxico, melhor cobertura e persistência nos tecidos foliares. O Nitrato de cobre e o sulfato de cobre complexado com ácido glucônico apresentaram maior fitotoxicidade em comparação as outras formulações de cobre utilizadas
