Potential use of endophytic bacteria to promote the plant growth of micropropagated banana cultivar Prata Anã

Endophytic bacteria isolated from shoot tip cultures of banana ‘Tropical’ and ‘Galil 18’ were identified at the genera and species levels by means of the profile of fatty acids test through gas chromatography and the potential of plant growth promotion of micropropagated ‘Prata Anã’ banana plantlets was evaluated. A completely randomized experimental design in a factorial scheme 2 × 9, with two immersion periods (30 and 60 min), eight isolates (endophytic bacteria) plus control (saline solution; 0.85% sodium chloride) with seven replications was used. The plantlets were cultured under greenhouse conditions and the evaluations were performed at 24 (DAP1) and 48 (DAP2) days after planting. The isolates of endophytic bacteria affected significantly pseudostem height, number of leaves and pseudostem diameter. Five isolates: 03, 05, 06, 07 and 08 showed percentages of increment index over 20% for pseudostem height. Among them, the isolate 07, Klebsiella pneumoniae pneumoniae showed the highest increment indices: 27.48, 13.68 and 13.55% for pseudostem height, number of leaves and pseudostem diameter, respectively. The results show the potential use of K. pneumoniae pneumoniae (Isolate 07) for growth promotion in micropropagated ‘Prata Anã’ banana plantlets.Keywords: Musa sp., Klebsiella pneumoniae pneumoniae, plant growth promoting bacteriaAfrican Journal of Biotechnology Vol. 12(31), pp. 4915-491

Reguladores de crescimento na frutificação efetiva e qualidade de frutos partenocárpicos de atemoia 'Gefner'

The objective of this work was to evaluate the effects of plant growth regulators on the effective fruit set and quality of atemoya 'Gefner' parthenocarpic fruit. The experiment was carried out in an orchard of atemoya 'Gefner' in Homestead, Florida, USA. A randomized complete block design was carried out with four treatments, five replicates, and six flowers per plot. Treatments were composed of: T1, 450 mg L‑1 naphthaleneacetic acid and 1,000 mg L‑1 gibberelic acid; T2, 100 mg L‑1 promalin and 1,000 mg L‑1 gibberelic acid; T3, 1,000 mg L‑1 gibberelic acid; and T4, artificial pollination (control). Effective fruit set, and fruit growth and quality were evaluated. The application of naphthaleneacetic and gibberelic acids on flowers of atemoya 'Gefner' provided high fruit set, similar to that of artificial pollination. Gibberelic acid application, associated or not with naphthaleneacetic acid or promalin, results in later and smaller atemoya 'Gefner' fruit than those obtained by artificial pollination, but with good proportion of pulp, excellent soluble solids content and, mainly seedless fruit (parthenocarpic fruit).O objetivo deste trabalho foi avaliar os efeitos de reguladores de crescimento vegetal sobre a frutificação efetiva e a qualidade de frutos partenocárpicos de atemoia 'Gefner'. O experimento foi realizado em pomar de atemoia 'Gefner', em Homestead, Flórida, EUA. Utilizou-se um delineamento experimental de blocos ao acaso, com quatro tratamentos, cinco repetições e seis flores por parcela. Os tratamentos foram compostos por: T1, ácido naftaleno acético a 450 mg L‑1 e ácido giberélico a 1.000 mg L‑1; T2, promalina a 100 mg L‑1 e ácido giberélico a 1.000 mg L‑1; T3, ácido giberélico a 1.000 mg L‑1; e T4, polinização artificial (testemunha). Foram avaliados a frutificação efetiva, o crescimento e a qualidade dos frutos. A aplicação dos ácidos naftaleno acético e giberélico a flores de atemoia 'Gefner' proporcionou elevada frutificação efetiva, semelhante à da polinização artificial. A aplicação do ácido giberélico, associado ou não ao ácido naftaleno ou à promalina, resulta na produção de frutos de atemoia 'Gefner' mais tardios e menores do que os oriundos da polinização artificial, mas com boa proporção de polpa, excelente teor de sólidos solúveis e, principalmente, frutos sem sementes (partenocárpicos)

Fruit quality of Tahiti acid lime and Sicilian lemon trees grown on different rootstocks and spacings in the semi-arid region

The objective of this work was to evaluate the fruit quality of Tahiti acid lime and Sicilian lemon trees grownon different rootstocks and planting spacings in the semi-arid region of the state of Minas Gerais, Brazil. Twoexperiments were conducted, using Tahiti acid lime tree scions (Citrus latifolia Tanaka) (1) and Sicilian lemontrees scions [Citrus limon (L.) Burm] (2). A randomized block design was used, with a 6×2 factorial arrangement consisted of six rootstocks: Cravo Santa Cruz lemon (Citrus limonia Osbeck), Swingle citrumelo [Citrus paradisi Macfaden × Poncirus trifoliata (L.) Rafinesque], Indio citrandarin and Riverside citrandarin [Citrus sunki (Hayata) hort. ex Tanaka × Poncirus trifoliata (L.) Rafinesque], Hybrid TSKC × (LCR × TR) - 059 [Citrus sunki (Hayata) hort. ex Tanaka × (Citrus limonia Osbeck × Poncirus trifoliata (L.) Rafinesque)], and Sunki Tropical tangerine [Citrus sunki (Hayata) hort. ex Tanaka]; and two planting spacings: 6.0 × 4.0 m and 6.0 × 2.0 m, with three replications and four plants per plot. The physical and chemical characteristics of fruits were evaluated. Most quality characteristics of Tahiti acid lime and Sicilian lemon are not affected by the different rootstocks and spacings used, but the fruits present excellent quality for the national and international markets. Tahiti acid lime plants grown on less vigorous rootstocks under denser spacings have fruits with higher pH, whereas those grown on more vigorous rootstocks have fruits with thicker mesocarps and lower soluble solid contents. The use of Sunki Tropical tangerine rootstock results in bigger Sicilian lemons, however, with lower soluble solid contents, whereas an opposite result is found with the use of Swingle citrumelo rootstocks.Objetivou-se com este trabalho avaliar a qualidade dos frutos da limeira ácida ‘Tahiti’ e do limão ‘Siciliano’, em diferentes porta-enxertos e espaçamentos no semiárido de Minas Gerais. O trabalho foi dividido em dois experimentos, (1) copas da limeira ácida ‘Tahiti’ e (2) copas do limoeiro ‘Siciliano’. Utilizou-se delineamento em blocos casualizados, em esquema fatorial 6 x 2, sendo seis porta-enxertos: limão ‘Cravo Santa Cruz’, Citrumelo ‘Swingle’, ‘Índio’, ‘Riverside’, ‘059’ e tangerina ‘Sunki Tropical’; distribuídas em dois espaçamentos: 6,0 m x 4,0 m e 6,0 m x 2,0 m, com três repetições e quatro plantas por parcela. Foram avaliadas as características físicas e químicas dos frutos. Os frutos do limão ‘Siciliano’ não apresentaram diferenças no comprimento, rendimento do suco e coloração da casca e polpa entre os diferentes porta-enxertos e espaçamentos. Das características avaliadas apenas o teor de sólidos solúveis (SS), teor de vitamina C, a massa fresca e o diâmetro foram influenciados. O SS e teor de vitamina C pelo porta-enxerto Citrumelo ‘Swingle’, enquanto que a massa fresca e o diâmetro pelo porta-enxerto Tangerina ‘Sunki Tropical’. Os frutos da lima ácida ‘Tahiti’ foram influenciados pelo porta-enxerto limão ‘Cravo Santa Cruz’ e pelo Citrumelo ‘Swingle’. O primeiro afetou o mesocarpo, formando frutos com maior espessura e menor teor de sólidos solúveis, enquanto o Citrumelo ‘Swingle’ incrementou o teor de sólidos solúveis nos frutos

Severity of banana leaf spot in an intercropping system in two cycles of banana Prata Anã

Prata Anã is the most planted banana cultivar in northern Minas Gerais, Brazil. It is however susceptible toseveral pathogens. This study was carried out to evaluate the disease severity of banana leaf spot in the Prata Anã cv. in thefirst and second cycle under six different planting systems. The randomized block experimental design was used with sixtreatments and four replications. In an evaluation of the severity of banana leaf spot, no disease symptoms were found onThap Maeo and Caipira. The evolution curve of the disease indicated seasonal effects in the first and second cycles. Theseverity of banana leaf spot was highest soon after the regional rainy period from November to March. A comparison of themeans of the evaluations indicated a reduction in disease severity from the first to the second cycle

Agronomic characteristics of Prata type banana plants under different irrigation systems

O objetivo deste trabalho foi avaliar as características agronômicas de bananeiras tipo Prata em três ciclos de produção, sob diferentes sistemas de irrigação, em condições semiáridas. Adotou-se o delineamento experimental de blocos ao acaso, com seis tratamentos em arranjo fatorial 3x2: três sistemas de irrigação – aspersão convencional, microaspersão e gotejamento – e dois genótipos – 'Prata-Anã' e PA42-44. Utilizaram-se quatro repetições e parcelas com seis plantas úteis. À época do florescimento, avaliaram-se: altura de planta; perímetro de pseudocaule; número de folhas vivas; comprimento e largura da terceira folha; área foliar total e índice de área foliar. À colheita, avaliaram-se: massa do cacho e das pencas; massa média das pencas; massa das três primeiras pencas; número de pencas e de frutos; massa, comprimento e diâmetro de fruto; e número de folhas vivas. O sistema de irrigação por gotejamento proporciona menor vigor, expresso pelo porte e perímetro do pseudocaule, para bananeiras tipo Prata, em comparação aos sistemas de irrigação por aspersão e microaspersão. A 'Prata-Anã' apresenta maior número de frutos e de pencas por cacho, enquanto seu híbrido PA42-44 apresenta maior massa, comprimento e diâmetro do fruto.The objective of this work was to evaluate the agronomic characteristics of Prata banana plants during three production cycles, under different irrigation systems, in semi-arid conditions. A randomized block design was adopted with six treatments, in a 3x2 factorial arrangement: three irrigation systems – conventional sprinkler, microsprinkler and drip – and two genotypes – 'Prata-Anã' and its hybrid PA42-44. Four replicates in plots with six useful plants were used. Plant height, pseudostem perimeter, number of alive leaves, length and width of the third leaf, total leaf area, and leaf area index were evaluated at flowering. Weight of bunch and hands, mean weight of hands, weight of the three first hands, number of hands and fruits per bunches, and weight, length and diameter of fruits and number of alive leaves were evaluated during the harvest season. The drip irrigation system provides smaller vigor to banana Prata, in comparison to conventional and to micro sprinkler systems, as can be seen by the size and perimeter of the pseudostem. The cultivar Prata-Anã shows a larger number of fruit and hands per brunch, while its hybrid PA42-44 shows larger weight, length and fruit diameter

Estado nutricional de bananeiras tipo Prata sob diferentes sistemas de irrigação

The objective of this work was to evaluate nutrient leaf contents and the productivity of 'Prata-Anã' banana submitted to different irrigation systems, during the first production cycle. The experimental design was in randomized blocks, with six treatments in 3x2 factorial arrangement: three irrigation systems (conventional sprinkler, microsprinkler and drip); and two genotypes (Prata-Anã and its hybrid PA42-44). Four replicates were used in a 3.0x2.5-m spacing. The evaluations were done at 90, 180 and 360 days after planting. The genotypes and the irrigation systems showed significant interaction for leaf contents of B and Cu, at 180 days after planting; and the genotypes differed from each other for leaf contents of N, P, K, Ca, Mg, Cu and Mn, independently of the irrigation system used. Nutrient leaf contents occurred in sufficient levels or above them. The lowest micronutrient leaf contents occur under drip irrigation. The genotypes have similar yield under the different irrigation systems.O objetivo deste trabalho foi avaliar os teores foliares de nutrientes e a produtividade de bananeiras tipo Prata, submetidas a diferentes sistemas de irrigação, durante o primeiro ciclo de produção. Adotou-se o delineamento experimental em blocos ao acaso, com seis tratamentos dispostos em esquema fatorial 3x2: três sistemas de irrigação (aspersão convencional, microaspersão e gotejamento); e dois genótipos (Prata-Anã e seu híbrido PA42-44). Utilizaram-se quatro repetições, no espaçamento de 3,0x2,5 m. Procedeu-se às avaliações aos 90, 180 e 360 dias após o plantio. Os genótipos e os sistemas de irrigação apresentaram interações significativas quanto aos teores foliares de B e Cu, aos 180 dias após o plantio; e os genótipos diferiram entre si quanto aos teores de N, P, K, Ca, Mg, Cu e Mn, independentemente dos sistemas de irrigação. Os teores foliares dos nutrientes ocorreram em níveis adequados ou acima deles. Os menores teores foliares de micronutrientes ocorrem sob gotejamento. Os genótipos apresentam produtividade similar nos diferentes sistemas de irrigação

Morphological characterization of new banana clones-elites

Abstract The characterization of clones is a very important step in genetic certification programs, as it describes and recognizes the plant material at every stage of production, allowing the monitoring of genetic quality, improvement and conservation of the germplasm. The aim of this work was to morphologically characterize two elite banana clones. The experimental design applied was in randomized blocks, with four replications, with six plants per parcel. The treatments consisted of two elite banana clones, Prata Gorutuba R1 and Prata Gorutuba R2 and four commercial cultivars: Prata Gorutuba, Prata Ana, Grande Naine and BRS Princesa. The morphological characterization was carried out in the second production cycle (daughter plant), using 23 qualitative descriptors, visually evaluated, classified according to the instructions for carrying out the distinguishability, homogeneity and stability (DHS) tests of banana cultivars. The elite clones Prata Gorutuba R1 and R2 differed from the cultivars Grande Naine and BRS Princesa regarding the descriptors tapering of the pseudostem, predominant color of the pseudostem, intensity of anthocyanin coloration and color of the underside of the basal sheath. The descriptors made it possible to group elite clones into the Prata group, a group that predominates in crops in Brazil, with characteristics already widely accepted by the market

Growth and production of ‘Prata Anã Gorutuba’ banana under different planting densities

Increased planting density, different types of thinning management, and the use of beneficial microorganisms have been adopted as strategic tools in the effort to increase crop yields in a sustainable manner. This investigation evaluated the growth and production of ‘Prata Anã Gorutuba’ banana (Musa spp., AAB) under different plant densities during two production cycles in the semiarid region of Minas Gerais, Brazil. Micropropagated plantlets were also inoculated with endophytic bacteria and cultivated as part of two mat management strategies. Planting density varied between 1,680 and 3,920 plant ha–1. During the experiment, water was less than optimal because of rationing due to drought in the region. Under field conditions, there was no difference between bacterially inoculated and non-inoculated plants. The dense planting system increased the crop cycle. The highest-density planting treatment (3,920 plant ha–1) resulted in the highest yield in the first cycle, but no net income was observed. However, the high-density planting treatments resulted in the highest yields and gross incomes in the second production cycle. Management with thinning of plants up to 10-months-old and thinning up to harvest associated with high planting density increased the length of the production cycles. Although the water restriction experienced in the first and second crop cycles, the vegetative and productive traits of ‘Prata Anã Gorutuba’ banana did not compromise the objectives of this study