Australian Journal of Crop Science   AJCS

Management of fungicides can affect resilience of cultivars to foliar diseases in oats

Laura Mensch Pereira, José Antonio Gonzalez da Silva, Ivan Ricardo Carvalho*, Christiane de Fátima Colet, Denize da Rosa Fraga, Juliana Maria Fachinetto, Odenis Alessi, Natiane Carolina Ferrari Basso, Cibele Luisa Peter, Cristhian Milbradt Babeski, Natália Guiotto Zardin, Lisa Brönstrup Heusner

Regional University of the Northwest of the State of Rio Grande do Sul, Ijuí, CEP 98700-000, RS, Brazil

Abstract
The entry and progression of oat foliar diseases affect yield potential, requiring a combination of genetic resistance and management technologies. The objective of the study is implementing a management system to reduce the use of fungicide in oats by the anticipation of the application and a longer interval from the last application to the grain harvest, together with the identification of cultivars that are more resilient to disease. The study was developed in 2018 and 2019, in soil of type Typical Dystroferric Red Latosol and Cfa (humid subtropical) climate, in Augusto Pestana, RS, Brazil. The experimental design was randomized blocks with three replications in a 23 x 5 factorial, for 23 oat cultivars and 5 conditions of fungicide use: control (no application); one application 60 days after emergence (DAE); two applications at 60 and 75 DAE; three applications at 60, 75 and 90 DAE and four applications at 60, 75, 90 and 105 DAE, with measurement of grain productivity. In oat cultivation, the early and sequential application of fungicide at 60, 75 and 90 days after emergence guarantees satisfactory productivity with a long interval from the last application to harvest for greater food security. The cultivars URS Altiva and IPR Artemis show resilience in the presence of foliar diseases in the absence and reduced use of fungicide, facilitating the transition between conventional and agroecological agriculture in oat cultivation.

Pages 407-413 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3720
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How does water stress affect Corymbia citriodora (Hook.) K.D. Hill & L.A.S. Johnson throughout the initial growth phase?

Robson Luis Silva de Medeiros*, João Vitor Oliveira de Souza, João Pedro Peixoto Fernandes, Reginaldo de Oliveira, Priscila Lupino Gratão, Rinaldo Cesar de Paula

Department of Agricultural Sciences, School of Agricultural and Veterinarian Sciences, São Paulo State University (Unesp), 14884-900, Jaboticabal, São Paulo, Brazil

National Institute of the Semiarid Region, Avenida Francisco Lopes de Almeida Serrotão, CEP 58434-700, Campina Grande, PB, Brazil

Abstract
Corymbia citriodora has the potential to be used in the expansion of the forestry sector in Brazil, as it presents greater tolerance to abiotic stresses than other commonly cultivated species. The plants are exposed to several stress events throughout their cycle that can compromise their growth and development. This study aimed to evaluate physiological, biochemical, and growth characteristics in C. citriodora plants grown under different irrigation regimes at different ages. Plants of C. citriodora grown in pots were submitted to five irrigation regimes (20, 35, 50, 65, and 80% of the maximum soil water retention capacity) for 105 days in a greenhouse. Plant growth, gas exchange, leaf water potential, chlorophyll, carotenoids, and proline contents, and lipid peroxidation by MDA content were evaluated at the end of this period. More restrictive irrigation regimes reduced seedling growth. Water availability affected physiological, biochemical, and morphological parameters. Water stress associated with plant growth increased stress levels.

Pages 414-422 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3726
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Bio-inputs promoting marandu grass growth: productivity, physiological response and nitrogen accumulation

Cássio Carlette Thiengo*, Danilo Messias de Oliveira, João Victor Silva Bernardes, Letícia Oliveira da Rocha, Eduardo de Sá Mendonça, Fábio Lopes Olivares, Diego Lang Burak

Department of Agronomy, Federal University of Espírito Santo, Center for Agricultural Sciences and Engineering, 29500-00, Alegre, Espírito Santo, Brazil
Center for Nuclear Energy in Agriculture, Stable Isotopes Laboratory, University of São Paulo, 134160-000, Piracicaba, São Paulo, Brazil
Laboratory of Cell and Tissue Biology and Center for Development of Biological Inputs for Agriculture, Universidade Estadual do Norte Fluminense Darcy Ribeiro, 28013-602, Campos dos Goytacazes, Rio de Janeiro, Brazil

Abstract
Nutrient replenishment is one of the significant factors limiting the full development of extensive pasturelands. As a result, bio-inputs have been increasingly used under field conditions to improve plant growth in low-fertility soils. This study aimed to evaluate their effects on the productivity, physiological responses to and nitrogen (N) accumulation in marandu grass (Urochloa brizantha cv. marandu). The experiment was carried out using a randomized block design with four treatments and three replicates in a greenhouse under controlled conditions. In low-fertility soils, lower synthetic fertilizer inputs were simulated (40% N-P-K) (Control), and three bio-inputs were additionally applied (bio-inputs + 40% N-P-K): Azo (Azospirillum brasilense seed inoculation); HS+Herb (leaf application of humic substances combined with a cocktail consisting of Herbaspirillum species), and Coinoc (a combination of Azo and HS+Herb). We evaluated the plant biometrics (shoot and root dry matter, stem diameter and height) and physiological parameters (CO2 assimilation rate, internal CO2 concentration, transpiration, instantaneous carboxylation efficiency, and the maximum quantum yield of photosystem II), as well as the N accumulation 45 days after seedling emergence. Azo-treatment did not differ from the control in most of the variables studied. HS+Herb and Coinoc significantly (p ≤ 0.05) increased the dry matter of shoots (+237% and +255%, respectively) and roots (+106% and 83%, respectively) compared to the control. These treatments (HS+Herb and Coinoc) significantly (p ≤ 0.05) increased (almost double) the size and stem diameter, improved physiological parameters, and accumulated more N (up to 89%) compared to the control. Applying humic substance-based bio-inputs combined with the Herbaspirillum species cocktail was more efficient in stimulating the growth of marandu grass grown in soil of reduced fertility.

Pages 423-430 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3811
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Changes in anthocyanins, total phenolics, total flavonoid, and antioxidant activity of Karanda fruit at different stages of maturity

Surasak Boontang and Sakunkan Simla*

Department of Agricultural Technology, Faculty of Technology, Mahasarakham University, Maha Sarakham, 44150, Thailand

Abstract
Karanda (Carissa carandas L.) is mostly eaten raw and contains numerous phytochemicals and high antioxidant capacity. The objective of this study was to investigate the effects of the Karanda fruit’s developmental stages on its phytochemical contents, antioxidant capacity, and volatile compounds. The study herein examined three developmental stages; unripe, semi-ripe, and ripe, based on their stage of maturity as observed in their color and texture. Phytochemical properties; including pH, titratable acidity, vitamin C contents, total soluble solid, total phenolic contents, total flavonoid content, anthocyanin contents, and antioxidant capacity (determined through FRAP, DPPH, and ABTS) were measured. Our results found significant differences in the phytochemical properties in each stage of development. Ripe fruits had the highest pH, total soluble solid, anthocyanin content, and antioxidant capacity determined by FRAP. Thirteen volatile compounds were identified in the fruit samples: eight compounds within the unripe fruits, nine within the semi-ripe fruits, and seven compounds were present in the fully ripe fruits. Alanine ethyl amide and acetic acid were major volatile compounds found in unripe and semi-ripe fruits, whereas tartronic acid was present in the fully ripe fruit. We may conclude that the ripe stage of development, having the highest phytochemical contents and antioxidant activity, is most suitable for harvest and most beneficial for human health. The information obtained in this study will be useful for the efficient utilization of Karanda fruit.

Pages 431-437 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3816
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Chemical composition and antioxidant activity of crude extracts from Pachira aquatica leaves, flowers and seeds

Isabelle Luiz Rahal, Herika Line Marko de Oliveira, Wanessa de Campos Bortolucci, Angelica Barbosa Dias, Gabriela Catuzo Canonico Silva, Rodrigo Sadao Inumaro, Maria Graciela Iecher Faria Nunes, Suelen Pereira Ruiz Herrig, José Eduardo Gonçalves, Zilda Cristiani Gazim*

Laboratory of Chemistry of Natural Products, Paranaense University, Umuarama, PR, Brazil
Cesumar Institute of Science, Technology and Innovation and Cesumar University, Maringá, PR, Brazil

Abstract
Pachira aquatica, an arboreal species belonging to the family Malvaceae, is widely cultivated as an ornamental plant. Its leaves are used in folk medicine for treating skin rashes and urticaria; its fruit peels find application in the treatment of diarrhea, diabetes, and anemia; and its lipid-rich seeds are used as human and animal food. This study aimed to determine the chemical composition and assess the antioxidant potential of crude extracts from P. aquatica leaves, flowers and seeds. The plant material was collected and then dried at room temperature. The crude extracts were prepared by dynamic maceration with solvent depletion. Chemical analysis was performed by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry. Antioxidant activity was assessed by the 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), ferric reducing antioxidant power (FRAP), β-carotene/linoleic acid co-oxidation, and total phenolic content assays. Eleven flavonoids, four phenolic acids, two organic acids and four coumarins were identified in extracts. Crude extracts from leaves, flowers and seeds had total phenolic contents of 28.74; 75.68; and 14.88 g GAE/mg; half‐maximal effective concentrations for DPPH• scavenging activity of 8.02; 0.69; and 4.01 mg/mL; FRAP activities of 0.038; 0.274; and 0.042 µM ferrous sulfate/mg; and the ability to reduce β-carotene/linoleic acid co-oxidation by 42.13%; 64.85%; and 30.37%; respectively. The utilization of antioxidant compounds found in P. aquatica leaves, flowers and seeds in industrial application are a promising strategy to add value to this plant.

Pages 438-446 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.23.17.05.p3830
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Do stimulate® and Ascophyllum nodosum seaweed promote the morphophysiological characteristics of Cordia alliodora seedlings?

Aline das Graças Souza, Oscar José Smiderle*, Sonicley da Silva Maia

Department of Agricultural Sciences, University Center of Maringá, Maringá, PR, Brazil
Department of Seeds, Brazilian Agricultural Research Corporation, Boa Vista, RR, Brazil
Department of Agricultural Sciences, Federal University of Roraima, Boa Vista, RR, Brazil

Abstract
Biostimulants in native forest seedlings, when absorbed and assimilated by plants, can function as activators or inhibitors of their metabolic and physiological processes. In view of the above, the present study establishes the following research problem: Can doses of Ascophyllum nodosum seaweed extract and Stimulate® be effective in the promotion of initial growth and morphophysiological indices of Cordia alliodora seedlings? The experimental design used was completely randomized, in a 4 x 2 factorial scheme, corresponding to four doses (0, 0.2, 0.4 and 0.6 ml L-1) and two hormones (Ascophyllum nodosum and Stimulate®), with five replicates, each of which composed of five seedlings (one in each container). The morphological variables evaluated were shoot height (H), stem diameter (SD), increments in stem diameter (ΔSD) and shoot height (ΔH), shoot dry mass (SDM, g plant-1), root dry mass (RDM, g plant-1), total dry mass (TDM, g plant-1), and Dickson Quality Index (DQI). Physiological variables were: net assimilation rate (EA, g.m-2.day-1), leaf relative growth rate (RA, g.m-2.day-1), leaf area ratio (FA, m2.g-1), specific leaf area (SA, cm2.g-1) and leaf mass ratio (Fw, g.g-1). The bioregulator Ascophyllum nodosum at dose of 0.2 ml L-1 promotes increments in height (ΔH) and stem diameter (ΔSD) of Cordia alliodora seedlings. Ascophyllum nodosum at dose of 0.2 ml L-1 has positive influence on the physiological indices studied in Cordia alliodora seedlings at 120 days after transplanting. The bioregulator Stimulate® at dose of 0.6 ml L-1 is not indicated to obtain Cordia alliodora seedlings with better quality and sturdiness and shorter nursery time. The bioregulator Ascophyllum nodosum at dose of 0.2 ml L-1 is recommended to obtain increments in height (ΔH) and stem diameter (ΔSD) in Cordia alliodora seedlings.

Pages 447-452 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3832
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The efficiency of liquid source nitrogen for foliar absorption in oat

Luana Henrichsen, Natiane Carolina Ferrari Basso, José Antonio Gonzalez da Silva, Ivan Ricardo Carvalho, Christiane de Fátima Colet, Denize da Rosa Fraga, Odenis Alessi, Gerusa Massuquini Conceição, Deivid Araújo Magano, Cibele Luisa Peter, Juliana Aozane da Rosa, Márcia Sostmeyer Jung, Cristhian Milbradt Babeski, Maria Eduarda Steidl

Regional University of the Northwest of the State of Rio Grande do Sul, Ijuí, Rio Grande do Sul, Brazil

Abstract
The objective of the study is to estimate the technical, economic and stability of nitrogen use efficiency in oats intercropped with soybean and corn in conventional management using urea and nutrient spraying for foliar absorption, considering the expression of biomass and grain yields in different cropping systems, subsidizing the validation of this technology. The study was carried out in Augusto Pestana, RS, Brazil, in a soybean/oat and corn/oat system. In each system, two experiments were carried out, one to quantify biomass yield and another to estimate grain yield, totally four experiments. In all experiments the design was randomized blocks with four replications in a 2x4 factorial, for 2 nitrogen sources (liquid and solid) with 4 doses (0, 30, 60 and 120 kg ha-1), respectively. The solid source (urea) with 45% of nitrogen for root absorption and the liquid source (N-Top®) with 28% of the nutrient for foliar absorption were applied at the phenological stage of the fourth expanded oat leaf. The analyzed variables were biomass and grain productivity, obtained by cutting the three central rows of each plot at the physiological and harvest maturity stages, respectively. The efficiency of using nitrogen from a liquid source via foliar absorption in oats promotes similar results when using urea. Regardless of the nitrogen source, doses of 45 and 75 kg ha-1 are more efficient in soybean/oat and corn/oat systems, respectively. Although the technical efficiency of liquid source nitrogen is proven, the high cost does not allow recommendation on a commercial scale.

Pages 453-462 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3843
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Toxigenic fungi collected in maize fields from four states of Mexico

Abiel Sánchez-Arizpe, José Luis Arispe-Vázquez*, Daniel Alejandro Cadena-Zamudio, Ma. Elizabeth Galindo-Cepeda, Adriana Antonio-Bautista, Leslie Carnero-Avilés, Juan Mayo-Hernández, Susana Elizabeth Ramírez-Sánchez

Departamento de Parasitología, Universidad Autónoma Agraria Antonio Narro, Antonio Narro #1923, C.P. 25315, Buenavista, Saltillo, Coahuila, México
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Km 2.5 Carretera Iguala-Tuxpan, Colonia Centro Tuxpan C.P. 40000, Iguala de la Independencia Guerrero, México
Departamento de Fitomejoramiento, Universidad Autónoma Agraria Antonio Narro, Antonio Narro #1923, C.P. 25315, Buenavista, Saltillo, Coahuila, México
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Km 2, Carretera Delicias-Rosales C.P. 33000, Centro, Cd. Delicias, Chihuahua, México
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Av. Biodiversidad 2470 C.P. 47600, Tepatitlán de Morelos, Jalisco, México

Abstract
Maize is the most important crop for the Mexican society. Phytopathogenic fungi pose a major challenge to this cereal. These fungi are harmful to people and animals, mainly as a result of their mycotoxins. The objective of this research was to identify the fungi found in 18 maize genotypes collected in fields from the Mexican states of Morelos, Coahuila, Chiapas, and Puebla. Pathogens were isolated in a potato dextrose agar (PDA) culture medium and identified using morphological criteria. The pathogens were purified using monoconidial cultures and sheltered at 4 °C ± 2 °C. An analysis of variance was carried out using the SAS® 9.1 statistical software. Fungi from the following genus and species were identified: Aspergillus, Penicillium, Alternaria, Bipolaris, Trichothecium roseum, and Fusarium verticillioides. It is worth mentioning that F. verticillioides and Penicillium sp. are the most common pathogens in maize genotypes, with an incidence of 63.68 and 6.57%, respectively. Moreover, along with genus Aspergillus, they are considered to be the most important toxicological fungi, given the harm that they cause to humans and animals. Therefore, management strategies are needed to guarantee that grains can be safely consumed by society.

Pages 463-468 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3846
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Hyparrhenia variabilis a potential invasive exotic weed at Mexico

Susana Elizabeth Ramírez-Sánchez*, Jorge Gabriel Sánchez-Ken, Jose Luis Arispe-Vazquezc, Filogonio de Jesús Hernández-Guzmán, Leslie Carnero-Avilés, Luis Miguel Tamayo-Esquer

Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Av. Biodiversidad 2470 C.P. 47600, Tepatitlán de Morelos, Jalisco, México
Ecology Institute A.C. Pátzcuaro, Michoacán, México
Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, Km 2.5 Carretera Iguala-Tuxpan, Colonia Centro Tuxpan C.P. 40000, Iguala de la Independencia Guerrero, México
National Institute of Forestry, Agricultural and Livestock Research (Researcher, Weeds, Experimental Field Iguala, Iguala, Guerrero, México
Campo Experimental Norman E. Borlaug. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias, km 12, Cd. Obregón, Sonora, México. AP. 155. CP. 85000., México

Abstract
The genus Hyparrhenia Andersson ex E.Fourn. is native to Africa, but presents in several countries and many parts of the world. Mexico is one of the countries, where Hyparrhenia rufa (Nees) Stapf (Poaceae) is found. However, it is classified as a highly invasive exotic species; therefore, is on the list of invasive species in Mexico. In recent years, the presence of Hyparrhenia cymbaria (L.) Stapfand and Hyparrhenia variabilis Stapf (Poacear) has been reported, while H. variabilis has been observed in the state at Morelos, Michoacán, and Jalisco. H. variabilis has been particularly identified in the municipality of Tepatitlan, Jalisco, Mexico. It has been observed that it grows densely and displaces native vegetation. Some studies mention that there are biotypes that have the ability to inhibit nitrogen-fixing bacteria, so it is necessary to study its biology and its inhibition capabilities around nitrogen fixation and seek strategies to stop its spread. The objective of this research was to review the information that exists on the species H. variabilis and its control. Apparently, there is a lack of information on this specie. However, there are some studies on other species of the genus such as H. rufa, which classified as highly invasive and some management reports can be used for H. variabilis. Therefore, it is necessary to develop management for the species based on literature available on H. rufa.

Pages 469-472 | Full Text PDF| doi: 10.21475/ajcs.23.17.05.p3848