Saline water irrigation strategies and potassium fertilization on physiology and fruit production of yellow passion fruit

ABSTRACT The objective of this study was to evaluate the effects of saline water irrigation management strategies and potassium doses on the concentration of photosynthetic pigments, gas exchange, and fruit production of ‘BRS GA1’ yellow passion fruit. The experiment was carried out under field conditions using a randomized block design, with treatments based on a 6 × 2 factorial scheme, related to six management strategies for irrigation with saline water (irrigation with low-salinity water throughout the crop cycle-WS; irrigation with high-salinity water in the vegetative stage-VE; flowering stage-FL; fruiting stage-FR; and successively in vegetative/flowering stages-VE/FL and vegetative/fruiting stages-VE/FR) and two doses of potassium (60 and 100% of the recommendation), with four replicates. The dose of 100% recommendation corresponded to 345 g of K2O plant-1 year-1. High electrical conductivity irrigation water (4.0 dS m-1) was used in different phenological stages according to treatment, alternating with water of low electrical conductivity (1.3 dS m-1). The synthesis of chlorophyll a and b, stomatal conductance, instantaneous carboxylation efficiency and water use efficiency of ‘BRS GA1’ yellow passion fruit were reduced under irrigation with water of 4.0 dS m-1 in all strategies adopted. Fertilization with 60% of the K recommendation promoted greater number of fruits and yellow passion fruit yield. Irrigation with 4.0 dS m-1 water in the vegetative/flowering and flowering stages reduced the yield of yellow passion fruit.

Optimization of pigment production by Rhodotorula minuta URM 5197 and Rhodotorula mucilaginosa URM 7409 using yellow passion fruit peel (Passiflora edulis)

The objective of this work was to optimize the production of pigments by Rhodotorula minuta and Rhodotorula mucilaginosa through submerged fermentation, using yellow passion fruit peel (Passiflora edulis), as the only substrate. The independent variables evaluated to optimize were: yellow passion fruit peel (YPFP), in grams (g) as culture medium, pH and fermentation time, in days. The study of pigment production and its optimization was carried out using the Doehlert matrix, with fifteen experimental conditions, of which thirteen had different combinations and two repeated the central point. The fixed variables were 30ºC and 150 rpm. Data analysis was performed using the Statistica software version 10.0. The largest amount of total pigments and total carotenoids produced by R. minuta was 28±0.01 mg/L and 72.8±0.026 µg/g, respectively; while for R. mucilaginosa the production of total pigments was 37±0.002 mg/L and total carotenoids 236.8±0.013 µg/g. The optimum production point of total pigments for R. minuta was 2.3g of YPFP, pH 6.5 and 5 days and for R. mucilaginosa 2.5g of YPFP pH 6 and 5 days. In samples of total pigments, the presence of 0.29mg/L of β-carotene for R. minuta and 0.83 mg/L for R. mucilaginosa was identified. It is possible to conclude that yellow passion fruit peel can be used as a nutrient source for Rhodotorula spp growth and pigment production with total carotenoids and β-carotene in its composition.

Atividade biológica em solos cultivados com maracujazeiro amarelo adubados com composto orgânico / Biological activity in soils cultivated with yellow passion fruit fertilized with organic compost

O objetivo deste trabalho foi avaliar o efeito da adubação orgânica de fundação em cultivo de maracujazeiro sobre a atividade biológica no solo. Os experimentos foram conduzidos em Rio Branco, AC, em um ARGISSOLO VERMELHO AMARELO Alítico plíntico, textura franca arenosa e em Porto Acre, AC, em ARGISSOLO VERMELHO AMARELO distrófico plíntico de textura franco argilosa. O delineamento experimental utilizado foi o de blocos casualizados com 5 tratamentos e 4 blocos e quatro amostras, totalizando 20 parcelas experimentais. Os tratamentos foram constituídos por covas cilíndricas com 0,15 m de profundidade e 2,0 m de diâmetro, aplicados 1/3 v/v de composto em diâmetros de 0,4 m; 0,8 m; 1,2 m; 1,6 m e 2,0 m, constituindo os diferentes tratamentos, com seus respectivos volumes: 0,007; 0,03; 0,06; 0,10; 0,16 m³, com amostragem realizadas a 0,5; 1,0 e 1,5 m do colo da planta. Foram avaliadas as características biológicas: respiração edáfica, respiração basal, biomassa microbiana e quociente metabólico. Foi verificado que em solos de textura franco arenosa sob oito anos de cultivo orgânico, o aumento da área adubada com composto orgânico não aumenta a atividade biológica do solo. Em solos de textura franco argilosa a atividade basal é maior com o aumento da adubação orgânica e a atividade microbiana maior com o distanciamento do colo da planta.

GAS EXCHANGE AND PRODUCTION OF PASSION FRUIT AS AFFECTED BY CATIONIC NATURE OF IRRIGATION WATER1

ABSTRACT Yellow passion fruit is a fruit species widely cultivated throughout the Brazilian semi-arid territory, but its yield is affected by the quality of the waters of this region. In this context, the objective was to evaluate the gas exchange and production of passion fruit cv. BRS Rubi do Cerrado irrigated with waters of different cationic natures. The study was conducted in drainage lysimeters under greenhouse conditions in Campina Grande, PB, Brazil, in a randomized block design, and the treatments were eight cationic natures of irrigation water (S1 - Control; S2 - Na+; S3 - Ca2+; S4 - Mg2+; S5 - Na+ + Ca2+; S6 - Na+ + Mg2+; S7 - Ca2+ + Mg2+ and S8 - Na+ + Ca2+ + Mg2+) with three replicates. Plants in the control treatment were irrigated with water of low electrical conductivity (ECw = 0.4 dS m-1), while those of the other treatments were irrigated using water with ECw of 3.5 dS m-1. The treatments Na+ + Ca2+, Na+ + Mg2+ and Ca2+ + Mg2+ were prepared in the equivalent ratio of 1:1, and Na++Ca2++Mg2+ in the ratio 7:2:1, respectively. Water salinity of 3.5 dS m-1 reduced gas exchange, and stomatal conductance and transpiration were the most sensitive variables of passion fruit. The number of fruits of passion fruit cv. BRS Rubi do Cerrado decreased with water salinity, regardless of the cationic nature. The waters of calcic and calcic+magnesian nature caused the greatest deleterious effects on the production variables of passion fruit, at 259 days after transplanting.

Avaliação de mudas de maracujazeiro com diferentes tipos de substratos e concentrações salinas

The yellow passion fruit (Passiflora edulis f. flavicarpa Degener) crops have been gaining notoriety in Brazil, whose cultivation extends to almost all regions. The aim of this study was to evaluate the growth of yellow passion fruit seedlings in response to the interaction between substrate composition and irrigation water salinity levels. The experimental trial was installed in a randomized block design, with a factorial scheme (3x6) consisting of two factors: three levels of salinity and six types of substrates, distributed in four replications, each plot consisting of a polyethylene bag composed of two plants. The factor levels of salinity, electrical conductivity: 0.3, 1.2 and 2.1 dSm-1 did not influence the physiological growth and development of the seedlings, the substrates resulted in statistically significant effects, the cattle manure presented the highest percentage in levels of physiological growth and development of the plant.

Fruit quality of wild, sweet and yellow passion fruit genotypes in Distrito Federal, Brazil

Despite the importance of passion fruit for the Brazilian fruit market, there are still many agronomic and fruit quality problems to be solved, in order to increase this crop performance. The objective of this study was to evaluate the quality of twelve genotypes of wild, sweet and yellow passion fruit, aiming to identify promising materials considering fruit quality, in Federal District, Brazil. An experiment was carried out at the Água Limpa Farm of the Universidade de Brasília (UnB) from 2016 to 2018, in a randomized block design, with 12 treatments, 4 replicates and 6 plants/plot. At the harvesting time, six fruits per plot were randomly collected for the following physicochemical analysis: fruit mass, pulp mass with and without seeds, length/longitudinal diameter, width/transverse diameter, length/width ratio, husk thickness, predominant color of the pulp (L*, C*, h*), number of seeds, seed size, total soluble solids content, total titratable acidity, total soluble solids/total titratable acidity ratio and pH. High heritability values ​​and relation of genetic/environment variation coefficients ratio were observed for most of the characteristics evaluated. The genotypes of yellow passion fruit MAR20#21 P2 x FB 200 P1 R2 and MAR20#19 ROXO R4 x ECRAM P3 R3 showed the best characteristics of fruit mass and pulp mass with seed. All the genotypes studied showed values ​​of total soluble solids above 11ºBrix. Positive and significant correlation was observed between fruit mass and length/width ratio, indicating that oblong fruits have higher fruit mass.

Análise econômica da produção de maracujazeiro amarelo orgânico irrigado e em plantio profundo no sudoeste amazônico / Economic analysis of production of irrigated organic yellow passion fruit in southeast amazon

O objetivo deste trabalho foi avaliar a viabilidade econômica do plantio profundo de mudas altas de maracujazeiro amarelo em sistema de cultivo orgânico e irrigado. O delineamento utilizado foi em blocos casualizados com parcelas subdivididas 2x4, com 4 blocos, sendo as parcelas os cultivos irrigado e sequeiro e as subparcelas as 4 profundidades de plantio (0,20 m; 0,40 m; 0,60 m e 0,80 m). Antes do plantio, foi aplicado AIB na concentração de 4.000 mg kg-1 no caule das mudas de plantio profundo. Foram avaliados: produção de cobertura operacional e total, custo fixo médio, custo variável médio, custo total médio, relação benefício custo, lucratividade, índice de rentabilidade, remuneração da mão de obra familiar, receita líquida e receita total. O plantio do maracujazeiro amarelo com utilização da irrigação aumenta o custo de produção, mas proporciona rendimentos econômicos positivos. O plantio em sequeiro é mais lucrativo, devido ao menor dispêndio com insumos e equipamentos. O custo total médio (R$/kg) do fruto provenientes de plantas sob plantio nas profundidades de 0,40; 0,60 e 0,80 m, comparado ao plantio raso de 0,20 m, é de -0,6%; +12,6% e +49,7%, respectivamente, e a receita líquida inferior em 2,8%; 12,6% e 38,5%.

Fenologia da floração e frutificação do maracujazeiro amarelo sob cultivo orgânico no sudoeste amazônico / Flowering and frutification phenology of yellow passion fruit under organic cultivation in the southwest amazon

Conhecer a resposta do maracujazeiro aos efeitos das mudanças edafoclimáticas ao longo do seu ciclo e em todos os estádios do seu desenvolvimento é fundamental para estabelecer estratégias e técnicas mais adequadas, desde o plantio até o final da vida útil da cultura, para manter e ampliar os rendimentos físicos e econômicos. Nesse intuito, objetivou-se realizar a caracterização da fenologia de floração e frutificação do maracujazeiro em função da combinação de irrigação, polinização e cultivo protegido. O delineamento experimental foi em blocos casualizados em parcelas divididas (2 x 2 x 2) com oito tratamentos e quatro repetições contendo quatro plantas por unidade experimental. O ambiente protegido foi instalado na parte superior de cada espaldeiras, constituído de filme plástico aditivado transparente de 100 m como material para a cobertura. A irrigação foi do tipo micro aspersão e a polinização manual ou natural (entomófila). Avaliou-se: número médio de frutos por planta; Massa média de frutos; Sazonalidade da produção de frutos; taxa de frutificação; porcentagem de frutos abortados; taxa de refugo; número de flores por planta. Baseado neste experimento conclui-se que: o maracujazeiro não paralisa o florescimento e produção de frutos e há quatro picos de produção; A combinação da utilização da cobertura com filme plástico, polinização artificial e cultivo em sequeiro proporciona maior massa média dos frutos; A maior taxa de frutos abortados ocorre em março e nos meses de maio a julho ocorrem as maiores taxas de frutos com baixa qualidade comercial.