Australian Journal of Crop Science   AJCS

Arabica coffee accessions originated from Ethiopia with resistance to nematode Meloidogyne paranaensis

Melina Marques Holderbaum, Dhalton Shiguer Ito, Débora Cristina Santiago, Luciana Harumi Shigueoka, Lucas Eduardo Fernandes, Gustavo Hiroshi Sera*

Universidade Estadual de Londrina (UEL) – Postgraduate Program in Agronomy – Londrina (PR), Brazil
Instituto Agronômico do Paraná (IAPAR) – Plant Protection Department – Londrina (PR), Brazil
Instituto Agronômico do Paraná (IAPAR)–Plant Breeding Departmet – Londrina (PR), Brazil

Abstract
The aim of this study was to evaluate the resistance of Ethiopian Coffea arabica from IAPAR’s germplasm bank to Meloidogyne paranaensis. Two experiments were carried out in a greenhouse in IAPAR, Londrina, Paraná State, Brazil. A completely randomized design was used with 15 treatments, eight replications and one plant per plot. 14 accessions of C. arabica from Ethiopia were evaluated and the cultivar Mundo Novo IAC 376-4 was used as a susceptible control. Seedlings with three to four pairs of leaves were transplanted into plastic cups with a capacity of 700 mL and 1200 eggs and/or J2 of M. paranaensis (IP) were inoculated after one month. The evaluations were performed 130 days after inoculation, when the data of the number of eggs and J2 per gram of roots, the final population of nematodes (FP) were obtained and the reproduction factor (RF) was calculated using the formula: RF = IP / FP. To classify the resistance levels of the genotypes, the reduction of the reproduction factor (RRF) was used. The Ethiopian accessions were classified from highly resistant to highly susceptible. Most of the Ethiopian coffees were highly resistant to M. paranaensis. The genotype Geisha also showed resistance, but is still in heterozygous condition.

Pages 1209-1213 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p1763
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Production and profitability of yacon grown in different spatial arrangements

Arnaldo Henrique de Oliveira Carvalho*, Fábio Luiz de Oliveira, Wallace Luís de Lima, Ariany Teixeira da Graça, Joab Luhan Ferreira Pedrosa, Magno do Carmo Parajara

Instituto Federal do Espírito Santo - Campus Ibatiba, Brazil
Departamento de Agronomia - CCAE/UFES, Brazil
Instituto Federal do Espírito Santo - Campus de Alegre, Brazil
Doutorado em Produção Vegetal - CCAE/UFES, Brazil
Doutorando em Produção Vegetal - CCAE/UFES, Brazil
Graduando em Agronomia - CCAE/UFES, Brazil

Abstract
The interest in yacon has generated a demand for information that may enhance the production system. Among them are the studies on the different spatial arrangements of planting spacing. Therefore, the purpose of this study was to evaluate the production and yield of yacon cultivated in different arrangements, varying the spaces between the lines and the plants. The experimental design was a randomized complete block design, being the parcels composed by three spacing between lines (0.80, 1.0 and 1.20 meters) and the subplots by three spacing between plants within the lines (0.40, 0.50 and 0.60 meters), distributed in 9 treatments with four replications. At harvest time, evaluations on the accumulation of dry mass in the plant and tuber root production data (number, weight, total productivity, and per class) were made. Profitability indicators were estimated (Gross Income, Operational Profit and Benefit-Cost ratio). The arrangements of 0.80 x 0.40 m and 1.00 x 0.50 m produced higher tuberous roots yield (37.5 and 39.8 t ha-1, respectively), but the arrangement 1.00 x 0. 50 m had a higher profit (US$ 13,854.91) and a better benefit-cost ratio (4.9), which is the most indicted.

Pages 1214-1220 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2158
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Comparison of methods for the extraction of proteins from root and leaf tissue of sugarcane (Saccharum spp.) for proteomic analysis

Luciana da Silva Viana, Paulo Pedro da Silva, Velber Xavier Nascimento, Alessandro Riffel, Antônio Euzébio Goulart Sant’Ana

Centro Universitário CESMAC, Rua Conego Machado, Farol, 57051-160, Alagoas, Brazil
Universidade Federal de Alagoas, Campus A. C. Simões, Centro de Ciências Agrárias, Laboratório de Pesquisas em Recursos Naturais, Av. Lourival Melo Mota, s/n, Tabuleiro do Martins, 57072-970, Maceió, Alagoas, Brazil
Embrapa Tabuleiros Costeiros, Tabuleiro do Martins, P.O. Box 2013, 57061-970, Maceió, Alagoas, Brazil

Abstract
The extraction of proteins from plants is a crucial procedure for successful protein determination such as purification, separation, and mass spectrometry. Protein extraction from plant tissues is generally difficult due to the presence of various molecules (cell wall, polysaccharides, and lipids) and interfering compounds. For this reason, the step of separation of proteins is a big challenge in obtaining good results in plant proteomic studies, notably from sugarcane. The current study assesses three extraction methods to prepare protein samples for proteomic analysis. Method 1 (control): TCA/acetone, method 2: TCA/acetone modified and Method 3: Phenol/SDS/ammonium acetate. Plants of cultivar RB92579 were grown in 10L pots under ideal humidity conditions in a greenhouse for 60 days. Samples collected on leaves +1 and roots were carried out using nitrogen and stored in an ultra-freezer at -80ºC for later use in proteome assays. For the tested methods, a comparison was made between the quantitative and qualitative data obtained from the tissue of sugarcane leaves and roots. According to the results obtained, methods 2 and 3 produced the best yield in the extraction of total proteins from the leaves and roots of sugarcane, when compared to (control) method 1 (TCA/acetone). This can be observed when comparing the quantitative and qualitative data obtained using the different extraction methods. By comparing methods 2 and 3, the latter showed a massive gain of extracted proteins much greater than the first method, mainly when the extraction of total proteins from the roots are compared. Similarly, the 2-DE gels run after using method 3 showed less background, compared to method 2. Another observation was the presence of different “spots” in the 2-DE gels between the samples extracted using methods 2 and 3. Method 3 (phenol / SDS / ammonium acetate) presented better results for extraction of proteins and in the 2-DE gels, with a greater number of total and specific “spots”, greater reproducibility and less background. This method could be utilized as the standard method for proteomic studies in sugarcane.

Pages 1221-1229 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2184
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Development of cabbage cultivar ‘60 days’ seedlings on substrates formulated from babassu stem biomass

Samuel Ferreira Pontes*, Edmilson Igor Bernardo Almeida, Raissa Rachel Salustriano da Silva-Matos, Selma Maria Dias de Moraes Costa, Rafaela Bezerra de Araújo, Sâmia dos Santos Matos, Washington da Silva Sousa, Kleber Veras Cordeiro, Janaiane Ferreira dos Santos, Taciella Fernandes Silva, Ronny Sobreira Barbosa and Paula Sara Texeira de Oliveira

Campus Professora Cinobelina Elvas, Federal University of Piauí, CEP 64900-00, Bom Jesus, PI, Brasil
Center for Agricultural and Environmental Sciences, Federal University of Maranhão, CEP 65500-000, Chapadinha, MA, Brasil

Abstract
Cabbage is a vegetable of considerable socioeconomic importance and is the fifth most widely cultivated vegetable in Brazil. In recent years, raising seedlings using locally available substrates has become a more viable alternative for small and medium-size rural producers. In this regard, we sought in this study to evaluate the development of seedlings of the cabbage cultivar ‘60 days’ on substrates formulated from babassu stem biomass. Research was carried out in a greenhouse covered with a shade screen providing 50% light interception. The experimental design was completely randomized with six treatments, four repetitions, and eight plants per replicate. The treatments consisted of the following substrates formulated using different proportions of babassu stem biomass (BSB) and sand: S1 - 100% sand; S2 - 20% BSB + 80% sand; S3 - 40% BSB + 60% sand; S4 - 60% BSB +40% sand; S5 - 80% BSB + 20% sand; and S6 - 100% BSB. The development of cabbage seedlings was evaluated at 30 days after sowing, with data being submitted to variance analysis followed by Duncan’s test to identify significant treatment effects at the 5% probability level. We accordingly found that the use of an alternative substrate, formulated based on babassu stem biomass, had beneficial effects with respect to promoting cabbage seedling growth. On the basis of the findings of this study, we recommend the use of a substrate comprising 60% babassu stem biomass and 40% sand for the vigorous growth of ‘60 days’ cabbage seedlings.

Pages 1230-1235 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2226
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Resistance to nematode Meloidogyne paranaensis in Arabica coffee genotypes introgressed with Coffea liberica

Gustavo H. Sera*, Filipe G. Carvalho, Inês C. de B. Fonseca, Luciana H. Shigueoka, Santino A. da Silva, Angelita G. da Silva1, Dhalton S. Ito

Instituto Agronômico do Paraná (IAPAR), Plant Breeding Department, Rodovia Celso Garcia Cid km 375, Zip code 86047-902, Londrina-PR, Brazil
Universidade Estadual de Londrina (UEL), Agronomy Department, Rodovia Celso Garcia Cid km 380, Zip code 86057-970, Londrina-PR, Brazil
Instituto Agronômico do Paraná (IAPAR), Plant Protection Department, Rodovia Celso Garcia Cid km 375, Zip code 86047-902, Londrina-PR, Brazil

Abstract
The aim of this study was to prove that Arabica coffee introgressed with C. liberica, have resistance to Meloidogyne paranaensis (Mp). Open pollinated fruits were harvested from mother plants of 29 Arabica coffee genotypes from the IAPAR germplasm bank. Seeds were collected from the fruits and were sown to obtain seedlings to test the resistance to Mp. The experiment was set up in a completely randomized design with 29 coffee genotypes, 8 replications, and one plant per plot. Cultivars Catuaí Vermelho IAC 99 and IPR 100 were used as susceptible and resistant checks, respectively. Seedlings with three to four pairs of leaves were inoculated with 1,400 eggs and juveniles J2 of Mp (IP). At 120 days after inoculation, seedlings were evaluated by counting the nematodes per gram of roots, and the final nematodes population was obtained (FP). The reproduction factor (RF) was calculated using the formula: RF = FP/IP. The reproduction factor reduction was used to classify the resistance levels of genotypes, which were classified as highly resistant (HR), resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S) an highly susceptible (HS). All genotypes differed from Catuaí in resistance factor (RF), five of which did not differ from IPR 100 for RF, and only the line IAPAR 15242 had RF < 1.0. Out of 28 Arabica genotypes introgressed with C. liberica, five HR, 11 R, 11 MR and one MS were identified. However, only IAPAR 15242 and IPR 100 were classified as HR and presented 100% of HR plants, but only the first showed an RF < 1.0. Results revealed that these Arabica coffee genotypes with introgression of C. liberica genes have great potential to be used in breeding programs and they are a new alternative as a source of resistance.

Pages 1236-1241 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2240
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Integration of UAV data with soil water balance models for evaluation/monitoring of maize water stress

Alimonti Claudio, Baiocchi Valerio*, Spadaro Carlo, Spadaro Raffaele

DICMA, Sapienza University of Rome, I-00184 Rome, Italy
Department of Civil, Constructional and Environmental Engineeering (DICEA), Sapienza University of Rome, I-00184 Rome, Italy

Abstract
UAV based photogrammetry and 3D mapping are gaining fast and wide applications around the world majorly due to the relatively low-cost advantage it offers in the acquisition of high resolution multispectral acquisitions, compared to Aerophotogrammetry and satellite acquisitions. This research seeks to demonstrate the applicability of UAV photogrammetry visible, multispectral and thermal in investigating some physiological indexes of plants, reflecting plant physiological traits. A maize field in Latina (Italy) was acquired using a Fly Novex drone and with different cameras for the various acquisitions and consequently for different flight heights. The obtained images were processed using different photogrammetric models and a variable number of Ground Control Points (GCPs) for the georeferencing and accuracy assessment as well. Subsequently, by combining hydrological simulation methods and the use of physical indicators of the state of water stress, a method is proposed for predicting crop water consumption. The study conducted on the agricultural land of test site has provided useful results in terms of water savings, with an estimated value of three quarters of the total cubic meters of water needed to bring the land to saturation.

Pages 1242-1251 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2287
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Gas exchange and putrescine content as drought stress indicators in corn cultivars fertilized with silicon

Hudson Carvalho Bianchini*, Douglas Jose Marques

José do Rosário Vellano University-UNIFENAS, Alfenas, MG 37130-000, Brazil

Institute of Agricultural Sciences, Federal University of Uberlândia, Monte Carmelo, Brazil

Abstract
The effects of drought stress on maize have been extensively reported in tropical and subtropical areas, including morphological changes in plants and reductions in the grain yield. The development of sustainable alternatives that help mitigate the negative impacts of water stress is indispensable for the development of agricultural crops. This study evaluates the effect of silicon fertilization in two irrigation blades, on gas exchange, putrescine content, quantification of Ca, K, Zn, and Fe by neutron activation and grain yield in two maize cultivars, tolerant and sensitive to drought stress. Two experiments were conducted, the first using BR-1010 (sensitive to drought stress) and the second using DKB-390 (tolerant to drought stress), in 19 dm-3 pots with one plant in each pot. The experiment was organized in randomized blocks, in a factorial scheme, combining two irrigation blades (30 percent and 100 percent of necessary water replacement) and two silicon conditions per pots: control (-Si), and 27g Si (+Si) using calcium silicate (10.5 percent Si) with four replicates. The contents of putrescine, Ca, K, Zn, and Fe, as well as transpiration rate, stomatal conductance, and net photosynthetic contents were quantified. Maize yield was measured at the end of the study. It was concluded that supplementation with Si contributes to a 12 percent increase in yield for BR-1010 (drought sensitive) and 14 percent for DKB-390 (drought tolerant). Si increased the net photosynthetic rate, transpiration rate, and stomatal conductance in DKB-390. The content of putrescine increased in plants submitted to drought stress and can be considered as an indicator of drought stress. The leaf contents of Ca, K, Zn, and Fe varied according to the cultivars and water blade studied.

Pages 1252-1258 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2339
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Influence of bifurcation on thinning, productivity and harvester production costs of Pinus taeda L.

Carlos Cézar Cavassin Diniz, Romano Timofeiczyk Junior, Renato Gonçalves Robert, Eduardo da Silva Lopes, João Carlos Garzel Leodoro da Silva, Felipe Martins de Oliveira, Gustavo Silva Oliveira*

Department of Forestry Sciences, Federal University of Paraná – UFPR, Curitiba, Paraná, Brazil
Department of Forest Engineering, State University of the Center-West, Irati - Paraná, Brazil
Latin American Union of Technology (ULT-FAJAR), Faculdade Jaguariaíva, Jaguariaíva, Paraná, Brazil

Abstract
In this work, we present that how bifurcation in Pinus trees can influence productivity and harvester production costs. Our example draws from one harvesting machine that works in thinning operations in forest plantations of Pinus taeda L. in a small Brazilian forestry company. To get daily productivity, we use the machine’s system, which provides such daily information as total production. We also used a time and motion study to obtain the meantime to cut, delimb, and process the tree stem into logs. In this way, we separated the normal trees from the forked trees to get the operating cycle time of the machine and get the productivity to the two types of trees. The continuous timing method was used for this purpose. The results show an increase of up to 22.9% in the operational cycle time for cutting forked trees, resulting in reduction of productivity of 5.58 m³ for each hour worked. The production cost increased by 23.3% on operation of forked trees, as the machine took more time to perform the partial activities of the operational cycle. This study can help many companies and contractors to calculate the appropriate productivity and production harvest cost according to the type of tree stems from the plantation forest.

Pages 1259-1263 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2377
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Stress-resilient maize for climate-vulnerable ecologies in the Asian tropics

P.H. Zaidi*, Thanh Nguyen, Dang N. Ha, Suriphat Thaitad, Salahuddin Ahmed, Muhammad Arshad, Keshav B. Koirala, Tirtha R. Rijal, Prakash H. Kuchanur, Ayyanagouda M. Patil, Shyam S. Mandal, Ramesh Kumar, S.B. Singh, Bhupender Kumar, J.P. Shahi, M.B. Patel, Murali K. Gumma, Kamal Pandey, Ramesh Chaurasia, Azizul Haque, K. Seetharam, Reshmi R. Das, M.T. Vinayan, Zerka Rashid, S.K. Nair, B.S.Vivek

CIMMYT Asia Maize Program, ICRISAT campus, Patancheru-502324, Hyderabad, India
National Maize Research Institute, Ha Noi, Vietnam
Nakhan Suwan Field Crop Research Center, Tak Fa, Nakhan Sawan, Thailand
Bangladesh Agricultural Research Institute, Gazipur, Bangladesh
Maize & Millet Research Institute, Sahiwal, Pakistan
National Maize Research Program, Rampur, Chitwan, Nepal
University of Agricultural Sciences, Raichur, Karnataka, India
Bihar Agriculture University, Sabor, India
Indian Institute of Maize Research, Ludhiana, Punjab, India
Institute of Agricultural Sciences, BHU, Varanasi, U.P., India
Main Maize Research Station, Gujarat Agriculture University, Godhara, Gujarat, India
International Crops Research Institute for Semi-arid Tropics, Hyderabad, India
Corteva AgriSciences, Hyderabad, India
Kaveri Seeds Pvt. Ltd., Hyderabad, India
BRAC, Dhaka, Bangladesh

Abstract
Most parts of the Asian tropics are hotspots of climate change effects and associated weather variabilities. One of the major challenges with climate change is the uncertainty and inter-annual variability in weather conditions as crops are frequently exposed to different weather extremes within the same season. Therefore, agricultural research must strive to develop new crop varieties with inbuilt resilience towards variable weather conditions rather than merely tolerance to individual stresses in a specific situation and/or at a specific crop stage. C4 crops are known for their wider adaptation to range of climatic conditions. However, recent climatic trends and associated variabilities seem to be challenging the threshold limit of wider adaptability of even C4 crops like maize. In collaboration with national programs and private sector partners in the region, CIMMYT-Asia maize program initiated research for development (R4D) projects largely focusing on saving achievable yields across range of variable environments by incorporating reasonable levels of tolerance/resistance to major abiotic and biotic stresses without compromising on grain yields under optimal growing conditions. By integrating novel breeding tools like - genomics, double haploid (DH) technology, precision phenotyping and reducing genotype × environment interaction effects, a new generation of maize germplasm with multiple stress tolerance that can grow well across variable weather conditions were developed. The new maize germplasm were targeted for stress-prone environments where maize is invariability exposed to a range of sub-optimal growing conditions, such as drought, heat, waterlogging and various virulent diseases. The overarching goal of the stress-resilient maize program has been to achieve yield potential with a downside risk reduction.

Pages 1264-1274 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2405
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Development and validation of chromatographic methods to quantify organic compounds in green coffee (Coffea arabica) beans

Wilder Douglas Santiago, Alexandre Rezende Teixeira, Juliana de Andrade Santiago, Ana Cláudia Alencar Lopes, Rafaela Magalhães Brandão, Alex Rodrigues Caetano, Maria das Graças Cardoso*, Mario Lúcio Vilela Resende

Chemistry Department, Federal University of Lavras, Lavras, MG, Brazil
Phytopathology Department, Federal University of Lavras, Lavras, MG, Brazil
Biology Department, Federal University of Lavras, Lavras, MG, Brazil

Abstract
Coffee is one of the oldest and most consumed beverages. The raw material for obtaining a good quality coffee drink is the grain. Bioactive compounds and organic acids in coffee beans are reflections of a series of attributes that, together, confer to the coffee peculiar flavor and aroma. This study aimed to identify trigonelline, chlorogenic acid, caffeine and organic acids in green coffee beans, and to validate the chromatographic method using High-Performance Liquid Chromatography (HPLC). Coffea arabica green coffee beans were used in this experiment. Trigonelline, chlorogenic acid, caffeine, and organic acids were identified and quantified by HPLC. Selectivity, linearity, limit of detection, limit of quantification, precision, and accuracy were used to validate the methods. Three bioactive compounds (trigonelline, chlorogenic acid, and caffeine) and seven organic acids (oxalic, citric, malic, quinic, succinic, lactic, and acetic acids) were quantified in the samples. The mean values for trigonelline, chlorogenic acid (5-ACQ), and caffeine ranged from 1.28 to 1.66, 3.47 to 4.73 and 1.26 to 1.59 g 100g-1, respectively. The values of organic acids, as well as the phenolic compounds, agree with those reported by the literature for green coffee beans of C. arabica. The validation parameters allowed the method to be considered linear, exact, and precise. Therefore, it resulted in a method reliable for studies of the composition of food matrix or quality control of green coffee beans.

Pages 1275-1282 | | Full Text PDFdoi: 10.21475/ajcs.20.14.08.p2433
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Comparison of methods to evaluate resistance of lettuce genotypes against Bremia lactucae

Ana Carolina Pires Jacinto, Aline José da Silveira, Isadora Gonçalves da Silva, Renata Castoldi, Carolina Andrade Franco, Rafael Resende Finzi, Marcus Vinícius Marin, Leila Trevisan Braz, Gabriel Mascarenhas Maciel

Instituto de Ciências Agrárias, Universidade Federal de Uberlândia, Campus de Monte Carmelo, CEP: 38.500-000, Monte Carmelo, MG, Brasil
Gulf Coast Research and Education Center, University of Florida, Zip Code: 33598, Wimauma, Flórida, United States
Departamento de Produção Vegetal, Universidade Estadual Paulista “Júlio de Mesquita Filho”, CEP: 14.884-900, Jaboticabal, SP, Brasil

Abstract
For the lettuce crop, there is no specific or standard methodology to evaluate genotype resistance of lettuce against downy mildew. Therefore, the aim of this work was to compare three methodologies for the identification of resistance to downy mildew. The experiment was carried out at Universidade Federal de Uberlândia, Monte Carmelo Campus between 2017 and 2018. The statistical method used was a completely randomized design with 12 treatments (cultivar Solaris, used as a control; and 11 genotypes of lettuce F5: 6: UFU-Crespa 75 # 2, UFU-Crespa 189 # 2, UFU-Crespa 206 # 1, UFU-Lisa 66 # 3, UFU-Lisa 66 # 7, UFU-Lisa 215 # 3, UFU-Lisa 215 # 6, UFU-Lisa 215 # 10, UFU-Lisa 215 # 12, UFU-Lisa 215 # 13, UFU-Lisa 215 # 14) and four replications. The seeding of genotypes was carried out in transparent boxes and after 15 days the inoculation was performed using a spore suspension (1x104 sporangia/ml) and sterile deionized water for the controls. The disease progression was assessed by three methods: Mesquita, Dickinson & Crute and Horsfall & Barrat. The data were standardized and submitted to the univariate analysis of variance by the F test and multivariate analyzes. The univariate clustering results allowed the separation of the genotypes into two distinct resistance groups for the Dickinson & Crute and Mesquita methods. In the multivariate analysis, more formation of groups among genotypes with different levels of resistance to downy mildew in the Mesquita method was observed. The methodology proposed by Mesquita was more efficient in discriminating genotypes with different levels of resistance to downy mildew, separating them in a larger number of groups.

Pages 1283-1287 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2435
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Marker-assisted selection for transfer of submergence tolerance, bacterial blight resistance and yield enhancement in the rice backcross derivatives

Shibani Mohapatra, Akshaya Kumar Bastia, Alok Kumar Panda, Sharat Kumar Pradhan*

ICAR- National Rice Research Institute, Cuttack, Odisha, India
North Orissa University, Baripada, Odisha, India
School of Applied Sciences, KIIT Deemed to be University, Bhubaneswar, Odisha, India

Abstract
Achieving the demand and supply of rice for the increasing global population will be a challenging task beyond 2040. Therefore, the yield potential of popular rice varieties needs to be increased. The production from lowland rice can be enhanced by managing the major biotic and abiotic stresses faced in the ecology. In this work, we have developed the pipelines for gene stacking of submergence tolerance, bacterial blight resistance and yield component QTLs in the popular rice variety ‘Swarna’ by marker-assisted backcross breeding approach. Genotyping results of 796 BC1F1 backcross derived lines showed the presence of GW2, OsSPL14, SCM2 yield component QTLs, Sub1A for submergence tolerance and bacterial blight resistance genes xa5 and Xa21 in the progenies. The four stacked QTLs and two resistance genes were observed in six backcrosses derived progenies only. These progenies will be used in the next generation for further selection and evaluation for enhancing submergence tolerance, yield potential and bacterial blight resistance in Swarna rice variety background.

Pages 1288-1294 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2518
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Genetic progress in maize from advanced cycles of reciprocal recurrent selection through REML/BLUP

José Arantes Ferreira Júnior, Gabriel Moreno Bernardo Gonçalves, Jocarla Ambrosim Crevelari*, Julio Cesar Fiorio Vettorazzi, Vivane Mirian Lanhellas Gonçalves, Nayara Norrene Lacerda Durães, Alexandre Pio Viana and Messias Gonzaga Pereira

Universidade Estadual do Norte Flumin¬ense Darcy Ribeiro/UENF, Laboratório de Melhoramento Genético Vegetal/LMGV, Av. Alberto Lamego, 2000, Parque Califórnia, 28013-602, Campos dos Goytacazes, RJ, Brazil

Abstract
Breeding methods such as reciprocal recurrent selection (RRS) is very important alternative to breeders. This strategy, besides allowing continuous genetic progress, helps maintaining the genetic variability of populations. The aim of the present study was to estimate genetic parameters, as well as to predict selection gains in advanced cycles of reciprocal recurrent selection of maize progenies through mixed models. Two selection cycles were considered. We evaluated 196 and 169 progenies in the 15 and 16 cycles, respectively. The yield potential of the progenies was evaluated from the following characteristics: grain yield, number of ears, weight of ears and weight of 100 seeds. The estimate of variance components and the prediction of genetic values were based on the REML/BLUP method. Overall, the genetic parameters were increased in the 16th cycle estimates compared to the previous cycle. It is worth highlighting that heritability coefficient for the grain yield was (0.81) in the 16th cycle, since it resulted in 21% of selection gain. Results showed that, even after sixteen recurrent selection cycles, the populations under selection have high potential for satisfactory genetic gains.

Pages 1295-1301 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2562
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Decontamination methods of tanks to spray 2,4-D and dicamba and the effects of these herbicides on citrus and vegetable species

Gustavo Dutra Roesler, Luana Carolina Gomes Jonck, Rafael Pires Silva, Ana Victoria Jeronimo, Andreia Cristina Silva Hirata, Patrícia Andrea Monquero*

Department of Natural Resources and Environmental Protection, São Carlos University, Araras, São Paulo State, Brazil

APTA/Polo da Alta Sorocabana, Presidente Prudente, São Paulo State, Brazil

Abstract
In agriculture, the development of plants resistant to 2,4-D and dicamba tends to result in increased use of these herbicides in agricultural areas and consequently increases the risk of excessive herbicide use in susceptible species. The aims of the present study are to assess the effects of 2,4-D and dicamba on citrus (Citrus sinensis var. Pêra Rio), lettuce (Lactuca sativa var. Stella) and tomato (Lycopersicum esculentum var. Santa Clara) and determine the best method for spray tank decontamination after applying such herbicides. All the experiments followed a completely randomized design with five replications. To study the effects of 2,4-D and dicamba on sensitive plants, experiments were performed on the following cultivated species: citrus, lettuce and tomato. Each species was subjected to 2,4-D (D, 670 g i.a. ha-1) and dicamba (D, 560 g i.a. ha-1) applied at doses of 0 D, 1 D, 0.5 D, 0.12 D, 0.03 D, 0.007 D and 0.001 D (of commercial doses (Ds)). In another experiment, the following methods were adopted to clean tanks used to spray 2,4-D and dicamba at commercial doses: wash with water (1x), water (2x), water (3x), water + 96% alcohol (1:1), water + detergent (2.5%) or no washing. The tanks were filled with water after treatment. The young tomato plants were used as bioindicators. Regarding plant sensitivity, citrus plants exhibited low potential for suffering losses due to 2,4-D and dicamba drift. The plants tolerated a dose of 0.12 D for both herbicides. Lettuce and tomato were extremely sensitive to 2,4-D and dicamba. Lettuce tolerated 2,4-D at a dose of 0.007 D but showed phytotoxicity symptoms; the tolerated dicamba dose was 0.03 D. Only the 0.03 D dose of 2,4-D was tolerated by tomato. Although the tomato plants presented phytotoxicity symptoms, the tolerated dicamba dose was 0.007 D. For the tank cleaning experiment, the spray tank cleaning by thoroughly washing in water (2x) was the most appropriate method to clean tanks used to spray 2,4-D. Washing with water (2x, at a minimum), water + alcohol (1:1) or water + detergent was equally effective to clean tanks filled with dicamba. Therefore, the study shows that the application of 2,4-D and dicamba in areas close to young Citrus sinensis plants should be avoided given that vegetable species, such as lettuce and tomato, do not tolerate the minimum drift of these herbicides. Double washing with water would be the most economical and effective method of cleaning tanks used to house these herbicides.

Pages 1302-1309 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2586
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Biomass growth and development in air-cured burley and flue-cured virginia tobacco varieties

Luis Felipe Boaretto*, Fabricio Silva Coelho*, João Leonardo Corte Baptistella, Paulo Mazzafera

Souza Cruz LTDA, Av. Frederico Augusto Ritter, 8000 - Distrito Industrial, Cachoeirinha – RS, Brazil
Departamento de Produção Vegetal, Escola Superior de Agricultura “Luiz de Queiroz”, Universidade de São Paulo, Piracicaba, SP, Brazil
Departamento de Biologia Vegetal, IB, Universidade Estadual de Campinas, Campinas, SP, Brazil

Abstract
Research on the accumulation and partitioning of biomass in the tobacco cycle is scarce, particularly those comparing different varieties. The objective of this work was to study the partition of biomass in air-cured burley - ACB (BAT2101) and flue-cured virginia - FCV (CSC4704) varieties. In a greenhouse experiment, the two varieties were transplanted into pots containing a mixture of fine sand and substrate (1:1). Samples were taken for a period of 98 days, with 7 day intervals. In each harvest, dry mass and leaf area were measured, and specific leaf mass, leaf area ratio, relative growth rate, net assimilation rate, and root to shoot ratios were estimated. The data showed that carbon partitioning in plants of both varieties is influenced by root growth, which was 50% higher in ACB by the end of the experiment. The higher accumulation of mass in the roots of this variety may be related to the fact that it requires more nitrogen than virginia and, therefore, it could be a mechanism for increased uptake of this element. ACB also had higher specific leaf mass than FCV, which may be related to the body of ACB. This information is important for choosing varieties adapted for field conditions, as well as for the genetic improvement of tobacco. Furthermore, from the point of view of crop management, this knowledge may provide useful information for maximizing leaf growth.

Pages 1310-1318 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2589
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Fuzzy logic simulation of oat yield after using hydrogel and nitrogen biopolymer management

Osmar Bruneslau Scremin, José Antonio Gonzalez da Silva, Ivan Ricardo Carvalho*, Ângela Teresinha Woschinski De Mamann, Odenis Alessi, Vanessa Pansera, Francine Lautenchleger, Roberto Carbonera, Leonardo Norbert, Natiane Carolina Ferrari Basso

Regional University of the Northwest of Rio Grande do Sul, Ijuí, Brazil. Street of Comércio 3000, Universitário, Ijuí/RS, Brazil
State University of Central-West - Street Presidente Zacarias, 875, Guarapuava/PR, Brazil
Federal Institute of Education, Science and Technology of Rio Grande do Sul, Street Nelsi Ribas Fritsch, 1111, Neighborhood Esperança, Ibirubá/RS, Brazil

Abstract
The fuzzy logic is an efficient tool for simulation and validation of new technologies in agriculture. The objective of the study is to adapt the fuzzy logic model for simulation of biomass and oat grain yield by nitrogen involving the nonlinearity of the maximum air temperature in the conditions of use of the biopolymer hydrogel, considering high succession systems and low release of residual N. The study was conducted in 2014 and 2015, in a randomized block design with four replicates in a 5 x 5 factorial. Five hydrogel doses (0, 30, 60, 90 and 120 kg ha-1) were added in the groove next to the seed; and 5 doses of N-fertilizer (0, 30, 60, 90 and 120 kg ha-1) applied at the fourth expanded leaf stage, respectively. The cultivar was URS Corona. The pertinence functions and the linguistic values established in the input and output variables to simulate the biomass yield and oat grains in the succession systems are adequate observed productivity. The fuzzy model makes it possible to estimate the biomass and oat grains productivity efficiently under the conditions of use of the hydrogel as a function of the nitrogen doses and maximum air temperature, adding to the existing models of simulation.

Pages 1319-1327 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2591
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Morphological characteristics and soybean yields after using different limestone sources

Adaniel Sousa dos Santos, Leandro Pereira Pacheco, Rafael Felippe Ratke, Weverson Lima Fonseca, Alan Mario Zuffo*, Francisco de Alcântara Neto, Júlio César Azevedo Nóbrega, João Batista da Silva Oliveira, Tiago de Oliveira Sousa, Aline Sousa dos Santos

Federal University of Piauí, 64900-000, Bom Jesus, Piauí, Brazil
Federal University of Rondonópolis, 78735-901, Rondonópolis, Mato Grosso, Brazil
Federal University of Mato Grosso do Sul, 79560-000, Chapadão do Sul, Mato Grosso do Sul, Brazil
Federal University of Piauí, 64049550, Teresina, Piauí, Brazil
Federal University of Recôncavo da Bahia, 44380-000, Cruz das Almas, Bahia, Brazil

Abstract
In this study, the growth and productive characteristics of the soybean were investigated in no-till system after using limestone in a tropical soil of the Brazilian Cerrado. The study was conducted in a Typic Hapludox. The sources of limestone came from Piauí miners (C1, C2 and C3) and from a mining company in Ceará (C4) plus a control treatment (without limestone), with four replicates, during the 2013/2014 and 2014/2015 growing seasons, in a randomized block design. The limestone was applied in October 2012, using a gravity distribution. The limestone rate applied was 2.73 Mg ha-1 to raise the soil base saturation to 60%. The final plant stand, relative chlorophyll index, leaf area index, shoot dry matter, photosynthetically active radiation, the efficiency of photosynthetically active radiation, number of stems, pod number per plant, thousand-grain mass and grain yield of the soybean were evaluated. There were significant differences between the sources of limestone, with emphasis on the sources C1 and C4 due to the greater increases in plant growth and soybean grain yield (79% and 90%, respectively, in the 2014/2015 harvest). Soybean yield is correlated to the vegetative and reproductive development of the plant when cultivated in a tropical soil of the Cerrado corrected with limestone.

Pages 1328-1334 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2618
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Phosphorus (P) improves industrial tomato quality and yield in soil with high phosphorus content

Arthur Bernardes Cecílio Filho*, Bruno Trevizaneli, Sergio Manuel Rugeles-Reyes

Department of Plant Production, Sao Paulo State University, Jaboticabal, Brazil
Predilecta Industry, Guaíra, Brazil
Department of Agricultural Sciences, National University of Colombia, Bogotá, Colombia

Abstract
Soils under intensive and successive cropping with central pivot irrigation tend to present high nutrient contents, especially phosphorus (P), which is a nutrient with a great impact on the yield and quality of agricultural products. Among the rotating crops, the application of high P rates is common in processing tomato, although not supported by research. This work evaluates the effect of phosphate fertilization (0, 200, 400, 600, 800, and 1000 kg ha-1 P2O5) on the yield and quality of industrial tomato ‘Heinz 9553’ grown in a soil with high available P content (145 mg dm-3) resulting of an intensive vegetables cultivation, which have high demand by P. The highest total (127.4 t ha-1) and commercial (108.6 t ha-1) yields were obtained with 413.9 and 384 kg ha-1 P2O5, respectively. The results showed that pH of tomato juice, the percentages of green, red, and commercial fruits were not influenced by the applied P rates. However, nutrient delivery increased the soluble solids content up to 356 kg ha-1 P2O5, which is interesting for tomato processing. After harvesting the fruits, the available soil P content was increased with P supply to the plants. Due to improve in both commercial yield and soluble solids characteristics, the tomato crop shall be fertilised with P even though the soil has high P content.

Pages 1335-1341 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2629
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Post-emergence nicosulfuron application enhanced leaf-stem ratio in maize-intercropped with Urochloa species after shading and sunlight re-exposure

Lucas F. N. Souza, Silas M. Oliveira, Rodrigo E. M. Almeida*, Clovis P. Junior, João L. C. Baptistella, José L. Favarin

University of São Paulo, Department of Crop Science, Piracicaba, Brazil
Embrapa Pesca e Aquicultura, Palmas, Brazil

Abstract
Low rates of nicosulfuron used in post-emergence provide an advantage to maize during the coexistence of the crops, when maize is intercropped with Urochloa grasses. Nonetheless, the effect of this practice on the morphology of these grasses is not known, neither how it affects forage growth after the coexistence period nor when the grass is re-exposed to full sunlight. The aim of this study was to determine biomass and leaf-stem ratio of Urochloa hybrid cv. Mulatto II (CIAT 36087), Urochloa brizantha (Hochst. ex A. Rich.) and Urochloa ruziziensis (Germ. & Evrard) after the development in a shade simulated environment promoted by maize in intercrop systems. The treatments consisted of three brachiaria species with two herbicides managements. Evaluations occurred at 0, 30 and 60 days after the sunlight re-exposure (DASR). Nicosulfuron application and Urochloa species did not affect biomass yield. However, herbicide increased leaf-stem ratio of the species between 25% at 0 DARS to 62% at 30 DARS on old tillers (tillers that grew under shade). The biomass yield, as well the leaf-stem ratio of the new tillers was not affected. Among the species, the greater ratio of leaves in the plant biomass was recorded for Urochloa brizantha (Hochst. ex A. Rich.) and Urochloa hybrid cv. Mulatto II (CIAT 36087). Nicosulfuron use in post-emergence enhanced the leaf-stem ratio of Urochloa grasses after sunlight re-exposure and a reliable alternative to improve forage quality in intercrop systems.

Pages 1342-1347 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2632
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Growth analysis of tomato for industrial processing as a function of nitrogen doses

Leonardo Correia Costa, Arthur Bernardes Cecílio Filho*, Rodolfo Gustavo Teixeira Ribas, Alexson Filgueiras Dutra, Antonio Márcio Souza Rocha, José Carlos Barbosa

São Paulo State University – Unesp, 14884-900, Jaboticabal, SP, Brazil.
Federal Institute of Education, Science and Technology of Rondônia (IFRO), Campus Cacoal, Rondônia, Brazil

Abstract
Nitrogen (N) is considered to be the nutrient that most affects plant growth. Understanding this mechanism helps in crop management and planning. This study analyzes the growth of tomato plants (Heinz 9553) for industrial purposes as a function of N doses (0, 60, 120 and 180 kg ha-1). The experiment was carried out from April to August 2015, in Barretos, São Paulo State, Brazil. The experimental design was a randomized blocks, in plots subdivided in time, with three replicates. Growth assays were performed at 14, 28, 42, 56, 70, 84, 96, 112 and 126 days after transplanting (DAT). Fertilization with 180 kg ha-1 N provided greater leaf area, leaf dry mass, shoot dry mass (leaves + stems), fruit dry mass, total dry mass, leaf area index, leaf area ratio and leaf mass ratio at the end of the cycle. The lowest relative growth rate and specific leaf area were verified with 180 kg ha-1. For all N doses, the absolute growth rate was small up to 56 DAT and, subsequently, N doses promoted distinct increases in the index.

Pages 1348-1354 | Full Text PDF| doi: 10.21475/ajcs.20.14.08.p2648