Australian Journal of Crop Science   AJCS

FEBRUARY 2021 | 10.21475/ajcs.21.15.02


Floral traits and flowering behaviors of Malaysian rice cytoplasmic male sterile and maintainer lines and its relationship with out-crossing performance

Shahida Hashim, Phebe Ding, Mohd Firdaus Ismail, Asfaliza Ramli

Malaysian Agricultural Research and Development Institute (MARDI), Penang, Malaysia
Universiti Putra Malaysia, Selangor, Malaysia


Abstract
Rice is a strictly self-pollinating crop. However, in hybrid rice seed production, an effective male sterility system is used to produce hybrid seed in bulk. In hybrid rice system, the pollen grains of cytoplasmic male sterile (CMS) are sterile and the female organ of the CMS depends on the fertile pollen released by the maintainer or restorer lines via out-crossing or cross-pollination in order to produce seed. Floral trait and flowering behavior of CMS and its corresponding maintainer or restorer lines are essential factors in hybrid rice seed production because they influenced the out-crossing or cross-pollination between parental lines. Two local CMSs and their corresponding maintainer lines were developed through breeding program in Malaysian Agricultural Research and Development Institute (MARDI) namely 0025A/0025B and 0047A/0047B. This study was carried out on floral traits and flowering behavior of these two hybrid line. Present studies have shown that there were variations between the CMS and its maintainer lines whether on floral trait or flowering behavior for both hybrid rice combinations. The results showed that stigma characters for both 0025A and 0047 were superior than their respective maintainers. Therefore, it is expected that the out-crossing rate would be high. Seeding date intervals need to be done on 0025A/0025B during nursery stage because the on-set of flowering between parental lines was significantly different. Panicle of both CMS was also classified as just exserted and partially-exserted and application of exogenous hormones such as gibberellic acid was useful to improve panicle elongation and consequently increase the seed set and yield. Correlation study indicates that the stigma area of both 0025A and 0047A has significant positive correlation with out-crossing rate.

Pages 180-186 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p1732
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The relationship between soil chemical properties and phytochemical contents of non-centrifugal cane brown sugar in Thailand

Kanyaphat Meerod, Monthana Weerawatanakorn* and Wanwisa Pansak

Department of Agro-Industry, Naresuan University, 99 Moo 9, Tha Pho, Phitsanulok 65000, Thailand
Department of Agricultural Science Faculty of Agriculture Natural Resources and Environment, Naresuan University, 99 Moo 9, Tha Pho, Phitsanulok 65000, Thailand


Abstract
In Thailand, NCS products from sugarcane are traditionally produced by the evaporation of raw cane juice obtained from a pressing machine. NCS products enhance flavor and supply both energy and nutritional value through the vitamins, minerals and bioactive compounds which occur naturally in sugarcane produced without molasses removal. Soil quality and choice of cane cultivar affect the nutraceutical components of brown cane sugar products grown in diverse areas. Differences in nutraceutical components of NCS products obtained by traditional processes were investigated form sugarcane planted in two different areas of Sukhothai Province, with varied soil qualities based on the same cane variety (LK-92-11). The soil classification was carried out according to the Staff Soil Survey (2014) and classified as Aquic Haplustalfs and Aeric Endoaquepts soil types. NCS products from sugarcane planted in Aquic Haplustalfs contained high nutraceuticals and antioxidant activities compared with sugarcane planted in Aeric Endoaquepts. EC and potassium content of the soils showed significant negative correlation with policosanols, total phenolics, total flavonoid contents, and antioxidant activities of the NCS products. Pearson’s correlation indicated that higher electrical conductivity and potassium content of the soils were attributable to lower amounts of policosanols, total phenolics, and total flavonoid contents as well as antioxidant activities. We suggested that electrical conductivity and potassium content of soil should be concerned and monitored to obtain high level of nutraceutical of NCS product made from sugarcane.

Pages 187-195 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2270
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Effect of salicylic acid in post-harvest quality of ‘BRS Kampai’ peaches submitted to different cold storage periods

Jorge Atílio Benati*, Caroline Farias Barreto, Renan Navroski, Roseli de Mello Farias, Carlos Roberto Martins, Marcelo Barbosa Malgarim

School of Agronomy Eliseu Maciel, Federal University of Pelotas, Capão do Leão Campus, Pelotas, RS, Brazil
State University of Rio Grande do Sul, São Borja, RS, Brazil
Embrapa Clima Temperado, Pelotas, RS, Brazil
School of Agronomy Eliseu Maciel, Federal University of Pelotas, Capão do Leão Campus, Pelotas, RS, Brazil


Abstract
Fast ripening of fruits is one of the main hindrances to peach preservation. Even though the use of cold storage has extended commercialization periods, fruit quality is affected during storage. This study aimed at evaluating the influence of application of salicylic acid (SA) during cold storage, followed by commercialization simulation, regarding physical and chemical characteristics of ‘BRS Kampai’ peaches, which were harvested in the 2017 crop. The experiment was conducted in a completely randomized factorial design (4×3: SA concentrations × storage days), with four replications of ten fruits each. SA was applied at the following concentrations: 0, 2, 4 and 6 mM. Afterwards, fruits were submitted to cold storage at 1±0.5ºC and 80-85% relative humidity. Analyses were carried out on harvest day, on the 10th cold storage day, followed by a day at room temperature (20ºC) and on the 20th cold storage day, followed by a day at room temperature. Fruits were evaluated in terms of their mass loss, epidermis color, chromatic hue, pulp firmness, soluble solids (SS), pH and titratable acidity (TA). Both application of SA and cold storage contributed to decrease mass loss and TA, besides increasing the SS/TA relation. Fruits which were stored for 20 days and kept at room temperature for a day exhibited the highest values of SS and the lowest values of both brightness and pulp firmness. SA was efficient to maintain the quality of ‘BRS Kampai’ peaches submitted to cold storage for 10 and 20 days and an extra day of commercialization simulation.

Pages 196-200 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2549
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Green bean biochemical attributes of Arabusta coffee hybrids from Kenya using HPLC and soxhlet extraction methods

Jane Jerono Cheserek*, Kahiu Ngugi, James Wanjohi Muthomi, Chrispine O Omondi, Njoroge Kihara Ezekiel

Kenya Agricultural and Livestock Research Organization(KALRO) – Coffee Research Institute, P.O Box 4-00232, Ruiru, Kenya
University of Nairobi- Department of Plant Sciences and Crop Protection, Faculty of Agriculture, College of Agriculture and Veterinary Sciences, P.O Box 30197-00100, Nairobi Kenya
Kenya Agricultural and Livestock Research Organization(KALRO) – Industrial Crops Research Institute, P.O. Box 16, Mtwapa, Kenya


Abstract
Robusta coffee yields higher than Arabica coffee. However it is limited by the inferior cup quality. The biochemical compounds found in coffee interact and determines the final cup quality. The objective of the study was to characterize the biochemical compounds found in Arabusta coffee hybrids. Twenty coffee genotypes including the Arabusta hybrids, backcrosses, Robusta and Arabica coffee were established at KALRO-Alupe (Busia) and Siaya -ATC in the year 2015. Coffee cherry was harvested and processed in 2018 and the green beans were analysed for sucrose, oil, trigonelline, caffeine and chlorogenic acids using the HPLC and soxhlet method. There were significant differences amongst the genotypes for these biochemical compounds across the two different environments (Busia and Siaya counties). Robusta recorded higher levels of caffeine and chlorogenic acids while the Arabusta hybrids recorded intermediate levels of the biochemical compounds between the Robusta and Arabica coffee species. The Genotype by Environment (G x E) interaction effect was only significant for chlorogenic acids. Caffeine, sucrose, oil and trigonelline levels were significantly high for genotypes evaluated in Siaya when compared to Busia. Chlorogenic acid had a positive significant association with caffeine, but was negatively correlated with coffee oil and sucrose. Coffee oil indicated a positive significant association with sucrose and Trigonelline. The Principal Component Analysis (PCA) differentiated the genotypes based on the levels of biochemical compounds indicating high genetic variation amongst the genotypes. Arabusta hybrids exceeded Robusta coffee in performance of biochemical compounds which implies that there was a successful introgression of quality genes.

Pages 201-208 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2581
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Economic feasibility of abscisic acid application to uniform ‘Rubi’ grapes coloration

Francisco José Domingues Neto*, Katia Nachiluk, Priscilla Rocha Silva Fagundes, Marco Antonio Tecchio

São Paulo State University (UNESP), School of Agriculture, Botucatu, José Barbosa de Barros Street, 18.610-307, Botucatu, São Paulo, Brazil
Institute of Agricultural Economics (IEA), Paulista Agribusiness Agency of the Secretariat of Agriculture and Supply of the State of São Paulo, Brazil


Abstract
São Miguel Arcanjo municipality (23º 31 ’S, 47º 35’ O and average altitude of 660 m) is part of one of the three main grape productive regions of São Paulo state, Brazil. The ‘Rubi’ grapes (Vitis vinifera) production constraint in that region is to achieve the variety characteristic coloration, which affects commercialization. The color of the berry grapes is due to the existence of anthocyanins and their accumulation seems to be at least in part regulated by abscisic acid. Therefore, exogenous applications of this regulator may increase the anthocyanins concentration in the grapes' skin. The aim of this paper is to evaluate the economic feasibility of abscisic acid application for treatment of the ‘Rubi’ grapes color uniformization and the impact of this application in the production cost. Production costs were calculated for the abscisic acid treated grapes and the non-treated grapes for a ‘Rubi’ grapes variety in the sixth year of production and recommended abscisic acid concentration for the region (400 mg L-1 at the beginning of the maturation + 200 mg L-1 at 25 days after first application). The abscisic acid was applied on the berry bunches in the morning using a backpack sprayer that provided full and uniform coverage. Economic feasibility was determined by the increment in the sale price of the final product due to the berries’ quality achieved with the treatment. The cost components measured were: production cost, variable and fixed cost quota, effective operational cost, total operational cost, operational profit and profitability index. Technical coefficients input prices, machinery and implements compose the production cost and were surveyed at the property where the experiment was performed. The cost structure is the Total Operating Cost to which social charges, machinery depreciation, interest rate and depreciation of a one-hectare area with a lifespan of 20 years were added. Prices paid to producers in the same period were collected from CEAGESP database for the profitability analysis. The Total Operating Cost for grape’s production with abscisic acid treatment was 26.12 % superior to the one of the grapes produced without the treatment, thus adding a US$ 0.15 increment in the paid price per kilogram of the final product. Therefore, this experiment has shown that abscisic acid application is a profitable investment that adds value to the final product cultivated in low thermal amplitude regions where the grapes cannot achieve the variety’s characteristic coloration.

Pages 209-214 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2594
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Volatile organic compounds produced by Trichoderma sp. morphophysiologically altered maize growth at initial stages

Juliana Lopes dos Santos, Evandro Alves Ribeiro*, Rodrigo Silva de Oliveira, João Henrique da Silva Luz, Bruno Henrique di Napoli Nunes, Hanrara Pires de Oliveira, Renato de Almeida Sarmento, Rubens Ribeiro da Silva, Aloísio Freitas Chagas Junior

Functional and applied ecology Laboratory, Federal University of Tocantins, Gurupi Campus, Gurupi, Brazil
Laboratory Soils, Federal University of Tocantins, Gurupi Campus, Gurupi, Brazil
Agromicrobiologist, and Applied Biotechnology Laboratory, Federal University of Tocantins, Gurupi Campus, Gurupi, Brazil


Abstract
Fungi of the genus Trichoderma are important microorganisms for increasing plant growth. However, few studies have evaluated the potential of volatile compounds produced by the fungus Trichoderma spp. and it's potential as promoters and beneficiaries with respect to maize cultivation. Thus, this work aimed to evaluate the efficiency of volatile compounds produced by Trichoderma spp. and their potential for morphophysiological improvement in the initial growth of corn crops. The experiment was conducted in a factorial scheme (2x6+1), arranged in a completely randomized design, with two evaluation times (7 and 15 days after emergence (DAE) and five Trichoderma spp. isolates (plus one control). The isolates were classified as the following species and identified with the following codes: UFT-25: Trichoderma harzianum; UFT-37: Trichoderma pinnatium; UFT-57: Trichoderma virens; UFT-201: Trichoderma asperellum and UFT-204: Trichoderma longibrachiatum. The volatile compounds produced by Trichoderma spp. and inoculated in culture medium present in each experimental unit without direct contact with the roots of the plants, promoted an increase mass production and changed morphology and physiology, especially plant height, leaf area, absolute and relative growth rate, Falker chlorophyll index, instantaneous carboxylation efficiency (RuBisCo), and net photosynthesis rate.

Pages 215-223 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2605
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Remote hyperspectral sensing for the early detection of Melanaphis sacchari Zehntner, 1897 (Hemiptera: Aphididae) infestations in sorghum leaves

Ruth Artemisa Aguilera Hernández, Manuel Darío Salas Araiza, Adriana Saldaña Robles, Alberto Saldaña Robles, Mónica Trejo Durán, Noé Saldaña Robles*

Graduate Program in Biosciences, Life Science Division, University of Guanajuato Campus Irapuato-Salamanca, Irapuato, Guanajuato 36500, Mexico
Agronomy Department, Life Science Division, University of Guanajuato Campus Irapuato-Salamanca, Irapuato, Guanajuato 36500, Mexico
Agricultural Engineering Department, Life Science Division, University of Guanajuato Campus Irapuato-Salamanca, Irapuato, Guanajuato 36500, Mexico
Multidisciplinary Studies Department, Engineering Division, University of Guanajuato, Campus Irapuato-Salamanca, Yuriria, Guanajuato 38944, Mexico


Abstract
This paper aims to study the reflectance signature information of infested and non-infested sorghum leaves (Sorghum vulgare L.) by sugarcane aphid (Melanaphis sacchari) to discriminate infested sorghum. The study treatments were 0 (0 aphids/leaf), 1 (1-20 aphids/leaf), 2 (21-50 aphids/leaf), 3 (> = 51 aphids/leaf), 4 (> = 51 aphids/leaf + visible damage), 5 (abiotic stress) and 6 (> = 51 aphids/leaf + abiotic stress). An Ocean OpticsTM HR4000 spectrometer was used. The multifactor ANOVA and Kruskal-Wallis tests at 95% confidence indicated that the reflectance at 402.95, 528.43, 658.36, 788.13, and 965.14 nm wavelengths have significant differences between treatments and with the control. Also Kernel Discriminant analysis was carried out and the combination of the wavelengths centered at 788.17 and 965.14 nm allows 70 % of correct classification of treatments. The results indicate that it is possible to detect M. sacchari infested sorghum by using the spectral information of some specific wavelengths. This study may enable the research of an aerial sensor to make recommendation maps of application pesticides.

Pages 224-232 | Full Text PDF | doi: 10.21475/ajcs.21.15.02.p2735
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Pollen fertility differences in the progenies obtained from a cross between eggplant (Solanum melongena L.) as a seed parent and eggplant cytoplasmic substitution lines as pollen parents

Shiro Isshiki, Ichiro Nakamura, kenji Ureshino, Md. Mizanur Rahim Khan*

Faculty of Agriculture, Saga University, Saga 840-8502, Japan
Faculty of Agriculture, University of the Ryukyus, Okinawa 903-2213, Japan


Abstract
To the best of our knowledge, there is no report about pollen fertility of the progenies developed using eggplant (Solanum melongena L.) as a seed parent and eggplant cytoplasmic substitution lines as pollen parents. Pollen fertility of these progenies is very important to use as restorer line in the eggplant’s hybrid breeding program. In this study, pollen fertility was investigated for the progenies which were produced using S. melongena ‘Uttara’ as a seed parent and the eggplant cytoplasmic substitution lines as pollen parents. To assess pollen fertility, pollen stainability and in vitro germination ability were investigated. Although the nuclear and the cytoplasmic genome of the progenies were almost identical to eggplant ‘Uttara’, a clear difference was observed in the pollen fertility due to the difference in the pollen parents having different wild Solanum cytoplasms. The progenies produced using the functional cytoplasmic male sterile (CMS) lines as a pollen parent, whose cytoplasm donor were S. kurzii, S. violaceum and S. virginianum, showed pollen release type and high pollen fertility almost equal to eggplant ‘Uttara’. It is considered that the characteristics of these progenies were almost the same as eggplant. On the other hand, the progenies that produced using the fertility restored lines of the pollen non-formation type CMS lines as a pollen parent, whose cytoplasm donors were S. aethiopicum, S. anguivi and S. grandifolium, showed pollen release type and low pollen fertility, i.e., pollen staining ability was about 54% and pollen germination ability were about 35%. It is considered that the cause of this low pollen fertility was the incompatibility between the eggplant cytoplasm and the eggplant nuclear genome, which seems to be modified in the process of continuous backcrossing under the wild Solanum cytoplasms. It is suggested that complete nuclear substitution is difficult by continuous backcrossing with eggplant in the alloplasmic lines with S. aethiopicum, S. anguivi and S. grandifolium cytoplasm donors. Incompatibility between the normal eggplant cytoplasm and the modified eggplant nuclear genomes of the alloplasmic lines with S. aethiopicum, S. anguivi and S. grandifolium cytoplasms might be a cause for the low pollen fertility of the investigated progenies.

Pages 233-237 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2785
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Productive potential of watermelon under different plant spacings in the semi-arid region of Brazil

Antônio Veimar da Silva*, Carla Michelle da Silva, Caio Nunes Gonçalves, Manoel Cícero de Oliveira Filho, Caike de Sousa Pereira, Maria Jany Kátia Loiola Andrade, Wagner Rogério Leocádio Soares Pessoa

Universidade Federal da Paraíba – UFPB, Areia – PB, Brazil
Universidade Federal de Viçosa-UFV, Minas Gerais, Brasil
Universidade Federal do Piauí – UFPI, Bom Jesus – PI, Brazil
Universidade Estadual do Piauí – UESPI, Picos – PI, Brazil


Abstract
This study aimed to evaluate the growth and development of watermelon plants under different plant spacings in the Semi-arid region of Brazil. A randomized block experimental design was used with four treatments and eight replications. Data were submitted to analysis of variance and the Tukey test. The treatments were composed by the following spacings: T1: 3.0 x 0.8 m; T2: 3.0 x 0.6 m; T3: 2.0 x 0.8 m and T4: 2.0 x 0.6 m (spacings between rows and between plants, respectively). The plant length, number of leaves, stem diameter, leaf area, number of flowers, number of fruits per plant, average fruit weight, total fruit production, number of commercial fruits, average weight of commercial fruits, total weight of commercial fruits and percentage of commercial fruits were evaluated in this study. There was a significant difference in the growth traits: stem diameter and leaf area at 30 days after sowing (DAS), and plant length, stem diameter and number of leaves at 60 DAS, with no significant statistical difference in the remaining days and nor for the number of flowers. The watermelon plants showed adequate vegetative and productive development at the 2.0 x 0.8 m plant spacing in the edaphoclimatic conditions of the semi-arid region under study. This spacing is well suited to small producers in the semi-arid region, which are dependent on agriculture with small areas and can obtain good productivity with no need to use larger areas due to spacing.

Pages 238-243 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2796
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Stability and adaptability of elite upland rice lines using Bayesian-AMMI model

Joel Jorge Nuvunga, Alessandra Querino da Silva, Cristian Tiago Erazo Mendes*, Gabriel Cossa, Luciano Antonio de Oliveira, Carlos Pereira da Silva, Nelio Cândido, Hermínio Bento Inácio, Júlio Sílvio de Sousa Bueno Filho

Universidade Eduardo Mondlane-Escola Superior de Empreendedorismo de Chibuto, Moçambique, Av. Samora Machel Cx Postal 25/26, Gaza-Moçambique
Faculdade de Ciências Exatas e Tecnologia (FACET), Universidade Federal da Grande Dourados, CP 364, Mato Grosso do Sul, Brazil
Departmento de Estatística (DES), Universidade Federal de Lavras, CP 3037, Minas Gerais, Brasil
Instituto de Investigação Agrária de Moçambique, Av FPLM PAN, cx postal 2590-Nampula-Moçambique

Abstract
Rice is one of the world’s most important crops. The search for genotypes that are more productive and have wide adaptation to different environments is paramount. One of the major breeder’s obstacles faced is identification of superior strains is the presence of Genotype × Environment Interaction (GEI), which motivated the development of countless statistical procedures aiming to offer more efficient studies. In this work we analysed adaptability and stability of 13 upland rice lineages as part of a genetic improvement program in nine different environments, resulting from local combination and years of agriculture. The experiment was conducted in a completely randomized block design, with three replicates. The main variable is the grain storage in kg/ha. The model applied is the Bayesian Main Additive Effects and Multiplicative Interaction (Bayesian-AMMI). Our implementation implies an extra assumption of random effects from genotypes coming from a single population as opposed to previous works in the literature. Credibility regions with maximum posteriori density allowed identification of cultivars with higher average yield. Stable genotypes showed an initial evidence of adaptation to an environment in this rice breeding program. Bayesian-AMMI is flexible, and starts to be more widely used, but our suggestion is promising in making it a more powerful tool.

Pages 244-250 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2882
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Pre-sowing treatment of maize seeds by cold atmospheric plasma and pulsed electromagnetic fields: Effect on plant and kernels characteristics

Sofia Chanioti, Nikolaos Katsenios, Aspasia Efthimiadou, Panagiota Stergiou, Zacharoula-Maria Xanthou, Marianna Giannoglou, Panagiotis Dimitrakellis, Evangelos Gogolides, George Katsaros

Institute of Technology of Agricultural Products, Hellenic Agricultural Organization-DEMETER, Sofokli Venizelou 1, Lykovrissi 14123, Attica, Greece
Institute of Soil and Water Resources, Department of Soil Science of Athens, Hellenic Agricultural Organization-DEMETER, Sofokli Venizelou 1, 14123, Lykovrissi, Attica, Greece
Institute of Nanoscience and Nanotechnology, NCSR “Demokritos”, Aghia Paraskevi 15341, Attiki, Greece


Abstract
The effect of cold atmospheric plasma (CAP) (45 kHz sinusoidal AC high voltage at 6 kV peak-to-peak for 5-15 min) and pulsed electromagnetic fields (PEMF) (amplitude 12.5 mT, repetitive frequency 3 Hz for 30 min) as pre-sowing treatments was studied on the germination, physiology, yield and quality characteristics of maize hybrid seeds with high and low germination capability. The measurements conducted during the plant growth were the dry weight, chlorophyll content, photosynthetic rate, transpiration rate and stomatal conductance, while for the harvested kernels, the color, texture, sphericity, size, ash, total protein and total crude content were estimated. The results showed that CAP and PEMF pre-sowing treatments favored the growth and physiology of both maize plants improving their germination rate significantly. Their chlorophyll content, photosynthetic rate, transpiration rate, stomatal conductance as well as dry weight were also improved. Both CAP and PEMF treatments, resulted in maize yield increase by 18-25% and by 10-20% compared to untreated samples for the low and high germination capability seeds, respectively. With regards to the quality of the harvested corn grains, their total protein and crude fiber content obtained by CAP treatment for 15 min were significantly increased by 26% and 29% for low germination seeds and by 36% and 42% for high germination seeds, respectively, compared to untreated samples. The results indicate that either CAP or PEMF pre-sowing treatments could be used as alternative ameliorative tools in order to improve maize growth, productivity, yield and quality of the final products.

Pages 251-259 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2932
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Potential of two cover crops, signal grass and ruzi grass: suggested allelopathic effect on some important weeds

André Luís Gnaccarini Villela, Rodrigo Martinelli, Thiago Ferreira Zenatti, Luiz Rufino-Jr., Patricia Andrea Monquero, Patrícia Marluci Conceição, Fernando Alves de Azevedo*

Syngenta Brazil, Holambra (SP), Brazil
Instituto Agronômico (IAC), Centro de Citricultura “Sylvio Moreira”, Cordeirópolis (SP), Brazil
Universidade Federal de São Carlos (UFSCar), Centro de Ciências Agrárias, Araras (SP), Brazil


Abstract
There is evidence that signal (SG) and ruzi (RG) grass have an allelopathic effect on weeds. This study aim to evaluate this effects on difficult-to-control weeds: hairy beggarticks (HB), benghal dayflower (BD), horseweed (H), sourgrass (S) and tall windmill grass (TWG). The first experiment was installed in a completely randomized design with 2 donor species (SG and RG) × 4 extract concentrations (0, 75, 150 and 225 mg ml−1) in factorial scheme with four replicates. Weed germination percentage was evaluated in three-day intervals. In the second experiment, the weeds emerged in substrates previously cultivated with SG and RG, in completely randomised block design with four replicates. The emergence, shoot growth and root growth were evaluated. The results were as follows: (i) on horseweed (H), 84% germination inhibition by RG leaf extracts and 38% emergence inhibition by SG root exudates were observed; (ii) on benghal dayflower (BD), 84% germination inhibition by RG leaf extracts and 37% emergence inhibition and 4.3 times the SRL values than control by RG root exudates; (iii) on hairy beggarticks (HB) 52% germination inhibition by RG leaf extracts scored, while SG root exudates reduced 43% of the emergence, 24% shoots biomass accumulation and 11.3% root length; (iv) on sourgrass (S) 71% germination inhibition by both donor plants and 75% germination inhibition by RG leaf extracts were measured. Finally, on tall windmill grass (TWG) 69% germination inhibition was observed upon using both donor plants. It can be concluded that foliar allelochemicals inhibit the germination of: BD > S > TWG > H > HB, while root exudate allelochemicals, inhibit the emergence and root development of all weeds.

Pages 260-270 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2958
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Growth and yield traits of pickling cucumber plants to measure the impact of different irrigation management practices

Fernando Soares de Cantuário, Leandro Caixeta Salomão, Carmen Rosa da Silva Curvêlo, João de Jesus Guimarães, José Magno Queiroz Luz, Luiz Leonardo Ferreira, Alexandre Igor Azevedo Pereira*

Horta Field Lab, Instituto Federal Goiano, Campus Urutaí, GO, Brasil
Departamento de Engenharia Agrícola, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista, SP, Brasil
Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Uberlândia, MG, Brasil
Departamento de Agronomia, UNIFIMES, Mineiros, GO, Brasil


Abstract
Cucumber (Cucumis sativus L) is mostly cultivated by family-based farmers worldwide and processed to pickles by small to mid-sized industries generating employment and income. But irrigation management needs better investigation for adapting adequate sustainable practices. The rational use of irrigation water still has been neglected nowadays, but can improve cucumber production. The objective was to evaluate different irrigation levels on growth and yield parameters of the Amour F1 cucumber hybrid through time under greenhouse. Treatments consisted of five irrigation levels (amounts of water applied of 62, 93, 124, 155 and 186 mm), ranging from water stress to excess water. The experimental design was randomized blocks, with four replications. Vegetative growth and yield showed different responses to the irrigation levels. Plant height and internode length were less influenced by the irrigation levels, throughout the time, than stem diameter and root length. Cucumber yield was low with 62 mm and 93 mm, higher with 124 mm irrigation, and delayed in time at 155 mm and 186 mm. Water excess (186 mm) was not beneficial for pickling cucumber plants, and the amount of 124 mm was satisfactory for their development and yield. The results of this study may allow adoption of sustainable irrigation practices with no waste of agricultural water, a scarce resource worldwide.

Pages 271-277 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2972
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Postharvest conservation of Tommy atkins mango fruits during storage using Moringa oleifera oil-based coating

Semirames Silva*, Ana Paula Sousa, Josivanda Gomes, Romário Andrade, Gustavo Lima, Eliezer Siqueira, Wilton Silva, Cleide Silva e Silva, Francisco Filho, Ana Regina Campos

Agricultural Engineering Department, Federal University of Campina Grande, Paraiba, 58428-830, Brazil
Agroecology Department, Federal Institute of Paraiba, Sousa Campus, Sousa, Paraiba, 58805-345, Brazil


Abstract
Among several biodegradable coatings used to extend the shelf life of fresh fruits, those that can be obtained from Moringa oleifera stand out due to their extraordinary biochemical, antibacterial and antifungal properties. Another aspect is their constitution which is composed of proteins, lipids, carbohydrates, carotenoids, vitamins, minerals and natural bioactive compounds, that can be applied for the development of functional foods due to their nutritional and pharmaceutical properties. The objective of this study was to evaluate the effect of bio-based coating produced from different concentrations of Moringa oleifera seed oil added to cassava starch in the postharvest conservation of Tommy atkins mango fruits. The bio-based coating was applied to mango fruits stored at room temperature (27 °C) for 15 days. Mangoes were submitted to the following treatments: moringa oil (Moringa oleifera) in 4 concentrations: 0.5% (v/v) + cassava starch; 1% (v/v) + cassava starch; 1.5% (v/v) + cassava starch and a control treatment without coating (0%), during 15 days of storage (0, 3, 6, 9, 12 and 15 days), adding up to 24 treatments with three replications. The application of moringa-oil-based coating prolonged the postharvest shelf life of the Tommy atkins mango by maintaining the physicochemical and physical properties during 12 days of storage at room temperature when compared to control treatment. M. oleifera oil-based coatings delayed the degradation of the pigments, making the bio-coated fruits gain shine and remain with it.

Pages 278-283 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2984
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Temporal and spatial progress of Cowpea aphid-borne mosaic virus (CABMV) in passion fruit (Passiflora edulis Sims)

Roger Yochiharu Kotsubo, Karina Silva dos Santos, Lucas Henrique Fantin, Vitória Carolina Antunes Chaves, João Valdecir Casaroto Filho, Vinicius Ferrari Tissiano, Rúbia de Oliveira Molina*

Institute of Rural Development of Paraná - IAPAR-EMATER (IDR-Paraná), Celso Garcia CID Highway, km 375, CEP 86001-970, Londrina, PR, Brazil
Mand State University (UEL), Celso Garcia CID Highway, km 380, CEP 86057-970, Londrina, PR, Brazil


Abstract
Among the diseases that affect passion fruit, those causing fruit hardening is considered the most important. Cowpea aphid-borne mosaic virus (CABMV) is an important disease that is transmitted by several aphid species during the bite, making the use of insecticides infeasible to control these vectors. In order to understand the epidemiological behavior of the disease, this study aimed to study the temporal progress and spatial pattern of CABMV in the field. Healthy seedlings of passion fruit with 2.0 meters height were implanted in the field condition at the experimental station of the IDR-Paraná, Brazil. The evaluations were performed weekly observing the symptoms of boloosity, mosaic, chlorosis and wilting. For the analyses, the logistic, gompertz and monomolecular models were adjusted to CABMV incidence data in passion fruit. The spatial pattern of the disease was characterized by the dispersion index and Taylor's Power Law. The logistic model was the one that best described the progress in the incidence of the disease. The incidence progress rate of CABMV was 0.037, 0.077 and 0.060 % day-1. At the beginning of the epidemic, the pattern was random. The initial dispersion mechanism was occured through aphid vectors, como Aphis gossypii Glover, Aphis fabae Scopoli, Aphis solanella Theobald, Toxoptera citricida Kilkaldy, Uroleucon ambrosiae Thomas and Uroleucon sonchi L. infected with CABMV that starts its test bite randomly. The pattern of disease dispersion began to be added when the incidence of plants reached 10 and 7%, in the 2015/16 and 2017/18 harvests, respectively. The random spatial pattern suggested that infected aphids enter several points of the orchard and infected plants become a source for secondary infections, characterizing aggregate pattern. Thus, the eradication of alternative hosts abroad can be adopted as management strategies of CABMV.

Pages 284-289 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2997
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Correlations between characters and path analysis in sweet sorghum (Sorghum bicolor (L.) Moench) genotypes for juice production

Taniele Carvalho de Oliveira, Marco Antonio Aparecido Barelli, Valvenarg Pereira da Silva*, Rafhael Felipin-Azevedo, Danilo de Lima Gonçalves, Paulo Ricardo Junges dos Santos, Juliana Parisotto Poletine, Carla Galbiati, Flávio Dessaune Tardin

Graduate Program in Amazon Biodiversity and Biotechnology, Rede Bionorte, State University of Mato Grosso (UNEMAT), Campus Cáceres-Mato Grosso, Brazil
Faculty of Agricultural and Biological Sciences, State University of Mato Grosso - UNEMAT, Campus Cáceres-Mato Grosso, Brazil
Department of Agronomic Sciences, State University of Maringá - UEM, Umuarama Regional Campus - Umuarama, Paraná, Brazil
Brazilian Agricultural Research Corporation (Embrapa) - Maize & Sorghum - Sete Lagoas, MG, Brazil


Abstract
Sweet sorghum presents stems with juice similar to that of sugar cane, rich in fermentable sugars, that may be used in off-season for sugar and ethanol production optimizing the sugar-ethanol sector. The objective of this work was to determine genetic correlations between characters and perform path analysis between juice volume and its components. Twenty-five sweet sorghum genotypes were evaluated in randomized blocks design with three repetitions and studied variables were: number of days to flowering; plant height; number of stems; weight of green mass; weight of dry mass; number of leaves; diameter of stems; volume of extracted juice and percentage of total soluble solids. In order to verify the existence of variability among the genotypes, data were subjected to variance analysis by F-test. Subsequently, genetic parameters were determined, as soon as genetic correlation estimator’s method, performed by t-test, to determine phenotypic correlation and bootstrap method for determining environmental and genetics correlation coefficient. Before performing path analysis a multicollinearity diagnosis was also conducted. The results of genetic correlation and path analysis point weight of green mass as the main variable influencing the juice volume, allowing these characters in indirect selection for increasing juice volume.

Pages 290-296 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p3083
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Control period and economic threshold level of glyphosate tolerant weeds in 2.4-D resistant soybean

Eduardo Roncatto*, Arthur Arrobas Martins Barroso, Juliana Calegarim, Felipe Ridolfo Lucio, Paulo Fernando Adami

Universidade Federal do Paraná/UFPR – Depto. de Fitotecnia e Fitossanidade, R. dos Funcionários, 1540 – Curitiba, PR – Brazil
Corteva Agrisciences –Alameda Itapecuru, 506 – Barueri, SP – Brazil
Universidade Tecnológica Federal do Paraná- UTFPR –Estr. p/ Boa Esperança, km 04. Dois Vizinhos, PR - Brazil


Abstract
Weed densities, species, costs of control, crop value and interference periods should be considered for weed management. With this regard, three experiments were carried out to evaluate weed control periods and weed density in a new soybean cultivar. In ths first trial, control efficacy was measured by visual phytotoxicity of four weed species I. hederifolia, E. heterophylla, Conyza spp. and R. brasiliensis using four different herbicides with two doses each: glyphosate (720 and 1,440 g ea ha-1), 2.4-D (670 and 1,340 g ea ha-1), glufosinate (400 and 600 g ea ha-1) and glyphosate + 2.4-D (410 + 390 and 820 + 780 g ea ha-1). Herbicides were sprayed in an entirely randomized 4x8+1 factorial scheme with six repetitions. In the second experiment, 2,4-D-resistant soybean growth was measured under increasing densities of the same weeds (21 plants m² vs 21, 42, 84, 168 and 336 plants m²). This experiment was conducted under entirely randomized design with 25 treatments with four repetitions. Critical level of damage and economic threshold level of each weed species in soybean were measured using non-linear regressions. In a third experiment, weed with soybean were submitted to increasing periods of control and coexistence (7, 14, 21, 28, 35, 49 and 70 days after soybean emergence, plus two control treatments). Glufosinate and glyphosate+2.4-D (820 + 780 g ea ha-1) showed greater weed control than glyphosate alone (720 g ea ha-1). The yield loss of 0.85, 2.12, 5.71 and 34.24% were found for each weed of E. heterophylla, I. hederifolia, R. brasiliensis and Conyza spp., coexisting with soybean. There was a soybean grain yield loss of 50% in the weedy treatment. Soybean weed management should occur between 18thand 48th days after its emergence. Economic threshold level on soybean yield suggested is below one plant of Conyza spp. and R. brasiliensis per m-². The use of glufosinate and glyphosate+2,4-D provides a greater flexibility of herbicide use for farmers.

Pages 297-304 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p3085
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Herbicides in agronomic performance and chlorophyll indices of Enlist E3 and Roundup Ready soybean

André Felipe Moreira Silva*, Felipe Ridolfo Lucio, Lucas Rafael de Marco, Ana Ligia Giraldeli, Alfredo Junior Paiola Albrecht, Leandro Paiola Albrecht, Ricardo Victoria Filho, Felipe Alves Nunes

University of São Paulo, “Luiz de Queiroz” College of Agriculture, Piracicaba, São Paulo, Brazil
Corteva Agriscience, Mogi-Mirim, São Paulo, Brazil
Federal University of Paraná, Palotina, Paraná, Brazil


Abstract
Soybean DAS-44406-6 (Enlist E3) is tolerant to glyphosate, 2,4-D and glufosinate. However, more information is needed about selectivity of 2,4-D choline on Enlist E3 soybean, alone or in mixtures. The aim of this study was to evaluate herbicide effects on agronomic performance and chlorophyll indices of soybean. Glyphosate on Enlist E3 and RR soybean at different stages of development, and 2,4-D choline alone and in mixture with glyphosate or glufosinate in Enlist E3 soybean. Studies were conducted in 2016/17 and 2017/18 seasons. Experiment 1 consisted of application of glyphosate. The treatments were arranged in a 2x4 factorial (event x growth stage). For event, Enlist E3 and RR were used. For stage, control (without application), V4, V6 and R2 were used. Experiment 2 consisted of application of 2,4-D choline, glyphosate, glufosinate and associations, at V4 of Enlist E3 soybean. Crop injury, chlorophyll indices and agronomic performance were evaluated. The equivalent selectivity of glyphosate for Enlist E3 and RR soybean, regardless of the stage was verified. 2,4-D choline, alone or in mixtures, did not reduce chlorophyll indices and yield of Enlist E3 soybean after application at V4. Enlist E3 soybean was found to be tolerant to 2,4-D choline, glyphosate and glufosinate. Thus, given the possibility of using other herbicides, in addition to glyphosate, Enlist E3 soybean may be an alternative for glyphosate resistant weeds.

Pages 305-311 | Full Text PDF| doi: 10.21475/ajcs.21.15.02.p2999