José Ricardo Peixoto

INFLUÊNCIA DE DIVERSOS SUBSTRATOS NO DESENVOLVIMENTO DE MUDAS DE MARACUJAZEIRO AZEDO (Passiflora edulis Sims f. flavicarpa DEG)

With the purpose of evaluating the influence of substrate on the development of yellow passion fruit, an experiment in a greenhouse at Embrapa Cerrados Station has been conducted. The experimental design was a randomized block in a factorial scheme 2 x 4 x 3 x 2, totalizing 48 treatments, 18 useful plants by plot and four replications. The treatments had consisted of combinations of: two commercial substrate (PlantmaxR ¾ to the base of VermiculiteR plus pines bark and VermiculiteR ¾ to the base of VermiculiteR); three organic sources ¾ f.o. (humus, cows manure and NutriplantaR (product base of bacteria) and absence of f.o., in the ratio of 3:1 of the basic substrate for f.o.; two formulated fertilizers [OsmocoteR as 14-14-14 (product of slow release of nutrients) and 4-14-8, of normal release], besides the absence of fertilizer and, absence and presence of Glomus etunicatum. The artificial substrate PlantmaxR was upper than the VermiculiteR in all the analyzed features. Among the f.o., the NutriplantaR with cows manure had provided the best performance. The OsmocoteR promoted the biggest development of seedlings, followed by 4-14-8. The presence of absence of f.o. matched with PlantmaxR practically did not influence the analyzed features. It must not use Glomus etunicatum associated the PlantmaxR, due to the high phosphorus content in this substrate.

Características físicas e químicas em nove genótipos de maracujá-azedo cultivado sob três níveis de adubação potássica

It was evaluated the effect of three levels of potassium fertilization on physical and chemical characteristics of fruits of nine genotypes of sour passion fruit (Passiflora edulis Sins. var. flavicarpa Deg.). The design used was based on randomized blocks in factorial scheme 9 x 3, being nine genotypes of passion fruit and three levels of potassium fertilization (0, 640, 1280 kg of K2O ha-1.year-1), summing to 27 treatments, with four replication. It was observed more influence of the potassium over physical characteristics of the sour passion fruit. The total yield was linear with application of potassium. There was a square effect in the doses of potassium over the fruit length, in the length/diameter ratio, in the peel thickness and in the mean number of seeds per fruit.

Reação a doenças e produtividade de um clone de maracujazeiro-azedo propagado por estaquia e enxertia em estacas herbáceas de Passiflora silvestre

Diseases induced by soil-borne pathogens cause expressive losses in passion fruit crops in Brazil. The use of resistant rootstocks could be an alternative to control these diseases. Passiflora nitida is one of the wild species of Passifloraceae, which have presented resistance to these diseases, but its utilization as seedling rootstock has been limited mainly due to differences of thickness between rootstock and the graft of the commercial cultivars. This problem can be solved by using grafting on rootstock of rooted-herbaceous cuttings and hypocotyledonary grafting, but data about the performance and yield of grafted passion fruit in field conditions are yet scarce in Brazil. The objective of this work was to evaluate the reaction to disease attack, yield and physical characteristics of fruits from a commercial passion fruit clone propagated by rooted cuttings, by grafting on rooted cuttings of a wild P. nitida (source EC-PN 1) and by seeds. The plants were cultivated in a red-yellow latosol with a drip irrigation system and oriented on a vertical espalier of 1,90 meters high. Harvest occurred weekly during 14 months and disease eva1uations were carried out at 17, 18 and 19 months after the planting. Plant yields from rooted cuttings were twice greater than those from grafted plants or seedlings. The plants propagated by grafting and rooted cuttings were lesser affected by diseases.

Características físico-químicas de cinco genótipos de maracujazeiro-azedo cultivados no Distrito Federal

The aim of this work was to evaluate the physical-chemical characteristics of five genotypes of passion fruit cultived in Brasilia in three seasons: February, March and April of 2005. The experiment wascarried out in the experimental area of the Agua Limpa Farm of the UnB, Brasilia-DF. It was used the delineation blocks with four repetitions, five genotypes, three evaluation periods and seven useful plants per share. The five genotypes were evaluated: Rubi Gigante, EC-3-0, EC-L-7, Redondao and Gigante Amarelo. The fruits produced on April/2005 present greater length, fresh fruit of mass, pulp, and juice, titrable acidity, pH and number of seeds. Genotype Rubi Gigante presents fruits with lesser length and highest soluble solids. Genotypes Redondao and Gigante Amarelo present fruits with lesser relation length/diameter. The genotypes Gigante Amarelo and Redondao consequently present fruits with a lesser thickness of the rind and the highest ovarian socket, with a highest amount of pulp. This last genotype also got fruits with the highest diameter, soluble solid and lower pH. This characteristic is important for processing; therefore fruits with high acidity present a reduction in the addition of acidifying in juice. The prolongated format predominated in the fruits of the five genotypes at the three analyzed periods.

Variabilidade genética de acessos obtidos de populações cultivadas e silvestres de maracujazeiro-doce com base em marcadores rapd

Sweet passion fruit (Passiflora alata Curtis) is gaining importance in the in natura fruit market due to differential value. Genetic breeding is crucial to improve crop quality and productivity. Molecular markers of DNA have been very useful by allowing obtaining a virtually unlimited number of genetic polymorphism without environment influence. This works objective was to study the genetic variability of 17 sweet passion fruit accesses, using RAPD molecular markers. One access of P. quadrangularis and another of P. edulis were used as outgroups. Genomic DNA samples of each one of them were extracted and 11 decamers primers (OPD 04, 07, 08 e16; OPE 18 and 20; OPF 01 and 14; OPG 08; OPH 12 and 16) were used to obtain the markers. The markers have been converted into a matrix of binary data, used as base to estimate genetic distances between accesses and to perform grouping and graphic dispersion analysis. From the total amount of markers, considering only P. alata accesses, it was observed 87 (62.12%) polymorphic bands, showing great intraspecific variability. Grouping analysis based on genetic distances allowed to subdivide 17 P. alata accesses in, at least, five groups of genetic similarity. The wild accesses contributed the most to the genetic basis expansion of the studied materials, opening good prospects for their use in breeding programs.

Análise da recuperação do genitor recorrente em maracujazeiro-azedo por meio de marcadores RAPD

Brazil is the largest world producer of passion fruit, however, it has been observed a reduction in the productivity in recent years due, mainly, to phytosanitary factors. At Embrapa Cerrados, the transfer of resistance genes from wild to commercial species of passion fruit has been made through interspecific hybridations, followed by a backcrossing molecular marker-assisted program. The objective this work was to verify the recovery of recurrent genome at the plants RC4 and RC5 [(Passiflora edulis x Passiflora setacea) x Passiflora edulis] based on RAPD markers. The study was developed at Embrapa Cerrados Laboratory of Genetics and Molecular Biology. DNA samples of each genetic material (17 RC4 plants, 16 RC5 plants, Passiflora edulis and Passiflora setacea) were amplified to obtain RAPD markers. There were used 12 decamer primers for plants RC4 and 14 decamer primers for plants RC5. The RAPD markers generated were converted into a matrix of binary data. There were a high percentage of polymorphic markers as a result of interspecific base crossing. The smallest genetic similarity was observed between species P. edulis and P. setacea, highlighting the large genetic distance of these commercial and wild varieties, respectively.

Cultivo de brócolos de inflorescência única no verão em plantio direto

The objective of this work was to evaluate single head broccoli cultivars production in summer under no-tillage (NT). The experimental design was randomized blocks with a split-plot design and three replicates. The plots were constituted by the cover crops: pearl millet (Pennisetum glaucum), corn (Zea mays), a mix of corn and black velvet-bean (Estilozobium aterrimum), sorghum sudangrass (Sorghum bicolor X S. sudanense), besides the conventional tillage (CT) - soil after fallow prepared with plow and disk harrow. Cultivars Avenger, Demoledor, Grandisimo, Green Storm Bonanza, Legacy and the material HECB-01-06, represented the sub-plots. No differences were found among NT and CT concerning broccoli yield. There were significant differences between cultivars for the evaluated variables. The cultivar Avenger presented the highest yield (13.2 t ha-1), average weight (458 g), diameter (15.3 cm) and quality of the curds (index for visual aspect of 4.0). Therefore, considering the benefits proportionated by NT, with the maintenance of high productive levels, equivalent at CT, its adoption is recommended.

Efeito dos substratos artificiais no enraizamento e no desenvolvimento de estacas de maracujazeiro-azedo (Passiflora edulis Sims f. flavicarpa Deg)

The experiments were carried out (August to November of 1999 and 200) under greenhouse conditions in Embrapa Cerrados, Planaltina-DF. In the first assay, passion fruits (Cv. Marilia-MSC) cuttings containing two internodes were immersed in IBA (indolbutiric acid) solution at 2000 ppm for 10 seconds and planted in expanded polystyrene trays, with 72 units containing eight organic substrates. The evaluation was made 90 days after planting, by determining the percentage of rooted and budded cuttings and the incidence (% of died cuttings) of Colletotrichum gloeosporioides. The Plantmax Florestal EstacaO exhibited higher level of budding and rooting and lower incidence of C. gloeosporioides compared to the substrate Plantmax HortalicasO. The NutriplantaO combined with OsmocoteO was more efficient than the Plantmax Florestal EstacaO. In the second assay, the cuttings of hybrid RC1 ((F1: Marilia X Roxo Australiano) x Marilia) were collected in August 2000 and treated with 2000 ppm of IBA. The organic substrates used were twelve. The results indicated that the rooting level of RC1 cutting was similar for all substrates. The addition of 1g of Osinocote per cutting, 30 days after they were planted in substrate plantmax florestal estaca, prorrided the better development to aerial portion for the RC1 hybrid.

Microenxertia ex vitro para eliminação do vírus CABMV em maracujá-azedo

O objetivo deste trabalho foi avaliar diferentes meios de cultura, utilizados sobre o ponto da enxertia, na microenxertia ex vitro para a eliminacao do Cowpea aphid-borne mosaic virus (CABMV), em plantas de maracuja-azedo (Passiflora edulis Sims f. flavicarpa Deg.). Apices caulinares, provenientes de plantas infectadas, foram microenxertados em plântulas obtidas pela germinacao de sementes em substrato comercial esterilizado. Foram conduzidos experimentos com a microenxertia realizada no hipocotilo e no epicotilo, e foram utilizados cinco meios de cultura, que diferiam na concentracao de fitorreguladores, aplicados no local da enxertia. O indice medio de microenxertos com folha expandida foi de 27,22 e 32,22%, quando a microenxertia foi realizada no hipocotilo e no epicotilo, respectivamente. Na microenxertia realizada no hipocotilo, nao houve efeito da aplicacao de meios de cultura. Na microenxertia realizada no epicotilo, o meio MS acrescido de 0,1 mg L-1 de AIB e 1 mg L-1 de BAP proporcionou 53,3% de microenxertos com folha expandida, numero superior aos demais tratamentos e maior desenvolvimento das brotacoes. A indexacao realizada pelo teste ELISA indireto, 80 a 100 dias apos a microenxertia, mostrou que 93% das plantas testadas nao apresentavam virus detectavel.

Seleção de clones de batata-doce resistentes a insetos de solo

O objetivo deste trabalho foi selecionar clones comerciais de batata-doce para a regiao do Triângulo Mineiro. Dos clones avaliados, 60 foram obtidos por policruzamentos e cedidos pela Universidade Federal de Lavras (UFLA), tres, entre produtores rurais dos municipios de Araguari, Uberlândia e Machado, todos do Estado de Minas Gerais, e outros nove foram usados como testemunhas (Brazlândia Branca, Brazlândia Rosada, Surpresa, Rio Doce, Morena Roxa, Coquinho, Arroba, Pira 1 e o Clone 042). O experimento foi instalado no espacamento de 1,10 x 0,45 m, utilizando-se o delineamento blocos casualizados, com 72 tratamentos, quatro repeticoes e 16 plantas por parcela. Entre os clones avaliados 32,8% apresentaram alta ou moderada resistencia a insetos de solo. O clone 95041 foi o mais produtivo, com 28.048,96 kg/ha. Os clones 95009, 95010, 95014, 95020, 95033, 95042 e 95057 foram altamente resistentes a insetos de solo.