Rita de Cássia Souza Dias

Avaliação de cultivares de cebola em Petrolina-PE

With the objective of identifying high productive and better quality onion cultivars for the tropical semi-arid region of Brazil, field trials were conducted at Petrolina, Pernambuco State, Brazil, from February until July of 1996.The experimental design was a randomized complete blocks with four repetitions and twenty treatments (Cultivars Granex-429, Texas Grano-PRR, Brownsville, Houston, Texas Grano-502, Texas Grano-438, Conquista, Composto IPA-6, Belem IPA-9, Franciscana IPA-10, Valeouro IPA-11, Alfa Tropical (CNPH-6179), CNPH-5898, CNPH-6074, CNPH-6040, CNPH-6067, Bola P. Empasc, XP-1, XP-2 and Crioula Mercosul). Production of commercial bulbs ranged forms 21.41 to 61.78 ton/ha. Texas Grano-PRR had the highest yield (61.78 ton/ha), followed by Granex-429 (58.28 ton/ha), Texas Grano-438 (56.97 ton/ha), Brownsville (55.38 ton/ha), Texas Grano-502 (53.97 ton/ha) and Houston (53.35 ton/ha).

Mudas de melancia produzidas com substrato à base de pó de coco e soluções nutritivas

The choice of substrate is one of the most important stages for the seedlings production and must take into account the nutritional requirements of cultivated species. Thus, the objective was to evaluate the substrate using coconut dust associated with nutrient solutions to produce seedlings of watermelon. The experiment was carried out at Embrapa Semi-Arid in Petrolina, Pernambuco state, Brazil, in a greenhouse in a completely randomized design with ten replications in a factorial arrangement 2 x 10 (cultivars of watermelon and substrates). The cultivars used were: Opara and Top Gun. The coconut fiber was associated with nutrient solutions as follows: T1= control treatment composed of the commercial organic substrate Plantmax® (SC), T2= coconut powder (PC), T3= coconut powder + melon solution (PC+SM), T4= coconut powder + solution of Hoagland and Arnon 12.5% (12.5% PC+HS), T5= coconut powder + solution of Hoagland and Arnon 25% (PC+HS 25%), T6= coconut powder + solution of Hoagland and Arnon 50% (PC+HS 50%), T7= coconut powder + solution of Hoagland and Arnon 75% (PC+HS 75%), T8= coconut powder + solution of Hoagland and Arnon 100% (100% PC+HS), T9= coconut powder + Aminoagro Mol (PC+AM), T10= coconut powder Aminoagro Root (PC+AR). The solutions were applied eight times, 10 mL on each application, since the fourth day after sowing date (DAS), when the evaluation of seedlings emergence began. At 24 DAS we evaluated the fresh weight of shoots and roots, root length, number of roots in the upper third and contents of macro and micronutrients in the aboveground part. The cv. Top Gun presented higher levels of nutrients, except for iron and copper. The treatments T6, T7 and T8 presented levels of nutrients in plants similar to the commercial substrate Plantmax. In general, the combinations of coconut dust associated with the nutrient solution of Hoagland and Arnon at 50, 75 and 100% and Aminoagro Root proved to be promising for the formation of watermelon seedlings on the growth and nutritional status.

Cultivo de melão orgânico: fosfatos naturais como fontes alternativas de fósforo

Aiming to evaluate the efficiency of natural phosphates in melon organic cropping under irrigation, two experiments were carried out in Petrolina-PE, one in a Yellow Argisol (PA) and other in a Grey Argisol (PAC). The evaluated treatments were: 1 - without P, 2 - 50 kg ha-1 of P2O5 as triple super phosphate (TS), 3 - 100 kg ha-1 of P2O5 as TS, 4 - 150 kg ha-1 of P2O5 as TS, 5 - 100 kg ha-1 of P2O5 as thermo phosphate, 6 - 100 kg ha-1 of P2O5 as natural phosphate of Gafsa and 7 - 100 kg ha-1 of P2O5 as natural phosphate Fosbahia. The melon crop showed similar responses to the P application in both soils, whose maximum productivities of 26.00 t ha-1 and 25.46 t ha-1 were obtained with 107.6 kg ha-1 and 118.6 kg ha-1 of P2O5 in PA and PAC, respectively. The efficiency of thermo phosphate, phosphate of Gafsa and Fosbahia in relation to TS assumed the sequence of 86.2%, 77.1% and 71.9% in PA and 101.5%, 72.3% and 67.3% in PAC. These results suggest that thermo phosphate is the most appropriated phosphate source to be used in the melon organic cropping. It is necessary 843.12 kg of thermo phosphate to produce 25 t ha-1 of melon fruit that represent 3.4% of the production cost.

Desempenho de genótipos de melancia de frutos pequenos em diversas densidades de plantio

O experimento foi realizado em campo da UNEB, Juazeiro (BA). Foram avaliados tres espacamentos combinados com dez genotipos de melancia diploides, sendo oito hibridos experimentais, provenientes do Programa de Melhoramento Vegetal da Embrapa Semiarido e duas cultivares comerciais (Sugar Baby e Smile), quanto ao desempenho agronomico e qualidade de frutos. Os hibridos experimentais Hib 02, Hib 03, Hib 04, Hib 05 e Hib 07 apresentaram as melhores taxas de emergencia sendo que os hibridos 02, 03 e 06 estiveram entre os melhores para altura e diâmetro do colo das plantas aos 21 dias e para massa fresca da parte aerea no final do ciclo. Os espacamentos utilizados nao afetaram o desenvolvimento das plantas de melancia, como tambem nao afetaram a qualidade fisiologica dos frutos dos genotipos avaliados. De maneira geral, nao foram observadas diferencas com relacao a qualidade dos frutos entre os hibridos e as cultivares, mostrando-se dessa forma bastante promissores para o seu futuro lancamento no mercado.

Phenotypic variability among pumpkin accessions in the Brazilian semiarid

The aim of this study was to estimate the phenotypic divergence among fourteen pumpkins accessions of the cucurbits Germplasm Active Bank of Embrapa Semiarido, in order to support breeding program to these species. Nine morphoagronomic descriptors were analyzed by the principal components and by UPGMA techniques. In the analysis of principal components, the formation of three contrasting clusters was observed, each one composed of two accessions. There occurred also the formation of one core group composed of five accessions, being the accessions called 683 and 684 collected in Bahia and the other in Maranhao. The most divergent accessions were 620, 624 and 748. The variables of the greatest contribution to the genetic divergence were diameter, weight and average length of the fruit. In the UPGMA analysis, obtained from the symmetric matrices generated by the Mahalanobis distance for the nine descriptors, there was the formation of one core group, composed of ten accessions, whose similarity was 45.71%, with geographically divergent accessions presenting the greatest similarity. Three accessions were not clustered with others. The study identified phenotypic variability for the analyzed characters and the absence of relationship between place of collection and phenotypic diversity.

Sources of Resistance in Accesses of Cucurbita spp. to Virus Species from the Genus Potyvirus

The identification of source of resistance in cultivated cucurbits species is very important for the development of resistant cultivars to control diseases caused by virus from the genus Potyvirus. The present research had the objective to evaluate the phenotypic reactions and the behavior of pumpkin (Cucurbita spp.) accessions to the virus species from the genus Potyvirus: Papaya ringspot virus type Watermelon (PRSV-W), Zucchini yellow mosaic virus (ZYMV) and Watermelon mosaic virus (WMV). Twenty-eight accessions of pumpkin from the Cucurbit Germplasm Bank from Embrapa Semiarido, Petrolina, PE, Brazil were evaluated. Twelve young plants from each pumpkin accession were inoculated with each one of the virus species and were maintained at greenhouse for their symptom reaction evaluations. All possible virus infections or absence of infection were confirmed by plate-trapped antigen enzyme linked immunosorbent assay (PTA-ELISA) against antisera specific to PRSV-W, ZYMV and WMV at the Plant Virus Laboratory, Universidade Federal do Ceara. Three pumpkin accessions showed extreme resistant to WMV and eight accessions presented mild mosaic when inoculated with PRSV-W. The most severe symptoms were observed on those accessions inoculated with ZYMV and 50% of the accessions showed to be highly susceptible. On the other hand, the pumpkin accessions inoculated with WMV presented the mildest symptoms, indicating that 39% of them were resistant, and 39% were tolerant. The Cucurbita spp. accessions BGC 518, BGC 530, BGC 567, and BGC 683 that showed resistance to one or more than one virus species constitute promising sources of resistance for developing virus resistant pumpkin cultivars or hybrids.

Evaluation of onion cultivars at Petrolina, Pernambuco State, Brazil

With the objective of identifying high productive and better quality onion cultivars for the tropical semi-arid region of Brazil, field trials were conducted at Petrolina, Pernambuco State, Brazil, from February until July of 1996.The experimental design was a randomized complete blocks with four repetitions and twenty treatments (Cultivars Granex-429, Texas Grano-PRR, Brownsville, Houston, Texas Grano-502, Texas Grano-438, Conquista, Composto IPA-6, Belem IPA-9, Franciscana IPA-10, Valeouro IPA-11, Alfa Tropical (CNPH-6179), CNPH-5898, CNPH-6074, CNPH-6040, CNPH-6067, Bola P. Empasc, XP-1, XP-2 and Crioula Mercosul). Production of commercial bulbs ranged forms 21.41 to 61.78 ton/ha. Texas Grano-PRR had the highest yield (61.78 ton/ha), followed by Granex-429 (58.28 ton/ha), Texas Grano-438 (56.97 ton/ha), Brownsville (55.38 ton/ha), Texas Grano-502 (53.97 ton/ha) and Houston (53.35 ton/ha).