Ranulfo Correa Caldas

Produtividade e qualidade de maracujá-amarelo irrigado, adubado com nitrogênio e potássio

Passion fruit is an outstanding tropical fruit and the north region of Minas Gerais State seems suitable for growing it. A study on nitrogen (N) and potassium (K) levels for maximum physical and economic production was carried out in Quartzarenic Neosol of that region aiming to obtain high yields and superior fruit quality of yellow passion fruits. The experiment was implanted in March 1996, with plants spaced 3.5 m x 5.0 m, and irrigated by microsprinkler. The experimental design was a factorial randomized block with five levels of N (0, 100, 200, 400, and 800 kg/ha/year) and K2O (0, 200, 400, 800, and 1600 kg/ha/year), with four replications. From November/1996 to October/1997 it was observed a negative nitrogen effect on fruit number for the fresh fruit market, but no significant effects on fruit quality. On the other hand, potassium had a positive effect on fruit weight and diameter, but a negative one on yield, mainly for doses of 400 kg of N/ha, and no significant one on fruit quality. Considering yield, it is recommended 100 kg of N and 200 kg of K2O/ha/year, for experiment conditions.

Germinação e crescimento de espécies de maracujá

This work aimed to verify the germination and speed of emergence index of passion fruit species to obtain plants suitable for grafting. The experiment was carried out in a greenhouse at Embrapa Cassava and Tropical Fruits, in Cruz das Almas, BA from January to June, 2002. It was used a completely randomized design and the treatments were constituted of five passion fruit species: Passiflora edulis Sims f. flavicarpa Deg., Passiflora edulis Sims, Passiflora giberti N.E. Brown, Passiflora laurifolia L. and Passiflora alata Curtis, with four replications. The species constitute five different groups for the variable, speed of emergence index and, concerning to the germination, two different groups, one formed by the species P. giberti and P. laurifolia and the other by the species P. edulis Sims f. flavicarpa, P. edulis Sims and P. alata. Regarding to plant height, the species P. giberti had the highest average, 40,40 cm, constituting a group that is different from the others. The species P. edulis and P. edulis f. flavicarpa presented better speed of emergence index and germination, consequently the plants obtained were ready for grafting in a shorter period of time.

Doses e fontes de nitrogênio em fertirrigação no cultivo do maracujá-amarelo

Passion fruit yield is influenced by several production factors, among them the climate, the soil and the manuring and irrigation practices. Nitrogen (N) is the most absorbed nutrient by the passion-fruit plant and has structural functions in the plant, and it can be supplied by nitric, ammoniacal and starchy sources. The experiment objective was to evaluate nitrogen sources and doses applied in fertirrigation of passion-fruit (Passiflora edulis Sims f. flavicarpa Deg.) production and fruit quality in 17 months of production in a Coastal Tableland Yellow Latosol in Bahia State, Brazil. It was studied, in randomized blocks with split-plots, two sources of N (urea and calcium nitrate), on the plots, and five N doses (0, 100, 200, 400 and 800 kg ha-1), on the split-plots with three replicas. The yellow passion-fruit was planted in a spacing of 3.00 x 1.25 m, in a total area of 1,237.50 m2, and evaluated from january 2000 to january 2002. The results showed maximum yield of 34 ton ha-1, applying 457 kg of N ha-1, in urea form. Nitrogen fertilizer and sources did not interfer in the fruit characteristics and juice quality.

Influência da salinidade sobre o crescimento, absorção e distribuição de sódio, cloro e macronutrientes em plântulas de maracujazeiro-amarelo

The presence of sodium (Na) and chloride (Cl) in growth medium have leaded to crop growth due to because of negative effects of these ions such as changes in plant capacity of uptake, transport and use of essential nutrients. The objective of this work was to evaluate the influence of salinity on growth, uptake and transport of Na, Cl and macronutrients in yellow passion fruit plants. Three levels of NaCl (0, 50 and 100 m mol L-1) were tested. Experiment was finished after 50 days of growing in 2.2 dm3 pots. It was noticed that height, leaf number, leaf area and dry mass of all parts of the plant were reduced by salinity. The concentration of Na and Cl ions increased with the increasing of salinity. However, ions were retained partially in roots (Cl) and in older leaves (Na). Concentration of nitrogen (N), phosphorous (P) and calcium (Ca) were not affected by salinity. Actually, concentration of potassium (K) was reduced in all parts of the plant while sulfur (S) was reduced only in roots. Based upon the short reduction on growth characteristics, it was concluded thatyellow passion fruit crop has a moderated tolerance to saline stress.

Efeito de doses de NPK sobre os teores de nutrientes nas folhas e no solo, e na produtividade do maracujazeiro amarelo

This work evaluated the effect of nitrogen, phosphorus and potassium fertilization on nutrient levels in the leaves of yellow passion fruit (Passiflora edulis f. flavicarpa Deg.) and on the chemical properties of the soil, in order to maximize yield and optimize fertilizer applications. The experiment was carried out from May/96 to April/98, on a Yellow Latosol, in Cruz das Almas city, State of Bahia, Brazil. It was used a randomized block design, in a fractionated factorial arrangement ½ of 43, with two incompleted blocks. It was evaluated four doses of N (0, 100, 200 and 300 kg ha-1 year-1), of P2O5 (0, 80, 160 and 240 kg ha-1 year-1) and K2O (100, 300, 500 and 700 kg ha-1 year-1). Soil samples and leaves were collected at 12 and 24 months after planting. Yield was evaluated in the first and second production years. Nitrogen fertilization did not affect the N level in the leaves but decreased boron and reduced the soil pH during the second production year. Phosphorus fertilization increased, in average, only 12% of the P levels in the leaves, and 35 times in soil. Potassium fertilization increased nutrient contents in leaves and in soil over the optimum level. Maximum yield of 22 t ha-1, during two years, was obtained with application of 244 kg of N, 72 kg of P2O5 and 285 kg of K2O ha-1.

Teores foliares de nutrientes em genótipos de bananeira

The leaf diagnosis is quite useful for the determination of the nutritional state of plants. The nutritional banana tree demands can differ in accordance with genetic characteristics. The aim of present work was to determinate the macro and micronutrients contents in the third leaf of banana genotypes. Twenty four banana genotypes were selected (triploids and tetraploids), in two production cycles (1999 and 2000), in the Active Germoplasm Bank of Banana at Embrapa Mandioca e Fruticultura Tropical, in Cruz das Almas, Bahia, Brazil. The leaf contents of macronutrients (N, P, K, Ca, Mg and S) and micronutrients (B, Cl, Cu, Fe, Mn and Zn) were determined. The results showed that occurred variation in leaf contents among plants in the same genome group and between the first and second production cycles, with higher medium levels in the second cycle for N, P, Ca, Mg, S, Cu and Mn and lower ones for K, Cl, B, Fe and Zn. The nitrogen contents 21.6 to 28.5 g kg-1 and K 13.7 to 30.8 g kg-1 and they were the macronutrients with the highest contents in the leaves. The chlorine contents was 10.4 to 24.7 g kg-1, manganese 43 to 574 mg kg-1 and iron 56 to 212 mg kg-1,and they were the micronutrients with the highest contents in leaves.

Teores de nutrientes nas folhas de bananeira, cv. Pacovan, sob irrigação

Por meio da analise quimica dos nutrientes na folha, e possivel avaliar o estado nutricional da planta, em que os resultados obtidos sao comparados a padroes que se baseiam na correlacao entre a concentracao do nutriente nas folhas e o desenvolvimento ou producao da cultura. Objetivou-se definir os teores padroes de macro e micronutrientes nas folhas de bananeiras cv. Pacovan sob irrigacao, no polo Petrolina-PE/Juazeiro-BA. Nos bananais selecionados, foram marcadas 20 bananeiras e amostradas as folhas na epoca do florescimento, para analise quimica, e anotado o peso dos cachos de dois ciclos de producao subsequentes. Realizou-se a analise estatistica descritiva, com os dados de plantas com pesos de cachos em quatro estratos ( 10 e 15 e 20 kg), considerando os cachos superiores a 20 kg como em condicoes ideais de nutricao. As faixas dos teores padroes definidas para cv. Pacovan, sob irrigacao, no Distrito de Irrigacao Senador Nilo Coelho, em Petrolina-PE, foram: 22-24 g de N/kg; 1,7-1,9 g de P/kg; 25-28 g de K/kg; 6,3-7,3 g de Ca/kg; 3,13,5 g de Mg/kg; 1,7-1,9 g de S/kg; 13-16 mg de B/kg; 6-7 mg de Cu/kg; 71-86 mg de Fe/kg; 315-398 mg de Mn/kg; e 12-14 mg de Zn/kg.

Beauveria bassiana Strains for Biological Control of Cosmopolites sordidus (Germ.) (Coleoptera: Curculionidae) in Plantain

The objective of this study was to select strains of Beauveria bassiana for controlling Cosmopolites sordidus (Germ.) in plantain farms (cv. Terra) of the “Recôncavo” and southern regions in the state of Bahia, Brazil. The virulence of 32 B. bassiana isolates against C. sordidus was determined under laboratory conditions. Three isolates (CNPMF 407, CNPMF 218, and CNPMF 416) were selected for evaluation under field conditions in plantations located in the counties of Mutuípe and Wenceslau Guimarães. Population of C. sordidus was estimated every 15 days by using pseudostem traps. The efficiency of the three strains of B. bassiana was compared to chemical control (carbofuran, 4g/trap) and absence of control. Carbofuran caused around 90% of adult mortality after 12 months, with a reduction in the population of C. sordidus since the first evaluation. A low number of trapped insects was observed in the fungus-treated plots, suggesting the efficiency of the isolates in controlling the C. sordidus population. The strain CNPMF 218 was the most efficient in controlling C. sordidus adults in both locations, causing around 20% mortality, leading to 40% population size reduction after 12 months.

Fitonematoides associados a bananais 'Pacovan' sob condição de cultivo irrigado: relação com a produção

Among the factors that affect the productivity of banana, stand out pests, diseases and inadequate cultural practices. In this context, plant parasitic nematodes have great importance for reducing the efficiency of water and soil nutrients absorption by the roots, causing the plants to fall down near harvest. About 146 nematode species have already been reported associated to banana roots. Nevertheless, only Radopholus similis, several species of the genus Meloidogyne, Helicotylenchus, Pratylenchus and Rotylenchulus cause significant losses in banana plantations. In plantations located in irrigated areas in the municipal districts of Petrolina/PE and Juazeiro/BA, questionnaires were applied to obtain information about the history of the area, including plant nutrition, fertility, cultural practices, incidence of pests and post-harvesting practices. It was observed that 90% of the area belonged to small farmers. The major problems pointed out were: inadequate management, including harvesting and post-harvesting practices, presence of nematodes and strong winds. In this research a survey of the occurrence of plant parasitic nematodes was carried out. Thus, this research aimed to identify the genera of the plant parasitic nematodes found, and to study the relationship between the banana production in the several selected areas with the population of plant parasitic nematodes in the soil and in the banana root system. In each selected area, 20 banana plants were marked and samples of soil and roots were taken. Each sample was composed of four samples of each plant to represent the population of nematodes. The genera of the most abundant nematodes were Helicotylenchus, Meloidogyne and Rotylenchulus. Nevertheless, the production was neither related to the number of farms in each location, nor with the plant parasitic nematode density (Helicotylenchus sp., Meloidogyne sp., Rotylenchulus sp., Pratylenchus sp. and Radopholus similis) associated with the soil or banana roots. It could be inferred that the cultural practices adopted in each location of irrigated banana production had a positive influence on the banana production (weight of bunches) under different plant parasitic nematode populations.

Leguminosas e seus efeitos sobre propriedades físicas do solo e produtividade do mamoeiro 'Tainung 1'

An experiment was carried out at the Agronomy School of Federal University of Bahia, Brazil, Cruz das Almas, during the period of June 1998 to December 2000, with the objective of evaluating the impact of good management practices on soil physical properties of an alic and cohesive yellow Latosol and the productivity of papaya. The treatments were: 1. manual weeding with hoe in total area; 2. harrowing in the interrows and herbicide in the rows; 3. manual weeding with hoe in total area + subsoiling ; 4. subsoiling + jack bean (Canavalia ensiformis) in the rows; 5. subsoiling + Crotalaria juncea in the rows; 6. subsoiling + cowpea (Vigna unguiculata) in the rows; 7. subsoiling + liming + gipsum and jack bean in the rows; 8. subsoiling + spontaneous vegetation in the rows, cutting when necessary. The statistical design was randomized blocks with three replications. Experimental plots contained 36 plants, of which 16 useful, in spacing 3 x 2 m. The treatments with subsoiling was performed in the experimental area in a crossed way before the planting. Leguminous plants were sowed in May/June and mowed in September/October. The weed control in rows was mechanical (T1 and T3) and chemical with glyphosate at dosages of 1% (v/v) in the other treatments. The treatments with management of leguminous plants in the papaya interrows provided the greatest benefits in the soil physical properties. Treatments with leguminous plants and spontaneous vegetation produced significantly higher fruit yields , expressed in total fruit weight (ton per hectare) and showed the highest number of fruit per hectare.