QUIMIOTERAPIA E TERMOTERAPIA NO CONTROLE DO Colletotrichum gloeosporioides, AGENTE DA MANCHA MANTEIGOSA, EM CAFEEIRO (Coffea arabica L.) / Chemotherapy and thermothetapy to control of Colletotrichum gloeosporioides, agent of blister spot in coffee (Coffea arabica L.)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Seeds play a fundamental role in the dissemination of plant pathogens to long distances and transmission of them to plant. In many crops, fungi can be associated with seeds in all the stages of crop production in addition to surviving longer. For coffee plantation, the transmission by seeds of Colletotrichum gloeosporioides, causal agent of blister spot is a big problem, because most of the plantations are formed by seedlings obtained from seeds. In this context, the objectives of this present work were to evaluate the efficiency of the chemotherapy (in seeds) and thermotherapy (in fruits and seeds) in the seeds healthy and germination quality and possible biochemical changes in the fruits. For evaluation of the efficiency of the chemical control in inoculated seeds with isolates obtained from seeds of plants without blister spot symptom (isolate 1), the following products were tested: (g of a. i. /100 kg of seeds): pencycuron (250), tolyfluanid (500), carbendazim+thiram (150+350), fludioxonil (25), tiram (480) and triadimenol (150). The thermal treatments was done by immersing the non- inoculated seeds or the inoculated ones with isolated 1, or with the isolate obtained from shoot die-back of coffee (isolated 2) in hot water at (50 e 60 ÂC, per 1 minute, 7 minutes and 30 seconds and 15 minutes) in water bath. The not inoculated or inoculated fruits (with isolate obtained from coffee fruits - isolated 3) of plants without symptoms of blister spot were submitted to the termotherapy per 1 minute in water bath. Samples of the inoculated fruits were collected for biochemical analyses. The blotter and germination (by paper roll) test were carried out. The chemical treatments were efficient for the reduction of the incidence of C. gloeosporioides in the coffee seeds. The seeds treated with the fungicides tolyfluanid, tiram and triadimenol presented the biggest percentages of normal germinated seedlings. The termotherapy demonstrated efficient in fruits and seeds on the controlling C. gloeosporioides in coffee seeds. However, the temperature of 60Â C per 15 minutes should not be used because is harmful for the coffee seed germination causing seed embryo death. There were variations in total protein, total soluble phenols, and in the activities of peroxidase and polypfenol oxidase enzymes when different isolates are used in the inoculation of the fruits.

ASSUNTO(S)

germinaÃÃo cafà fruit coffee semente fruto. germination fitopatologia seed

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