Australian Journal of Crop Science   AJCS

Leaf sampling to assess mineral nutrient composition of physic nut plants (Jatropha curcas L.)

Rosiane de Lourdes Silva de Lima*, Carlos Alberto Vieira de Azevedo, Hans Raj Gheyi, Jairo Osvaldo Cazetta, Genelicio Souza Carvalho Junior, Nair Helena de Castro Arrriel

Federal University of Campina Grande - Academic Unit of Agricultural
Engineering, Campina Grande, PB, Brazil
Federal University of Recôncavo of Bahia - Nucleus of Soil and Water Engineering, Cruz das Almas, BA, Brazil
Unesp - Universidade Estadual Paulista - Technnology Department, Jaboticabal, SP, Brazil
State University of Paraiba, Campina Grande, PB, Brazil
Company Brasilian of Research Agropecuária (Embrapa). Embrapa Algodão,Campina Grande, PB, Brazil

Abstract
The physic nut is an important plant for biodiesel production. However, research is still lacking as to the best leaves to be sampled in determining ideal mineral content. It is important that all factors causing variations in the mineral nutrient concentrations in leaves are identified and evaluated to determine the most efficient sampling technique. The positions of the leaves on the branches and on the plant shoot are critical variables affecting leaf composition. Thus, this study aimed to determine the best leaf position for sampling to evaluate the health status of adult physic nut plants. The experiment was conducted in the field, using a 5 × 3 factorial design, with leaves sampled at five positions on the branch (1st, 2nd, 3rd, 4th, and 5th node, from the apex), and three sections of the plant crown (apical, middle, and basal), in a completely randomized design with four replications, and four plants per plot. The concentration of macronutrients (N, P, Ca, Mg, and S) and micronutrients (Cu, Fe, Mn, and Zn) were determined for all samples. The results indicated that the sampling of leaves at the 3rd and 4th node of the flower-bearing branches, located in the middle section of the plant canopy, was the most indicative of the mineral composition of adult jatropha plants.

Pages 1069-1074   Read More   DOI: 10.21475/ajcs.2016.10.08.p6913
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Morphometry, in vitro-ex vitro germination and tetrazolium testing of stinking passionflower [Passiflora foetida var. glaziovii Killip] (Passifloraceae) seeds

Poliana Rangel Costa, João Paulo Bestete de Oliveira, Anderson Geyson Alves de Araújo, José Carlos Lopes, Edilson Romais Schmildt, Wagner Campos Otoni, Rodrigo Sobreira Alexandre*

Federal University of Espírito Santo, Department of Agricultural and Life Sciences, Brazil
Federal Institute of Espírito Santo, Campus Ibatiba, Brazil
Federal University of Espírito Santo, Department of Plant Production, Brazil
Federal University of Viçosa, Department of Plant Biology/BIOAGRO, Brazil
Federal University of Espírito Santo, Department of Forest Sciences and Wood, Brazil

Abstract
Passiflora foetida L. has broad utility as a medicinal and ornamental plant; however, information regarding varieties and the physiological potential of their seeds are scarce. Here, we aim to evaluate in vitro and ex vitro germination behaviour and to adapt tetrazolium methodology for P. foetida var. glaziovii Killip. The botanical identification and characterisation were performed through the observation of morphological characters and consultation of the relevant literature. Ex vitro germination was performed on rolled and flat Germitest paper at continuous (25 °C) and alternating (20 and 30 °C; night and day, respectively) temperatures. Seeds with the completely removed integument were used for in vitro germination and tetrazolium tests. The in vitro germination test was performed with MS medium using seeds conditioned under different light qualities (white, red, far-red or darkness) and at two temperature regimes (25 °C; 20 and 30 °C alternating temperature). For the tetrazolium test, seeds were soaked in different concentrations of tetrazolium salt (2.5, 5.0, 7.5 or 10 g L-1) at different temperatures (30, 35, 40 or 45 °C) for two hours in the dark. This is the first record of P. foetida var. glaziovii, a wild herbaceous vine with glandular trichomes on its leaves, bracts and stipules; fruit bacoid, elliptic, glabrous, in Espírito Santo State, Brazil. The seeds are small (approximately 4.87 mm long and 2.15 mm wide) and non-photoblastic, and in vitro germination must be performed using an alternating temperature (20 and 30 °C) regime. The best result of germination was achieved using a concentration-temperature combination of 10 g L-1 tetrazolium and 30 °C.

Pages 1075-1082   Read More   DOI: 10.21475/ajcs.2016.10.08.p7175
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Effects of conventional and organic farming systems on bio-agronomic and quality traits of durum wheat under Mediterranean conditions

Anna Iannucci* and Pasquale Codianni

Council for Agricultural Research and Economics, Cereal Research Centre (CREA-CER), S.S. 673, Km 25,200, 71122 Foggia, Italy

Abstract
The effects of conventional and organic farming systems on 10 durum wheat (Triticum durum Desf.) cultivars were studied over a 3-year period (2012-2014) in Foggia (southern Italy). The aim was to compare their agronomic and qualitative characteristics, and to test their adaptability and stability to these different management practices in terms of seed yield. The experiment followed a split-plot design, with three replications in each year. Six traits were investigated: heading time, plant height, seed yield, test weight, 1000-seed weight, and protein content. The data from the analysis of variance indicated that there were significant differences between years, cropping systems, and genotypes for all of these characteristics. The mean seed yield for the organic system was 40% lower than that of the conventional system. The wheat quality was affected by cultivation management, with protein content 19% higher under the conventional system. The highly significant differences found for the genotype  environment interaction of the seed yield indicated the possibility to choose the stable genotypes across environments. Three univariate (b, S2d, R2) and two multivariate (additive main effect and multiplicative interaction stability value, yield stability index) stability statistics were used. Based on these analyses, the varieties ‘Iride’ and ‘Saragolla’ showed high-stability responses and good seed yield under both farming systems. Therefore, these can be recommended for less fertile environments, such as organic farming systems in Mediterranean areas. On the contrary, the genotype ‘Anco Marzio’ was well adapted for high seed yield in more fertile environments.

Pages 1083-1091   Read More  DOI: 10.21475/ajcs.2016.10.08.p7179

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Effects of micronutrients application on soybean yield

Juliano Magalhães Barbosa*, Cláudia Fabiana Alves Rezende, Wilson Mozena Leandro, Rafael Felippe Ratke, Rilner Alves Flores, Átila Reis da Silva 

Department of Soils and Crop Science; Federal University of Goias; Campus Samambaia, Zip Code: 74900-000; Goiânia, GO - Brazi
UniEVANGÉLICA; University Center of Anapolis; University City; Zip Code: 75083-515; Anápolis – GO
Department of Soils; Federal University of Goias
Department of Soils; Federal University of Piauí; Campus Professora Cinobelina Elvas; Zip Code: 64049-550, Bom Jesus, Brazil

Abstract
Soil fertilization with micronutrients increases micronutrient levels in cultivated areas providing yield gains of different cultures in different production systems. Therefore, the objective of this study was to estimate the agronomic efficiency of a powder fertilizer (a source of micronutrient; 6.8% Mn, 3.9% Zn, 2.1% Fe, 1.2% Cu and 1.1% B), applied to the soil in the agronomic performance of the soybean crop. The experiment was carried out under field conditions, in an Oxisol. The random block design was used, with five treatments and four replicates. The treatments consisted of five doses of the fertilizer: 0, 33.33 kg ha-1, 66.66 kg ha-1, 133.32 kg ha-1 and 66.66 kg ha-1 + 1.4 ton ha-1 of calcium oxide. The contents of Mn, Zn and Fe increased in the soil in all treatments, but no effect was observed in leaf contents with the application. The levels of Zn and Mn are adequate. The dose 133.32 kg ha-1 leads to an increase in the productivity of soybean plants in the Cerrado biome.

Pages 1092-1097   Read More Supplementary Data   DOI: 10.21475/ajcs.2016.10.08.p7367
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Diversity analysis of tomato genotypes based on morphological traits with commercial breeding significance for fresh market production in eastern USA

Krishna Bhattarai, Frank J. Louws, John D. Williamson, Dilip R. Panthee*

Department of Horticultural Science, North Carolina State University, Mountain Horticultural Crops Research and Extension Center, Mills River, NC 28759, USA
Center for Integrated Pest Management and Department of Plant Pathology, North Carolina State University, Raleigh, NC 27695, USA
Department of Horticultural Science, North Carolina State University, Raleigh, NC 28759, USA

Abstract
Tomato is one of the most economically important vegetable crops in the world. Objective of this study was to determine the genetic diversity of tomato based on its horticultural traits. Seventy- one tomato genotypes were planted and grown in two replications with randomized complete block design for two years. Diversity analysis produced six distinct clusters based on average-linkage method. Five principal components (PC) explained more than 92% of the phenotypic variation. Clusters produced in this analysis can be of importance for breeding programs developing specific fruit types based on consumer’s demand.

Pages 1098-1103   Read More   DOI: 10.21475/ajcs.2016.10.08.p7391

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Cover crops affect the soil chemical properties under no-till system

Simone Cândido Ensinas, Ademar Pereira Serra*, Marlene Estevão Marchetti, Eulene Francisco da Silva, Elaine Reis Pinheiro Lourente, Eber Augusto Ferreira do Prado, Flávia Araújo Matos, Pedro Henrique Altomar, Matheus Andrade Martinez, Douglas Costa Potrich, Vanessa do Amaral Conrad, Maílson Vieira Jesus, Tárik Cazeiro El Kadri

Universidade Federal da Grande Dourados (UFGD), City of Dourados, State of Mato Grosso do Sul, Brazil
Brazilian Agricultural Research Corporation (EMBRAPA), City of Campo Grande, State of Mato Grosso do Sul, Brazil
Faculdade de Ciências Agrárias/Universidade Federal Rural do Semi-Árido (UFERSA), City of Mossoró, State of Rio Grande do Norte, Brazil

Abstract
The purpose of this study was to assess the changes in soil chemical properties affected by the cover crops cultivated in crop rotation in short-time of no-till implementation under Rhodic Hapludox soil. This research was carried out from October 2010 to February 2014. The experiment was set up in completely randomized blocks in a factorial design with eight treatments (cover crops) and three soil depths (0-5, 5-10 and 10-20 cm) with four repetitions. The cover crops were: fall-winter maize (T1), intercropping fall-winter maize with B. ruziziensis (T2), intercropping fall-winter maize with B. brizantha cv. Marandu (T3), intercropping fall-winter maize with Crotalaria spectabilis (T4), B. ruziziensis (T5), B. brizantha cv. Marandu (T6), Pennisetum glaucum L. (T7) and set-aside area (T8). The T6 and T7 effected exchangeable Mg+2, it was observed higher exchangeable Mg+2 in T6 (2.39 cmolc dm-1) and T7 (2.43 cmolc dm-1) in comparison to T1. The phosphorus content showed interactive effect between cover crops and soil depth. In the comparison among the depths, the P contents were higher in 5-10 cm, which showed improvement of 24.6% and 25.2% in comparison to 0-5 and 10-20 cm layers, respectively. The cover crops evaluated in this research affected the exchangeable Mg+2 and K+, as well as the Mg+2 and K+ saturation. The P content changed in response of cover crops, which was important to observe that this nutrient may increase the content with adoption of cover crops in no-till system. The species used in this research might be recommended to integrate a crop rotation system with the possibility of increasing P availability in topsoil depth in no-till system.

Pages 1104-1111   Read More   DOI: 10.21475/ajcs.2016.10.08.p7408
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Soil management, seed treatment and soil compaction on the sowing furrows affect grain yields of upland rice genotypes

Veneraldo Pinheiro, Luís Fernando Stone, Adriano Stephan Nascente*

Brazilian Agricultural Research Corporation (EMBRAPA), Rice and Beans Research Center, PO Box 179, 75375-000, Santo Antônio de Goiás, State of Goiás, Brazil

Abstract
The water availability for flood irrigated rice (Oryza sativa L.) is decreasing worldwide. Therefore, developing technologies to allow growing rice in aerobic condition, such as a no-tillage system (NTS) can contribute to produce upland rice grains without yield losses and also in saving more water. The objective of this study was to determine the effect of soil management, seed treatment and compaction on the sowing furrow on grain yield of upland rice genotypes. We made two trials, one in an NTS and another using conventional tillage, CT (one plowing and two diskings). The field experiments were performed in the Central Region of Brazil in Cerrado soils. For each trial, the experimental design was a randomized block design in a factorial scheme, with three replications. The treatments consisted of a combination of 10 genotypes with 2 compaction pressures on the sowing furrow (25 kPa and 126kPa) and 2 types of seed treatment (with and without pesticide). Under CT, the seed treatment did not contribute to increase upland rice grain yields. However, under NTS the grain yield of some genotypes [BRS Esmeralda (from 723 to 1,766 kg ha-1), BRS Pepita (from 930 to 1,874 kg ha-1), AB072044 (from 523 to 1,579 kg ha-1), and AB072085 (from 632 to 1,636 kg ha-1) at 25 kPA soil compaction pressure, and Sertaneja (from 994 to 2,167 kg ha-1), BRS Pepita (from 1,161 to 2,100 kg ha-1), and AB072085 (from 958 to 2,213 kg ha-1), at 126 kPA soil compaction pressure] increased with the use of this practice. At CT the higher soil compaction pressure on the sowing furrow (from 25 kPa to 126 kPa) increased rice grain yield only when it was used seed treatment and the genotypes Serra Dourada (from 1,239 to 2,178 kg ha-1), Sertaneja (from 1,510 to 2,379 kg ha-1), and Cambará (from 1,877 to 2,831 kg ha-1). On the other hand, under NTS, increasing soil compaction pressure on the sowing furrow allowed for an increased rice grain yield of Serra Dourada (from 1,553 to 2,347 kg ha-1), Esmeralda (from 723 to 1,643 kg ha-1), AB072044 (from 523 to 2,040 kg ha-1), and Cambará (from 1,243 to 2,032 kg ha-1) without seed treatment and Sertaneja (from 1,385 to 2,167 kg ha-1) and AB072044 (from 1,579 to 2,356 kg ha-1) with seed treatment. In CT the most productive genotypes were AB062008 (2,714 kg ha-1) and BRSMG Caravera (2,479 kg ha-1), while at NTS were the genotypes: BRSGO Serra Dourada (2,118 kg ha-1), AB072047 (1,888 kg ha-1), AB062008 (1,823 kg ha-1), BRSMG Caravera (1,737 kg ha-1), Cambará (1,716 kg ha-1), AB072044 (1,625 kg ha-1), BRS Esmeralda (1,604 kg ha-1), and BRS Pepita (1,516 kg ha-1).

Pages 1112-1117   Read More   DOI: 10.21475/ajcs.2016.10.08.p7551
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Development of super early genotypes for the dry bean (Phaseolus vulgaris) as affected by nitrogen management

Adriano Stephan Nascente*, Alexandre Bryan Heinemann, Luciana Christina Alves, Paulo Holanda Rosa, Luis Fernando Vieira Naves, Anne Carullyne Francino Garcia

Brazilian Agricultural Research Corporation (EMBRAPA), Rice and Beans Research Center, PO Box 179, 75375-000, Santo Antônio de Goiás, State of Goiás, Brazil
Montes Belos Faculty, 76100-000, Sao Luis de Montes Belos, State of Goiás, Brazil
UniAnhanguera University, 74423-115, Goiânia, State of Goiás, Brazil

Abstract
The super early genotypes (SEG) of dry bean (Phaseolus vulgaris L.) have a shorter life cycle (65-75 days) when compared with the season length of traditional cultivars (90-100 days). Timing of nitrogen top-dressing fertilization could be different because of this reduction in length of the SEG life cycle. This study aimed at characterizing, by using growth analysis and vegetation index, super early genotypes of dry bean development as affected by timing of nitrogen application. Field experiments were conducted in the 2014 and 2015 growing seasons in central Brazil with a randomized block experimental design with split plots scheme and four replicates. The plots comprised the dry bean genotypes (Colibri – check cultivar, CNFC 15873, CNFC 15874, and CNFC 15875), and subplots comprised applications of N at different timings: 90 kg of N at sowing, 90 kg N at top-dressing; 45 kg of N at sowing plus 45 kg at top-dressing, with urea as the source of N. We also used a control treatment without N application. The CNFC 15874 super early genotype of dry bean had the higher grain yield (2776 kg ha-1) and differed from the CNFC 15873 genotype (2492 kg ha-1). Nitrogen fertilization allowed higher grain yield (2619 kg ha-1, when applied N at sowing, 2605 kg ha-1, when applied N at sowing and at top-dressing, and 2680 kg ha-1, when applied N at top-dressing) than the control, 2360 kg ha-1 (no N fertilization). The time of N fertilization in super early genotype of dry bean did not affect grain yield.

Pages 1118-1126   Read More   DOI: 10.21475/ajcs.2016.10.08.p7596
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Trait association for improved grain yield of extra-early maturing maize hybrids evaluated in the forest and transitional zones of Ghana

G.B. Adu*, R. Akromah, M.S. Abdulai, K. Obeng-Antwi, H. Alidu, K.M.L. Tengan

CSIR-Savanna Agricultural Research Institute, Nyankpala, Tamale, Ghana
Department of Crops and Soil Sciences, Faculty of Agriculture, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
CSIR-Crops Research Institute, Kumasi, Ghana

Abstract
The present study used sequential path analysis and factor analysis to determine the interrelationship between grain yield and other agronomic traits of 100 extra-early maturing maize genotypes. The objective was to identify traits with the greatest influence on grain yield for use as selection criteria in future breeding programmes. The coefficient of correlations revealed that grain yield correlated positively with ear aspect, days to anthesis, days to silking, plant height, and number of ears harvested per plot and plant stand. Grain yield was however, negatively correlated to husk cover and ear number per plant. Path analysis identified plant height and number of ears harvested per plot to have a positive direct effect on grain yield while ear number per plant had a negative direct effect on grain yield. Also, plant stand, number of ears harvested per plot and ear aspect were identified to have the greatest influence on yield by factor analysis.

Pages 1127-1135   Read More Supplementary Data   DOI: 10.21475/ajcs.2016.10.08.p7650
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Agriculture and forest: A sustainable strategy in the Brazilian Amazon

Lucieta Guerreiro Martorano*, Marco Antonio Siviero, Daiana C. Monteiro Tourne, Sabrina Benmuyal Vieira, David R Fitzjarrald, Carlos A. Vettorazzi, Silvio Brienza Júnior, Jorge Alberto Gazel Yeared, Élio Meyering, Leila Sheila Silva Lisboa

Embrapa Eastern Amazon, Belém, Pará, Brazil
Grupo Arboris, Dom Eliseu, Pará, Brazil
ESALQ/CENA, Piracicaba, São Paulo, Brazil
University at Albany – SUNY, Albany, New York, USA
ESALQ/USP, Piracicaba, São Paulo, Brazil
Forest Management, Head of Embrapa Amapá, Macapá, Amapá, Brazil
Sciences at ESALQ, Belém, Pará, Brazil

Abstract
Large-scale agriculture is increasing in anthropogenically modified areas in the Amazon Basin. Crops such as soybean, maize, oil palm, and others are being introduced to supply the world demand for food and energy. However, the current challenge is to enhance the sustainability of these areas by increasing efficiency of production chains and to improve environmental services. The Amazon Basin has experienced a paradigm shift away from the traditional slash-and-burn agricultural practices, which offers decision makers the opportunity to make innovative interventions to enhance the productivity in previously degraded areas by using trees to ecological advantage. This study describes a successful experiment integrating the production of soybean and paricá (Glycine max L. and Schizolobium amazonicum) based on previous research that indicated potential topoclimatic zones for planting paricá in the Brazilian state of Pará. This paper shows that a no-tillage system reduces the effects of drought compared to conventional tillage still used by many farmers in the region. The integrated system was implemented during the 2014/2015 season in 234.6 ha in the high-potential zone in the municipality of Ulianópolis, Pará. Both soybean and paricá were planted simultaneously. Paricá was planted in 5 m x 2 m inter-tree spacing totaling 228x103 trees per hectare and soybean, in 4 m x 100 m spacing, distributed in nine rows with a 0.45 m inter-row distance, occupying 80% of the area. The harvested soybean production was 3.4 t ha-1, higher than other soybean monocultures in eastern Pará. Paricá benefited from soybean fertilization in the first year: It exhibited rapid development in height (3.26 m) and average diameter (3.85 cm). Trees and crop rotation over the following years is six years for forest species and one year for each crop. Our results confirm there are alternatives to the current production systems able to diminish negative impacts resulting from monoculture. In addition, the system provided environmental services such as reduced soil erosion and increased carbon stock by soil cover with no-tillage soybean cultivation. The soybean cover contributes to increased paricá thermal regulation and lower forestry costs. We concluded that innovative interventions are important to show local farmers that it is possible to adapt an agroforest system to large-scale production, thus changing the Amazon.

Pages 1136-1143   Read More   DOI: 10.21475/ajcs.2016.10.08.p7727
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Effect of different conductor tubes on the longitudinal distribution of soybean seeds

Dauto Pivetta Carpes*, Airton Dos Santos Alonço, Tiago Rodrigo Francetto, Cristian Josue Franck, Mateus Potrich Bellé, Otávio Dias da Costa Machado

Federal University of Santa Maria, Postgrad Program in Agricultural Engineering, City Santa Maria, State of Rio Grande do Sul, Brazil
Federal Institute of Santa Catarina, São Carlos City, State of Santa Catarina, Brazil
Federal Institute of Rio Grande do Sul, Bento Gonçalves City, State of Rio Grande do Sul, Brazil

Abstract
Some crops have great sensitivity to the population variation and also to the spacing arrangement between seeds in the seeding row. This way, the longitudinal distribution of seeds by seed metering mechanisms must be highly accurate. The objective of this study was to evaluate the effect of the seed conductor tube type, combined with pneumatic and horizontal disc meter mechanisms, varying the seeding density rate. The experiment was conducted in a laboratory using a seed meter test bench. Treatments consisted of a combination among two seed meters, six conductor tubes and four peripheral speeds for the discs, corresponding to the densities of 250, 300, 350 and 400 thousand soybean seeds ha-1, organized in a three-factor scheme with four repetitions. When increasing seeding density rate with the same ground speed, there was a reduction in the acceptable spacing percentage, however, conductor tubes with a parabolic profile, angle close to 30 degrees showed the best performance in relation to longitudinal seed distribution, regardless of the type of seed meter used.

Pages 1144-1150   Read More   DOI: 10.21475/ajcs.2016.10.08.p7733
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Peruvian carrot (Arracacia xanthorrhiza Bancroft) as raw material for producing special native starches

Magali Leonel*, Ezequiel Lopes do Carmo, Célia Maria Landi Franco, Adalton Mazetti Fernandes, Emerson Loli Garcia, Thaís Paes Rodrigues dos Santos

Center for Tropical Roots and Starches (CERAT), São Paulo State University (UNESP), Botucatu, São Paulo, Brazil
Department of Food Engineering and Technology, Institute of Biosciences, Language, and Physical Sciences, São Paulo State University (UNESP), São José do Rio Preto, São Paulo, Brazil

Abstract
The use of natural starches in food or non-food industries is difficult, as there are no starches with essential properties for a particular application. Thus, it is important to identify different alternative starch sources with wide variability in starch properties. The aim of this study was to evaluate roots production and starch properties of Peruvian carrot genotypes [BGH clones (4560, 5741, 5744, 5746, 5747, 6414, 6513, 6525, 7609) and “Amarela de Senador Amaral” cultivar] growing in Brazil. The experimental design was randomized complete block design with four replications. After eight-month growing of Peruvian carrot plants, roots were collected and the total production of roots, and their dry matter and starches contents were analyzed. The roots were processed for starch extraction. Starches were evaluated for phosphorus and amylose contents as well as for thermal and pasting properties. Results showed differences for all parameters analyzed for roots and starches between materials. Peruvian carrot starches presented varied chemical, thermal and pasting properties which can be exploited by food industry as native starches.

Pages 1151-1157   Read More   DOI: 10.21475/ajcs.2016.10.08.p7739
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Physiological aspects of corn plants related to mesotrione herbicide selectivity

Ismael Lourenço de Jesus Freitas, Weverton Pereira Rodrigues, Silvério de Paiva Freitas, Jalille Amim Altoé Freitas, Reynaldo Tancredo Amim, Antonio Teixeira do Amaral Junior, Eliemar Campostrini

Centro de Ciências e Tecnologias Agropecuárias, Universidade Estadual do Norte Fluminense (UENF), Avenida Alberto Lamego 2000, 28013-602 Parque Califrórnia, Campos dos Goytacazes, Rio de Janeiro, Brazil.
Instituto Federal de Educação, Ciência e Tecnologia Fluminense, campus de Cambuci, Estrada Cambuci Km 05, s\n, 28430-000 Três Irmãos, Cambuci, Rio de Janeiro, Brazil

Abstract
The objective of the present study was to assess the physiological aspects related to the activity of mesotrione herbicide at different doses in corn plants. The experiment was performed, in a greenhouse, on UENF 506-8 hybrid grown in 12 L pots with substrate (2:1 sand and clay). A randomized complete block design in a 3 x 5 factorial scheme, with four replications was used. Plants at fourth leaf stage were exposed to three doses (0, 0.15 and 0.30 kg ha-1) of herbicide mesotrione. After three, four, five, six and 13 days after application (DAA) of herbicide mesotrione gas exchange and chlorophyll a fluorescence (considering a JIPTest analysis) were measured. Plant height (PH), leaf area (LA), canopy(CDM) and root dry matter were measured at 28 DAA, when plants were at V12 stage and ca. 85 to 90% grown of its total area. -The results showed that UENF 506-8corn hybrid was remarkably tolerant to dose of 0.15 Kg ha-1 without deleterious effects on photochemistry and biochemistry pathway, maintaining the values of several JIPTest parameters and gas exchange. However, decreases in photosynthetic rate, stomata conductance, and transpiration and several JIPTest parameters were observed when the plants were exposed to dose of 0.30 kg ha-1 although there was no harmful damage on most of the growth parameters. However, dose of 0.15 Kg ha-1 should be recommended since dose as high as 0.30 kg ha-1 caused decrease in CDM.

Pages 1158-1163   Read More  DOI: 10.21475/ajcs.2016.10.08.p7787
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Adaptability and stability parameters of total seed yield and protein content in cowpea (Vigna unguiculata) genotypes subjected to semi-arid conditions

Danillo Olegario Matos da Silva*, Carlos Antonio Fernandes Santos, Leonardo Silva Boiteux

Universidade Estadual de Feira de Santana (UEFS), Programa de Pós-graduação em Recursos Genéticos Vegetais. Avenida Transnordestina, SN, Novo Horizonte, 44.036-900, Feira de Santana-BA, Brazil
Embrapa Semiárido. CP 23, CEP 56302-970, Petrolina-PE, Brasil
Embrapa Hortaliças, CP 218, CEP 70351-970, Brasília-DF, Brasil

Abstract
The selection of superior cultivars through the combination of high yield and protein content cowpea seeds in semi-arid tropical regions have a huge positive impact on the production-market chains in places where there is short availability of protein sources for human consumption. The main aim of the present study is to estimate the adaptability and stability parameters of total seed yield and protein content in cowpea genotypes in order to release new cultivars by combining these value-added traits. Forty-four inbred lines and cultivars were assessed under seven different environmental conditions, either rain-fed or irrigated crop management, in seven sites the Brazilian semi-arid region. The seed protein content was quantified through the Kjeldahl method. Grain yield was adjusted in mean of plant per plot by the covariance method. Statistically significant differences in the genotype as well as in the genotype×environment interaction were observed in all the assays. The inbred lines presenting the highest protein contents showed the lowest grain yields, and it indicated the prominent “phenotypic cost” of protein in overall cowpea seed production. However, the breakage between the herein assessed association was observed in inbred lines subgroups such as ‘C3Q’, ‘C3M’, ‘C2S’, and ‘CIJ’. These lines showed yield close to or above 1050 kg/ha and mean protein content of 27%, as well as good adaptability and stability in different environments, as it was simultaneously indicated through two methodologies. Therefore, these inbred lines may represent a potential elite germplasm in cowpea breeding programs and/or in the releasing of new cultivars adapted to the semi-arid region.

Pages 1164-1169    Read More   DOI: 10.21475/ajcs.2016.10.08.p7828
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Cotton growth and yield dynamics across canopy layers in response to soil waterlogging

Ullah Najeeb*, Daniel K.Y. Tan, Michael P. Bange

Plant Breeding Institute, School of Life and Environmental Sciences, Faculty of Agriculture and Environment, The University of Sydney, Sydney, Australia
CSIRO Agriculture and Food, Australian Cotton Research Institute, Narrabri, Australia

Abstract
Due to an indeterminate growth habit, we hypothesised that different canopy layers of cotton might be variably influenced by soil waterlogging. The field-grown cotton cultivar (Sicot 71BRF) was waterlogged at early (WLearly, 77 days after planting [DAP]) and late reproductive phases (WLlate, 101 DAP) for 120 h. Data from different canopy layers e.g. bottom eight (MSN1-8), middle five (MSN9-13), and upper five main stem nodes (MSN14+) were collected 1 d (post-WL) and 7 d after termination of waterlogging (post-recovery). Both waterlogging events significantly reduced post-WL dry biomass, leaf N concentration and fruit development on MSN1-8. In addition, WLearly significantly reduced photosynthesis and increased total soluble sugars (TSS) in the MSN1-8 and MSN14+ leaves, although MSN14+ leaves restored photosynthesis, N levels and TSS at recovery. It suggested that WL plants maintained photosynthesis of the upper leaves possibly by transporting N from the lower canopy leaves. Reduction (22%) in seed cotton yield under WLearly was the result of fruit loss from first position fruits of the upper and lower sympodial fruiting branches (FB1-5 and FB11+). Despite restoring the growth through improved photosynthesis and N supply, no yield recovery on FB11+ suggested that the plants used these assimilates for growth of the established fruits. No significant yield reduction in response to WLlate suggested that the established cotton bolls were less sensitive to abscission across all canopy layers.

Pages 1170-1181   Read More   DOI: 10.21475/ajcs.2016.10.08.p7855
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Adaptability and stability of ‘Valenciana’ onion populations in the Brazilian tropical semi-arid

Antonio Esmael Silva de Oliveira*, Carlos Antônio Fernandes Santos , Lucas Nunes da Luz, Valter Rodrigues Oliveira, Jonas Araújo Candeia, José Luiz Sandes de Carvalho Filho,Danillo Olegário Matos da Silva

Universidade Federal Rural do Pernambuco, Av. Dom Manuel de Medeiros, s/n, Dois Irmãos,Recife, PE, Brazil
Embrapa Semiárido. CP 23, CEP 56302-970, Petrolina-PE, Brasil
Universidade da Integração Internacional da Lusofonia Afro-Brasileira 4Embrapa Hortaliças, CP 218, CEP 70351-970, Brasília-DF, Brasil
Instituto Agronômico de Pernambuco. Belém do São Francisco, PE, Brazil
Universidade Estadual de Feira de Santana. Feira de Santana, Bahia, Brazil


Abstract
Brown onions of the ‘Valenciana’ type are not available for short-day growing conditions in the Northeast of Brazil. The goal of this study was to estimate parameters of adaptability and stability in order to release ‘Valenciana’ onion cultivars in the Northeast of Brazil. Eight populations of onions derived from a cross between ‘Baia population’ בValcatorce INTA’ and improved by recurrent selection were associated with six commercial onion cultivars, included as controls; they were evaluated in five experiments carried out in the municipalities of Petrolina, Pernambuco, Juazeiro, Bahia and Belém do São Francisco, Pernambuco. The experimental design was a randomized block design with three replications. Total and commercial bulb productions were evaluated for adaptability and stability parameters according to the methodologies of Eberhart and Russell, Lin and Binns and Main Effects and Multiplicative Interaction (AMMI). Significant genotype × environment interaction was observed for the two analysed variables. Eberhart & Russell and AMMI showed similar results for the overall cultivars, while some discrepancies were observed under the Lin & Binns method. The three methodologies produced concordant results for the ‘Valenciana’ onion types. The 25CA10 and T811CR13B’Valenciana’populations demonstrated broad adaptability and stability, associated with bulb production close to some cultivars and the commercial hybrid, and will be protected and released as new cultivars in the Northeast region of Brazil.

Pages 1182-1187   Read More   DOI: 10.21475/ajcs.2016.10.08.p7890
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SNP association analysis of resistance to verticillium wilt (Verticillium dahliae Kleb.) in spinach

Ainong Shi*, Beiquan Mou*, Jim Correll, Dennis Motes, Yuejin Weng, Jun Qin, Wei Yang

Department of Horticulture, University of Arkansas, Fayetteville, AR 72701, USA
Crop Improvement and Protection Research Unit, US Department of Agriculture, Agricultural Research Service (USDA-ARS), 1636 E. Alisal Street, Salinas, CA 93905, USA
Department of Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA; 4Vegetable Research Center, University of Arkansas, Alma, AR 72921, USA

Abstract
Verticillium wilt, caused by Verticillium dahliae Kleb., is an important disease of spinach (Spinacia oleracea L.) and use of genetic resistance is the most economical method of controlling this disease. The objective of this research was to conduct molecular association analysis for Verticillium wilt resistance in spinach. A total of 95 USDA spinach accessions were evaluated for resistance to Verticillium wilt in this study. Phenotyping was conducted using a 0-4 scale of disease severity scores of Verticillium wilt and genotyping was performed using 2,878 SNPs which were postulated from genotyping by sequencing (GBS). STRUCTURE 2.3.4 and MEGA 6 were used for population structure and genetic diversity analysis. The single marker regression (SMR) from QGene, general linear mode (GLM) and mixed linear mode (MLM) from TEASSEL, and compressed mixed linear model (cMLM) and enriched compressed mixed linear model (EcMLM) from GAPIT were used for association analysis of Verticillium wilt resistance. Significant genetic variation of Verticillium wilt disease resistance was observed among the 95 spinach accessions with a wide range from 0.3 to 3.0 on a 0-4 scale. Two well-differentiated genetic populations and admixtures were postulated in the spinach panel. Five SNP markers, AYZV02052595_108, AYZV02112284_14543, AYZV02123399_146, AYZV02164612_331, and AYZV02170942_274 were identified to be associated with Verticillium wilt resistance with R-squared values from 9.3 to 18.2%. These markers may provide a tool utilized in molecular spinach breeding to select Verticillium wilt resistance through marker-assisted selection.

Pages 1188-1196   Read More Supplementary Data   DOI: 10.21475/ajcs.2016.10.08.p7893 

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Changes in organic carbon pool in a tropical soil planted to rice in relation to photosynthetic carbon fixation

Ashmita Bharali, Kushal K. Baruah*, Nirmali Gogoi

Department of Environmental Science, Tezpur University, Napaam - 784028, Assam, India

Abstract
Information on the fate of photosynthesized carbon (C) in plant soil system is essential for understanding the soil organic carbon pool and carbon dynamics in agricultural ecosystem. Our objectives in the present study were to quantify the photosynthetic carbon fixation by high yielding rice genotypes and contribution of rice ecosystem to soil organic carbon pool in a tropical rice soil. A field experiment was conducted during 3 consecutive monsoon rice season (July – December) of 2012, 2013 and 2014 in a randomized block design (RBD). A portable photosynthesis system was used for measurement of flag leaf photosynthesis. Stomatal frequency of the flag leaves were studied by scanning electron microscopy (SEM). Soil organic carbon storage was estimated by a total organic carbon (TOC) analyzer. Differences in flag leaf photosynthetic carbon fixation amongst the varieties were significant. Differential ability for carbon partitioning in terms of biomass accumulation were also noteworthy (p = 0.000). Flag leaf photosynthetic rate observed in the study showed a good correlation (r = 0.486, p ≤ 0.05) with the stomatal frequency of the flag leaves. The leaf stomatal frequency ranged from 605 to 783 mm-2 of leaf area with a high in the rice variety, Swarnamahsuri and low in Gitesh. There were significant differences in cumulative methane (CH4) emission amongst the four rice varieties. The grain productivity in retaliation to genetic differences of the rice varieties highly favored their correlations with flag leaf photosynthesis (r = 0.999, p ≤ 0.01) and leaf area index (r = 0.961, p ≤ 0.01). Above ground and below ground dry matter of the plants were found to influence the quantity of soil organic carbon and soil C storage. Our results also clearly bespoke that a rice ecosystem can effectively sequester carbon (0.338 Mg C ha-1 yr-1) at 0 - 15cm depth of soil. The results led us to conclude that lowland rice ecosystem is a good sink of carbon dioxide (CO2).

Pages 1197-1206     Read More   DOI: 10.21475/ajcs.2016.10.08.p7897

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Up-regulation of wheat nitric oxide synthase gene in response to Zataria multiflora essential oil dispersion

Mohammadreza Raisi-Nafchi, Gholamreza Kavoosi*, Seyed Mehdi Nassiri

Institute of Biotechnology, Shiraz University, Shiraz, 71441-65186, Islamic Republic of Iran
Department of Biosystems Engineering, Shiraz University, Shiraz, 71441-65186, Islamic Republic of Iran

Abstract
Overproduction of nitric oxide (NO) results in nitrative stress, in turn causing peroxidation of lipids, oxidation of protein and damage to nucleic acids among many others. Presumbly, a simple mode to suppression of nitrative stress is found to be a natural antioxidant from aromatic plants. Zataria multiflora essential oil (ZO) is known for its potent antioxidant activities. Highly insoluble in water, ZO can be easily degraded by light, oxygen, high temperature and extreme pH. Dispersion of ZO into polyvinylpyrrolidone (PVP) might enhance its stability and self-life while storage and applications. The present research assesses in vitro antioxidant function of PVP/ZO dispersion versus nitrite and nitric oxide (NO). Followed by this efficiency of the PVP/ZO dispersion on the production of nitric oxide synthase (NOS) mRNAs in the wheat seedlings in hydroponic condition was evaluated. PVP and PVP/ZO dispersions characterized with negative zeta-potential was a non-Newtonian shear-thickening fluid. PVP/ZO was fraught with effective in vitro nitrite (IC50, 160 µg/mL) and NO (IC50, 168 µg/mL) scavenging activities. The result indicated that PVP/ZO dispersion up-regulated NOS (3.5 folds, at 30 µg/mL) mRNA production while down-regulated it at higher concentration. Hence, once applied at low concentration PVP/ZO can be promising as plant modulator for plant growth regulation.

Pages 1207-1212    Read More   DOI: 10.21475/ajcs.2016.10.08.p7903
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Flowering synchronization in hybrid rice parental lines

Vitor Henrique Vaz Mondo, Adriano Stephan Nascente*, Péricles de Carvalho Ferreira Neves, James Emile Taillebois, Manoel Oliveira Alves Cardoso Neto

Brazilian Agricultural Research Corporation (EMBRAPA), Rice and Beans Research Center, PO Box 179, 75375-000, Santo Antônio de Goiás, State of Goiás, Brazil
CIRAD - Centre de Coopération Internationale en Recherche Agronomique pour le Développement.
Uni-anhanguera University, Goiânia, Goiás, Brazil

Abstract
The cultivation of hybrid rice is a technology that allows for an increase in grain yield of 30% relative to the grain yield of conventional cultivars. However, the main challenge for this technology is related to seed production, which has high production costs and low seed yields. Therefore, agronomic techniques that could enhance flowering synchrony of parental lines in the field are essential for an efficient production system of hybrid rice seeds. The objective of this work was to study the effects of sowing depth, plant density and fertilization with nitrogen or phosphorus as potential techniques to increase the pollen availability in the field and, consequently, the flowering synchrony between parental lines in the production of hybrid rice seeds. The experiments were conducted during two growing seasons in the Central Region of Brazil. All of the experiments were conducted as a randomized complete block in a split plot scheme; however, the experiment with P fertilization had a factorial design. Our research allow inferring that nitrogen fertilization technique applied to the soil or foliar at the time of panicle differentiation does not affect the time of onset of flowering of rice varieties INTA Puitá CL and L106R, which are potential R lines for the production of hybrid rice. Agronomic techniques of variation in sowing depth, seeding rate and the phosphate fertilization affect the time of onset of flowering from 10 to 19 degree-days, which could represent two days in the crop cycle, for the line L106R. Such techniques constitute potential alternatives for use in hybrid rice seed production systems and could be applied in alternated blocks of R lines in the field to obtain longer periods of pollen availability in the field.

Pages 1213-1221   Read More   DOI: 10.21475/ajcs.2016.10.08.p7603