Australian Journal of Crop Science   AJCS

April 2022 | 16(04):2022 | ERALY VIEW | 10.21475/ajcs.22.16.04


Initial development and physiological potential of soybean and maize as a function of vigor level and seed size

Michele Renata Revers Meneguzzo, Géri Eduardo Meneghello, Ivan Ricardo Carvalho*, Fernanda Da Motta Xavier, Vanessa Pinto Gonçalves, Diéli Witte Maass, Sheila Bigolin Teixeira, Andrea Bica Noguez Martins, Francine Lautenchleger, Nadia Canalli Lângaro

Universidade Federal de Pelotas, Avenida Eliseu Maciel, s/nº, CEP 96001-970 Capão do Leão, RS, Brasil
Universidade Regional do Noroeste do Estado do Rio Grande do Sul , Brasil
Universidade Estadual do Centro-Oeste (Unicentro), Brasil
Universidade de Passo Fundo - UPF, Brasil


Abstract
This work aimed to evaluate the initial development of soybean and maize plants due to the vigor level and the seed size used. Soybean seeds of cultivar 5855 RSF IPRO (BMX ELITE) and hybrid maize Fórmula Viptera were classified in two sizes of sieve (6.00 and 6.50 mm - soybean; 7.50 and 7.00 mm - maize) and two levels of vigor for soybean and three levels of vigor for maize. The experimental design was completely randomized in a 2 x 2 bifactorial scheme (sieve size x vigor levels) for soybean and 2 x 3 (sieve size x vigor levels) for maize, with four replications. The variables evaluated were germination, first germination count and emergence in bed. In the evaluation of seedling initial performance, shoot, root and total length, volume and dry mass were evaluated at 7, 11 and 14 days after sowing for soybean and at 7, 14 and 21 days for maize seeds. High vigor soybean and maize seeds presented high physiological quality, as well as in the development of plants, where larger and of high vigor soybean seeds showed higher plant length and dry mass. The classification of seeds through the level of vigor influences the physiological quality of soybean and maize seeds. Larger seeds with higher vigor showed greater length and initial development of seedlings, being indicated the use of seeds of something vigor.

Pages 431-435 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p2395
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Potato plants micropropagated and grown from mini tubers: nutritional efficiency to phosphorus

Darlene Sausen*, Ivan Ricardo Carvalho, Márcio Renan Weber Schorr, Miriam da Silva Tavares, Raíssa Schwalbert, Anderson Cesar Ramos Marques, Camila Peligrinotti Tarouco, Ritieli Baptista Mambrin, Francine Lautenchleger, Fernando Teixeira Nicoloso

Federal University of Santa Maria, Santa Maria, RS, Brazil
Regional University of the Northwest of the State of Rio Grande do Sul, Ijuí, RS, Brazil
National Supply Company, Porto Alegre, RS, Brazil
Goiás State University, Posse, GO, Brazil
Riograndense Higher Education Center, Marau, RS, Brazil
University of the Midwest (UNICENTRO), Guarapuava, PR, Brazil


Abstract
One of the main concerns for the establishment of sustainable agriculture is the development of cultivars that absorb and use phosphorus (P) better. It is possible to produce quality seed potatoes from sprouts, microtubers, minitubers and minicuttings in closed off-soil growing systems. However, little is known if the origin of the propagating material interferes with the nutritional efficiency of phosphorus (P) by plants. Thus, the objective of this work was to compare the nutritional efficiency of P between plants produced from minitubers and micropropagation. For this, two experiments were carried out, one with plants produced from mini-tubers and the other from plants from micropropagation. Both experiments were carried out in a greenhouse and in a growing system without soil, using clones Asterix, Atlantic, SMIC 148-A and SMINIA 793101-3 and two levels of P in the nutrient solution (2.32 and 23. 2mg P L-1). The propagative origin of potato plants changes with the biomass ratio between root and shoot and plants from minitubers have a higher harvest rate, higher utilization efficiency and a higher P response rate in P biomass production than plants from micropropagation. Therefore, we recommend that selection of PUE clones should occur with plants from mini-tubers, since the responses to PUE by plants from micropropagation are not representative, under the conditions tested in this work.

Pages 436-440 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p2918
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Effect of different soil water tensions and potassium fertilization on the production and quality of netted melon (Cucumis melo L.) in the Amazon area

Joycilene Teixeira do Nascimento*, Maria do Bom Concelho Lacerda Medeiros, Joaquim Alves de Lima Júnior, Helane Cristina Aguiar Santos, Pedro Daniel de Oliveira

Department of plant production, Federal Rural University of the Amazon (UFRA), Brazil

Abstract
The objective of this study was to evaluate the production and qualitative behavior of netted melon in a protected environment subjected to different soil water tensions and potassium doses, applied via fertigation. The experimental design was randomized blocks (RBD) in a 4 x 5 factorial scheme with 20 treatments and three replicates, consisting of five percentage doses of potassium (0, 50, 100, 150 and 200%) and four soil water tensions (15, 30, 45 and 60 kPa). The variables analyzed were average yield (t ha-1), transverse and longitudinal diameter of fruits (mm), pulp thickness (mm), °Brix (%) and pH. Yield and fruit longitudinal diameter were decreased linearly with the increase in soil water tension. The best result for yield and fruit longitudinal diameter of 51.24 t ha-1 and 127.7 mm were achieved, respectively, when irrigation performed at 15 kPa tension. The lowest value was found at the maximum tension (60 kPa). Regarding potassium doses, a quadratic model fitted to the data, with maximum values of yield and longitudinal diameter at the K2O doses of 235.30 and 232.82 kg ha-1, respectively. The interaction of T x K led to higher values of °Brix under 247.68 and 371.52 kg ha-1 of K2O with tension of 24.67 kPa, with no difference between both. The best result of fruit transverse diameter was observed under combination of 371.52 kg ha-1 of K2O and 15 kPa tension. Irrigation at tension of 15 kPa and K2O dose of 247.68 kg ha-1 can be indicated for the study conditions.

Pages 441-447 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3137
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Growth of lettuce (Lactuca sativa var. iceberg) irrigated with brackish water under competition

Brenner Cabalheiro dos Santos, Víctor Alves Amorim, Larissa Pacheco Borges, Brunno Nunes Furtado, Jaime Santos do Rego Júnior, Fábio Santos Matos*

Postgraduate program in Plant Production, Universidade Estadual de Goiás, Brazil

Abstract
The objective of this work was to evaluate the effects of salt stress and competition on the development and growth of lettuce plants (Lactuca sativa var. iceberg). The plants were grown under greenhouse conditions with 50% interception of solar radiation. Iceberg lettuce seedlings were transplanted to 8-liter pots with surface area of 4.9 dm2 filled with 5 kg of a substrate composed of soil, sand, and manure at the ratio of 3:1:1 v v-1. The experiment was set up in a completely randomized design with a 6 × 2 factorial arrangement (six salinity levels and one or two plants per pot), and three replications. An electrical conductivity meter was used to determine the salinity level; NaCl was added to the water until reaching 0, 2, 4, 6, 8, and 10 dS m-1. The lettuce plants were sensitive to salt stress; however, the plants can be irrigated with brackish water with electrical conductivity equal to or lower than 2 dS m-1 without significant decreases in shoot fresh weight, therefore meeting the social demand for use low quality water in agriculture. The morphophysiological plasticity of lettuce plants increases the competitive potential of plants in high density crops, with one plant per 2.45 dm2.

Pages 448-453 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3260
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Overexpression of the mitochondrial MT-sHSP23.6 gene during antioxidant activity in tomato cv. Micro-Tom subjected to flooding

Letícia Winke Dias, André Pich Brunes, Angelita Celente Martins, Vitor Mateus Kolesny, Carine Simioni*, Roberto Luis Weiler, Cesar Valmor Rombaldi, Francisco Amaral Villela

Universidade Federal do Rio Grande do Sul (UFRGS), Departamento de Plantas Forrageiras e Agrometeorologia, Avenida Bento Gonçalves, 7712, 91501-970, Porto Alegre, RS, Brazil
Universidade Federal de Pelotas (UFPel), Departamento de Fitoetecnia, Campus Universitário, Avenida Eliseu Maciel, s/n, 96160-000, Capão do Leão, RS, Brazil


Abstract
Plants that are grown under flooding stress conditions form reactive oxygen species, both during oxygen deficiency and after reoxygenation. The tolerance of plants under these conditions depends on an efficient antioxidant system, which may be influenced by the higher expression of heat shock proteins, such as mitochondrial MT-sHSP23.6. The objective of the present study was to determine whether the overexpression of this gene increases the antioxidant activity in tomato cv. Micro-Tom plants subjected to flooding during the vegetative stage of four fully expanded leaves. The experiment was performed with three genotypes of tomato plants (Solanum lycopersicum Mill. cv. Micro-Tom), one non-transformed denominated “WT” and two modified for high and low expression of the MT-sHSP23.6 gene, subjected to normal irrigation conditions, 72 hours of flooding, and 24 and 192 hours of recovery after the removal of flooding, consisting of a 3x4 split-plot factorial design with four replications. Plants were collected at the vegetative stage of 4 fully expanded leaves to determine superoxide dismutase, ascorbate peroxidase and catalase activities, hydrogen peroxide accumulation and lipid peroxidation. Overexpression of the mitochondrial MT-sHSP23.6 gene in the evaluated plants resulted in higher antioxidant system activity. However, it did not necessarily lead to less damage caused by oxidative stress. Low expression of this gene resulted in lower antioxidant system activity and greater damage caused by reactive oxygen species.

Pages 454-460 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3376
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Potential of N2-fixing endophytic bacteria isolated from maize roots as biofertiliser to enhance soil fertility, N uptake, and yield of Zea mays L. cultivated in alluvial soil in dykes

Nguyen Quoc Khuong, Le Vinh Thuc*, Hua Huu Duc, Tran Ngoc Huu, Tran Thi Bich Van, Le Thi My Thu, Le Thanh Quang, Do Thi Xuan, Tran Chi Nhan, Nguyen Thi Thanh Xuan, Ly Ngoc Thanh Xuan

Department of Crop Science, College of Agriculture, Can Tho University, Can Tho, Vietnam
Biotechnology Research and Development Institute, Can Tho University, Can Tho, Vietnam
Experimental and Practical Area, An Giang University, An Giang, Vietnam; Vietnam National University, Ho Chi Minh City, Vietnam


Abstract
This study aimed to (i) select the endophytic bacteria from maize roots for their N2-fixing ability and (ii) evaluate the efficacy of potent indigenous bacterial strains on soil fertility, nitrogen (N) uptake, and growth and yield of maize. A total of 31 maize root samples were collected from An Giang province in Vietnam to isolate the bacteria. The pot experiment was conducted in nine treatments: (i) 100% N of the recommended fertiliser formula (RFF), (ii) 85% N of RFF, (iii) 70% N of RFF, (iv) 55% N of RFF, (v) 85% N of RFF plus a mixture of two potent strains of nitrogen-fixing endophytic bacteria (NFEB), (vi) 70% N of RFF plus a mixture of two potent strains of NFEB, (vii) 25% N of RFF plus a mixture of two potent strains of NFEB, (viii) 0% N of RFF plus a mixture of two potent strains of NFEB, and (ix) 0% N of RFF. The experiment was conducted in the greenhouse to collect soil and plant samples at harvest and observe their growth and agronomic parameters. The results showed that two acid-resistant endophytic bacterial strains were selected and identified as Enterobacter cloacae ASD-21 and E. cloacae ASD-48. At 85% N level, a mixture of the two endophytic bacteria strains was applied as biofertilisers and proved their ability to significantly enhance NH4+ content and N uptake, with an increase of 14.8 mg NH4+ kg-1 and 0.26 g N pot-1, respectively. A mixture of the two potent strains of NFEB produced higher values in plant height, stem diameter, cob length, and cob diameter compared to 100% N of RFF. It replaced 15% N of RFF but still maintained the maize grain yield.

Pages 461-470 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3417
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Morphological characteristics and DNA barcoding in bach hop (Lilium poilanei Gagnep) in Vietnam

Bui Thi Thu Huong, Duong Xuan Anh, Nguyen Huu Cuong, Ngo The An, Dong Huy Gioi*, Ho Manh Tuong, Chu Hoang Ha, Tran Thi Thu Ha, Khuat Huu Trung, Tran Dang Khanh*

Vietnam National University of Agriculture, Trau Qui, Gia Lam, Ha Noi, Vietnam
Biotechnology Institute, Vietnam Academy of Sciences and Technology, Hoang Quoc Viet, Cau Giay, Ha Noi, Vietnam
Agricultural Genetics Institute, Vietnam Academy of Agricultural Sciences, Cau Giay, Ha Noi, Vietnam
Institute of Forestry Research and Development, Thai Nguyen University of Agriculture and Forestry, Vietnam


Abstract
The Lilium genus is a member of the Liliaceae family and is comprised of approximately 110 to 120 species. This genus is considered the largest genome with a haploid DNA content in the plant kingdom and is currently receiving much attention for its great commercial and trading prospects. Among them, Lilium poilanei belongs to the Sinomartagon group, plays an important role in the breeding of Asiatic hybrids. L. poilanei, widely known as an endemic plant in mountainous areas of Sapa, Vietnam and has been intensively exploited due to great commercial significance. In this study, the morphological characteristics and DNA sequence data including the nuclear ribosomal DNA segments of ITS, ITS2, and plastid matK, psbA-trnH and rbcL, rpoC1 were applied to identify L. poilanei collected. The results showed that some morphological details of the lily were specifically analyzed and both markers ITS2 and rpoC1 disclosed superiority in discrimination of L. polinanei with 100% similarity score by the one of ours reported in NCBI Genebank with the accession number of KR632775.1 and KR632777.1, respectively, while the remaining regions have been neither unamplified nor unsuccessfully discriminated and identified. Our findings in morphology and barcodes were reliable, effective and powerful for distinguishing L. poilanei and may identify other species of the family of Liliaceae.

Pages 471-478 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3421
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Nutrient balance in a constructed wetland system using treated domestic wastewater on ornamental sunflower crops

Jazmin Del Carmen de la Cruz Magaña, Delvio Sandri*, Sabrina Magaly Navas Cajamarca, Daniel Fernando Salas Mendez, Jesus Manuel Perez Clara

Doctoral Study Agronomy Program, Faculty of Agronomy and Veterinary Medicine, University of Brasilia, Brasília, Federal District, Brazil.
Associate Teacher II, Faculty of Agronomy and Veterinary Medicine, University of Brasilia, Brasília, Federal District, Brazil


Abstract
This study aimed to assess the nutrient dynamics of raw and treated wastewater (RWW and WW) in constructed wetlands (CW) for the irrigation of ornamental sunflowers, compared to freshwater (Fw) in Red Yellow Latosol (RYL) with (OF) and without (WF) inorganic fertilization. The study was carried out from July 10th to October 2nd of 2019. Wastewater was applied in pots with 10 kg of RYL. The amount of salts in the RWW, influent and effluent of CW and UnS (Uncultivated System), were evaluated in eleven samples. The study also assessed the following: plant height (PH), stem diameter (SD), number of leaves (NL), leaf area index (LAI), the inner diameter of the capitulum (IDc), the outer diameter of the capitulum (ODc), number of petals in the bud (NP), days after harvest (DAH), fresh phytomass in the aerial part (FPAP), dry phytomass in the aerial part (DPAP), fresh phytomass of the capitulum (FPc), dry phytomass of the capitulum (DPc), nutrient content in the aerial sunflower, and chemical composition in the RYL. The average removal efficiency of K+, Ca2+, and Fe in the CW was 34.33, 37.88, 39.82, and 45.40%, respectively. The PH (86.54 cm), SD (11.75 mm), NL (21), and LAI 3646.73 cm2) were higher in the WWOF treatment at 70 days after sowing. Treated wastewater without fertilization (WWWF) presented higher P, K, S, B, and Mn absorption. Freshwater with fertilization accumulated greater amounts of N, and WWOF accumulated greater amounts of Zn. Wastewater increased the P content and decreased K+ and Ca2+ in RYL. Irrigation with domestic WW in CW provided salts to the soil and increased the growth and quality of sunflowers irrigated with Fw.

Pages 479-487 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3430
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Liming in soils with plinthic materials of the Brazilian Savanna: potentials and limitations

Olavo da Costa Leite, Saulo de Oliveira lima*, João Henrique Silva da Luz*, Rubens Ribeiro da Silva, Rodrigo Ribeiro Fidelis, Rodrigo de Castro Tavares, Juliana Barilli, Ângela Franciely Machado

Federal University of Tocantins, Campus Gurupi, Gurupi, TO, Brazil
University of Sao Paulo, “Luiz de Queiroz” College of Agriculture, Piracicaba, SP, Brazil


Abstract
The expansion of agriculture has been taking place in marginal soils with low productive potential, such as Plinthosols. The liming can increase the economic and environmental sustainability of agriculture. However, there are no studies on the dissolution or recommendation of limestone for Plinthosols. The objective was to evaluate the effect of limestone doses on the chemical attributes of three soils with different gravel contents (ironstone concretions). The soils were collected (0-20 cm layer) in native areas of the central region of the Brazilian Savanna. They were classified as Red-Yellow Latosol (RYO) and two Concretionary Pétric Plinthosol (with 29% [CPP-29] and 72.8% [CPP-72] of soil volume with gravel). A factorial scheme (3x6) with the three soils (RYO, CPP-29, and CPP-72), six limestone doses, and four replications. The evolution of pH was verified at 10, 20, 30, and 40 days after the beginning of incubation (DAI), and determined the chemical attributes (Al, H+Al, Ca, Mg, BS, V%, P, and K) at 40 DAI. The doses to reach pH 6 were 1.4 t ha-1 for RYO, 3.9 t ha-1 for CPP-29, and 2.7 t ha-1 for CPP-72. Al3+ neutralization was 100% with doses above 3.5, 2.5 and 0.5 t ha-1 for CPP-29, CPP-72, RYO. There was a significant increase in Ca and Mg contents in all soils. However, the Soil CPP-72 did not reach a critical level for Ca (>2.41 cmolc dm-3) and Mg (>0.91 cmolc dm-3) for Plinthosols with higher plinthite content. Thus, we recommend using agricultural practices that increase the capacity of the soil to retain and recycle nutrients.

Pages 488-494 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3438
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Gold Standard in selection of rainfall forecasting models for soybean crops region

Marcio Paulo de Oliveira*, Miguel Angel Uribe-Opazo, Manuel Galea, Jerry Adriani Johann

Federal University of Technology – Paraná (UTFPR), Toledo, Paraná, Brazil
Western Paraná State University – (UNIOESTE), Cascavel, Paraná, Brazil
Pontificia Universidad Católica de Chile, Santiago, Chile


Abstract
Rainfall data forecasting is essential in agricultural sciences due to impacts caused by water excess or deficit on crop growth. Our study aimed to develop a method to select rainfall forecast models using references with negligible error denoted as the gold standard. To this end, we used forecasting models from national centers such as Canadian Meteorological Center (CMC), European Center for Medium-Range Weather Forecasts (ECMWF), National Center for Environmental Prediction (NCEP), and Center for Weather Forecasting and Climate Studies (CPTEC). The study area comprised the western mesoregion of Paraná State (Brazil), and data were gathered from October to March between the soybean crop seasons of 2010/2011 and 2015/2016. Ten-day period clusters, corresponding to 240 h forecasts in the centers, were used to assess agreement with the gold standard. Our results showed that forecasting center selection must be based on rainfall value ranges and geographic locations. Selection according to the highest agreement with the gold standard was estimated at 76.9% for range 1 in CPTEC, 38.5% for range 2 and 4 in ECMWF, and 38.5% for range 3 in NCEP. In conclusion, the proposed method was efficient in selecting forecasting centers in areas of interest.

Pages 495-500 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3449
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Non-destructive estimation of tomato fruit properties by interactive consecutive model series

Murat KILIC*, M. Kadri BOZOKALFA

Department of Agricultural Structures and Irrigation, Faculty of Agriculture, Ege University, Bornova, Izmir, Turkey
Department of Horticulture, Faculty of Agriculture, Ege University, Bornova, Izmir, Turkey


Abstract
Fruit shape is an important quality parameter, and such variables as fruit diameter, height, weight, cross-sectional area and volume are components affecting this feature. In particular, these properties are the most important parameters in industrial applications for fruit grading, in determining the conditions of optimum packing, in providing the most suitable transportation facilities, and in optimizing crop production strategies. In this investigation, mathematical models were devised which enable estimation of the cross-sectional area, weight and volume of the fruit by a non-destructive method in the field before harvest. The modelling process was carried out by means of data analysis approaches and interactive consecutive calculation series for the Bandita F1 tomato cultivar. The correlation between the measured and estimated cross-sectional area, weight and volume of the fruit were 0.9672, 0.9809 and 0.9684, respectively. Apart from this, the accuracy rates of the models proposed for the estimation of the cross-sectional area, weight and volume are 97.12%, 95.40% and 95.37% respectively. In addition, the performance and validity of the models are in the “very good” category according to the all three analyses of NS, RSR and PBIAS. These results indicated that the models proposed gave high rates of accurate results.

Pages 501-511 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3464
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Genotype × environment interaction and stability analysis on physicochemical traits of Malaysian rice hybrid across the environments

S. Elixon, Y. Mohd Rafii, R. Asfaliza, J. Mashitah, R. Shairul Izzan

Rice Research Centre, Malaysian Agriculture Research and Development Institute (MARDI), Malaysia
Institute of Tropical Agriculture and Food Security, Universiti Putra Malaysia (UPM) Serdang, Malaysia
Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia (UPM), Serdang, Malaysia


Abstract
In the development of new varieties, physicochemical properties such as grain quality, milling, and chemical content are important. Twenty rice hybrids were tested in various environments in this study. Using multivariate and univariate models, the major goal is to identify rice hybrids with acceptable physicochemical properties and high stability. According to the ANOVA, variance due to season×genotype×location revealed a significant difference in length to width ratio, head rice recovery, and amylose content. Milled grain length and width varied from 6.64 to 7.32 mm and 1.78 to 2.06 mm, respectively, throughout the environments. The head rice recovery and amylose content, on the other hand, varied from 84.83 to 94.68% and 16.51 to 22.21%, respectively. The stability analysis for head rice trait using genotype superiority, static stability, Wrickie ecovelance, Nassar and Huehn, AMMI stability value, and coefficient of variation stability analysis, revealed that hybrids G2, G13, G8, G16, G7, G9, G6, G17, and G18 were the most stable. For Amylose content, hybrids G7, G4, G19, G10, G5, G17, G3, G12 and G11 were significantly stable. Except for G5, all hybrids demonstrated stable performance in the multivariate stability analysis for head rice recovery. Similarly, hybrids G3, G4, G5, and G7 responded in minimum GE interaction in multivariate analysis for amylose content. This discovery can help breeders pick potential hybrids by identifying the physicochemical attribute expression that was examined in different conditions.

Pages 512-521 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3468

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Competitiveness of swamp rice against Echinochloa crus-galli and Monochoria vaginalis weeds

Sujinah*, Dwi Guntoro, Sugiyanta

Agronomy and Horticulture, IPB University, Bogor, Indonesia
Indonesian Center for Rice Research, Subang, Indonesia
Department of Agronomy and Horticulture, IPB University, Bogor, Indonesia


Abstract
Weed competition, especially with Echinochloa crus-galli and Monochoria vaginalis, is a major constraint in rice production as they reduce yield by competing with crops for resources such as light, nutrients, and water. Therefore, this study aims to determine rice competitiveness against Echinochloa crus-galli and Monochoria vaginalis weeds. The experimental design was a split-plot with four replications, with the main plot being weed-free, E. crus-galli, and M. vaginalis treatments, while the subplot was rice varieties namely Inpara 3, 4, 7, and 8. The result showed that existence of weeds reduced the plant height, tillers, photosynthetic rate, leaf area, biomass, percentage of filled grain, and yield of rice due to competition, with losses up to 15%. Furthermore, the rice varieties differed in their yield performances and weed competitiveness. The grain yield ranged from 7.75 t ha-1 to 5.96 t ha-1 for Inpara 4 and 8, respectively, under the weed-free condition. A low weed tolerance and suppress ability was found in Inpara 7, both for E. crus-galli and M. vaginalis. Inpara 8 had a low weed tolerance in E. crus-galli, but high in M. vaginalis, while Inpara 4 produced the highest yield in a weedy condition, along with high weed tolerance and suppress ability. Traits related to the leaf area and rice dry weight at grain filling stage are associated with rice competitiveness. Based on the results, competitive rice can be an important strategy for reducing hand weeding and herbicide inputs in rice production.

Pages 522-530 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3537
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Biodiversity and community structure of Arthropod in tropical rice fields under organic and conventional ecosystems

Mohammad Yunus, Burhanuddin Nasir, Sri Anjar Lasmini, Reski Leme’ Piri

Department of Agriculture, Agriculture Faculty of Tadulako University, Palu, Indonesia, 94118

Abstract
The practice of conventional rice cultivation using inorganic fertilizers and synthetic chemical pesticides can affect the stability of ecosystems. This study aimed to compare the diversity and community structure of arthropods in tropical rice field under organic and conventional ecosystems. This research was conducted at Oloboju, located at an altitude of 120 m above sea level. The soil type was inceptisol. The research used observation and exploration methods. The sampling of arthropods in the field used a sweep net, a pitfall trap, a yellow pan trap and by hand. The variables measured were the taxonomic composition and relative morpho-species abundance, family and order composition. Relative morpho-species abundance was assessed based on functional roles, number of species, and the total number of individuals. The results show that the Shannon diversity index value (H') and Margalef richness index (Dmg) were higher in organic rice ecosystems than conventional. On the other hand, the organic rice ecosystem had a Simpson dominance index value (C) and an evenness index (E) lower than the values of C and E in conventional rice ecosystems. The organic ecosystem had a community structure of arthropod of 9 orders, 24 families, and 28 morpho-species, with an abundance of 4,002 individuals, while the conventional ecosystem had a community structure of arthropod of 7 orders, 17 families, and 20 morpho-species with an abundance of 1,789 individuals. The practice of organic rice cultivation would increase the biodiversity index towards ecosystem balance so that it could be used as an alternative to pest control.

Pages 531-538 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3551
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Industrial treatment of soybean seeds subjected to high volumes of fungicides, insecticides, biostimulants and micronutrients during storage

Renata Cristiane Pereira, Breno Gabriel da Silva, Alessandro Lucca Braccini, Silas Maciel de Oliveira, Carla Coppo, Géssica Gaboardi De Bastiane, Murilo Fuentes Pelloso, Yana Miranda Borges

State University of Maringá, Maringá, Paraná, Brazil
University of São Paulo, São Paulo, Brazil
Federal Institute of Education, Science and Technology of Amazonas, Manaus, Amazonas, Brazil


Abstract
The objective of this study was to examine the performance of soybean seeds at different storage periods as well as their physiological quality after the application of spray mixtures of insecticides, fungicides, polymers, micronutrients and biostimulants. The experiment was laid out in a completely randomized design with four replicates. Treatments were as follows: T1 - untreated seeds (control); T2 - insecticide and fungicide + polymer + drying powder; T3 - insecticide and fungicide + polymer + drying powder + micronutrient; and T4 - insecticide and fungicide + polymer + drying powder + micronutrient + biostimulant. For each industrial seed treatment (IST), the specific spray volumes tested were 0, 400, 600 or 1100 mL 100 kg seeds-1. Soybean seeds were stored for 0, 15, 30, 45, 60 and 90 days and subsequently evaluated for physiological potential. At each storage period, the following tests were conducted: germination, first count, accelerated aging, emergence speed index, final emergence in sand substrate, whole-seedling length, shoot length and root length. Industrial seed treatment reduces seed physiological quality. The seed treatment corresponding to the highest spray volume provided the lowest means in all tested treatments. For all analyzed variables, the ST4 treatment, to which biostimulant was added, presented the lowest averages, indicating that the greater the volume of spray, the greater the damage caused to the physiological quality of the seeds, both before and after storage.

Pages 539-544 | Full Text PDF| doi: 10.21475/ajcs.22.16.04.p3563