australian journal of crop science   AJCS

Sorghum [Sorghum bicolor (L.) Moench] breeding for resistance to leaf and stalk anthracnose, Colletotrichum sublineolum, and improved yield: Progress and prospects

Maletsema Alina Mofokeng*, Hussein Shimelis, Mark Laing, Nemera Shargie

Agricultural Research Council, Grain Crops Institute, Private Bag x 1251, Potchefstroom, 2520. South Africa

African Centre for Crop improvement, School of Agriculture, Earth and Environmental Sciences, Private Bag X 01, Scottsville, 3290. South Africa

Abstract

Sorghum is one of the main staple food crops for millions of subsistence farmers in Africa. Biotic and abiotic challenges are the major production constraints of the crop. Amongst the sorghum biotic constraints, anthracnose is the major devastating disease causing up to 80% of yield reduction. The productivity and profitability of sorghum is limited by several biotic constraints, most notably anthracnose caused by the aggressive fungal pathogen Colletotrichum sublineolum. The most effective and environmentally responsible strategy to control anthracnose is through the incorporation of resistance genes. However, although several sources have been identified, the lack of information with regard to its genetic control of resistance has limited their adequate use in breeding programs. Additionally, the limitations of breeding regarding the leaf and stalk anthracnose resistance and also the need for evaluating materials for resistance and yield in different environments is of major importance. There is limited information about the combining ability, gene action and genetic effects and relationships between anthracnose resistance and grain yield which is required in devising appropriate strategies for developing resistant and high yielding sorghum varieties. This review provides theoretical basis of the progress and challenges for breeding sorghum for anthracnose resistance and improved yield.

Pages 1078-1085 | Read More| doi: 10.21475/ajcs.17.11.09.pne347

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Do the nutrition and physiology of eucalyptus seedlings respond to silicon (Si) supply?

Nikolas de Souza Mateus*, Eric Victor de Oliveira Ferreira, Fábio Henrique Silva Floriano de Toledo, José Lavres and José Leonardo de Moraes Gonçalves

University of São Paulo, São Paulo, Brazil

Federal University of São João Del Rei (UFSJ), Minas Gerais, Brazil

University of São Paulo, Center for Nuclear Energy in Agriculture, São Paulo, Brazil

Abstract

In Brazil, Eucalyptus plantations are found, generally in soils with naturally low chemical fertility. Silicon (Si) can improve photosynthesis, decrease plant transpiration and increase water use efficiency (WUE). This study aimed to evaluate the effect of Si supply at five rates (0, 0.25, 0.50, 0.75 and 1.00 mmol L−1) for growing Eucalyptus clone IPB8 seedlings (E. urophylla × E. grandis) in Clark’s nutrient solution in a greenhouse. Plant growth, nutritional status, gas exchange, leaf water potential (Ψw), leaf area (LA), inclination angle of leaves and stomatal density (SD) were measured. There was no significant response in Eucalyptus seedling growth due to Si application, which was related to the absence of benefits provided by Si in plant nutritional status and physiology. The efficiency of assimilation (EA), efficiency of translocation (ET) and efficiency of utilization (EU) did not show significant results either. The low ET indicates that Si was highly accumulated in the root (75.4 % in relation to total Si absorbed by plants), which may also have contributed to the lack of the benefits expected. Despite that, Si application promoted higher rates of photosynthesis when compared to plants with 0 mmol Si L−1, increasing the total dry matter production by up to 28 % at an Si rate 0.50 mmol L−1, which also provided a trend of higher growth, EU, LA and SLA, showing it to be the best rate for this Eucalyptus species.

Pages 1086-1093 | Read More| doi: 10.21475/ajcs.17.11.09.pne422

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Association mapping of agronomic traits of canola (Brassica napus L.) subject to heat stress under field conditions

Mizanur Rahaman, Sujan Mamidi, Mukhlesur Rahman*

Department of Plant Sciences, North Dakota State University, Fargo, ND 58102, USA

HudsonAlpha Institute for Biotechnology, Huntsville, AL, USA

Abstract

Brassica is a cool season crop and is susceptible to high temperatures. Developing heat stress tolerant varieties will help the crop to sustain under high temperature and can be used to extend the geographical range of cultivation. We have phenotyped 84 spring type Brassica napus accessions in field under natural heat conditions. Data on various agronomic traits were collected at the end of flowering to maturity stages. An association mapping study was performed to identify QTL associated with heat stress tolerant agronomic traits. A total of 37,269 single nucleotide polymorphism markers were used for this study. Multiple markers distributed on most of the chromosomes were identified. A total of 6, 11, 7, 11 and 7 QTL were identified those explained 52.2%, 71.8%, 53.2%, 73.5% and 61.0% of the total phenotypic variations for plant height, main raceme height, pods on main raceme, pod length, and sterile/aborted pod, respectively. Multiple candidate genes known to be involved in abiotic stress and abortion of different organs were identified in the vicinity of the QTL. For instance, B. napus BnaA03g09160D gene involved in programmed cell death and pollen sterility, BnaA05g33770D and BnaA05g33780D genes associated with pollen sterility and pod abortion were identified in the QTL regions.

Pages 1094-1105 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.09.pne512

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Molecular variability and population structure of a core collection of date palm (Phoenix dactylifera L.) cultivars from Australia and the Middle East

Ahmed Al-Najm, Shuming Luo, Nabil M. Ahmad*, Mohammad Pourkheirandish, Richard Trethowan

Plant Breeding Institute, Faculty of Agriculture and Environment, University of Sydney, 107 Cobbitty Road, Cobbitty, NSW 2570, Australia

University of Basrah, Date palm research center, Basrah, Iraq

Abstract

Understanding genetic relatedness in date palm (Phoenix dactylifera L.) germplasm is important for effective plant improvement. Microsatellite (SSR) markers were used to assess the molecular variation and population structure of 60 Australian locally selected and exotic genotypes (24 female, 30 male and 6 related species), 12 Iraqi female cultivars and 10 female cultivars from Jordan. The main objectives were to survey genetic diversity and determine population structure in this core date palm collection which includes the most important and widely distributed cultivars in Australia. These Australian accessions were then compared to those originating from the date palm center of origin in the Middle East. PCR of 17 SSR primers (co-dominant markers) produced a total of 313 alleles ranging from 5 to 31 with an average of 18.4 alleles per locus. The PIC value for these 17 primers ranged from 0.4771 to 0.8199 with a mean of 0.670. The mean expected heterozygosity (0.841), mean observed heterozygosity (0.946) and Shannon’s information index (2.067) indicated a high level of genetic diversity among the accessions. Multi-locus DNA fingerprints based on the 17 SSR loci unambiguously differentiated all accessions and revealed an absence of duplicated samples. Ordination and cluster analyses showed that the Australian accessions did not group together geographically; instead separate male and female groups differentiated among the six clusters. A Bayesian cluster analysis also partitioned the accessions into six groups and this result was largely compatible with the result of ordination analysis. The Australian date palm germplasm is highly diverse and thus provides an effective platform for plant improvement, enhancement of date production and the conservation of genetic resources.

Pages 1106-1115 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.09.pne517

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Attributes of growth, physiological quality and isoenzymatic expression of common bean seeds produced under the effect of gibberellic acid

Cristian Troyjack, Ítala Thaísa Padilha Dubal, Felipe Koch, Vinícius Jardel Szareski, João Roberto Pimentel, Ivan Ricardo Carvalho, Maicon Nardino, Gustavo Henrique Demari, Francine Lautenchleger, Velci Queiróz de Souza, Francisco Amaral Villela, Tiago Zanatta Aumonde, Tiago Pedó

Federal University of Pelotas, CEP 96010-610, Capão do Leão, RS, Brazil

Federal University of Santa, Santa Maria, RS, Brazil

Federal University of Pampa, Dom Pedrito, RS, Brazil

Abstract

The gibberellins (GA) present an essential role in many aspects of plant development, seed germination, internode elongation, flower and fruit development. Thus, this work aimed to evaluate the growth attributes and the physiological quality of bean seeds from plants submitted to the application of gibberellic acid, revealing great importance in some characters of agronomic interest. Seeds of genotypes (Phaseulus vulgaris) Mouro and BRS Embaixador and four concentrations of gibberellic acid (zero, 50, 100 and 200 mg L-1) were used. Seed germination, first count, germination speed, primary root and shoot length, dry matter of seedlings, shoot height, stem diameter, first pod insertion, pod number and seeds per pod were evaluated. Giberelic acid promoted an increase in plant height and a reduction in stem diameter. Seeds produced under doses of GA3 did not influence seed germination and dry matter of the seedlings at higher doses, being dependent on the cultivar. In this way, the application of increasing doses of GA3 in bean plants increases the height of insertion of the first pod, while the physiological quality of the seeds produced is affected by the acid doses.

Pages 1116-1122 | Read More| doi: 10.21475/ajcs.17.11.09.pne531

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Distribution of organic metabolites after Fusarium wilt incidence in tomato (Solanum lycopersicum L.)

Muhammed Alsamir, Tariq Mahmood, Nabil Ahmad, Richard Trethowan

Plant Breeding Institute, Faculty of Agriculture and Environment, University of Sydney, Cobbitty, NSW 2570, Australia

The Date Palm Research Center, University of Basrah, Basrah, Iraq

Abstract

Tomato is an important vegetable crop worldwide and Fusarium wilt is a significant disease of tomato in many countries. One hundred and fifty three diverse tomato genotypes collected from local and exotic sources were screened for resistance to F. solani in the greenhouse. Significant variation in genotype response to inoculation was observed. The organic metabolite profiles of resistant and susceptible genotypes were assessed to determine the basis of resistance. Significant genetic variation was observed for ABA, malic acid, citric acid, fructose, glucose, sucrose, L-proline and myo-inositol. The disease treatment produced significant changes in fructose, glucose, proline and sucrose and significant genotype-by-treatment interaction was observed for ABA, citric acid, fructose, glucose, malic acid and sucrose, indicating that genetic improvement of these traits is feasible. Disease incidence was strongly associated with citric acid (R2 = 0.84), sucrose (R2 = 0.72) and L-proline (R2 = 0.76). Principal component analysis confirmed that citric acid and L-proline were important in determining plant disease response. Genetic variation for Fusarium wilt resistance can be used to develop new tomato cultivars with improved disease resistance.

Pages 1123-1129 | Read More| Supplementary Data| doi: 10.21475/ajcs.17.11.09.pne536

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Biochemical composition of oil palm fruits (Elaeis guineensis var. BRS Manicoré hybrid) in 11 years of growth and development

Sabrina Santos de Lima, Ismael de Jesus Matos Viégas*, Heráclito Eugênio Oliveira da Conceição, Cândido Ferreira de Oliveira Neto, Ricardo Shigueru Okumura

Abstract

The determination of biochemical composition during fruit development is important for understanding the metabolic and nutritional processes in oil palm. The main aim of this study was to determine the biochemical composition in oil palm fruits (BRS Manicoré hybrid) during the development. The experimental design was completely randomized with six evaluation periods (4, 5, 6, 7, 9 and 11 years of planting) in four replications. In oil palm fruits, concentration of total soluble carbohydrates was higher in 7th year (2.14 mmol of glutamate g DM-1); 9 (2.41 mmol of glutamate g DM-1); and 11 years (2.66 mmol of glutamate g DM-1) of development. The total soluble amino acid had higher concentrations at 4th and 5th years with values of 112.11 and 105.97 µmol of amino acids g DM-1, respectively. The total soluble protein was increased from 5 (2.00 mg of protein g DM-1) to 11 years (2.19 mg of protein g DM-1) during development of BRS Manicore. Regarding the sucrose concentration, the highest values were observed at 9 (16.19 mg of sucrose g DM-1) and 11 years (18.69 mg of sucrose g DM-1), while for the starch concentration the best values were observed at 4 (0.81 mmol of glutamate g DM-1) and 5 years (0.70 mmol of glutamate g DM-1) of oil palm development. At the initial development stage of oil palm (4 to 5 years of planting) the total soluble amino acids (112.11 µmol of amino acids g DM-1) and starch concentrations (0.81 mmol of glutamate g DM-1) showed higher values. The results showed that at 11 years of planting BRS Manicoré hybrid presented higher values of soluble carbohydrates (2.66 mmol of glutamate g DM-1), sucrose (18.69 mg of sucrose g DM-1) and protein concentration (2.19 mg of protein g DM-1). After 11 years of oil palm development, the products supposed to be the highest, the age at which greater accumulations of biochemical compounds may occur in fruits.

Pages 1130-1136 | Read More| doi: 10.21475/ajcs.17.11.09.pne598

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In vitro cultivation of purple basil Ocimum basilicum L. ‘red rubin’ at different levels of salts, charcoal, sucrose and potassium iodine

Flávio Julian da Silva, Andressa Bezerra Nascimento, Letícia Neris Barbosa, Hélida Mara Magalhães*

Programs in Biotechnology Applied to Agriculture. Paranaense University, Mascarenhas de Moraes Square, 4282, 87502-210 Umuarama, Paraná, Brazil

Paranaense University, Umuarama, Mascarenhas de Moraes Square, 4282, 87502-210 Umuarama, Paraná, Brazil

Abstract

Ocimum basilicum‘red rubin’ is highly valued for its essential oil, and is widely used in folk medicine, but few studies examining in vitro propagation techniques for this basil variety are available. We examined the development of red rubin basil seedlings grown in vitro in different concentrations of mineral salts, charcoal combined with sucrose, and potassium iodine in three series of tests. In the first series, five concentrations (0, 25, 50, 75 and 100%) of Murashige and Skoog salts (MS culture medium) were used to germinate sterilized seeds of O. basilicum. In the second test, to evaluate the combined effects of charcoal and sucrose on basil growth, three concentrations of charcoal (0, 3.0, and 4.5 g/L) and two of sucrose (30 and 60 g/L) were used. In the third test, the seeds were sown onto culture medium enriched with five different concentrations of potassium iodine (0, 25, 50, 75 and 100µM); 0.5 μM benzyl aminopurine (BAP) and 1.0 μM naphthalene acetic acid (NAA) were added to all germination media. A completely randomized experimental design was used in all tests, with five replicates, four vials per test, and 4 seeds per vial. In Test 2, seedling oxidation (%) and the numbers of leaves and shoots were submitted to non-parametric analysis using the Kruskal Wallis test (p ≤0.05). The other data were submitted to analysis of variance (p≤0.05). The qualitative means were evaluated by the Tukey test (p≤0.05), and the quantitative means by polynomial regression (p≤0.05). The results showed that 100% MS culture medium was most indicated for ‘red rubin’ seed germination and aerial portion production, while 70-80% MS was indicated for root production. A sucrose level of 30 g/L (standard) combined with 4.5 g/L of activated charcoal allowed the best seedlings development and inhibited callus formation. Activated charcoal limited copper and zinc uptake by O. basilicum seedlings, but not enough to hamper their development. Increasing concentrations of potassium iodine reduced all of the growth variables analyzed in this basil variety.

Pages 1137- 1145 | Read More| doi: 10.21475/ajcs.17.11.09.pne624

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Morphometric indexes and dendrometric measures for classification of forest sites of Eucalyptus urophylla stands

João Victor Nobre Carrijo*, Eder Pereira Miguel, Alba Valéria Rezende, Ricardo de Oliveira Gaspar, Ildeu Soares Martins, Milton Serpa de Meira Junior, Humberto Angelo e Caroline Maiara de Jesus

University of Brasilia (UnB) – Department of Forestry, Darcy Ribeiro Campus, 70910-900, Brasilia, Brazil

Abstract

The main goal of this study was to verify the applicability of morphometric indexes and dendrometric measures to assess production capacity and volumetric prognosis of forest sites under E. urophylla stands/plantation. During forest measurement inventory, 21 randomized permanent sample plots were monitored from the third to the sixth year of cultivation, registering individuals with standard minimum features, collecting the variables diameter at breast height (DBH), crown diameter (CD), total height (TH), and crown height (CH). A volume estimation equation was adjusted using the software Statistica 7, which were used for estimation the wood volume of each sample in each year of cultivation. Furthermore, other three stand variables were collected: arithmetic mean diameter (MD), quadratic mean diameter (QMD), and dominant height (DH); along with three morphometric indexes: slenderness degree (SD), salience index (SI), and crown formal (CF). Amongst five sigmoidal models adjusted for site classification three of them were considered best choice for different variables: Richards (MD, QMD, and CF); Gompertz (DH); Weibull (SD and SI). All variables presented satisfying adjustment precision for the Clutter prognosis model. Despite a small advantage found in some indexes on statistical tests, there was no significant difference between the six variables on an Analysis of Variance (ANOVA) for volume prediction, which brought us the conclusion that all variables are efficient for site quality classification.

Pages 1146-1153 | Read More| doi: 10.21475/ajcs.17.11.09.pne682

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Agronomic effectiveness of rhizobia strains on cowpea in two consecutive years

Gustavo Ribeiro Xavier, Norma Gouvêa Runjanek, Carolina Etienne de Rosália e Silva Santos, Ana Dolores Santiago de Freitas, Vinicius Santos Gomes da Silva*, Aleksandro Ferreira da Silva, Juscélia da Silva Ferreira, Newton Pereira Stamford, Lindete Míria Vieira Martins, Jakson Leite, Luiz Balbino Morgado, Rosa Maria Cardoso Mota de Alcantara

Abstract

Cowpea (Vigna unguiculata L Walp) is a legume of great social and economic importance in tropical regions. The plant is tolerant to soil and climatic adversity, while it has high nutritional value with high protein, minerals and vitamins contents. The cowpea legume has a very high ability to fix N2 which is important because it can reduce the costs of soluble mineral fertilizers and may contribute to sustainable agriculture, preserving the environment and natural resources. In order to observe the influence of Rhizobia the agronomic effectiveness of cowpea strains was tested in two consecutive years compared with the mineral N fertilization. The experiments were carried out in different soils of the Brazilian Northeast (semiarid and rain forest region) which measured the effectiveness of rhizobia on grain yield. The results revealed the effectiveness of strain BR 3299 in the experiment that significantly increased the grain yield (3 times when 50 kg ha-1 of N, and 2 times when 80 kg ha-1 N were used). The Rhizobia treatment promoted the grain yield (up to 1,600 kg ha-1), compared to application of 80 kg ha-1 of N. In general, all applied strains promoted the Brazilian Northeast average cowpea yield (300-400 kg ha-1).

Pages 1154-1160 | Read More| doi: 10.21475/ajcs.17.11.09.pne715

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Crop-livestock integration under no-tillage: genuine Brazilian technology with economic and environmental sustainability: A review

Alyne Dantas Mendes de Paula, Diego Tolentino de Lima, José Luiz Rodrigues Torres, Gabrielly Isaac Rodrigues, Ernane Miranda Lemes

Agronomist, Graduate Program in Agronomy, Institute of Agricultural Sciences at the Federal University of Uberlândia. Av. Amazonas s/nº, Umuarama. Uberlândia-MG, Brazil. Zip code: 38400-902.

Plant Production, Federal Institute of Mining Triangle (IFTM) – Uberaba Campus, MG, Brazil. Rua João Batista Ribeiro, 4000. Uberaba-MG, Brazil. Zip code: 38064-790.

Abstract

Crop-Livestock Integration System (CLIS) under no-tillage system (NTS) is a technology that has proven critical to the maintenance of agricultural and environmental sustainability in Brazilian tropical conditions. It is one of the alternatives developed by national research for producers to optimize and diversify the use of agricultural areas to obtain higher incomes by area with lower costs, besides recovering degraded areas and improve the physical, chemical and biological soil. The aim of this review is to disseminate results and gather information to demonstrate that CLIS under NTS is a Brazilian technology with economic and environmental sustainability is applicable to several regions. It was observed that the use of CLIS with NTS in our tropical climate conditions is an important tool that provides food production (grains), meat and milk with sustainability in most regions.

Pages 1161-1167 | Read More| doi: 10.21475/ajcs.17.11.09.pne454

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Resistance of important bean genotypes to the Mexican bean beetle [Zabrotes subfasciatus (Bohemann)] during storage and its control with chemical synthetic and botanical insecticides

Carlos E.A. Luz, Tamíris A. Araujo, Arthur V. Ribeiro, Cristina S. Bastos*, Jorge B. Torres, Yann S.T. Krieger

Departamento de Entomologia (DDE), Universidade Federal de Viçosa (UFV), Campus Universitário s/no., 36570-000, Viçosa, MG, Brazil

Universidade de Brasília (UnB), Faculdade de Agronomia e Medicina Veterinária (FAV), Instituto Central de Ciências Ala Sul (ICC-SUL), Campus Darcy Ribeiro, 70910-900, Asa Norte, Brasilia, DF, Brazil

Universidade Federal Rural do Pernambuco (UFRPE), Departamento de Agronomia-Entomologia (DEPA), 52171-900, Dois Irmãos, Recife, PE, Brazil

Abstract

During storage, beans can be infested with many insect-pests including Zabrotes subfasciatus, a key pest of these crops. This study aimed to identify bean genotypes demonstrating antixenosis and/or antibiosis to Z. subfasciatus and to test their integration with chemical control. The ultimate goal of assessment was to distinguish whether genotypic and insecticidal factors can provide effective beetle control. The tested genotypes were (a) Phaseolus vulgaris group: CCB, BSCB, BCB and PCB; (b) Vicia faba group: YBB, WBB and SBB; and (c) Vigna unguiculata group: C and GC. Initial assays were run to select genotypes (without insecticide treatment) that would be further tested with insecticides. Final assays included genotypes with varying degree of antibiosis and antixenosis treated with a neem formulation (Natuneem®) and distilled water (control) plus deltamethrin (Decis®) which latter was used only in the final antibiosis assay. The insecticides were used at the rates of 3 and 0.1 mL of Natuneem® and Decis®, respectively, per 30 mL of distilled water. There were no differences in preference of Z. subfasciatus adults among non-treated genotypes (initial assays), although neem-treated genotypes altered the preference and reduced infestation from 40.54-100% (final assays). In antibiosis tests, oviposition and density of emerged adults were reduced among C and SBB, and SBB also reduced the weight of emerged adults. Insecticides reduced oviposition in 53–100% and yielded half to five-fold fewer emerging insects weighing 35%–40% less in antibiotic genotypes. SBB was the most antibiotic genotype and this and other genotypes possessing antibiosis had a synergistic effect with neem or deltamethrin.

Pages 1168-1175 | Read More| doi: 10.21475/ajcs.17.11.09.pne519

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Induction of resistance to fall armyworm (Spodoptera frugiperda) (Lepidoptera: Noctuidae) in transgenic and conventional corn plants

Marcos Felipe de Castro Lourenço, Alexandre José Rosa, Ana Paula Silva Siqueira, Lucas da Silva Araujo, André Cirilo de Sousa Almeida*, Flávio Gonçalves de Jesus, Paulo César Ribeiro da Cunha

Instituto Federal de Educação e Tecnologia Goiano -Campus Urutaí (IFGoiano), Rodovia Geraldo Silva Nascimento, km 2,5, Zona Rural, Urutaí, GO. CEP: 75790-000, Brazil

Instituto Federal de Educação e Tecnologia Goiano -Campus Morrinhos (IFGoiano), Rodovia BR 153, km 633, Zona Rural, Morrinhos, GO. CEP: 75650-000, Brazil

Abstract

The fall armyworm (Spodoptera frugiperda) is an important pest of corn in Brazil. Insecticides are applied to reduce the losses caused by this pest. Integrated control methods, including resistance induction in plants using silicon and transgenic hybrids, must be used to reduce the impacts caused by insecticide application. The aim of this study was to assess the effects of calcium silicate application (CaSi4) to the sowing furrow on S. frugiperda damage to and incidence on conventional and transgenic genotypes with different Bt technologies. The treatments were arranged in a randomized block design in a 3x4x4 factorial scheme with three corn hybrids, Morgan 30A91 PRO Power Core® (Cry1F, Cry1A105, Cry2Ab2 Bt toxin), Morgan 20A55 Herculex® (Cry1F Bt toxin) and AG 1051 (conventional); four silicon doses, 0, 300, 600 and 900 kg. ha-1 calcium and magnesium silicate (Agrosilicio Plus®, Ca = 25%, Mg = 6%, Si = 10.5%); and four assessment times, 15, 30, 45 and 60 days after emergence (DAE). Four replicates were performed. The mean number of caterpillars per plant, damage caused by S. frugiperda, and production components were assessed. Calcium and magnesium silicate application induced resistance in corn plants, thus reducing the damage caused by S. frugiperda. Corn responded to resistance induction with increasing doses of calcium and magnesium silicate. The transgenic hybrid with three proteins (Morgan 30A91 PRO) improved protection against S. frugiperda. The interaction between silicate fertilization and transgenics produced a synergistic effect, suggesting a viable alternative for S. frugiperda control.

Pages 1176-1180 | Read More| doi: 10.21475/ajcs.17.11.09.pne530

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Physiological performance and competitive ability in kale (Brassica oleracea var. acephala ‘Manteiga da Georgia’) intercropped with important aromatic species and herbs

Ana Régia Alves de Araújo Hendges*, Marcelo de Almeida Guimarães, Hozano de Souza Lemos Neto, Rosilene de Oliveira Mesquita

Instituto Federal de Educação, Ciência e Tecnologia do Maranhão. 65.840-000, São Raimundo das Mangabeiras, Maranhão, Brazil

Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Fitotecnia. 60356-001, Fortaleza, Ceará, Brazil

Abstract

The effectiveness of intercropping depends on the complementarity or the adaptive capacity of species during the period of coexistence. Kale is a plant that displays differing responses to environmental factors, and may therefore display different behaviour when grown with other species. The aim of this study was to analyse the physiological behaviour and competitive ability of kale when intercropped with the Welsh onion, coriander, basil and parsley. The experiment was carried out under field conditions, in a randomised block design with nine treatments and five replications. The following were evaluated: net photosynthesis, stomatal conductance, CO2 concentration of the sub-stomatal chamber, transpiration rate, ratio between the CO2 concentration of the sub-stomatal chamber and the CO2 concentration of the environment, instantaneous carboxylation efficiency, aggressivity index, and the competitive and compensation ratios. The kale plants displayed values for net photosynthesis (A) and instantaneous carboxylation efficiency (A/Ci) of 18.75 µmol CO2 m-2 s-1 and 0.060 respectively, the lowest values for all the treatments under evaluation. The kale displayed less competitive ability. The more aggressive crops were the Welsh onion (2.25) and coriander (2.08). The parsley displayed the lowest competitive effect, having no effect on yield in the kale. The conclusion is that the coriander was prejudicial to the photosynthetic performance of the kale. The intercropping system with parsley was the most advantageous, due to the balance seen in interference between species for productive resources.

Pages 1181-1187 | Read More| doi: 10.21475/ajcs.17.11.09.pne533

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Combining ability for traits associated with yield and quality in super sweet corn (Zea mays L. saccharata)

Universidade Estadual do Norte Fluminense Darcy Ribeiro, Avenida Alberto Lamego, nº 2000, Parque Califórnia, Cep 28013-602, Campos dos Goytacazes, RJ, Brazil

Abstract

Most commercial super sweet corn lines focus on simple hybrids. Information about the general combining ability (GCA) and about the specific combining ability (SCA) are relevant for hybrid development. The aim of the present study is to estimate the general and specific combining ability effects associated with yield and quality traits of super sweet corn. Nine lines (Flint) and ten lines (Dent) were crossed in a partial diallel fashion to produce 90 F1 hybrids. The hybrids and ten checks were assessed through the duplicate simple lattice design, with four repetitions, in two environments of Rio de Janeiro State, during the 2015 season. Data of six agronomic traits associated with yield, and five traits associated with quality were recorded. The results showed that GCA and SCA were significant (P ≤0.01) for almost all herein studied traits. The relative magnitude of GCA and SCA mean squares indicated the prevalence of additive effects for the quality traits, as well as non-additive effects for yield traits. The GCA and SCA (P≤0.01) interactions showed different genotype responses to the different environments. The "Flint" L1 inbred line presented the highest concentration of alleles favoring the increment for most of the traits. This line was the most suitable for the formation of new super-sweet hybrids. Three crosses (L8 x L18, L1 x L13 and L6 x L15) showed desirable SCA effects for almost all traits. These crosses are valuable and could be used in corn breeding programs in order to achieve high yielding and quality combinations.

Pages 1188-1194 | Read More| Supplementary Data | doi: 10.21475/ajcs.17.11.09.pne538

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Spray droplet spectrum and spray deposition in different soybean sowing systems

State University of Goiás, Henrique Santillo Campus (CCET), Zip Code: 459, Post Code: 75132-400, Anápolis, Brazil

University of Brasília, Department of Agronomy, Darcy Ribeiro Campus, Zip Code: 04357, Post Code: 70904-970, Asa Norte, Brasilia/DF, Brazil

Abstract

Soybean, Glycine max (L.) Merrill, can adapt to the environment and management alterations, in particular to the use of different spacings and plant populations. This paper aimed at checking the influence of the morphological changes of soybean plants grown in the cross sowing systems on the spray droplet spectrum and spray deposition. The experiment was conducted in the summer of 2013/2014 harvest season, using the randomized block design with factorial arrangement of 2 x 3 x 3, being two sowing systems (cross and in line), three cultivars (BRS Valiosa RR with determinate growth habit, NA 7337 RR with semi-determinate growth habit and BMX Potencia RR with indeterminate growth habit) and three sowing densities (245,000; 350,000 and 455,000 plants per ha-1). To study the spray deposition, it was applied a solution composed of water and brilliant blue marking dye (FCF blue dye, Duas Rodas Ltd.), after the application, four leaves of each soybean were collected from their parts (lower, middle, higher) in five plants per plot. The results showed that the cross sowing system provided lager canopy closure between lines 50 days after soybean emergence, facilitated by the population increase. There is a difference in the droplet deposition in the canopy parts of the plant on both sowing systems. The cultivar with semi-determinate growth habit, NA 7337 RR, allowed better spray deposition in the lower plant parts. The cross sowing system does not interfere with spraying quality in relation to the conventional system (in line).

Pages 1195-1202 | Read More| doi: 10.21475/ajcs.17.11.09.pne543

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Coffea arabica lines with resistance to nematode Meloidogyne paranaensis derived from crossings with IPR 100

Instituto Agronômico do Paraná (IAPAR), Plant Breeding Department, Rodovia Celso Garcia Cid, km 375, 86047-902, Londrina-PR, Brazil

Universidade Estadual de Londrina (UEL), Agronomy Department, Rodovia Celso Garcia Cid, km 380, 86057-970, Londrina-PR, Brazil

Abstract

The aim of this work was to evaluate the reaction of IPR 100 derived Arabica coffee lines to the nematode Meloidogyne paranaensis and to investigate the association between the parameters used to select resistant genotypes. The experiment was carried out in a greenhouse at IAPAR in Londrina - PR, Brazil. The resistance to M. paranaensis of nineteen Coffea arabica F3 lines derived from the cross “PRFB E9705-9” × ‘IPR 100’ and three from the cross ‘IPR 100’ × “Sarchimor E9601 III-19-1” were assessed. Plants with three to four pairs of leaves were inoculated with 5000 M. paranaensis eggs and J2 juveniles. After 90 days of inoculation, the variables reproduction factor (RF), fresh weight of roots (FWR) and number of eggs and J2 juveniles per gram of roots (Nematodes.g-1) were assessed. Reduction in the reproduction factor (RRF) and host susceptibility index (HSI) were used to classify the resistant levels. Resistant lines were identified and the use of RRF, HSI and RF indices together helped to identify genotypes with resistance to nematodes. In the present study, statistical difference between the FWR of the genotypes was observed. Thus, if the indices are used alone, it is likely that HSI is better, since it can minimize possible interference in the classifications due to differences between the root volumes of the assessed genotypes. The percentage of plants with different resistance levels based on the classification of RRF and HSI and percentage of resistant plants based on RF are useful to identify homozygous and heterozygous genotypes.

Pages 1203-1209 | Read More| doi: 10.21475/ajcs.17.11.09.pne557

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Development and yield of maize in response to inoculation of associative diazotrophic bacteria and nitrogen doses

Julio Cezar Fornazier Moreira, Salomão Lima Guimarães*, Erineudo Lima Canuto, Edna Maria Bonfim-Silva

University of São Paulo/ESALQ, Department of Soil Science, 13418-900, Piracicaba, SP, Brazil

Federal University of Mato Grosso, Department of Agricultural and Environmental Engineering, Institute of Agricultural Sciences and Technology, Road Rondonópolis/Guiratinga, Km 06, 78735-901, Rondonópolis, MT, Brazil

Federal Institute of Education, Science and Technology Mato Grosso, 78106-000, Santo Antônio do Leverger, MT, Brasil

Abstract

The use of diazotrophic bacteria features an important alternative to nitrogen (N) supply to crops. However, the efficiency of biological nitrogen fixation (BNF) depends on the capacity of bacterial-plant interaction. One strategy to improve this interaction is to select bacterial strains adapted to local edaphoclimatic conditions. Thus, we hypothesized that diazotrophic bacteria isolated under local edaphoclimatic conditions have a better efficiency of interaction with the plant, resulting in a greater N supply capacity for the Zea mays crop. This study evaluated the effects of inoculation of diazotrophic bacteria and N doses on the development, yield and nutrition of maize grown in Campo Verde (Mato Grosso, Brazil) in the 2013/2014 crop season. The experiment was conducted under a randomized block design in bifactorial scheme 4×3. The treatments consisted of a commercial inoculant (strains Ab-V5 and Ab-V6 of Azospirillum brasilense), two isolates of associative diazotrophic bacteria (MTAz8 and MTh2, similar to Azospirillum sp. and Bacillus sp., respectively) and absence of inoculation (control), combined with three N doses (0, 55 and 110 kg·ha-1) with four replicates. Plant height, spike insertion, stem diameter, chlorophyll index, N concentration in leaves and grains, grain yield and aboveground dry matter were evaluated. There was significant interaction of inoculation and N doses in aboveground dry matter. The other variables, except for stem diameter, were influenced by only one factor, inoculation or N doses. Our results show that inoculation of isolates MTAz8 and MTh2 promotes a substantial increase in the production of aboveground dry matter in relation to the commercial inoculant, confirming our hypothesis. In addition, our results suggest that inoculation promotes increases in grain yield, even without application of N fertilizer.

Pages 1210-1215 | Read More| doi: 10.21475/ajcs.17.11.09.pne561

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Agro-industrial quality of plant cane, first and second ratoon in sugarcane varieties

Vinicius Santos Gomes da Silva, Mauro Wagner de Oliveira, Abraão Cícero da Silva*, Aleksandro Ferreira da Silva, Elaine Rocha Galvão, Mayame de Brito Santana

Department of Agronomy, University Federal Rural of Pernambuco, UFRPE, Brazil

Department of Agronomy, University Federal of Alagoas – UFAL, Brazil

Department of Agronomy, University of Bahia State, UNEB, Brazil

Abstract

The variables related to the agro-industrial quality in sugarcane considered as main tools are being used by producers to choose the varieties to be planted. In general, cultivars that present a better industrial yield for the manufacture of sugar and alcohol have great importance promoting crop sustainability. In this research, the objective was to evaluate the industrial quality of four sugarcane varieties during plant-cane, first and second ratoon crops. The experimental design was a randomized block, with four treatments and five replications. The varieties studied were RB867515, RB92579, SP813250 and VAT90212. In first and second ratoon cycles, the industrial quality of the four varieties was evaluated by determining the fiber content, apparent sucrose (Pol), purity, soluble solids (Brix) and total recoverable sugars (TRS). The results showed that varieties RB867515, RB92579, SP813250 and VAT90212 were similar for agro-industrial quality. In first ratoon crop, only fiber was same between varieties. The RB867515 evidenced larger soluble solids and recoverable sugars. In second ratoon crop, the RB92579 evidenced larger apparent sucrose (Pol) and soluble solids (Brix) and total recoverable sugars (TRS).

Pages 1216-1220 | Read More| doi: 10.21475/ajcs.17.11.09.pne688

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Soil dynamic alterations and use efficiency of nitrogen by Brachiaria species

Gustavo Castoldi*, Jhônatas Gomes dos Reis, Mariângela Brito Freiberger, Darliane de Castro Santos, Ciro Antonio Rosolem

Goiano Federal Institute, Rede Arco Norte. Rio Verde, GO, Brazil

São Paulo State University (UNESP), College of Agricultural Sciences. Botucatu, SP, Brazil

Goiano Federal Instituto. Campos Belos, GO, Brazil

Abstract

Under certain circumstances species of the Brachiaria genus, particularly B. humidicola might be able to suppress the biological nitrification in soil. This study aimed to investigate the ability of four Brachiaria species cultivated in Brazil to promote changes in the N dynamics in the soil as well as its capacity in use efficiently N under low N availability. In a greenhouse condition and using a Quartzipsamment soil, four species of Brachiaria (B. brizantha, B. decumbens, B. humidicola and B. ruziziensis) and two cut managements (“single cut” – performed at 140 days after seeding (DAS) and “cut/regrowth”– performed at 55 DAS and 85 days after the first cut (140 DAS), plus a control treatment containing only soil were compared in a factorial design (4×2+1). The following evaluations were performed in plants: dry matter of shoots and roots, total N content, N accumulated and N use efficiency; and soil (which was split in rhizospheric and non-rhizospheric): ammonium, nitrate and total–N contents and pH value. Based on the soil inorganic–N content, there was no detectable effect of species in the soil nitrification process. Moreover, the highest ability of uptaking and using the N was observed in B. humidicola, which in the “single cut” management proved to be able to produce 201 g of shoot dry matter in response to each 1 g of N accumulated.

Pages 1221-1227 | Read More| doi: 10.21475/ajcs.17.11.09.pne604