Australian Journal of Crop Science   AJCS

Impact of ryegrass cover on lowland rice establishment

Marcos Belinazzo Tomazetti*, Edinalvo Rabaioli Camargo, João Paulo Sousa Gomes, José Maria Barbat Parfitt, Jaqueline Trombetta da Silva, Ivana Santos Moisinho, Harriet Brickhill, Germani Concenço

Department of Plant Protection, Federal University of Pelotas, Pelotas, Brazil
Brazilian Agricultural Research Corporation - EMBRAPA, EMBRAPA Clima Temperado, Pelotas, Brazil
Rice Extension, Leeton, Australia

Abstract
This study aimed to analyze the impact of ryegrass as a soil cover on soil moisture level, initial rice establishment, grain yield and weed control in irrigated rice planted after ryegrass. The experiment was conducted under field conditions in randomized blocks design with four replications. Ryegrass (cv. BRS Ponteio) was planted in autumn and glyphosate was used as a knockdown before rice planting. Ryegrass plants were cut at 0, 0.15, 0.30 or 0.45 m above ground, resulting in different mulching levels. Rice (cv. Irga 424 CL) was planted in spring and was managed according to local crop recommendations. Although positive to the overall cropping system, ryegrass mulching suppressed rice emergence, especially with ryegrass cutting heights above 0.30 m, thus increased seeding densities in rice fields with substantial ryegrass soil cover may be needed. Ryegrass mulching had no significant effect on weed suppression, with positive results being observed only with ≥ 3000 kg ha 1 of ryegrass dry mass mulching. However, the rice yield in relation to the bare soil treatment was 14.3% less when straw quantity was 4500kg ha-1, reinforcing the need for evaluating the benefits and costs of ryegrass as a cover crop in rice production.

Pages 1217-1223 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p2497
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Assessment of genetic variability in groundnut (Arachis hypogaea L.) genotypes grown under South African conditions using agronomic and SSR markers

Mofokeng MA, Amelework BA, Chipeta O, Sibiya J, Gerrano AS, Shargie N, Mashingaidze K

Agricultural Research Council-Grain Crops, Private Bag X 1251, Potchefstroom, 2520, South Africa
Agricultural Research Council-Vegetable and Ornamental Plants, Private Bag x 293, Pretoria, 0001, South Africa
African Centre for Crop Improvement, School of Agriculture, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X 01, Scottsville, 3209, South Africa

Abstract
Groundnut (Arachis hypogeae) is a legume crop grown in arid and semi-arid regions of the world. The objective of the study was to assess the presence of genetic diversity among fifty three groundnut genotypes of diverse origin using eleven agronomic and twenty SSR markers. The analysis of variance showed that highly significant variations exist among the genotypes for all phenotypic traits measured. Five principal components showed 71% of the total phenotypic variation. The SSR loci showed high values of polymorphic information content ranging from 0.31 to 0.89, with a mean of 0.71. Heterozygosity values ranged between 0.03 and 1.00 with a mean of 0.57. The genotypes showed a wide range of allelic diversity from 3 to 16, with a mean of 8.1 alleles per locus. Analysis of molecular variance (AMOVA) indicated that larger variability (59%) was due to variation within individuals, whilst the remaining variation was accounted for variation among individuals within population. Cluster analysis grouped the genotypes into two distinct clusters, where it showed that the discrimination of the genotypes was not dependant on the origin of the genotypes. The high gene flow observed among the different geographic origin might contribute to the low differentiation among the population. The SSR and phenotypic markers were able to detect wide genetic diversity and discriminate groundnut genotypes. The two genetically distinct groups observed in this study, can be used as source of genes of novelty and parental lines for transgressive segregation and for further broadening of the genetic base of the crop.

Pages 1224-1232 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.21.15.10.p2856
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Influence of seeding speed and spacing between corn crop lines in the Amazon

Gislayne Farias Valente*, Vicente Filho Alves Silva, Ricardo Shigueru Okumura, Daiane de Cinque Mariano, José Nilton da Silva, Bruno Borella Anhê, Lana Letícia Barbosa de Carvalho, Danyllo Amaral de Oliveira, Leonardo José Damasceno, Jessivaldo Rodrigues Galvão

Federal Rural University of the Amazon - UFRA, Belém, PA, Brazil
Federal Rural University of the Amazon - UFRA, Parauapebas, PA, Brazil
School of Agriculture "Luiz de Queiroz" - ESALQ/USP, Piracicaba, SP, Brazil
Federal University of Lavras - UFLA, Lavras, MG, Brazil

Abstract
The sowing stage in the crop implantation process is directly related to its productivity due to factors such as adequacy of the speed of operation of the seeder-fertilizer and the spacing between lines adopted according to each region of Brazil. Thus, the objective of the study was to evaluate the agronomic characteristics of corn in relation to the spacing between rows and speeds of operation of the seeder-fertilizer in the sowing process in the eastern Amazon region. The experiment was carried out in the experimental area of the Technological Center for Support of Family Farming, located in the municipality of Parauapebas, in the southeastern region of Pará. The experimental design used was in continuous bands (subdivided into five plots) of four treatments, resulting in the factorial arrangement 2 x 2, consisting of two operating speeds (5.5 and 6.5 km h-1) and two spacings between rows of the seeder-fertilizer (0.75 and 0.55 m), totaling 20 experimental plots to evaluate the crop. The evaluations carried out after sowing were: SD (seed depth), TS (total seeds), IP (initial population), PH (plant height), EH (ear height), SD (stem diameter), FP (final population) and SI (survival index). The use of spacing between lines of 0.75 m promoted an increase in stem diameter (2.10 cm), plant height (2.29 cm) and seed depth (4.97 cm). It was found that the increase in operating speed (6.5 km h-1) and the use of 0.55 m line spacing provides an increase in the final plant population (60,000 plants ha-1).

Pages 1233-1237 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p2922
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Nitric oxide improves gas exchange and growth in Physalis angulata plants under water deficit

Romeu da Silva Leite*, Marilza Neves do Nascimento, Daniele de Brito Trindade, Alismário Leite da Silva, Uasley Caldas de Oliveira, Ianna Kamyla Freitas Lima

State University of Feira de Santana, Biological Sciences Department, Feira de Santana 44.036-900, Brazil
Baiano Federal Institute of Science and Technology, Campus Guanambi, Guanambi 46.430-000, Brazil

Abstract
Plant sensitization with nitric oxide (NO) donors may improve the tolerance to abiotic stresses such as water deficit. Physalis angulata is a genetic resource growing in semiarid areas of Brazil, with the potential for fruit growing and medicinal uses. In this experiment sodium nitroprusside, a NO donor was sprayed at three concentrations (0, 50 and 100 µM) at 25 and 49 days after transplantation in well-watered plants and underwater deficit to evaluate the NO mitigating role. The gas exchange, photosynthetic pigments, water relations, growth and productivity parameters were evaluated. The water deficit negatively influenced most of the variables analyzed. However, the SNP spray was able to attenuate, reverse or act in the recovery of stress effects. There was an improvement in gas exchange, especially carbon assimilation, stomatal conductance and transpiration; as well as an increase in total chlorophyll content. The donated NO was able to influence the plant water status. Besides, it promoted an increase in growth parameters, especially in photoassimilates incorporation and yield. However, the NO supply to plants under well-watered conditions does not seem to affect the physiology parameters. The NO supply in micromolar concentrations can attenuate or even reverse the water deficit effects on this species, being an important tool for promoting tolerance to this abiotic stress.

Pages 1238-1245 | Full Text PDF| 10.21475/ajcs.21.15.10.p2930
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Multivariate techniques for identifying potential carrot hybrids

Agnaldo Donizete Ferreira de Carvalho, Giovani Olegário da Silva, José Magno Queiroz Luz, Roberta Camargos de Oliveira*, Lucas Medeiros Pereira, Luciano Dias Cabral Neto, Gabriel Mascarenhas Maciel

Empresa Brasileira de Pesquisa Agropecuária (Embrapa), Rodovia BR 280, km 231, n° 1151, Bairro Industrial II, C.P. 317, 89460-000, Canoinhas, SC, Brasil
Federal University of Uberlândia (UFU), Instituto de Ciências Agrárias (ICIAG). Av. Amazonas, s.n. Bloco 2E Sala 01, Uberlândia, Minas Gerais. CEP 38400-902. Brasil

Abstract
The adaptation of carrot cultivars to the environment is a fundamental factor for the cultivation. This study aimed to evaluate the agronomic potential of carrot genotypes cultivated in two periods by the hierarchical and optimization methods. The experiments were set as completely randomized block design. The treatments consisted of four experimental hybrids (Hybrid 8, 12, 14 and 17), three open-pollinated cultivars (Brasilia, BRS Planalto and Suprema), and a commercial hybrid (Verano), carried out at two cropping seasons. The unweighted pair-group using arithmetic averages (UPGMA), Tocher, and graphics of dispersion methods were applied. The UPGMA method and the graphic of dispersion enabled better separation of the genotypes evaluated in the growing seasons. The genotypes hybrid 12, cultivars Suprema and Verano presented a similar performance in both growing seasons. The cultivar Alvorada presented the greatest carrot yield (26.6 t ha-1) and leaf fresh mass (1538.6 g plant-1) in the spring-summer season, while hybrid 27 presents great potential for a great production (37.6 t ha-1) of carrots in the autumn season.

Pages 1246-1251 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3091
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Chitosan and arrowroot-based coatings increase shelf life and post-harvest quality of tomatoes

Bárbara Genilze Figueiredo Lima Santos*, Jaína Geovana Figueiredo Lima Santos, Albert Einstein Mathias de Medeiros Teodosio, Josivalter Araújo de Farias, Marinês Pereira Bonfim, Caciana Cavalcanti Costa, Kilson Pinheiro Lopes

Federal University of Paraíba, Areia, Paraíba, Brasil
Federal University of Campina Grande, Pombal, Paraíba, Brasil
Federal University of Ceará, Fortaleza, Ceará, Brasil

Abstract
Tomatoes have a prominent market position, providing various healthy compounds. Besides the ample fresh consumption, several tomato derivatives have great interest in worldwide culinary. However, this vegetable has a short post-harvest life due to its climacteric metabolism, impairing its consumption viability. In this context, studies to mitigate post-harvest losses are frequent, where edible coatings are alternatives to prolong the shelflife of food. Here we show the efficiency of using edible coating based on arrowroot starch and chitosan in conservation the post-harvest quality of tomatoes. Our results indicate that the arrowroot starch edible coating at 3% is able to prolong the shelflife and promote the safe consumption of this vegetable.

Pages 1252-1258 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3101
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Initial development of maize in response to different periods of seed immersion in humic acid (HA)

Marihus Altoé Baldotto*, Raphael Oliveira Melo, Lilian Borges Baldotto

Federal University of Viçosa, Forest Campus, Rodovia LMG 818, Km 6, CEP 35690-000, Florestal / MG, Brazil

Abstract
Currently, there is a higher demand for improved seeds, associated with the treatment with fungicides, insecticides, and recently inoculants and biostimulants. Treating corn seeds with humic acid (HA) triggers physiological and metabolic processes that can increase productivity. However, the effects of seed immersion time on plant performance are unknown. Therefore, this study aimed to test different periods of corn seed immersion in HA (10 mmol L-1 of C) and the effects on seedling development characteristics. The treatments consisted of soaking seeds for 00:00; 00:17; 01:00; 02:00; 04:00; 08:00; 16:00 and 24:00 hours. The experimental design was completely randomized, with four replicates. At 30 days after sowing, two plants per replicate were collected to determine the shoot, root, and total fresh and dry masses of the plants. The plants grown from seeds soaked for 8 hours had the strongest response among the plants analyzed in this study.

Pages 1259-1262 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3148
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Application of glycine on soybean plants submitted to water deficit

Walquíria Fernanda Teixeira, Luís Henrique Soares, Klaus Reichardt, Durval Dourado Neto

University Center of Patos de Minas – Unipam, 38700-207, Patos de Minas, Minas Gerais, Brazil
Crop Science Department, “Luiz de Queiroz” College of Agriculture – Esalq/USP, 13418-970, Piracicaba, São Paulo, Brazil.
Center for Nuclear Energy in Agriculture, University of Sao Paulo, Av. Centenário, 303, 13400-970, Piracicaba, São Paulo, Brazil

Abstract
Soybean is one of the most important crops in the world. Studies are necessary to improve its productivity, especially in stress environments. Therefore, the objective of this study was to evaluate the effect of glycine as seed treatment to soybean plants submitted to water deficiency, using twelve replicates per treatment. Glycine was applied at a dose of 9 mg kg-1 of seeds under high water deficit (performed at stage V4) and without water deficiency. Root development, antioxidant metabolism and dry mass accumulation of plants were evaluated. Results showed that the application of glycine to plants that were not subjected to water deficiency, promoted the increase of root development, accumulation of mass and reduction of stress in plants. This reflected in 10% increase in productivity compared to the control treatment. On the other hand, plants with glycine application subjected to water deficiency showed a reduction in dry mass accumulation and root development, indicating that these plants suffered the effect of stress. Untreated plants submitted to water deficiency showed symptoms of stress such as reduced accumulation of mass and productivity by 12%. Therefore, the present study reports that the application of glycine on seeds is not very efficient for attenuating stress in soybean plants submitted to water deficiency. However, in environments without water deficiency, the application of glycine on seeds affects the greater development of the plant and increased productivity.

Pages 1263-1268 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3159
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Characterization of sweet and bitter cassava (Manihot esculenta Crantz) genotypes through multivariate analysis

Amanda Gabriela Paiva Carréra*, Rodrigo Oliveira Aguiar, Roberto Lisboa Cunha, Igor Vinícius de Oliveira, Priscilla Diniz Lima da Silva Bernardino, Claudete Rosa da Silva, Fábio Israel Martins Carvalho, Cândido Ferreira de Oliveira Neto, Marcos Antônio Souza dos Santos, Job Teixeira de Oliveira, Priscilla Andrade Silva*, Elisa Ferreira Moura Cunha

Federal Rural University of the Amazon, CEP: 66077-830, Belém, PA, Brazil
Federal University of South and Southeast Pará, CEP: 68507-590, Marabá, PA, Brazil
Federal University of Mato Grosso do Sul, CEP: 79560-000, Chapadão do Sul, MS, Brazil
EMBRAPA Eastern Amazon- Laboratory of Sustainable System Analysis, CEP: 66095-903, Belém, PA, Brazil

Abstract
Cassava has importance as a source of human and animal food. With the objectives to select promising sweet and bitter cassava varieties for breeding programs, 27 genotypes were characterized in terms of their quantitative and qualitative properties. Roots were harvested from three plants per genotype, washed, peeled, sanitized. Regarding the yield, the storage root number (SRN), and the fresh storage root weight (FSRW), were determined, as well as the root fresh matter content (RFMC), and root dry matter content (RDMC), both expressed as a percentage. Among the cassava genotypes, the protein content ranged from 0.1-0.7%; lipids 0.3-2.1%; moisture 58.0-65.2%; 0.1-1.0% ash; fibers 0.9-1.9%; acidity 1,1-2,7%; pH 6.3-6.8; TSS between 0.8-1.2 ºBrix; glucose 0.1-0.8% and sucrose 0.5-1.0%, except for the fructose and starch contents, which did not vary significantly. The principal component analysis showed that the factors explain 84.2% of the total variability and through cluster analysis, evidencing cluster III for the highest starch yield and cluster I for the highest average of lipids and proteins.

Pages 1269-1278 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3182
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Genetic potential of tropical sweet corn hybrids and combining ability among parental inbred lines

Neyaz Rashid Mustafa, Ghizan Bin Saleh*, Pedram Kashiani

Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 Serdang, Selangor, Malaysia
Department of Agriculture Science, Faculty of Technical and Vocational Education , Universiti Pendidikan Sultan Idris, 35900 Tanjung Malim, Perak, Malaysia

Abstract
Superiority of sweet corn (Zea mays L. saccharata) hybrid varieties is reflected by their performance per se, heterosis they reveal and combining ability of their inbred parents. This study was conducted to investigate performance, combining ability, heterosis and heritability revealed by 15 F1 tropical sweet corn hybrids from a half-diallel cross involving six diverse inbred lines, at two locations in Malaysia. At each location, the hybrids were evaluated for ear yield and yield components in a randomised complete block design, in comparison with their inbred parents and a commercial hybrid variety Hybrid 530 as control. Hybrids H11, H12 and H15 were found to be the most superior for yield and yield components, hence could be further tested in large-scale trials, before release. Inbred lines FTT-1, EE0-2 and HAW-1 showed high positive GCA effects for yield and yield-related traits at both locations. Cross combinations HAV-2 × NTS-2, HSE-4 × NTS-2, NTS-2 × EE0-2 and EE0-2 × HAW-1 revealed high positive SCA effects for fresh ear yield and yield related traits at both location. Crosses among unrelated lines were found to produce superior hybrids. Both additive and non-additive gene effects were found important, although additive effects were predominating. The hybrids revealed substantially high heterosis, the highest being for number of ears per hectare and ear height. Moderate to high broad- and narrow-sense heritabi1ity estimates were displayed by the different traits measured.

Pages 1279-1288 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3189
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Assessment of agromorphological diversity of chickling-vetch (Lathyrus cicera L.) landraces in the traditional agroecosystems of Morocco

Salama El Fatehi*, Younes Hmimsa, Mohammed Ater

Department of Life Sciences, Polydisciplinary Faculty (Abdelmalek Essaadi University), Larache, Morocco
Applied Botany Laboratory, Agro-Biodiversity Team, Department of Biology, Faculty of Sciences (Abdelmalek Essaadi University), Tetouan, Morocco

Abstract
Legumes are an essential component of human and animal food, particularly in the Mediterranean area. While some legumes are widely cultivated and consumed, others are neglected and underused. This is the case of an ancient Mediterranean legume, chickling-vetch (Lathyrus cicera L.), currently considered as a marginal crop. In Morocco, this crop persists in some traditional mountain agroecosystems in the Tadla-Azilal region. This study allowed to specify the cultivated area and the socio-economic characteristics. The estimation of local ecotypes diversity was carried out using agromorphological descriptors on a collection gathering 13 accessions. The used descriptors include germination, phenology, morphology, and production. The analysis of variability revealed the existence of a structured diversity based on ecotypes differentiation with significant geographical and altitudinal influences. The absence of dormancy, precocity, and a short vegetative lifecycle unveil an interesting adaptive potential to aridity. Regarding productivity, the obtained estimates are comparable or above those mentioned in the literature for other provenances. Our results therefore show that local ecotypes contain important genetic resources for conservation and development. This is particularly relevant considering the current context of climate change, where the search for alternative crops, adapted to fit the predicted harsh conditions, is a priority for global food security.

Pages 1289-1297 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.21.15.10.p3220
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Assessment of Harmattan weather on cowpea (Vigna unguiculata, (L.) Walp.) production under drought stress

Vincent Ishola Esan*, Oluwafemi Oyeniyi Omilani, Yewande Omoronike Osuntoyinbo, Goodness Toluwanimi Olutayo, Titilayo E. Sangoyomi

Crop Production, Bowen University, Iwo, Nigeria
Department of Horticulture, Oregon State University, USA

Abstract
Drought stress is an environmental factor which restraints crop production and quality worldwide. It is now undeniable that drought limits the performance of crop plants. Annual water resources decline due to low rainfall and the reduction of the number of days of rainfall. The objectives were to: (1) screen existing cowpea genotypes at germination and seedling stages for their adaptation to water stress and (2) identify tolerant cowpea varieties to drought. The experiments were carried out both in the laboratory using an osmotic stress (laboratory drought stress) induced by polyethylene glycol 6000 (PEG 6000) and in an open field under different levels (control, moderate and severe) of drought conditions. Fourteen Cowpea varieties were used in this study. The drought stress was imposed on 21-days old seedlings and the experiment lasted for 3 months. In the laboratory, four treatments 0%, 6.5%, 13% and 16.5% PEG were used while in the open field two drought levels were imposed. The two experiments were laid out in randomized complete block design with three replications. Morphological, physiological and agronomic data were collected. Results showed that at High concentration (16.50% PEG6000), high germination percentage was recorded in Raphael variety (88%) followed by Tawa (71.11%) and Eginwogogo (60%) whereas germination was completely inhibited in ITG7K-449-35 variety. The morphological traits measured such as plant height, leaf width, leaf length was reduced by drought stress, the highest reduction (47%) was recorded in the leaf width of Tiligre variety. In the second year of the experiment, IT99K-573-2-1 and Eginwogogo varieties plants died after 20 days of drought treatment because it could not withstand the drought stress condition during harmattan (a dry and dusty wind in West Africa) period due to the rapid dryness of soil moisture content. The results of dendogram revealed that Raphael and Tawa were the most tolerant varieties.

Pages 1298-1305 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3221
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Yield of common bean cultivars and castor hybrids intercropped in two cultivation sites with oxisol in the Midwest region of Brazil

Rosane Angélica Anjos, Cristiane Lisboa, Gisele Silva, Valter Vaz, Itamar Teixeira*, Marcos Eduardo Araújo, Paulo César Corrêa, José Hortêncio Mota, Alessandro Silva, Amanda Lourenço

State University of Goiás, BR 153, 75132-903, Anápolis - GO, Brazil
Federal University of Viçosa, . Peter Henry Rolfs, 36570-900, Viçosa - MG, Brazil
Federal University of Goiás, 74690-900, Goiânia - GO, Brazil
University of Rio Verde, Fazenda Fontes do Saber, 75901-970, Rio Verde - GO, Brazil

Abstract
The consortium between bean and castor aims to increase the yield per unit area and sustainability in land use. This system has several benefits, but the use of different genetic materials must be carefully evaluated, especially the behavior of smaller castor hybrids, since little research on their use in a consortium system is available. This study aimed to evaluate the components of production and yield of common bean cultivars and small castor hybrids, in two field experiments conducted in the intercropping and monoculture systems, in 2015/2016 and 2016/2017 harvests, in two cultivation sites in the Midwest region of Brazil. The experiment was arranged in a completely randomized block design, in a 4 x 2 + 6 factorial scheme, composed of four common bean genetic materials of different growth types and colors (Pérola, BRS Esteio, BRS Pitanga, and BRSMG Realce), a consortium with two short castor hybrid cultivars (Tamar and Agima 110204) and six additional treatments and bean and castor genetic material in monoculture, with three replications. Agronomic components and grain yields were determined in both experiments, for bean cultivars and castor hybrids. Bean and castor genetic materials presented the same agronomic performance in the studied agricultural and local crops, regardless of the cropping system. The intercropping between common bean cultivars (BRS Esteio, BRSMG Realce and BRS Pitanga) and castor hybrids (Tamar and Ag Ima) was classified as viable by the area equivalence index, since this index presented values greater than 1.0 for the intercropping between these cultivars. Thus, it is recommended for common bean in a system intercropped with small castor hybrids, regardless of the cultivated genetic material.

Pages 1307-1313 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3255
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Grain mineral nutrient profiling and iron bioavailability of an ancient crop tef (Eragrostis tef)

Ayalew Ligaba-Osena*, Mitiku Mengistu, Getu Beyene, John Cushman, Raymond Glahn, Miguel Piñeros

Laboratory of Molecular Biology and Biotechnology, The University of North Carolina at Greensboro, Greensboro, NC, 27412, United States
Department of Biochemistry and Molecular Biology, University of Nevada, Reno; Reno, NV 89557, United States
Donald Danforth Plant Science Centre, St. Louis, MO, 63132, United States
Robert W. Holley Centre for Agriculture and Health, USDA-ARS, Cornell University, Ithaca, New York 14853, United States

Abstract
Tef (Eragrostis tef) is an underutilized food crop rich in minerals, vitamins, and amino acids. However, mineral profiling of diverse tef accessions, and estimation of bioavailable iron from tef has been lacking. In this study, we analyzed the mineral content of 41 tef accessions along with major cereals. Our analysis revealed that tef seeds contain significantly more minerals than maize, rice, and the wheat varieties used in this study. A significant variation in mineral content was also observed across the tef accessions. We also performed a relative estimation of Fe bioavailability from selected tef accessions and reference crops using an established Caco-2 cell bioassay. This bioassay measures human intestinal cell Fe uptake via intracellular ferritin formation, a storage protein that is a validated marker of Fe uptake. Higher levels of Fe uptake were observed in the PI-149307, PI-494425, and PI-195937 accessions, than those recorded in cells fed wheat, rice, or tef accessions PI-329681, PI-494408 PI-494293. There was no marked difference in phytic acid (PA) content between tef and wheat, while the PA level in rice was lower than tef and wheat. Enhanced Fe uptake evident in tef accession PI494425 could not be explained by seed Fe content. The Fe content of PI-494425 was lower than the other tef accessions, suggesting that other factors control the amount of bioavailable Fe from tef. Considerable variation in mineral content and bioavailable Fe between tef and other cereals indicate a potential for improving mineral nutrition from this vital food crop.

Pages 1314-1324 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3264
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Cassava yield indicators and total organic carbon in tropical soils under different fertilization treatments

Marcelo Laranjeira Pimentel, Iolanda Maria Soares Reis*, Jailson Sousa de Castro, Victor Sousa Portela, Maria Lita Padinha Correa Romano, Carlos Ivan Aguilar Vildoso, Eloi Gasparin, Eliandra Freitas de Sia

Faculty of Agrarian and Veterinary Sciences, Paulista State University, Jaboticabal, SP, Brazil
Federal University of Western Pará, Santarém, PA, Brazil
Department of Plant Biology, Federal University of Viçosa, Viçosa, MG, Brazil

Abstract
Cassava is a crop of major socioeconomic importance in Brazil because of its versatility and high yield in nutrient-poor soils. Fertilization can improve soil quality and further increase cassava yield. This study aimed to investigate the effects of different fertilizer sources on soil total organic carbon (TOC) and cassava yield indicators. The experiment was conducted on a family farm in Santarém, Brazil, in a randomized block design, with four treatments and five replications. Treatments were as follows: T1, unfertilized soil (control); T2, NPK fertilizer; T3, poultry manure; and T4, cattle manure. The variables analyzed were soil TOC, shoot fresh weight, plant height, marketable stem diameter, marketable root yield, and yield. Data were subjected to analysis of variance, Tukey’s test (p < 0.05), hierarchical clustering, and principal component analysis. Application of organic fertilizers (T3 and T4) increased soil TOC levels. Chemical fertilizer treatment (T2) resulted in the highest shoot fresh weight, yield, and marketable root yield. Marketable stem diameter was positively influenced by T2 and T4. There were no significant treatment effects on plant height. Hierarchical clustering isolated organic fertilizers (T3 and T4) from other treatments. Principal component analysis revealed two principal components, which together explained 87.77% of the total variance. Organic fertilizer application provided the highest TOC accumulation during the experimental period, whereas NPK fertilization was the most effective in increasing cassava yield in the first year of cultivation.

Pages 1325-1331 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3291
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Edible coatings maintain the phytochemicals in cold-stored ‘Kinnow’ mandarin Citrus nobilis Lour x C. deliciosa Tenora) fruit

Arvind Kumar Baswal*, Harvinder Singh Dhaliwal, Zora Singh, Bal Vipan Chander Mahajan, Anu Kalia

Department of Fruit Science, College of Horticulture and Forestry, Punjab Agricultural University, Ludhiana-141004, India
Department of Horticulture, School of Agriculture, Lovely Professional University, Phagwara-144411
Horticulture, School of Science, Edith Cowan University, Joondalup, Western Australia, 6027, Australia
Punjab Horticultural Postharvest Technology Center, Ludhiana-141004, India
Electron Microscopy and Nanoscience Laboratory, Department of Soil Science, College of Agriculture, Punjab Agricultural University, Ludhiana-141004, India

Abstract
Edible coatings usually maintain or improve the scavenger antioxidants and activities of defense-related enzymes consequently preserve the bioactive compounds. The effects of different coating treatments e.g. carboxymethylcellulose (CMC; 1.0, 1.5 and 2.0 g L-1), chitosan (0.5, 1.0 and 1.5 g L-1), beeswax (5, 10 and 15 g L-1) and control (uncoated fruit) and cold storage period (5-7 ºC, 90-95 % RH for 75 days) on the levels of total phenols, total antioxidant activity, flavonoids, protein, total free amino acids and sugars (total and reducing sugars) in the juice of cold-stored ‘Kinnow’ mandarin fruit during were assessed in 2017-18 and 2018-19. The fruit used in the experiment were harvested from the fifteen-year-old healthy trees previously grafted on rough lemon rootstock (Citrus jambhiri L.) and grown in the same block. The fruit coated with different coating treatments were stored at 5-7 ºC and 90-95 % RH for different storage periods (0, 30, 45, 60 and 75 days). The levels of total phenols, flavonoids, total antioxidant activity, total and reducing sugars in the fresh juice of the cold-stored fruit were determined following each cold storage period. Amongst different coating treatments tested, CMC (2.0 g L-1) coating proved to be the best treatment to maintain highest levels of bioactive compounds viz., total phenols, total antioxidant activity, flavonoids and total and reducing sugars as compared to the control during cold storage. In conclusion, coating with CMC (2.0 g L-1) was effective to extend the cold storage life and maintain the highest levels of health-promoting compounds in ‘Kinnow’ mandarin fruit without any symptoms of its toxicity to the fruit.

Pages 1332-1338 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3335
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Intercropping of potato within sugarcane plants in a double row planting system under wet climate

Endrizal*, Julistia Bobihoe, Jon Hendri, Araz Meilin, Jumakir, Busra B Saidi

Agricultural Technology Assessment Center, Jambi Province, Indonesia

Assessment Institute of Agricultural Technology, Jambi Province, Indonesia

Abstract
Growing sugarcane in a double row planting system is one way to increase the productivity and sugar cane yield. Intercropping within sugarcane crops can increase the growth and productivity of sugarcane. This study aims to increase the productivity of sugarcane by adding value to potato cropping. The study used Randomized Block Design, where the treatments ae as follows: sugar cane as a planting system (A), double castor planting system (PtoP 210/50 cm) with cuttings of sugarcane stem + potato’s (B); double distance planting system (PtoP 185/50 cm) with cuttings stem sugarcane + potato’s (C); double distance planting system (PtoP 160/50 cm) with cuttings sugarcane stem + potato’s (D); double distance wedge system (PtoP 135/50 cm) with cuttings of sugarcane stem + potato. The planting system (PtoP 110/50 cm) with cuttings of sugarcane stem without planting potato was considered as control (E). All planting systems were repeated four times. The results of the study showed that the agronomic growth of sugar cane crops in some planting systems is not different, but in C and D planting systems, the number of leaves and the number of tillers were higher compared to others. Potatoes crop production in planting systems C reached 11,880 tons ha-1, which is higher than the production of planting systems A (8,640 tons ha-1.) and planting systems B (8,400 tons ha-1). After combining the determining factors of sugar cane production, the C planting systems is recommended for development of sugarcane crops because is better than other planting systems. The population of sugar cane plants in the C planting systems reached 18,000 clumps of plants per hectare.

Pages 1339-1345 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3337
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The potential of soluble silicon for managing white root disease in rubber (Hevea brasiliensis)

Shaikh Mohd Hizami Shaikh Abd Hadi, Latiffah Zakaria, Siti Nordahliawate Mohamed Sidique, Murnita Mohmad Mahyudin, Nik Mohd Izham Mohamed Nor

School of Biological Sciences, Universiti Sains Malaysia, Pulau Pinang, Malaysia
Laboratory for Pest, Disease and Microbial Biotechnology (LAPDiM), Faculty of Fisheries and Food Science, Universiti Malaysia Terengganu, Malaysia
Northern Regional Office, Malaysian Rubber Board, Perak, Malaysia
Integrated Disease and Plant Management Unit, Malaysian Rubber Board, Selangor, Malaysia

Abstract
Rubber growers in Malaysia depend on soil drenching with propiconazole fungicide to control white root disease (WRD) caused by Rigidoporus microporus. The fungal infection affected the environmental ecosystem, giving rise to fungicide resistance. Recently, silicon (Si) has become an alternative to reduce and delay pathogenic fungal invasion. Therefore, the present study investigates the antifungal property of soluble silicon against R. microporus in rubber trees (Hevea brasiliensis). In vitro dose-response towards soluble silicon types, i.e., silicic acid, sodium meta-silicate, sodium silicate, and calcium silicate with different concentrations (10, 100, 500, 1000, 1500, 3000, 5000, and 8000 ppm) were determined on the Ayer Molek strain of R. microporus using the Poisoned Food Technique. Results showed that sodium meta-silicate inhibited mycelial growth (100%) at 5000 and 8000 ppm concentrations compared to other types of soluble silicon. However, silicic acid inhibited more than 50% R. microporus at a minimal concentration of 500 ppm, which could be considered the most effective antifungal from the soluble silicon group. Moreover, the higher pH values did not solely affect the inhibition rate of R. microporus. Microscopic observation showed the changes of R. microporus hyphae width grown on soluble silicon medium agar compared to the control (without Si). The Dipped Stick Inhibition Assay revealed that a higher concentration and more frequent soluble silicon application effectively inhibited R. microporus growth. Thus, this study proved that soluble silicon, especially silicic acid and sodium meta-silicate, showed promising results as antifungal agents and fungicidal in controlling white root disease.

Pages 1346-1354 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3343
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Growth, yield and oil content of sesame (Sesamum indicum L.) as influenced by sulphur levels under infertile soil

Darika Bunphan*, Ruchuon Wanna, Wanwipa Pinta, Goitseone Malambane

Department of Agricultural Technology, Faculty of Technology Mahasarakham University, Kantarawichai District, Mahasarakham 44150 Thailand
Faculty of Natural Resources Rajamangala University of Technology Isan Sakonnakhon Campus, Sakonnakhon 47160 Thailand
Department of crop and soil sciences, Faculty of Agriculture, Botswana university of agriculture and natural resources, Gaborone Botswana

Abstract
The aim of this research was to investigate the effect of sulphur (S) on growth, agricultural traits, seed yield and oil content in white, brown and black seed color of sesame grown under infertile soil. The experiment was conducted in RCBD arranged in factorial 3 × 4 with 3 reps under pot condition both dry and wet season; factor A was 3 cultivars of sesame and factor B was 4 levels of sulfur (S). The results showed that various cultivars of sesame responded differently to S levels. Some agronomic traits were not affected by S levels i.e. plant height, SCMR and 1000 seeds weight especially in wet season but these traits differed in various cultivars of sesame. Combined analysis of the two seasons was also done and the results showed that S levels did not affect to most traits except number of capsules, whereas interaction between cultivar and S level were found on number of branches, total dry weight and oil content, cv. KKU2 and KKU3 (black and brown seed). cv. KKU3 with application of S at 20 kg ha-1 showed highest total dry weight, whereas cv. KKU3 with application rate of S at 0 kg ha-1 showed highest oil content followed by cv. MK60 with 80 kg ha-1. Interestingly the black and brown seeded cultivars had a positive response to S levels as compared to the white seeded cultivar. From the result, we can conclude that the dry season is the optimal season for sesame production in low fertile soils and that black and brown seed color responds positive to S level than white. However, we strongly suggest that field study should be undertaken to correlate our results in natural growing conditions.

Pages 1355-1363 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.21.15.10.p3359
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Sustainable weed management in a lettuce growing conservationist system

Andreia Cristina Silva Hirata*, Patrícia Andrea Monquero, Edson Kiyoharu Hirata

Agency for Agribusiness Technology of São Paulo - APTA, Presidente Prudente, São Paulo State, Brazil
Department of Natural Resources and Environmental Protection, São Carlos University, Araras, São Paulo State, Brazil
Sato-Hirata Seedlings, Presidente Prudente, São Paulo State, Brazil

Abstract
Soil disturbance, irrigation, and nitrogen fertilization excesses in lettuce crops have reduced the sustainability of the sector and favoured competition against weeds. This study aimed to evaluate the effect of cover crops and nitrogen fertilization management on weed control, weed-species dynamics, and soil seed bank in successive lettuce cultivation under no-tillage. The experiment was carried out in a tropical region during summer and arranged in a (3×4) +1 factorial scheme. Treatments consisted of three soil cover managements (Crotalaria juncea, Urochloa ruziziensis, and fallow) and four nitrogen (N) topdressing rates (0, 60, 120, and 180 kg ha−1) in a lettuce crop under fertigation. A conventional tillage system under more intense soil disturbance was also evaluated at the highest N rate. The results showed that lettuce cultivation on U. ruziziensis stood out regarding weed control. Higher soil disturbance in the conventional tillage increased weed emergence (288.9 and 245.8 plants m−2) compared to the fallow area (13.9 and 38.9 plants m−2), U. ruziziensis (4.2 and 9.7 plants m−2), and C. juncea (56.9 and 20.8 plants m−2) in successive cultivations, respectively. Soil cover management changed the dynamics of weed species emergence, especially in the first cultivation. Nitrogen topdressings did not affect weed dry matter and density at the time of weeding. The average number of non-dormant weed seeds within the 0.0-0.10 m soil seed bank layer reached 7,077 seeds m−2, with no difference among treatments. Therefore, sustainable management of lettuce cultivation using cover crops in rotation, associated with no-tillage, effectively controls weed communities, with emphasis on U. ruziziensis, regardless of the nitrogen fertilization management.

Pages 1364-1371 | Full Text PDF| doi: 10.21475/ajcs.21.15.10.p3379