Australian Journal of Crop Science   AJCS

Spatio-temporal distribution of the leaf crown borer Eupalamides cyparissias in coconut (Cocus nucifera L.) plantation in a tropical region

Raphael Coelho Pinho*, Paulo Roberto da Silva Farias, Telma Fatima Vieira Batista, Artur Vinicius Ferreira dos Santos, Lucas Faro Bastos

Marabá Industrial Campus, Federal Institute of Pará (CMI-IFPA), 68508-970, Marabá, Pará, Brazil
Department of Plant Biology and Plant Health, Institute of Agricultural Sciences, Federal Rural University of the Amazon (UFRA), 66077-530, Belém, Pará, Brazil
Faculty of Geoprocessing, Federal University of Pará (UFPA), 67130-660, Ananindeua, Pará, Brazil
SOCOCO S/A – Agroindústrias da Amazônia, Brazil

Abstract
The leaf crown borer Eupalamides cyparissias (Fabricius, 1777) is an agricultural pest that deserves attention in the cultivation of coconut (Cocos nucifera L.) and other economically important palm trees (Areacaceae). Several studies address the use of geostatistics to understand the attack of pest insects in agriculture, but there are no studies on the spatial and temporal patterns of E. cyparissias in coconut trees. The presence or absence of the borer was verified monthly in all coconut plants of a plot measuring 12.5 hectares, from July 2018 to October 2020. The occurrence of the borer was verified by the appearance of two main symptoms in the coconut trees. Dispersion patterns of E. cyparissias were studied using semivariograms to determine the most suitable spatial distribution model for the species. Kriging maps were created. Exponential and spherical semivariogram models showed the best fit to the patterns of spatial dispersion of the borer, showing that the attack on the coconut plantation occurs in an aggregate, and in foci, with a range of 20 to 160 metres. The climatic data had no significant correlation with the infestation rate. These results show that geostatistics are an important tool to define reliable sampling plans for integrated pest management. It is useful to assess the spatial and temporal distribution of E. cyparissias.

Pages 879-886 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p3847
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Seasonality of Violet-winged grasshopper (Tropidacris collaris) (Stoll, 1813) (Orthoptera: Romaleidae) in the dwarf cashew

Gabriela Priscila de Sousa Maciel, Lucas de Lima Farias, Marcos Gonçalves Lhano, José Bruno Malaquias, Poliana Martins Duarte, Marcos Levi Saraiva Silva, Nivia da Silva Dias-Pini*

Programa de Pós Graduação em Agronomia/Fitotecnia, Universidade Federal do Ceará -Pici, s/n, Bloco 805, Fortaleza, Ceará, 60355-636, Brasil
Programa de Pós Graduação em Zootecnia, Universidade Federal do Ceará -Pici, Setor de Abelhas, Bloco 814, Fortaleza, CE, 60356-000, Brasil
Departamento de Entomologia da Embrapa Agroindústria Tropical, Rua Dra Sara Mesquita 2270, Fortaleza, Ceará, 60511-110, Brasil
Universidade Federal de São Carlos (UFSCar) Rod. Washington Luiz, s/n - São Carlos, São Paulo, 13565-905, Brasil
Rua Prof. Dr. Antonio Celso Wagner Zanin, Instituto de Biociências, UNESP - Campus de Botucatu, Botucatu, São Paulo, 250, 18618-689, Brasil

Abstract
Tropidacris collaris (Stoll, 1813) is a polyphagous pest, found throughout the South American continent.It has recently been reported to cause damage to cashew trees. The aim of this study was to evaluate the population dynamics of T. collaris in the dwarf cashew, the effects of climate variables on the population dynamics of T. collaris, and the population dynamics of T. collaris in relation to the phenological stages of the dwarf cashew. Violet-winged grasshopper was collected in a clonal garden with 35 dwarf cashew clones (Anacardium occidentale L.) in Pacajus, Ceará, Brasil. The specimens were randomly captured using an entomological net in two collectors spaced 10 m apart. The collections were made between 09:00 and 11:00, in two 45-min shifts separated by an interval of 15 min. In the laboratory, the insects were separated and weighed, and the females dissected to assess the degree of maturation of the ovaries (I, II and III) and classify the ovipositor valves. A greater abundance of adults was found in December 2017 and June 2018. The number of females with mature ovaries (type III) showed a positive correlation with ovipositors with open valves, such ovaries being registered in December 2017, and in January and July 2018. Wind speed, evapotranspiration and relative humidity showed a significant correlation with the nymph population of T. collaris. The greatest peaks in the nymph population were stimulated by the leaf fall/leaf flux phenological stages of the dwarf cashew. In this study we show some of the phenological aspects of T. collaris under field conditions, correlated with climatic and phenological variables of the cashew tree. These results may help in decision-making about the application of methods to control T. collaris in tropical regions, as this insect is polyphagous, and its large size has great potential for damage to several crops.

Pages 887-892 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p3900
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GC-MS olfactometry reveals sesquiterpenes α-humulene and δ-cadinene significantly influence the aroma of treated Aquilaria malaccensis essential oil

Yasotha Sundaraj, Ahmed Mediani, Kenneth Francis Rodrigues, Syarul Nataqain Baharum*

Metabolomics Research Laboratory, Institute of Systems Biology (INBIOSIS), Universiti Kebangsaan Malaysia (UKM), 43600 Bangi, Selangor, Malaysia
Faculty of Engineering and Life Sciences, Universiti Selangor (UNISEL), 45600 Bestari Jaya, Selangor, Malaysia
Biotechnology Research Institute, Universiti Malaysia Sabah (UMS), 88400 Kota Kinabalu, Sabah, Malaysia

Abstract
Aquilaria malaccensis is a tropical woody tree that produces agarwood, which is valued for its aromatic properties. Agarwood is widely used in traditional medicines and the cosmetics industry. Natural agarwood production in the wild, which occurs due to fungal infection, is scarce and cannot meet the market demand. Hence, many artificial techniques have been employed to stimulate the production of agarwood. Although many studies have determined the volatile compounds present in naturally produced agarwood, the characterisation of these compounds from differentially treated agarwood samples, particularly A. malaccensis, is still limited. This study was conducted to identify and differentiate the volatiles present in treated and healthy A. malaccensis wood and essential oil using the solid phase microextraction (SPME) and hydrodistillation techniques, respectively, coupled with gas chromatography-mass spectrometry (GC-MS) analysis. Subsequently, the olfactory active compounds in the treated agarwood essential oil were determined via gas chromatography-mass spectrometry, coupled with olfactometry analysis (GC-MS/O) with four panellists. The essential oil from the treated agarwood was found to be abundant in sesquiterpene and aromatic compounds (80.61%), which was a similar result to that obtained from the volatiles of the wood that yielded 86.94%. Among the major sesquiterpene constituents in the essential oil are α-cadinol (19.40%) and 10-epi-γ-eudesmol (13.39%), whereas α-humulene (13.33%), α-copaene (12.49%) and δ-guaiene (10.41%) predominated in the SPME extract. Meanwhile, GC-MS/O analysis revealed that the sweet, woody agarwood aroma is an orchestra of olfactory active compounds that are significantly influenced by sesquiterpenes such as α-humulene and δ-cadinene. This study highlights that although treated agarwood is rich in secondary metabolites, only a handful, particularly those belonging to sesquiterpenes, are actual aroma impact compounds.

Pages 893-901 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.23.17.12.p3916
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Planting season alters the interference of weeds in the common bean

Jorge Luis Tejada*, Leandro Borges Lemos, Ebson Silva, Pedro Luís da Costa Aguiar Alves

Department of Biology, São Paulo State University, Jaboticabal, SP, CEP 14844-900, Brazil
Department of Plant Production, São Paulo State University, Jaboticabal, SP, CEP 14844-900, Brazil
Department of Plant Production, National Agrarian University La Molina, Lima, CEP 15024, Peru

Abstract
The common bean has social, economic, culinary, and environmental relevance. Considering its low competitive capacity and the intensive use of herbicides, methods such as planting time can help in weed management. To determine the effect of the planting season on controlling weeds affecting common beans, an experiment was conducted during the summer planting and another in winter planting . For that seven incrementing periods were implemented: 0-10, 0-20, 0-30, 0-40, 0-50, 0-60 and 0-80 days after bean emergence with coexistence of weeds and the same periods with control of weeds, which established 14 treatments in four repetitions, under a random block design. Weeds were analyzed using a phytosociological method and their dry mass with yield examined by regression. The non-linear regression analysis determined the pre-interference period (PIP), the critical period for interference prevention (CPIP) and the total interference prevention period (TIP). The relevant species were Nicandra physaloides, Digitaria nuda and Raphanus raphanistrum. The TIP was similar in both planting seasons. The CPIP was 38 and 33 days in summer planting and winter planting, respectively. The PIP had six more days in winter planting compared to summer planting. The higher dry mass in weeds reduced yield by 14.7 % in winter planting, in relation to the summer planting, but the reduction was faster in this season. Winter planting conferred a certain competitive advantage to the crop over some weed species, thus it could be suggested planting common bean in that season.

Pages 902-909 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p3922
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Physiological quality of soybean seeds produced under different spatial arrangements of plants

Caio Sippel Dörr, Tainan Lopes de Almeida, Victor Mouzinho Spinelli, Deivid Araújo Magano*, Luciano Carlos da Maia, Luis Eduardo Panozzo

Universidade Federal de Pelotas/UFPEL, Departamento de Fitotecnia, Pelotas, RS, 96.160-000, Brazil 

Universidade Federal de Rondônia/UNIR, Departamento de Biologia, Porto Velho, RO, 76801-059, Brazil 

Universidade Regional do Noroeste do Estado do Rio Grande do Sul/Unijuí, Departamento de Estudos Agrários/ Deag, Ijuí, RS 97800-800, Brazil

Abstract
The present study aimed to evaluate the physiological effect of seeds on soybean genotypes in the southern region of Rio Grande do Sul. The test was developed in the field, in two agricultural crops, on a farm located in the District of Monte Bonito - Pelotas (RS, Brazil), in eutrophic haplic planosol soil, with geographic coordinates 31° 40' 27"S and 52°23' 28 "W. The experiment consisted of twelve treatments involving two factors: factor A - 3 soybean genotypes (NA 5909 RR (super early, growth indeterminate and maturation group A), NS 6006 IPRO (high grain weight, growth indeterminate and maturation group B 5.9), and NS 5959 IPRO (precocity, indeterminate growth and maturation group C) and factor B - 4 line spacing (0.17; 0.30; 0.45 and 0.60 meters). The experimental design used was randomized blocks in a factorial scheme (3x4) with four blocks. The plant population used was 330.000 plants ha-1. The evaluations of the physiological performance of seeds were germination, first germination count, length and dry matter of aerial part, root, and a total of seedlings, accelerated aging, and emergence in the field. Soybean plants better distributed in the cultivation area, in spacings of 0.17 and 0.30 meters, present greater plant height, stem diameter, and productive performance.the only genotype that presented a reduction in germination as the row spacing increased was 'NS 6006 IPRO', resulting in seeds with lower germination in the spacings of 0.45 and 0.60 m compared to the other genotypes under study. The reduction in the spacings, 0.17 and 0.30 meters, produced seeds with better physiological quality, evidenced in years with rain preceding the harvest.

Pages 910-918 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p3987
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Mycorrhization of three cultivars of Colocasia esculenta L. Schott and evaluation of their resistance to mildew caused by Phytophthora colocasiae

Djeuani Astride Carole*, Mbouobda Hermann Désiré, Wadawa Josué, Ngonkeu Mangaptche Eddy Léonard, Metopa Tankeu Joseph Durand, Sob Nguépi Innocent, Fotso, Niemenak Nicolas

Laboratory of Plant Physiology and Biochemistry, Higher Teachers’ Training College, Department of Biological Sciences, University of Yaoundé 1, Yaoundé-Cameroon
Departments of Plant Biology, Faculty of Science, University of Yaoundé 1, Yaoundé-Cameroon
Higher Teachers’ Training College of Bambili, University of Bamenda, Bamenda-Cameroon
Institute of Agricultural Research for Development (IRAD), Regional Biological Control and Applied Microbiology Laboratory, Yaoundé-Cameroon

Abstract
The objective of this work was to evaluate the effect of arbuscular mycorrhizal fungi on the development of taro leaf blight during the interaction of Colocasia esculenta - Phytophthora colocasiae. Three cultivars of C. esculenta were used with local names, Ekwanfre, Macoumba, and Banlah. The experimental device was a complete randomized block with two repetitions. Four treatments were applied (Control, Mycorrhizal, Infected, and Mycorrhizal+infected). After one month of growth, an artificial infection was carried out with a solution of spores of P. colocasiae of 5x104 sporangia/ml. Disease severity was assessed every 5 days for 20 days. On D20, cytological analysis, mycorrhizal status, metabolite content, and leaf antioxidant enzyme activity were determined. The results showed that the incidence of the disease is 100% from D10 for the treatment infected with the Macoumba cultivar. Mycorrhization inhibited the action of the pathogen. The incidence and severity of the disease are low and less than 50%, in the Mycorrhizal+infected treatment plants compared to the infected treatment. Cytological analysis revealed fungal, and mycorrhizal structures in the leaves and roots. The maximum frequency and intensity of mycorrhization were 73.33±02.51 and 12.83±04.75% in the mycorrhizal plants of the Macoumba treatment. The total chlorophyll content is less than 1 mg.g-1 of WF, in the three cultivars in infection condition. The contents of total soluble proteins, amino acids, and proline are higher in the plants of the infected treatment compared to mycorrhizal and Mycorrhizal+infected. The H2O2 produced was scavenged by APX and G-POD compared to CAT. These results make it possible to note that the AMFs used contribute to the protection of the C. esculenta plants against the harmful effects linked to the presence of P. colocasiae.

Pages 919-928 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p3990
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Genotypic variation of adaptive and yield component traits of introduced grain oats (Avena sativa L.) grown in Bangladesh

Md. Nashir Uddin*, Md. Ali Babar, Stephen A Harrison, Ummea Khairun Fatema, S. M. Mostafa Kamal Khan

Department of Biochemistry and Microbiology, School of Health and Life Sciences, North South University, Dhaka-1229, Bangladesh
Department of Applied Biological chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
Department of Agronomy, University of Florida, Gainesville, Florida, FL 32611, USA
Department of Agronomy, School of Plant, Environmental and Soil Sciences, Louisiana State University (LSU), Baton Rouge LA 70803, USA
Department of Statistics, Jagannath University, 9-10 Chittaranjan Avenue, Dhaka-1100, Bangladesh

Abstract
Oat (Avena sativa L.) is considered a nutritious cereal. Its demand has surged across the globe steadily for half a decade, including in Bangladesh. Because there is no local variety, the current supply in Bangladesh solely relies on imports. This study aimed to introduce grain oats from the United States of America (U.S.A.) to Bangladesh and determine the extent of their adaptability and yield in this new environment. One hundred oat accessions were introduced in collaboration between North South University, Bangladesh and the University of Florida, U.S.A. They were evaluated in field conditions from November 2019 to April 2020 in the Dinajpur district, Bangladesh in two replicated measurements of 13 morphological traits with RCBD design. The broad-sense heritability ranged from 11.7% to 90.0% for the measured traits. The yield-related trait, spikelet numbers, was positively correlated with height (0.30), dry weight (0.46), and harvest index (0.42) but negatively correlated with heading (-0.05), flowering date (-0.05), and tiller numbers (-0.16). Growth habit was negatively correlated with height (-0.07) and dry weight (-0.25). Principal components 1 and 2 explained 43.01% of the variability and were strongly influenced by heading and flowering date. Cluster analysis assigned the genotypes into six main clusters, and the analysis showed that spikelet numbers, growth habit, height, harvest index, and heading date were key yield-contributing and adaptive traits. Identifying traits highly correlated with oat yield could be useful for developing new varieties adapted to Bangladesh environments. This study is a pioneer; it paved the way to breed new high-yielding grain oat varieties for Bangladesh.

Pages 929-934 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.23.17.12.p4003
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Evaluation of damage caused by stink bug (Diceraeus melacanthus) (Dallas) and Euschistus heros (F.) (Heteroptera: Pentatomidae) to the maize seedlings

Ademar Novais Istchuk*, Josemar Foresti, Paulo Roberto da Silva, Vanda Pietrowski, Renata Ramos Pereira

Corteva Agriscience, Toledo, Paraná, Brazil
Corteva Agriscience, Planaltina, Distrito Federal, Brazil
Universidade Estadual do Oeste do Paraná, Marechal Cândido Rondon, Paraná, Brazil

Abstract
Understanding of different damage potentials between insect species feeding on maize [Zea mays (L.)] is critical for elaborating control decision tools. There is a lack of information on the damage that the stink bug Diceraeus melacanthus (Dallas) and Euschistus heros (F.) may cause to maize seedlings, especially under high densities. Therefore, we compared the damage of these species to maize in a greenhouse using four infestation levels (zero, two, four, and eight adults per plant), in a randomized complete block design with six replications. Five weekly evaluations were performed after infestation, and plants were harvested at physiological maturity. The results indicated that D. melacanthus caused more damage than E. heros in all infestation levels. Two adults of D. melacanthus per plant for 21 days resulted in the death of 96% of the plants. Euschistus heros caused four-times less damage to early-stage maize plants than D. melacanthus. Based on the regression analysis, the infestation of one E. heros adult per plant reduced the number of kernels per row and weight of harvested grain by 11%.

Pages 935-943 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p4004
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Soil mobilization in function of pneumatic seeding machine and sowing speed in maize

Antonio Tassio Santana Ormond*, Carlos Eduardo Angeli Furlani, Elizabeth Haruna Kazama, Rafael Henrique de Freitas Noronha, Franciele Morlin Carneiro, Antonio Augusto Nogueira Franco, Fenando João Bispo brandão

Department of Agricultural and Earth Sciences, State University of Minas Gerais, Passos, Minas Gerais, Brazil
Department of Agricultural Engineering, Laboratory of Agricultural Machinery and Mechanization, São Paulo State University, Jaboticabal, São Paulo, Brazil
Centro de Formação em Ciências Agroflorestais (CFCAf) - Federal University of Southern Bahia - UFSB, Itabuna, Bahia, Brazil
Federal Technological University of Paraná (UTFPR), Santa Helena, Paraná, Brazil
Federal Institute of Mato Grosso (IFMT), São Vicente campus, Brazil

Abstract
The sowing process can be affected by constructive differences related to the seeder, morphological and climatological conditions, and depending on the working speed used. The performance of the furrow opening components of the seeders is essential for obtaining good yields and productivity of maize crops. This work aims to evaluate maize sowing with a Massey Ferguson tractor model MF 7370 with power of 125 kW pneumatic seeder-fertilizer as a function of its behavior at the different displacement speeds. The statistical design used was randomized blocks, with six displacement speeds, approximately (V1=2.0; V2=4.7; V3=6.5; V4=8.1; V5=10.3 and V6=12.3 km h-1), for the maize crop, with four replications, totaling 24 experimental plots. The following soil mobilization parameters were evaluated: furrow width and depth, furrow mobilized area, and furrow opening angle. Furthermore, the following agronomic traits were also evaluated: the number of days for sowing emergence, initial and final sowing population, and grain yield. The mobilized area, angle, and depth of the furrowing fitted the quadratic regression model, while sulcus width had an increasing linear effect. Intermediate speeds V4 (8.1 km h-1) showed the highest values of the mobilized area and furrow depth and the lowest furrow angle value, whereas V3 (6.5 km h-1) presented the highest yield (8902 kg ha-1).

Pages 944-949 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.p4011
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Computational analysis of regulation and expression of plant DNA repair genes under various abiotic stresses reveals a stochastic correlation

Padinhatta Purayil Amritha, Rajeev Anjitha, Balu Sruthi, Meenakshi Anilkumar, Jasmine Madhukant Shah

Department of Plant Science, Central University of Kerala, Kasaragod, Kerala, India
Rajeev Anjitha: Department of Plant Science, Central University of Kerala, Kasaragod, Kerala, India
Department of Plant Science, Central University of Kerala, Kasaragod, Kerala, India
Vellore Institute of Technology, Vellore, Tamil Nadu, India
Department of Plant Science, Central University of Kerala, Kasaragod, Kerala, India

Abstract
Biotic/abiotic stresses are known to induce genome instability in all organisms. Plants being sessile, are more vulnerable to stresses. Thus, they have evolved mechanisms to protect their genome from the unpredictably changing environment. DNA repair genes play a critical role in preserving genome integrity. Plants have about 15 different DNA repair pathways comprising more than 100 genes. To gain a better understanding of how plant DNA repair genes perceive stress and regulate their expression, we performed a computational analysis of the putative binding sites of different abiotic stress-responsive transcription factors (ASRTFs) on their promoters, in the model plant Arabidopsis thaliana. Of the 12 different ASRTFs that we analysed, MYC2 had the highest number of 1876 putative binding sites. Diversity study in 135 DNA repair gene promoters revealed that these had about 6 to 12 types of putative binding sites for the ASRTFs. While RAD51 promoter had the highest number of 207 putative binding sites, RECQ4B had only 11. Comparison of the Arabidopsis eFP browser-based temporal/spatial expression profiles of these genes under nine different abiotic stresses revealed that all of these genes had altered expression under various stresses. Some genes exhibited similar expression profiles. To identify the reasons for their similar expression pattern, we compared the promoter sequences and putative cis-regulatory elements such as binding sites for ASRTFs and methylation-prone nucleotide repeats. Our analysis indicated that the gene expression and gene regulation mediated by ASRTFs, and DNA methylation have a stochastic correlation.

Pages 950-958 | Full Text PDF| doi: 10.21475/ajcs.23.17.12.poj3789