Paulo César Tavares de Melo

Desafios e perspectivas para a cadeia brasileira do tomate para processamento industrial

Some challenges for the Brazilian chain of processing tomatoes The purpose of this work is to provide information about technological problems that constitute challenges to the maximization of technical and the economic efficiency of the Brazilian chain of tomato processing. In the 90’s the Brazilian chain of the processing tomato showed expressive performance. However, there are several factors involved in the tomato production systems that still impair the optimization of the processing tomato production. Among those factors we detected not well adapted tomato cvs. to mechanical harvest besides being susceptible to diseases and insects, depreciating the fruits quality for processing causing decline indexes in the relationship matter/ processed products. In addition, the presence of fungus was observed in the concentrated pulp, tomato extracts and in other tomato derived products. These problems could be solved through better cultural practices, including better irrigation techniques (conventional system with central pivot and drip irrigation), fertilizer levels, culture rotation, more adequate systems in the preparation of transplant and mechanized harvest, better weeds control and integrated pest and disease management. Palavras-chave: Lycopersicon esculentum, cultivar, growing practices, nutraceutics, processing products.

Produtividade e qualidade de tomates Santa Cruz e Italiano em função do raleio de frutos

Yield and fruit quality of Santa Cruz and Italian tomatoes depending on fruit thinning The management of the tomato plant under greenhouse, with emphasis on fruit thinning, contributes significantly to the production of fruits of superior quality, expressing the potential of each cultivar. We determined the effect of fruit thinning on yield and its components in tomato hybrids of the Santa Cruz and Italian types of indeterminate growth, and we performed the qualitative characterization of the fruits, aiming in natura market. Twelve fresh-market tomato genotypes (six experimental hybrids and six commercial cultivars) and two training methods (with and without manual fruit thinning) were evaluated. A randomized complete block design was used in this trial, with splitplots and three replications. The plots were represented by genotypes and the subplots were constitued by training methods. Number of fruits per plant, yield of marketable and not marketable fruits, average fruit weight, fruit length and fruit width were measured. For quantitative characterization, pH, soluble solids concentration (SS), tritratable acidity (AT), ascorbic acid content, SS and AT ratio and lycopene content were measured. The fruit thinning increased marketable yield, average weight, length and width for the Santa Cruz hybrids THX-02 and THX-03 and for THX-04, THX-05 and Netuno, classified as Italian type. T he fruit thinning did not provide benefits for yield and its components for the other evaluated characteristics and genotypes. Giuliana and Sahel genotypes presented higher marketable yield and average fruit weight. Without fruit thinning, ‘Netuno’ reached the highest number of fruits per plant, but the hybrid Sahel showed higher marketable yield and average fruit weight. Thinning did not affect the organoleptic quality of the genotypes. ‘Avalon’ showed higher ascorbic acid content than ‘Netuno’ and ‘Sahel’, and ‘Debora Max’, ‘THX-01’, ‘THX-02’ and ‘THX-04’, which were similar to each other in the content of lycopene, overcame ‘Giuliana’, ‘Sahel’, ‘THX-03’, and ‘THX-06’.

Desafios e oportunidades para o agronegócio da cebola no Brasil

The challenges and the oportunities for the onion agribusiness The main objective of this work was to describe some socieconomic aspects of the onion production in Brazil and to detect the principal challenges and opportunities for the onion agribusiness. The onion cultivation in Brazil is a family activity (88%), generating about 250 thousand jobs directly involved in the production. The onion consumption in Brazil is nearly 85 thousand t per month. With the consolidation of the MERCOSUL, the onion import from Argentina and the national production has caused excess of supply in some months, generating losses and consequent damages for the producers. The Brazilian productive sector needs to improve the technological level of the onion production to reach greater technical and economic efficiency. However, it is necessary that Brazilian and Argentinian producers look for a better production forecast to avoid excess of supply during some periods of the year.

Desempenho de cultivares de tomateiro em sistema orgânico sob cultivo protegido

Organic agriculture in Brazil has been increasing about 30% per year over the last few years, since consumers are seeking for healthier foods, i.e. nutritious and free of pesticide residues. Among organically grown vegetable crops, tomato is an attractive economic opportunity for growers. However, the lack of information about management practices and adapted cultivars to organic production systems under protected cultivation are pointed out as important constraints that prevents this activity to expand. This work aimed at evaluating the performance of indeterminate tomato cultivars in organic management systems in unheated plastic greenhouse. In both experiments tomato plants were staked. Plant spacing was 1.5 m between rows and 0.35 m between plants. They were planted in double line and spaced 0.8 m between lines and 0.6 m between plants (about 20,000 plants ha-1). The experiment was set up in a randomized complete block design, with four replications and eight treatments (cultivars: Avalon, Colibri, HTX-5415, HTX-8027, Sahel, San Marzano, San Vito, and Jane). Sahel hybrid exhibited an outstanding performance for marketable yield under organic cultivation. Tomato pinworm (Tuta absoluta) was a serious limiting pest for organically grown tomatoes, responding for 17% of damage in the fruits harvested from the evaluated cultivars.

Diallel cross among fresh market tomato inbreeding lines

The general combining ability (GCA), specific combining ability (SCA), and heterosis were studied in a complete diallel cross among fresh market tomato breeding lines with reciprocal excluded. Fifteen genotypes (five parents and ten hybrids) were tested using a randomized complete block design, with three replications, and the experiments were conducted in Itatiba, Sao Paulo state, Brazil, in 2005/06. The yield components evaluated were fruit yield per plant (FP), fruit number per plant (FN), average fruit weight (FW); cluster number per plant (CN); fruit number per cluster (FC), fruit wall thickness (FT) and number of locules per fruit (NL). Fruit quality components evaluated were total soluble solids (SS); total titratable acidity (TA); SS/TA ratio, fruit length (FL); fruit width (WI); length to width ratio (FL/WI). The data for each trait was first subjected to analysis of variance. Griffings method 2, model 1 was employed to estimate the general (GCA) and specific (SCA) combining abilities. Parental and hybrid data for each trait were used to estimate of mid-parent heterosis. For plant fruit yield, IAC-2 was the best parental line with the highest GCA followed by IAC-4 and IAC-1 lines. The hybrids IAC-1 x IAC-2, IAC-1 x IAC-4 and IAC-2 x IAC-4 showed the highest effects of SCA. High heterotic responses were found for fruit yield and plant fruit number with values up to 49.72% and 47.19%, respectively. The best hybrids for fruit yield and plant fruit number were IAC-1 x IAC-2, IAC-1 x IAC-4 and IAC-2 x IAC-5, for fruit yield and plant fruit number, the main yield components.

Busca por Tomato yellow leaf curl virus e Tomato yellow leaf curl Sardinia virus em tomateiros

The disease caused by the virus complex of tomato yellow leaf curl (TYLC) is extremely severe in tomato plants, notably in Central America and Europe, and is caused by a complex of begomovirus species. The disease becomes predominant even in areas with the presence of other begomoviruses. In Brazil. the problems arisen from begomovirus infection are one of the major factors for damages and increasing the costs. The introduction of the TYLC complex implies in a great threat for growers. This study aimed to carry out detection tests based on PCR (polymerase chain reaction) and specific hybridization on suspected samples collected in the Sao Paulo State, Brazil. A total of 46 samples with symptoms resembling those caused by the TYLC complex were collected in Campinas county. All samples were negative for the detection of Tomato yellow leaf curl virus and Tomato yellow leaf curl Sardinia virus, the two most important virus from the TYLC complex. This result suggested that the two species have not yet been introduced in Brazil or that they are not widespread.

Correlations between yield and fruit quality characteristics of fresh market tomatoes

Genotypic, phenotypic and environmental correlations were estimated for all possible pairs among eleven characters of tomatoes. Fifteen treatments including five parents and ten hybrids of Instituto Agronomico (IAC) tomato breeding program were evaluated using a randomized complete block experimental design, with tree replications in Itatiba, Sao Paulo state, Brazil, during 2005/2006. The following traits were evaluated: fruit yield per plant (FP), fruit number per plant (FN), average fruit weight (FW), cluster number per plant (CN), fruit number per cluster (FC), number of locules per fruit (NL), fruit length (FL), fruit width (WI), fruit wall thickness (FT), total soluble solids (SS), and total titratable acidity (TA). The genotypic (rG), phenotypic (rF) and environmental correlations (rA) for two pairs of plant traits were estimated using the Genes© program. High similarity was found among the estimates of genotypic and phenotypic correlations. Positive and high phenotypic and genotypic correlations were observed between FP and the traits FN, FW and FT, and these associations contributed for yield increasing. FW and FT contributed to yield increase and should be considered together as primary yield components in tomato. Positive values of the genotypic and phenotypic correlations revealed that FP influenced FN with high direct effect and significant positive correlation. These traits may be included as the main selection criteria for tomato yield improvement.

Molecular characterization of potato cultivars using SSR markers

The potato crop has a very narrow genetic base, so the use of molecular markers is a very important tool in the characterization of germplasm banks and evaluation of genetic divergence. The objective of this study was to identify, using microsatellite or simple sequence repeat (SSR) markers, 38 accessions of potato from two collections of commercial cultivars. For the molecular characterization 10 loci were used, generating a total of 46 alleles, which were analyzed as binary data. A cluster analysis was performed with the Jaccard´s similarity coefficient and the UPGMA method, using the software NTSYSpc. On average, the number of alleles per locus was 4.6, ranging from two alleles for primers STM1049, STM 1053 and STM 1104 to 12 alleles per locus for primer STM0019a. Of the 46 alleles, only five were monomorphic, therefore presenting 89.1% polymorphism. The polymorphism information content (PIC) varied from 0.13 to 0.86, with an average of 0.54. The Jaccard´s coefficient varied from 0.41 to 0.93, showing high genetic variability among accessions. Two possible duplicates [Atlantic (Canada) and Atlantic (Chile), and Colorado and Agata (EPAMIG) (duplicates with these SSRs, which did not separate them)] were identified. High similarity was also shown by cultivars Chipie and Melodie (EPAMIG), Voyager and Gourmandine (EPAMIG), Eole and Caesar (EPAMIG), and Cupido and Sante (Pirassu). The most genetically divergent accessions (Lady Rosetta and HPC-7B) were also identified.

Desempenho de genótipos de coentro em Areia

Seven coriander genotypes were evaluated (lines HTV 9299, HTV 7299, HTV 0699, HTV 0999,HTV 0199 and cvs. Verdao and Palmeira), in Areia County, Paraiba State, Brazil, from May to July of 2003 in randomized blocks in four replications. Verdao (5,0 kg m-2) and Palmeira (4,3 kg m-2) cultivars and the lines HTV 9299 (4,4 kg m-2), HTV 7299 (4,5 kg m-2) and HTV 0999 (4,3 kg m-2), exhibited the greatest yield of green mass (GM), while the line HTV 0199, with 2.9 kg m-2 of GM, showed the lowest yield. Lines HTV 7299 (0.73) and HTV 0199 (0.81) presented the largest values for the ratio leaves:stalks. Verdao and Palmeira cultivars and lines HTV 7299, HTV 0999, HTV 0699 and 9299 persented 65; 58; 35; 29; 40 and 59%, respectively, of plant bolting (PB) at 42 days after sowing date, while Line HTV 0199 presented only 11%. Line HTV 7299 might be an alternative for coriander cropping in Areia.

Use of X-ray to evaluate damage caused by weevils in cowpea seeds

No Brasil, o feijao-caupi [Vigna unguiculata (L.) Walp], tem destaque na Regiao Nordeste, sendo uma cultura tipica da agricultura familiar. A importância dos danos causados por pragas de armazenamento em sementes da referida especie, em relacao a sua qualidade, tem sido evidenciada em varios trabalhos. Atraves de imagens de raios X e possivel visualizar as estruturas internas da semente, identificando possiveis alteracoes e danificacoes. Dessa forma, esse trabalho teve o objetivo de identificar os danos causados por caruncho (Callosobruchus maculatus) e sua relacao com a qualidade fisiologica das sementes de feijao-caupi, por intermedio da analise de raios X. Foram utilizadas tres cultivares (IPA-206, BRS-Pajeu e BRS-Potengi) e duas linhagens (L 281.005 e L ESP 10). As amostras foram submetidas ao teste de raios X e ao teste de germinacao, a fim de determinar a relacao de causa e efeito entre os danos provocados pelo caruncho e a germinacao das sementes. Nas avaliacoes das imagens de raios X foi considerada a severidade e a localizacao dos danos na semente. Para os danos classificados como severos, localizados no eixo embrionario e, ou nos cotiledones, as sementes originaram plântulas anormais ou as sementes estavam mortas. Portanto, o teste de raios X e eficiente para a avaliacao de danos causados por caruncho em sementes de feijao-caupi, permitindo relacionar os eventuais danos com os prejuizos causados a germinacao.