Cupric Fungicides Research Articles

Fungicidas cúpricos, cloretos de benzalcônio e composto bioativo liquído (Bokashi): fitotoxicidade e controle da seca dos ponteiros causada por Erwinia psidii em goiabeiras

Diferentes formulacoes de fungicidas cupricos, cloretos de benzalconio e de composto bioativo liquido foram testados para o controle da seca dos ponteiros causada por Erwinia psidii em goiabeira (Psidium guajava), observando-se os possiveis efeitos fitotoxicos. O experimento foi conduzido em pomar comercial de goiabeira das variedades Pedro Sato e Comum, no municipio de Brazlândia, DF. Os tratamentos constaram dos seguintes produtos/L de agua: 5,0 g de sulfato de cobre (SC), 3,5 g de oxicloreto de cobre (OC), 3,0 g de hidroxido de cobre (HC), 3,0 mL de cloretos de benzalconio (CB) e 20,0 mL de composto bioativo liquido (CBL). A fitotoxicidade foi avaliada em botoes florais e frutos, em tres estadios de desenvolvimento, e a incidencia da doenca, em 10 ramos de frutificacao em cada quadrante da planta nos mesmos estadios. Na variedade Pedro Sato, em frutos de tamanho inferior a 15 mm nao foram observados sintomas severos de fitotoxicidade, no entanto, na variedade Comum foi possivel observar sintomas severos ocasionados pelos cupricos; em frutos entre 16 e 30 mm e acima de 31 mm, em ambas as variedades, foram observados sintomas moderados a severos, ocasionados principalmente pelo SC. No controle da doenca, os tratamentos com SC, OC, HC e CBL foram mais eficientes na variedade Pedro Sato, enquanto o CBL foi mais eficiente na variedade Comum. Em ambas as variedades o CBL mostrou menor Area Abaixo da Curva de Progresso da Doenca (AACPD).

Effectiveness of acibenzolar‐S‐methyl, fungicides and antibiotics for the control of brown eye spot, bacterial blight, brown leaf spot and coffee rust in coffee

AbstractThis study was carried out to evaluate the potential of acibenzolar‐S‐methyl (ASM), combined or not combined with fungicides and antibiotics for the control of brown eye spot (Cercospora coffeicola) and bacterial blight (Pseudomonas syringae pv. garcae) in coffee seedlings, and ASM combined with conventional fungicide application schedules for the control of coffee rust (Hemileia vastatrix) and brown leaf spot (Phoma costarricencis) under field conditions in two coffee crops in the State of São Paulo, Brazil. ASM protected coffee seedlings against C. coffeicola when applied at the rates of 2.5 and 5 g of active ingredient per hectolitre of water (g a.i. hL−1), providing 34–55% of disease control, and against bacterial blight, when applied at the rates of 2.5, 10 and 20 g a.i. hL−1, with 38–57% of disease control. Tebuconazole (100 g a.i. hL−1) and azoxystrobin (10 g a.i. hL−1) showed the best results for brown eye spot control. Oxytetracycline + streptomycin, kasugamycin hydrochloride, oxytetracycline + metallic copper, copper oxychloride and mancozeb + copper oxychloride also controlled bacterial blight in levels similar to those shown by ASM. In the field experiments, all fungicide application schedules tested, cyproconazole (December, February, April), epoxiconazole (December, March), tetraconazole (December, February, April), cyproconazole (December, February) and azoxystrobin (January, March) were effective for coffee rust control and provided partial control of brown leaf spot. The results also showed that for all experiments, there was no synergistic effect of the combination of ASM with azoxystrobin, cyproconazole or cupric fungicides.

High level of copper application to soil and leaves reduce the growth and yield of tomato plants

Copper-containing fertilizers, fungicides and bactericides are extensively used in greenhouses in Turkey. Informations on effects of these applications to plants are scarce. The aim of the present study was to investigate effects of Cu application to a calcareous soil and to leaves on the yield and growth of tomato plants. Cu was first applied to soil as CuSO4.5H2O in three different levels (0, 1000, and 2000 mg Cu kg-1) and then to leaves in three different frequencies (no application, biweekly and weekly) using two cupric fungicides (Cu oxychloride, and Cu salts of fatty and rosin acids) in pot experiments carried out in a computer-controlled greenhouse. Total yield, fruit number, dry root weight and plant height decreased with increasing Cu application to soil. Increasing levels of Cu applied to soil and leaves resulted in decreasing final fruit number, dry root weight and plant height in 4th, 5th and 6th weeks. Combined applications of Cu to soil and leaves could be more deleterious to plants than when Cu is applied only to soil or leaves.

Copper balances in cocoa agrarian ecosystems: effects of differential use of cupric fungicides

This paper presents a synthesis of an investigation of the fate of copper following the use of cupric fungicides in cocoa ecosystems in Bahia/Brazil. For the investigation three plantations were determined: Site A without fungicide applications, Site B under treatment for 5 years and Site C for 16 years. As input-output balances reveal the imbalance of processes and the existence (or non-existence) of a steady state of the ecosystem an attempt is made here to establish a balance of Cu cycling in the three cocoa plantations. The results so far obtained indicate that an input-output balance can be an appropriate means to reveal the accumulation of Cu within the ecosystem, as an anthropogenic agent.