Australian Journal of Crop Science   AJCS

Genetic variability, heritability and genetic gain for quantitative traits in South African sorghum genotypes

Maletsema Alina Mofokeng*, Hussein Shimelis, Mark Laing, Nemera Shargie

Agricultural Research Council, Grain Crops Institute, Private Bag X1251, Potchefstroom, 2520, South Africa
African Centre for Crop Improvement, School of Agriculture, Earth and Environmental Science, Private Bag X 01, Scottsville, 3209, South Africa

Abstract

Sorghum is one of the most important cereal crops grown in the world for human consumption, animal feed and bio-energy. The objective of the study was to estimate the genetic variability, heritability and genetic gain of some agro-physiological traits of 98 sorghum accessions in South Africa. The studies were conducted at Makhathini in KwaZulu-Natal and Burgershall in Mpumalanga provinces. The experiments were laid out in an alpha lattice design replicated twice. The plant height, panicle length, panicle width and panicle exsertion, rachis number, panicle weight, thousand seed weight, and grain yield per panicle were recorded. The data were subjected to analysis of variance using generalised linear model and means were separated using Duncan Multiple Range Test. Coefficients of variation were also determined. There were significant differences among the traits measured. Plant height was significant and positively associated with panicle length (r =0.139), panicle width (r = 0.127) and panicle weight (r = 0.1457). Panicle exsertion was highly significant and negatively correlated with all other traits except with plant height. The Principal Component analysis revealed three most important PCs contributing a total variation of 92.36%. The PC1, PC2, and PC3 contributed 42.53, 34.65 and 15.18%, respectively. Low, medium and high estimates of broad sense heritability were found in different plant characters under study. Highest heritability estimates were found in plant height, thousand seed weight, panicle length and rachis number. Values of genetic advance ranged between 0.39 to 17655.04 and the genetic gain (of the mean percent) ranged from 3.27 to 372.52. Greater magnitude of broad sense heritability coupled with higher genetic advance in traits studied provided the evidence that these were under the control of additive genetic effects indicating that selection in the germplasm should lead to a fast improvement of the traits.

Pages 1-10 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p718
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Zinc biofortification strategies in food-type soybean cultivars

Natália Trajano de Oliveira*, Pedro Milanez de Rezende, Maria de Fátima Píccolo Barcelos, Adriano Teodoro Bruzi

Department of Agriculture, Federal University of Lavras, 37200-000, Lavras, MG, Brazil
Department of Food Science, Federal University of Lavras, 37200-000, Lavras, MG, Brazil

Abstract
Reducing the risk of Zn-deficiency in humans by diversifying human diet and through agricultural interventions, such as agronomic biofortification, is still a major challenge. This greenhouse study used a number of biofortification strategies to investigate the effect of Zn fertilization on soybean grain cultivars intended for human consumption. A completely randomized 5×3 factorial design with four replications was used. The design included five different Zn application strategies as the main plot. These were (1) soil application; (2) foliar application at the vegetative growth stage 4 (V4) growth stage; (3) foliar application at vegetative growth stage 8 (V8); (4) foliar application at reproductive growth stage 4 (R4); and (5) a control (without Zn). Three soybean cultivars (BRS 213, BRSMG 790A, and BRS Favorita RR®) were assigned as sub-plots. Zinc foliar fertilization at stage R4 was found to be the most efficient method for soybean cultivation when Zn availability in the soil was low. The cultivars had different Zn accumulation responses, and the cultivar BRSMG showed the highest Zn increase. Zinc fertilization increased the protein content in soybean grain, plant height, and the number of grains per plant.

Pages 11-16 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p783
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Adaptability of a U.S. purple-fleshed sweetpotato breeding population in Uganda

Anastasie Musabyemungu, Peter Wasswa, Agnes Alajo, Doreen M. Chelagat, Milton A. Otema, Paul Musana, Placide Rukundo, Paul Gibson, Richard Edema, Kenneth V. Pecota, G. Craig Yencho, Benard Yada*

College of Agricultural and Environmental Sciences, Makerere University, P.O. Box 7062, Kampala, Uganda
National Crops Resources Research Institute (NaCRRI), Namulonge, P.O. Box 7084 Kampala, Uganda
Rwanda Agriculture Board, P.O Box 5016, Kigali, Rwanda
Department of Horticultural Science, North Carolina State University, Raleigh, NC27695-7625, USA

Abstract
Purple-fleshed sweetpotato varieties are important for their nutraceutical value due primarily to their high anthocyanin content. These varieties also often have high dry matter content preferred by consumers and processors in sub-Saharan Africa. However, improved purple-fleshed sweetpotatoes are not available in Uganda. This study was conducted to evaluate the adaptability of purple-fleshed sweetpotato genotypes for storage root yield, dry matter and anthocyanin content in Uganda. A bi-parental population of 159 clones from the cross NCP06-020 × NC09-188 introduced to Uganda from North Carolina State University was evaluated with three local checks in two sites and two seasons in Uganda. The trials were planted in two locations using alpha lattice design with two replicates and five sweetpotato vine cuttings per genotype. Storage roots and vines were harvested after five months and the agronomic characteristics were recorded. Dry matter and anthocyanin content of storage roots were analysed after harvesting. The mean storage root yield of clones across the two locations was 37.8 t/ha and 24.2 t/ha in the first season (2015A) and second season (2015B); respectively, with an overall mean of 31.0 t/ha. Storage root dry matter content ranged from 21.5 to 33.7% across locations and seasons with an overall mean of 29.1%. Storage root anthocyanin content across the two locations ranged from 0 to 12.6 mg/100g FW with the overall mean of 3.9 mg/100g FW. A total of ten genotypes showed significantly stable performance (P ≤ 0.001) across two locations and two seasons. Highly significant difference between genotypes for dry matter content, anthocyanin content and total storage root yields revealed significant genetic variability among the tested genotypes, which can be exploited for future crop improvement.

Pages 17-25 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1023
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A software for the delineation of crop management zones (SDUM)

Claudio Leones Bazzi, Eduardo Godoy de Souza, Kelyn Schenatto, Nelson Miguel Betzek, Alan Gavioli

UTFPR – Universidade Tecnológica Federal do Paraná, Câmpus Medianeira, PR, Master Program in Computer Technologies for agribusiness, Avenida Brasil, 4232 – Parque Independência, 85884-000, Medianeira, Paraná, Brazil
UNIOESTE – Universidade Estadual do Oeste do Paraná, Cascavel, PR, Post-Graduate Program in Agricultural Engineering, Rua Universtiária, 2069 – Jardim Universitário, 85819-110, Cascavel, Paraná, Brazil

Abstract
Agricultural management zones (MZs) are economic and environmentally friendly alternatives for the precision agriculture. However, several analyzes and procedures are required for the delineation of MZs, which is being considered a difficult task. The statistical analysis, selection of variables, generation of thematic maps of the selected variables, generation of MZs (empirical or clusteringmethods), and evaluation of the applied practices are among routine procedures. In order to facilitate the definition and use of MZs, the aim of this paper was to present a software for delimitation of management zones (SDUM). Therefore, we developed a computer tool developed at UTFPR to facilitate the generation and evaluation of MZs quickly and easily. The software was developed in Java language and can be run on any operating system. It can be downloaded from http//ppat.md.utfpr.edu.br/sdum/sdum-vm.ova. We performed tests in an experimental area, generating thematic maps of soil attributes and soybean yield. The software delineated and validated MZs, by assessing all functionalities. The statistical analysis, thematic maps, MZs and the results of MZs evaluation were shown through the graphical interfaces of the software, allowing easy interaction for the users.

Pages 26-34 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1026
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Identification of agronomical and morphological traits contributing to drought stress tolerance in soybean

Willian Giordani, Leandro Simões Azeredo Gonçalves, Larissa Alexandra Cardoso Moraes, Leonardo Cesar Ferreira, Norman Neumaier, José Renato Bouças Farias, Alexandre Lima Nepomuceno, Maria Cristina Neves de Oliveira, Liliane Marcia Mertz-Henning*

Londrina State University, Londrina, PR, Brazil
Embrapa Soja, Londrina, PR, Brazil
CNPq / Embrapa Soja, Londrina, PR, Brazil

Abstract
Abiotic stresses, especially drought, may seriously affect soybean yield. Due to the complexity of drought tolerance, one of the difficulties in selecting genotypes is the identification of traits contributing to improve stress tolerance. This study carried out soybean phenotyping under water deficit in vegetative and reproductive stages in field conditions at two consecutive crop seasons (2012/13 and 2013/14). The experiment was performed in Londrina, PR, Brazil, with two soybean cultivars with distinct levels of drought tolerance, BR 16 (sensitive) and Embrapa 48 (less sensitive). Water deficit was applied through rainout shelters, moving on rails to cover plots when the rainfall begins and uncover them when it ends. Then, some agronomic and morphological traits were measured. Multivariate statistics through the principal component analysis (PCA) associated with the biplot graph identified traits contributing to greater yield stability under drought. Result showed that water deficit affected soybean yield, mainly in the reproductive stage, in which Embrapa 48 had greater yield stability when compared to BR 16. However, opposite results were obtained for stress induced in the vegetative stage, when Embrapa 48 was more negatively affected than BR16 cultivar. Seed weight influenced yield differences between cultivars. Lighter seeds, but in larger number, constituted an advantage under water deficit. Due to the difficulty in introducing all drought tolerance mechanisms in one genotype, breeding programs need to define selection parameters according to regional drought conditions.

Pages 35-44 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1109
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Assessment of genetic variability in sesame accessions using SSR markers and morpho-agronomic traits

Eveline de Sousa Araújo, Nair Helena Castro Arriel, Roseane Cavalcanti dos Santos, Liziane Maria de Lima*

Universidade Estadual da Paraíba/ Embrapa Algodão, Pós-Graduação em Ciências Agrárias, Campina Grande, PB, Brazil
Embrapa Algodão, Campina Grande, PB, Brazil

Abstract
The genetic variability of thirty-six sesame accessions were evaluated using molecular and morpho-agronomic data, aiming to identify divergent genotypes for further use in breeding program. Ten SSR markers and twenty seven morpho-agronomic traits were used to estimate genetic divergence by means of multivariate Tocher and UPGMA methods. The GENES program was used for statistical analysis of data. We observed that molecular and morpho-agronomic data were efficient to estimate divergence among the accessions. In molecular aspect, the ZM_22, ZM_45 and ZM_34 markers showed broad contribution by presenting polymorphism rates of 0.53, 0.44 and 0.39, respectively. The groups formed in the Tocher model were not similar to those formed by the UPGMA method. Among the groups formed, the study of genetic diversity allowed identification of characteristics of interest such as precocity in the genotypes ABG 591 and ABG 649. The degree of similarity assembling revealed the most similar (ABG 591, ABG 616, BRA 649, ABG 141 and ABG 688) and identifying the most divergent (ABG 648 and ABG 200) genotypes. These results revealed significant genetic variability among the investigated accessions of the sesame ABG that can be applied in the breeding programs.

Pages 45-54 | Full Text PDF| Supplementary Data| doi: 10.21475/ajcs.19.13.01.p1157
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Foliar application of chitosan enhances growth and modulates expression of defense genes in chilli pepper (Capsicum annuum L.)

Rizkita Rachmi Esyanti*, Fenny Martha Dwivany, Soraya Mahani, Husna Nugrahapraja and Karlia Meitha

School of Life Sciences and Technology, Institut Teknologi Bandung, West Java, Indonesia

Abstract
Phytophthora capsici is one of the primary pathogens causing a global problem of severe losses in chilli production. The use of conventional fertilisers and fungicides to improve chilli production had been shown to elevate environmental and health issues. Hence, the foliar application of chitosan, natural deacylated chitin, to enhance growth and resistance in chilli pepper plants was investigated. The chilli plants were grown for 14 days before receiving chitosan application and 33 days before Phytophthora infection, physiological parameters were recorded during the growth period, and expression of resistance related genes was quantified at 72 hours after infection. Our results showed that physiological parameters, such as increment of height and leaves number, and chlorophyll content indicated an improved growth process in chitosan treated plants compared to the control. Plant resistance to Phytophthora infection was also investigated following chitosan application to highly (CM334), moderately (LABA), weakly (LADO) resistant and susceptible (15080) cultivars. The disease incidence and severity indices were reduced in chitosan-treated plants, except in highly and moderately resistant cultivars. Further, expression was also quantified for defence-related genes, including 9-lipoxygenase (CaLOX), Ca2+-bound calmodulin 1 (CaCaM1), receptor-like cytoplasmic protein kinase (CaPIK), Pto-interacting1 (CaPTI1) and resistance gene analogue 2 (CaRGA2). The results suggest that CaLOX, CaPTI1 and CaRGA2 genes were involved in defence mechanism to Phytophthora, with increased expression during infection. However, expression levels were reduced when Phytophthora infection was coupled with foliar chitosan application, indicating that chitosan may play a direct role in decreasing the pathogenicity of Phytophthora. In conclusion, this study suggests the promising role of chitosan as an alternative to conventional fertiliser and fungicide in chilli pepper plant.

Pages 55-60 | Full Text PDF| Supplementary Data| doi: 10.21475/ajcs.19.13.01.p1169
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Enhanced efficiency phosphate fertilizers and phosphorus availability in Acrudox

Eduardo Stauffer*, Felipe Vaz Andrade, Eduardo de Sá Mendonça, Guilherme Kangussú Donagemma

Federal University of Espírito Santo (Universidade Federal do Espírito Santo - UFES), Department of Plant Production, Alto Universitário, 29500-000, Alegre, Brazil
Brazilian Agricultural Research Corporation (EMBRAPA), National Centre for Soil Research, 22460-000, Rio de Janeiro, Brazil

Abstract
The objective of this study was to evaluate the influence on P availability of the application of polymer-coated phosphate and organophosphate fertilizers to the soil under different soil water matric potentials and contact times. The experiment was laid out in a randomized block design and replicated four times, with treatments distributed in a split-plot arrangement. The main plot comprised four phosphate fertilizers (conventional mono-ammonium phosphate, MAP; polymer-coated mono-ammonium phosphate, POL; pelletized mono-ammonium phosphate with filter cake, FC; and granulated mono-ammonium phosphate with swine compost, SC) and two soil water contents corresponding to two matric potentials (-10 and -50 kPa). The subplot comprised six contact times (2, 4, 6, 8, 10 and 14 days after fertilizer addition). P content was determined after extraction with Mehlich-1 or water. The highest available P contents in soil were obtained using MAP (1474.3 mg dm-3) followed by POL (1355.7 mg dm-3), FC (1235.5 mg dm-3) and SC (804.2 mg dm-3). The available P contents during the 14 days of the experiment relative to the control (MAP) values ranged from 88.5 to 95.4% for POL, 83.2 to 84.4% for FC and 54.9 to 54.2% for SC. These results evidenced the effects of the organic coating applied to the phosphate fertilizer on fertilizer solubility and the short-term release of P. A decrease in the soil water matric potential decreased P availability in the short term for fertilizers with coating technologies, especially for SC compared to MAP. This result indicates that organic coating technologies may hold promise for maintaining P availability over time.

Pages 61-68 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1242
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Interactions between endophytic bacteria and their effects on poaceae growth performance in different inoculation and fertilization conditions

Elisiane Inês Dall'Óglio Chaves*, Vandeir Francisco Guimarães, Eliane Cristina Gruszka Vendruscolo, Marise Fonseca dos Santos, Fernanda Freitas de Oliveira, Joel Antônio Cordeiro de Abreu, Maiara Pasuch Camargo, Vanessa Suzane Schneider, Emanuel Maltempi de Souza, Leonardo Magalhães Cruz, Edmar Soares de Vasconcelos

West State University of Paraná (UNIOESTE) - Campus Marechal Cândido Rondon – PR, Brazi
Federal University of Paraná (UFPR) – Campus Palotina – PR; 3 Federal University of Paraná (UFPR) – Campus Curitiba – PR, Brazil

Abstract
Plant growth-promoting bacteria (PGPB) are a broad group of microorganisms that offer a huge, unexplored potential. We assessed the genetic diversity of endophytic bacteria that were isolated from corn and wheat plants in 3 different types of soils: A1 (Red Argisol), A2 (Red Latosol) and A3 (Red Nitossol). Endophytic bacteria were isolated from seedlings using 7 solid culture media and were further analyzed by 16S gene sequencing. IAA (Indole-3-acetic acid) production and PSI (Phosphorus solubilization index) bacteria capacity were tested in a randomly scheme in triplicate. In vitro association was assayed with 6 randomly selected endophytic strains. The experiment design was arranged in a randomly scheme with 10 replications. In vivo assays were performed to evaluate plant growth promotion using a low-fertility soil in different inoculation and/or fertilization conditions. The experiment design was arranged in a factorial 3x4 scheme in triplicate. The following characteristics were evaluated in both experiments in triplicate: plant biomass, total nitrogen content (TN) and endophytic population. As results, a total of 136 isolates were collected, and from these isolates, 41 strains were sequenced and classified into 4 major phylogenetic categories. There was a 38-fold variation between the highest (Ensifer adhaerens) and the lowest (Agrobacterium larrymoorei) IAA producer, and only 14% of strains were high phosphate solubilizers. In vitro assays identified both positively (Burkholderia ambifaria) and negatively (Pantoea ananatis) associative strains. In vivo assays showed that plant genotype can limit or induce the endophytic microbiota and that plant microbiota are highly influenced by soil fertility.

Pages 69-79 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1249
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In vitro cultivation of Mouriri elliptica (Mart.) a species with alimentary and medicinal potential using alternative to agar media

Elisvane Silva de Assis, Aurélio Rubio Neto*, Fabiano Guimarães Silva, Letícia Rigonato de Lima, Paulo Dornelles, Sebastião Carvalho Vasconcelos Filho, Mariluza Silva Leite, Eduardo da Costa Severiano

Federal Institute of Education, Science and Technology of Goiás, Rio Verde Campus, Rod. Sul Goiana Km 01, Cx. P. 66. CEP 75.901-970, Rio Verde – Goiás, Brazil
State Secretary of Education of Goiás. Av. Anhanguera, 7171 – St. Oeste, CEP. 74110-010, Giânia, Goiás, Brazil

Abstract
Alternative supports can be successfully used in place of agar for in vitro culture to increase seedling vigor. The objective of the present study was to evaluate the efficiency of alternative support materials compared to agar in the in vitro cultivation of Mouriri elliptica (Mart.) in the absence or presence of naphthalene acetic acid (NAA). The alternative support materials used were medium-grain vermiculite, sugarcane (Saccharum spp. L.) bagasse and queen palm fiber [Syagrus romanzoffiana (Chamisso) Glassman]. For this, young plants with at least two axillary buds under in vivo conditions were transferred to in vitro condition considering four replications with three young plants. After 45 days was evaluated the growth and anatomical explant characteristics. Autoclaving these alternative supports without the media and proceeding the explant desinfestation was an efficient method to contamination control and plant growth in a in vitro condition. No differences were observed between agar, vermiculite and sugarcane bagasse cultures for most growth characteristics evaluated. Greater numbers of adventitious and secondary roots and greater root length were significantly observed in plantlets grown in the presence of vermiculite and the absence of naphthalene acetic acid. In the agar culture, roots had weak points and poorly differentiated tissues, with parenchymal tissue predominating. The addition of 2.0 mg L-1 naphthalene acetic acid used did not stimulate rooting in this specie. So, other auxin source and concentrations should be evaluated in future studies. Both support materials used, vermiculite and sugarcane bagasse, representing promising agar substitutes to obtain seedlings with roots.

Pages 80-87 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1258
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Drought and salinity stress management for higher and sustainable canola (Brassica napus L.) production: a critical review

Ayman EL Sabagh*, Akbar Hossain, Celaleddin Barutçular, Mohammad Sohidul Islam, Disna Ratnasekera, Narendra Kumar, Ram Swaroop Meena, Hany Sobhy Gharib, Hirofumi Saneoka, Jaime A. Teixeira da Silva

Department of Agronomy, Faculty of Agriculture, Kafrelsheikh University, 33156 Kafrelsheikh, Egypt
Wheat Research Center, Bangladesh Agricultural Research Institute, Nashipur, Dinajpur, 5200, Bangladesh
Department of Field Crops, Faculty of Agriculture, Çukurova University, 01330 Adana, Turkey
Department of Agronomy, Hajee Mohammad Danesh Science and Technology University, Bangladesh
Department of Agricultural Biology, Faculty of Agriculture, University of Ruhuna, 81100, Sri Lanka
Indian Council of Agricultural Research (ICAR), Indian Institute of Pulses Research, Kanpur – 208 024, India
Department of Agronomy, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi-221005, Uttar Pradesh, India
Plant Nutritional Physiology Laboratory, Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521, Japan
Independent researcher, P. O. Box 7, Miki-cho post office, Ikenobe 3011-2, Kagawa-ken, 761-0799, Japan

Abstract
The oil of canola (Brassica napus L.), a globally important major oilseed crop, is used for salads, frying, the development of margarines, shortenings, and other food products. However, the growth and yield of canola are mainly restricted by drought and salinity, which can become acute in climate change. The exogenous application of some antioxidants has been shown to enhance tolerance to drought and salinity in select plants. Therefore, a thorough understanding of the effect of drought and salinity stress is crucial for understanding their adverse effect on canola cultivation and to establish useful strategies to maximize oil productivity. Given the economic importance of this crop, we reviewed studies within the extensive canola literature to assess the adverse effects of abiotic stresses, with a special emphasis on drought, water deficit and salinity, and how these stresses impact its growth and productivity in a bid to determine the role that antioxidants might play in alleviating the adverse effects of environmental stresses. This review notes how the productivity of canola tends to decrease under different abiotic stresses due to their adverse effect on morphological, physiological and biochemical processes, including lowered or reduced leaf area, leaf relative water content, stability of cell membranes, photosynthetic capacity, stomatal conductance, damage to chlorophyll and the production of reactive oxygen species. In addition, this review also discusses management strategies that would allow researchers or farmers to mitigate salinity and drought stress by using compatible solutes, nutrient management or other means to maximize canola yield. The application of antioxidants to soil, in combination with essential nutrients, alongside other management strategies, may assist in alleviating the harmful effects of environmental stresses in canola production.

Pages 88-97 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1284
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Cultivation of common bean (Phaseolus vulgaris L.) subjected to shallow water table at riparian wetland in South Sumatra, Indonesia

Susilawati and Benyamin Lakitan*

College of Agriculture, Department of Agronomy, Universitas Sriwijaya, Inderalaya 30662, Indonesia
Research Center for Sub-optimal Lands (PUR-PLSO), Universitas Sriwijaya, Palembang 30139, Indonesia

Abstract
Common bean is a susceptible vegetable to excessive water condition in soil. Meanwhile, flooding occurrence and soil water table are unpredictable at riparian wetlands. These circumstances make cultivation of common bean in riparian wetland challenging. A field experiment was conducted at post flooding period but soil water table was still less than 30 cm below soil surface during transitional period from wet to dry season, in May to August 2017. Site location was a paddy field at Sungai Selincah Village, within riparian wetland ecosystem in South Sumatra, Indonesia. The paddy field is characterized by alluvial soil and periodically flooded for 4-6 months during rainy season. Raised beds were constructed for setting up water table positions at 10, 15, and 20 cm below soil surface. Results of this study indicated that common bean (Phaseolus vulgaris L.) could tolerate soil water table at depth of 15 cm or deeper without significant decrease in growth and yield. However, soil water table at depth of 10 cm significantly reduced plant height, number of trifoliate leaves, diameter of canopy, shoot dry weight, root length, number of primary lateral roots, chlorophyll content index (CCI) during reproductive stage, total number of pods, and cumulative yield. In conclusion, it is possible to grow common bean at riparian wetland ecosystem as early as soil water table has subsided to 15 cm below soil surface during transitional period from wet to dry season.

Pages 98-104 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1298
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Growth and nutrition of Pitombeira (Tasilia esculenta Radlk) seedlings in different substrates and biofertilizer application

Adailza Guilherme Cavalcante, Alian Cássio Pereira Cavalcante*, Antônio Gustavo de Luna Souto, José Flavio Cardoso Zuza, Murielle Magda Medeiros Dantas, Raunira Costa Araújo

Paulista State University, Department of Plant Science, Jaboticabal, São Paulo, Brazil
Federal University of Viçosa, Department of Plant Science, Viçosa, Minas Gerais, Brazil
Federal University of Paraíba, Department of Soil and Rural Engineering, Areia, Paraíba, Brazil
Federal University of Paraíba, Department of Agriculture, Bananeiras, Paraíba, Brazil

Abstract
The pitombeira (Tasilia esculenta Radlk.) is a fruit native to Brazil, which is being exploited in an extractive way. To get agronomic information, such as the formation of mudase to be used in future commercial plantations, therefore, the objective was to evaluate the initial development and accumulation of nutrients in pitombeira seedlings submitted to different organic substrates and biofertilizer application in the soil. The experimental design was in randomized blocks, with a factorial arrangement of 4 × 2 and five replications. The treatments corresponded to four substrates (W, control; CS, commercial substrate; RFV, composite of fruit and vegetable remnants of a university restaurant; SIP, residues of industrialized products) in the substrate without and with Supermagro biofertilizer. Ninety days after sowing, the plant height, stem diameter, total dry mass, Dickson Quality Index, and leaf content in macronutrients were evaluated. The use of residues of fruits and vegetables (RFV) and residues of industrialized products (SIP) is recommended for the composition of submetry of pitombeira because these contribute to the greater growth of pitombeira seedlings. The addition of organic residues increases the quality of pitombeira seedlings having higher quality as biofertilizer treatments. Commercial substrate (CS) increases nitrogen and potassium terrors for substrates with fruit and vegetable residues (RFV), and the residues of industrialized products (RPI) used for the propagation of pitombeira seedlings can be recommended for the production of seedlings, because they increase the leaf content of phosphorus, calcium, magnesium, and sulfur.

Pages 105-114 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1388
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Advances on exogenous applications of brassinosteroids and their analogs to enhance plant tolerance to salinity: A review

Miriam Núñez Vázquez, Yanelis Reyes Guerrero, Walfredo Torres de la Noval, Lisbel Martínez González, Marco Antonio Teixeira Zullo*

Instituto Nacional de Ciencias Agrícolas, km 3½ Carretera San José-Tapaste, San José de las Lajas, Provincia Mayabeque, CP 32 700, Cuba
Instituto Agronômico, Avenida Barão de Itapura 1481, CEP 13020-902, Campinas, SP, Brazil

Abstract
Soil salinity is one of the abiotic stresses, which reduces plant growth and limits crop productivity. Brassinosteroids are considered as the sixth class of plant hormones and they have pleiotropic effects on plants, among them, they can protect plants under abiotic stresses and especially under salt stress. This paper reviews the information published during the last sixteen years related to the effects of brassinosteroids and their spirostanic analogs in plants submitted to saline stress when they are used by means of seed treatments, through the application of foliar sprays or by rooting media. Brassinosteroids stimulated salt stress tolerance in plants is associated to a decrease of oxidative damage generated by this stress and the interaction between brassinosteroids and other plant hormones, for example: abscisic acid, ethylene and salicylic acid.

Pages 115-121 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1404
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Application of herbicides on parental lines (A clearfield® and R) of hybrid rice at post-flowering stage for production

Vitor Henrique Vaz Mondo, Adriano Stephan Nascente*

Empresa Brasileira de Pesquisa Agropecuária (Embrapa), Secretaria de Inovação e Negócios, Parque Estação Biológica - PqEB. Brasília, DF - Brazil - Postcode 70770-901, Brazil
Embrapa Arroz e Feijão, P.O. Box 179, Highway 462, km 12, Santo Antônio de Goiás, State of Goiás – Brazil - Postcode 75375-000, Brazil

Abstract
The hypothesis of this study is based on the fact that parental line A-Clearfield® (male-sterile genotype) (Clearfield provide has tolerance to imidazolinone herbicides) and line R (male-fertile genotype - pollinator) is sensitive to the herbicide. So after flowering, we may apply an imidazolinone herbicide (Kifix®) to the plantings to kill line R, and harvesting only the hybrid seeds. The objective was to test the use of imidazolinone herbicide on parental lines (A-Clearfield® which is resistant to Kifix herbicide) and R no Clearfield® (non-resistant to Kifix genotype) as a strategy to improve production of hybrid seed in rice. Two trials were conducted to evaluate (A) the use of doses of imidazolinone herbicide in line R (plant control, number of grains per panicles, grain yield and seed germination; and (B) the use of different doses of imidazolinone herbicide in line A Clearfield® grain yield and seed germination. Trials were conducted in the tropical region of Brazil in randomized complete block design in factorial scheme 5 x 2 x 2. The treatments were the combination of five Kifix (Imazapyr, 525 g kg-1 + Imazapic, 175 g kg-1) rates applied on two no Clearfield® rice genotypes (first trial) or Clearfield® rice genotypes (second trial) in two growing seasons. The results showed application of herbicide doses higher than 150 g ha-1 after full flowering stage can cause reduction in growth and development of no Clearfield® rice. The use of Kifix herbicide in CL (Clearfield®) rice cultivars did not affect the grain yield, mass of 1000 grains, seed germination, first count germination, seedling emergence and seedling length. New researches should be done to define plant arrangement suitable for line R (no Clearfield®) and line A Clearfield® to find the optimum condition to produce hybrid seeds. From our results, we could see that the use of parental line A Clearfield® with a line R no Clearfield®, after flowering, provided the production of only hybrid seeds in the area, without reduction in seed quality.

Pages 131-137 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1514
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Agronomic performance of creeping peanut (Arachis hypogaea L.), grown in different row spacing and plant densities under conditions of humid subtropical climate

Tiago Zoz, Antonio Carlos Torres da Costa, Fábio Steiner, André Zoz, Travis Wilson Witt, Alan Mario Zuffo*

State University of Mato Grosso do Sul – UEMS, Agronomy Deartment, MS 306 Road, Km 6, Cassilândia, Mato Grosso do Sul, Brazil
Western Parana State University - Unioeste, Agricultura Science Center, Marechal Cândido Rondon Campus, 1777 Pernambuco Street, Marechal Cândido Rondon, PR, Brazil
USDA-ARS, PA, CSRL, Plant Stress and Germplasm Development Research, Lubbock, TX 79415, USA

Abstract
In recent years, peanut (Arachis hypogaea L.) cultivation has increased in the humid subtropical areas of Brazil. However, there is little technical information for its cultivation under these conditions. The objective of this study was to evaluate the agronomic performance of cultivar RUNNER IAC 886, when grown in different row spacing and plant populations. The experiment was a randomized block design in a 2 x 4 factorial with two plant densities (seven and ten plants per meter) and four row spacings (0.40, 0.60, 0.80, 1.00 m), with four replications. The grain yield with ten plants per meter was approximately 32.1, 16.7, 13.7 and 11.5% higher than seven plants per meter for the row spacings of 0.40, 0.60, 0.80 and 1.00 m, respectively. The highest peanut grain yield was observed in the 0.6 m row spacing.

Pages 138-143 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1521
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Morphological and productive influence of harvest on coffee plants

Felipe Santinato*, Renato Adriane Alves Ruas, Rouverson Pereira da Silva, Carla Segatto Strini Paixão, Antonio Tassio Santana Ormond

Postgraduate Program in Agronomy, Crop Production, Federal University of Viçosa (UFV), Campus Rio Paranaíba, MG Road 230, km 7, PO Box 22, Rio Paranaíba, MG, Brazil
Department of Machinery and Agricultural Mechanization, UFV-Campus Rio Parnaíba River Paranaíba, MG, Brazil
Department of Rural Engineering, Universidade Estadual Paulista–UNESP/FCAV, Prof. Paulo Donato Castellane Access way, 14884-900 – Jaboticabal, SP–Brazil

Abstract
The harvest of coffee, manual or mechanical, causes damage to the plants in several ways. Such damage manifests negatively in the following harvest, increasing the bienniality of coffee. Therefore, the aim of this work was to evaluate the morphological and productive influence of the use of repeated operations of the harvester and manual harvesting in promoting coffee growth. The biennial production cycle, one of factors that most influence the coffee productivity, is an innate characteristic of the coffee, which refers the annual alternation of high and low fruiting. According to this, the objetive of the study was comparing mechanized crop harvesting with one to six operations of the harvester using a KTR harvester with manual harvesting in initially high-load crops and initially intermediate-load crops. An experimental design of randomized blocks with four replications was utilized. The damage to plants, variation in productivity between the second and the first harvest, leafiness for 270 days and the morphological composition of the branches of the plants were assessed. You can replace manual harvesting with mechanical harvesting using up to two operations of the harvester, regardless of the coffee load, with no increase in the amount of damage caused to plants or reduced productivity in the following harvest.Crops with high initial charge naturally defoliate more than crops with intermediate initial charge.Coffee has a high capacity for defoliation from one season to another irrespective of the defoliation intensity to which it is submitted.

Pages 144-150 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p6955
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Individual and population behavior of soybean plants grown in rows with different proportions of high- and low-vigor seeds

Mateus Pino, Luis Osmar Braga Schuch, César Iván Suárez Castellanos, Felipe Koch*, Vinícius Jardel Szareski, João Roberto Pimentel, Cristian Troyjack, Ivan Ricardo Carvalho, Andrea Bicca Noguez Martins, Francielen Lima da Silva, Márcio Peter, Manoela Andrade Monteiro, Gustavo Henrique Demari, Tiago Zanatta Aumonde, Tiago Pedó

Universidade Federal de Pelotas, Faculdade de Agronomia Eliseu Maciel, Departamento de Fitotecnia, Capão do Leão, Rio Grande do Sul, Brazil

Abstract
The objective of the present work was to evaluate the influence of high- and low-vigor soybean seeds on the agronomic characteristics, yield components and seed yield of individual plants and plant communities grown in rows containing different proportions of high- and low-vigor seedlings. The experiment was conducted in the county of Selbach-RS, Brazil, in the 2012/2013 crop year using the short-cycle soybean cultivar FPS Urano RR. The experimental design was completely randomized, with five replications. Seven different proportions of high and low seedling vigor distribution along the growing line were selected: T1 (100% HV); T2 (83.3% HV and 16.7% LV); T3 (66.6% HV and 33.3% LV); T4 (50% HV and 50% LV); T5 (33.3% HV and 66.6% LV); T6 (16.7% HV and 83.3% LV); and T7 (100% LV), where HV and LV indicate high and low vigor, respectively. Based on the results obtained, it was found that: plants originating from high-vigor seeds were taller than low-vigor plants at the V5 and R8 phenological stages; even when populations originated only from seeds with low vigor, yield levels did not reach those found for high-vigor seeds; values of thousand seed weight and number of pods per plant with one seed did not differ between high- and low-vigor seeds, individually; the yield components number of seeds and seeds per plant contributed most to increase yield for the vigor proportions studied; and populations formed only of seeds with high vigor exhibited a seed yield per area 21% (928 kg ha-1) greater than that formed only by low-vigor seeds.

Pages 151-158 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1044
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Comparison of grain yield and 2-acetyl-1-pyrroline (2AP) content in leaves and grain of two Thai fragrant rice cultivars cultivated at greenhouse and open-air conditions

Pittayaporn Boontakham, Phumon Sookwong, Sakda Jongkaewwattana, Sutee Wangtueai, Sugunya Mahatheeranont*

Rice Chemistry Research Laboratory, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
Lanna Rice Research Centre, Chiang Mai University, Chiang Mai 50200, Thailand
Division of Marine Product Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai 50100, Thailand
Center of Excellence for Innovation in Chemistry, Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand

Abstract
To verify how different growing environments affect the aroma quality and production yield of fragrant rice, two commercial Thai fragrant rice cultivars, Khao Dawk Mali 105 (KDML 105) and Pathum Thani 1 (PTT 1) were grown in a greenhouse and also open air. Between the two growing environments, the temperature difference averaged 6 ºC. Each rice cultivar was grown in clay loam and sandy loam soils. In addition, a water stress treatment was applied at the beginning of the grain filling stage and onward. Determination of 2-acetyl-1pyrroline (2AP) in both rice leaves and grain was accomplished using automated headspace-gas chromatography with selective nitrogen/phosphorus detection. The results showed that throughout all growth stages the rice leaf 2AP content was different for both rice cultivars depending on the soil type. The KDML 105 cultivar had higher 2AP content in clay loam soil compared to PTT 1. A reverse trend was observed in the sandy loam soil. The grain 2AP content and grain yield of both rice cultivars were lower for those plants grown in the greenhouse condition. The water stress treatment led to higher 2AP content in both the leaves and grain of the two rice cultivars, which averaged 19% higher for rice leaves and 22% higher for rice grain. However, the water stress treatment dramatically decreased grain yield for all growing conditions. The interaction effects of these environmental factors were analysed using a full-factorial design. The interaction between rice cultivar × temperature had the strongest effect on the 2AP content, whereas rice cultivar × soil type greatly affected rice grain yield.

Pages 159-169 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1431
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Drought tolerance indices for selection of drought tolerant, high yielding upland rice genotypes

Yosep S. Mau*, Antonius S.S. Ndiwa, Shirly S. Oematan, Jenny E.R. Markus

Faculty of Agriculture, Universitas Nusa Cendana, Jl. Adisucipto, Penfui, Kupang, NTT 85001 Indonesia

Abstract
The purposes of this study were (1) to assess the effectiveness of drought tolerance indices for selection of drought tolerance in upland rice, and (2) to identify the most suitable drought tolerance indices to select for drought tolerant, high yielding upland rice genotypes. This study employed a Split Plot design consisting of irrigation levels as the main plots, and rice genotype as the sub-plot treatments. There were three main plots: 100% field capacity (FC); 75% FC; and 50% FC level. The subplot treatments consisted of 40 upland rice genotypes. Grain yields under no-stress and stressed conditions were used to calculate drought tolerance indices. There were significant variations in grain yields and drought tolerance indices between different rice genotype treatments. The indices from the literature found to be most suitable for the selection of drought tolerant upland rice cultivars were STI, GMP, MRP, HARM, REI, ATI, YI, SNPI. Ten genotypes from among the 40 tested – namely HK-07, ADN-04, PMK-01, ADN-05, NGR-022, ALR-02, HK-06, and KMD-01 – were selected as combining drought tolerance with high yield potential.

Pages 170-178 | Full Text PDF| doi: 10.21475/ajcs.19.13.01.p1778

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