Estudo dá incidência e comparação dos diferentes fungicidas no controlo do Oídio do cajueiro - Oidium anacardii Noach iio distrito de Namacurra, província de Zambézia

Abstract

A study on powdery mildew (Oidium anacardii Noach) was carried out between August and November 1998, in Zambézia province, Namacurra district. The study aimed to: (1) make a contribution to the assessment of the level of infection caused by powdery mildew; (2) compare the different fungicides in controlling powdery mildew, in seedlings infected in the nursery and (3) assess the level of perception of the local community about the disease. Disease evaluation was based on visual observation of the infection rate in the cashew tree panicles. It was concluded that in all cells in the place where the work was done, the infection rate was high, ranging from 56 to 66% of infection in the panicles. A trial was conducted in the nursery using seedlings already infected, to compare the effect of different fungicides. The results obtained showed low levels of leaf infection at the high dose in all fungicides. Lower levels were found in Anvil and Sulfur fungicides, with indexes from 0.6 to 4.0% for high and low doses, respectively. In parallel with the assessment of the disease based on visual observation of the infection rate in the panicles, a semi-structured interview was carried out with farmers who own cashew trees, with a view to ascertaining the level of perception of the occurrence of the disease. A considerable part of the respondents answered positively about the knowledge of the occurrence of the disease, but on the other hand they were unable to say the name of the disease, they just limited themselves to describing the disease.