Antonio Apoliano dos Santos

Efeito do míldio na concentração de sólidos solúveis totais em frutos do meloeiro

Downy mildew caused by Pseudoperonospora cubensis is one of the most important diseases of the melon (Cucumis melo) in the Northeast of Brazil, where more than 80% of national melon production is concentrated. Downy mildew epidemics are constantly occurring, causing severe losses in the production of melon fruits. The effect of the disease on the concentration of total soluble solids (TSS), an important measure of fruit quality, was determined under field conditions using a yellow, odorless type melon naturally infected with downy mildew. Variable intensities of the disease were obtained by varying cultivation periods and applications of recommended fungicides for the control of the disease (methyl thiophanate + chlorothalonil, metalaxyl + mancozeb and cupper oxiclhoride). The results revealed that increased severity of the disease leads to an accentuated reduction of TSS, causing losses up to 49%. Among the parameters used to estimate the effects of the disease, the area under the disease progress curve was the most efficient, mainly as disease pressure increased.

Podridão basal pós-colheita do coco verde no estado do Ceará

A new post-harvest disease of coconut (Cocos nucifera) was recently detected in fruits exported to European countries. The main symptoms are the blacking and cracking of basal parts of the fruits. Water oozing may occurs as the infection progresses. The fungus Lasiodiplodia theobromae has been frequently isolated from the lesions. Inoculation tests proved that this pathogen is the causal agent of the coconut fruit basal rot. This is the first occurrence of this post-harvest disease in Brazil.

Reação de genótipos de Vigna unguiculata à sarna e efeito da doença sobre componentes de produção

The fungus Elsinoe phaseoli is the scab agent and has been causing serious damages to the cowpea (Vigna unguiculata), crop, mainly in the rainy period of Ceara States mountainous areas. The present work aimed to identify genetic resistance sources and to evaluate the disease effects on the yield and its components, the quality of the grain and the crop cycle. To do this, in 1995 and 1996, 16 genotypes were evaluated in two experiments. One at the rainy period as a rain-fed crop and the other at the dry period as a irrigated crop, in a randomized experimental design with four replications in Tiangua County, State of Ceara. Based on statistical analysis and evaluation of the variances, comparing the treatment averages, the correlation and the regression, it was verified that: in the scab susceptible plants both the cycle and the yield are negatively affected by the disease; all evaluated genotypes have variability in relation to the disease reaction; and the EPACE V-96 cultivar performed better and so can be utilized as parental in a breeding program.

Análise do progresso e danos causadas pelo amarelão do meloeiro

The analysis of progress and the yield losses due to melon yellowing, caused by Melon yellowing-associated virus (MYaV), were studied in two melon hybrids (Aclain and Frevo) under natural infection in a commercial field in Russas county, Ceara State (Brazil). Plants were monitored throughout a growing cycle following the incidence of melon yellowing. By the end of the cycle, fruits were harvested, weighted and sampled to estimate the total solid soluble (TSS). The linear, exponential, monomolecular, logistic and Gompertz models were used for examining their suitability in fitting growth data. The monomolecular model attained the best fitness to describe the data for both hybrids according to the coefficient of determination and error mean square, although the Gompertz model also described the data well for the Aclain hybrid. Fruit weight and TSS contents were not affected by melon yellowing in both hybrids.