Australian Journal of Crop Science   AJCS

Nutrients accumulation in black oat (Avena strigosa) and pearl millet (Pennicetum glaucum) after application of herbicides glyphosate or glufosinate-ammonium

Virginia Damin*, P.C.O. Trivelin

Escola de Agronomia, Universidade Federal de Goiás (EA/UFG), Av Esperança, sn, CP 131, CEP 74690-900, Goiânia-GO, Brazil
Centro de Energia Nuclear na Agricultura, Lab. Isótopos Estáveis. Av. Centenário, 303 cx.postal 96, CEP 13416-000, Piracicaba-SP, Brazil

Abstract
Cover crops used in conservative cropping systems can accumulate large amounts of nutrients, reducing nutrient losses from the soil-plant system and improving the nutrient use efficiency in crops. However, recent researches demonstrated that herbicides used to kill cover crop could decrease N status in the straw, reducing the nutrient availability to the cash crop. In this context, the aim of this work was to investigate the effect of glyphosate or glufosinate-ammonium application in K, P, Ca, Mg, S and C status in plant´s tissues of black oat (Avena strigosa) and peal millet (Pennicetum glaucum) desiccated with herbicides. An experiment was carried out under greenhouse conditions using a factorial design 2x3. The evaluated factors were cover crop (black oat or peal millet) and cover crop management (1-Control- mechanical cut, without herbicide application; 2-Glyphosate- cover crop desiccation with glyphosate; 3-Glufosinate- cover crop dessication with ammonium-glufosinate). Dry mass production, nutrients accumulation in plants part and entire plants and the nutrient´s utilization efficiencies were determined. The nutrients accumulation in plants was not reduced by herbicides; however, a lower dry matter and C accumulation was observed after herbicides application. Glyphosate increased K, P, S and C remobilization from leaves to stalks, but glufosinate did not affect it, suggestion a lower effect of this herbicide in nutrients availability to cash crop. Herbicides did not affect K, P, Ca, Mg and S losses from plants, thus the total amount of these nutrients in the system should be not affected by glyphosate or ammonium glufosinate utilization. However, since glyphosate changes these nutrients distribution among plant´s parts, increasing nutrients in the stalks and reducing nutrients in the leaves of pearl millet, it may affect nutrient availability to cash crops, since leaves mineralization is faster than stalks mineralization on soil. In this sense, the herbicide application is a practice that should be considered for prediction of nutrients availability in soil-plant systems, aiming improve the nutrient´s use efficiency.

Pages 1370-1376 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE679
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Selection of index leaf for foliar diagnosis of critical nutrient levels in physic nut (Jatropha curcas)

Enilson de Barros Silva*, Evander Alves Ferreira, Sávio Coelho de Magalhães, Carolina Mata Machado Barbosa Chaves, Eglerson Duarte, Mucio Magno de Melo Farnezi

Faculty of Agrarian Sciences at the Federal University of Jequitinhonha and Mucuri Valeys, Diamantina, Minas Gerais State, Brazil

Abstract
Basic information about mineral nutrition of physic nut is scarce. Especially, determination of index leaf to evaluate nutritional status is very rare. Therefore, objective of this study is to find the index leaf, the type and leaf position in the floral branch and propose critical levels of nutrients for nutritional diagnosis of physic nut. The nutrient concentrations in leaf limb, petiole and complete leaf and shoot dry weight of plant were recorded from the experiment under nutrient omissions in greenhouse. The complete leaf samples were also collected from two types of branches (main and lateral) and in three positions (apical, medial and basal of the branch), corresponding to the branches between the first and fourth, between the fifth and eighth and between the ninth and twelfth leaves, respectively, at flowering and seed productivity stages. These data were obtained from an experimental plot of NPK fertilization to define the position of the complete leaf to be sampled and to propose values of critical nutrient levels for physic nut. Critical levels of nutrients were proposed by means of reduced normal distribution criterion with field experiment data. The complete leaf (petiole and leaf limb) in the median position between the fifth and eighth leaves in the main and lateral branches in the full flowering of crop was indicated as sampling standard for the diagnosis of nutritional state of physic nut. In the present work, the critical levels of nutrients and macronutrients in leaf sampling were proposed as following (g kg-1): 27.8 for N, 1.4 for P, 11.8 for K, 12.8 for Ca, 6.7 for Mg and 1.3 for S and, micronutrients (mg kg-1): 78.8 for B, 14.2 for Cu, 139.7 for Fe, 129.3 for Mn and 20.4 for Zn.

Pages 1377-1384 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE764
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Effects of seed priming with ABA and SA on seed germination and seedling growth of sesame (Sesamum indicum L.) under saline condition

Hossein Safari, Shahab Madah Hosseini*, Arman Azari, Mohamad Heshmati Rafsanjani

Plant Production and Genetic Department., Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran
Soil Science Department, Faculty of Agriculture, Vali-e-Asr University of Rafsanjan, Rafsanjan, Iran

Abstract
In order to investigate the effect of seed priming with ABA and SA on germination indices of sesame in saline conditions, an experiment with three factors and four replicates arranged in completely randomized design. The first factor was type of growth regulator as ABA and SA, the second factor was concentration of growth regulator including 10, 50 and 500 ppm and the third factor was NaCl salinity (0, 2, 4, 6 and 8 dS/m). Seeds were soaked for 6 hours in distilled water, ABA or SA solutions, after which the solution was eliminated and the seeds were dried, deposited in separate Petri dishes between two filter papers and watered. During a 10-day period, germinated seeds number were counted daily and at the final day, randomly selected seedlings were weighed (fresh and dry) and their plumule and radicle lengths were recorded. The results showed that salinity decreased germination rate (GR) and uniformity (GU), but 10 and 50 ppm ABA or SA supply induced higher GP and GU at 4 dS/m and above, more pronounced at 8 dS/m . SA with 500 ppm concentration, however, impaired seed viability. On the contrary, plumule and radicle lengths of seeds primed by 10 and 50 ppm ABA and SA tended to be lower at 0, 2, 4 and 6 dS/m and higher at 8 dS/m than non-primed control. Almost similar results were obtained for seedling dry mass, although the effects of SA were more drastic. Overall, the results suggest a considerable ameliorative effect of ABA and/or SA seed pretreatment on germinability of sesame seeds under salinity but seedling growth may be retarded which is probably an acclimation and temporary response to salinity stress.

Pages 1385-1392 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE940
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Growth of young Brazilian mahogany (Swietenia macrophylla King.) plants under different doses of calcium

Mário Lopes da Silva Júnior, Sandra Andrea Seabra da Silva, Cassio Rafael Costa dos Santos*, Vânia Silva de Melo, Mábia Maria Duarte Alcantra, Rômulo José Alencar Sobrinho, Augusto José Silva Pedroso, Orivan Maria Marques, Ismael de Jesus Matos Viégas

Universidade Federal Rural do Amazonas, Departamento de Ciências do Solo, Avenida Tancredo Neves, 2501, Belém, PA, Brazil
Universidade Federal do Pará, Campus de Altamira, Rua José Porfino, 263 Altamira, PA, Brazil
Institudo de Educação, Ciência e Tecnologia do Pará, Campus Castanhal, BR-316 km 61, Castanhal, PA, Brazil
Embrapa Amazônia Oriental, Rua Dr. Enéas Pinheiro, Belém, PA, Brazil

Abstract
Knowledge of the nutritional status of vegetal species can anticipate the time at which seedlings are formed, which increases survival rate in the field after planting. The objective of this study was to evaluate the growth and nutrient content of mahogany seedlings according to increasing doses of Ca in the nutrient solution at a pressure ranging from 0.5 to 1.5 atm and a pH of 6. Seedlings of mahogany plants at 45 days of age and with four well-defined leaves were selected for the experiment. The experimental design was completely randomized, with five treatments (0, 80, 160, 240 and 320 mg L−1 of Ca) and five replications. At 71 days after treatment application, some variables were assessed: plant height, stalk diameter, root length, shoot dry matter (SHDM), root dry matter (RDM), SHDM/RDM ratio and Ca content in shoots and roots. The dose of maximum economic efficiency was 119 mg L−1, which corresponded to production of 27.79 g of total dry matter (TDM). The critical level of Ca for SHDM was 17.10 g kg−1. For the dose of 320 mg L−1 of Ca, a reduction in stalk diameter, root length, SHDM and RDM was observed when compared to the 240 mg L−1 dose. The greatest relative increment in mahogany plant growth was observed at the dose of 240 mg L−1 of Ca.

Pages 1393-1397 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE971
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Core collection of two important indigenous vegetables; Gboma eggplant (Solanum macrocarpon L.) and Jute mallow (Corchorus olitorius L.) in Africa: An important step for exploitation of existing germplasm and development of improved cultivars

Albert Owusu Kwarteng*, Richard Adu Amoah, Daniel Nyadanu, Clement Kwarteng Nyam, Jonah Zubil Ziyaaba, Jennifer Abogoom, Aisha Aziz, Kenneth Darko Anokye, Mary Dufie, Mercy Osei Boakye, Emmanuella Opoku Danso

School of Biodiversity, Agriculture and Food, Society and the Environment, Université Paris-Saclay, France
AgroParisTech, 16 rue Claude Bernard, Paris, France
Department of Crop and Soil Sciences, Kwame Nkrumah University of Science and Technology, Kumasi Cocoa Research Institute of Ghana, P. O. Box 8, Akim Tafo, Ghana

Abstract
Gboma eggplant (Solanum macrocarpon L.) and jute mallow (Corchorus olitorius L.) are important indigenous vegetables of Africa. Even though these two indigenous vegetables are important in terms of nutrition, medicine and resilience of livelihoods, they have been neglected by scientific research and their value chain has not been developed. To ensure effective management and utilization of these important genetic resources in breeding programmes, it is important to collect their core collections. Therefore, eighteen different accessions of gboma eggplant and one hundred and six of jute mallow were evaluated using RCBD with three replications. Results revealed diversity and significant variation among the various agronomic traits of both jute mallow and gboma eggplant. Correlation analyses between morphological traits of both species revealed positive and negative relationships, indicating predictable success for eventual breeding activities. Principal component analyses revealed traits of agronomic importance such as plant height, leaf length and number of leaves per plant as the most important traits for the distinction and separation of Corchorus olitorius accessions. The leaf blade length, leaf blade width, fruit colour at ripeness, plant height and fruit length were the most important traits for the distinction and separation of Corchorus olitorius accessions. Furthermore, hierarchical cluster analysis grouped the accessions into distinct clusters and accessions from the same geographical origin were classified separately. Nineteen accessions and six accessions were selected to constitute core collections of one hundred and six and eighteen accessions of jute mallow and gboma eggplant, respectively. Examination of the phenotypic traits showed that the genetic variation expressed for each trait in the entire collection has been preserved in the core collection. Core collections of these indigenous vegetables have many potential uses for the development of improved cultivars and should increase the utilization of germplasms of these important indigenous vegetables of Africa.

Pages 1398-1409 | Full Text PDF| Supplementray Data PDF| doi: 10.21475/ajcs.18.12.09.PNE993
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Silicon (Si) reduces the effects of salt stress on germination and initial growth of lettuce (Lactuca sativa L.)

Hozano de Souza Lemos Neto*, Marcelo de Almeida Guimarães, Italo Marlone Gomes Sampaio, Ana Régia Alves de Araújo Hendges, Alexandre Bosco de Oliveira, Sebastião de Medeiros Filho

Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Fitotecnia. 60356-001, Fortaleza, Ceará, Brazil
Universidade Federal Rural da Amazônia, Instituto de Ciências Agrárias, Departamento de Solos, Belém, Pará, Brazil
Instituto Federal de Educação, Ciência e Tecnologia do Maranhão. 65.840-000, São Raimundo das Mangabeiras, Maranhão, Brazil

Abstract
Salinity is one of the abiotic stresses that most limit crop productivity. This makes it essential to search for alternatives that would ensure the viability of production under such conditions. The aim of this work was to evaluate the potential of silicon for reducing the detrimental effects of salt stress on seed germination and initial seedling growth in five lettuce cultivars. Two experiments were carried out in a completely randomised design with four replications. In the first experiment, the germination behaviour of five lettuce cultivars (Year Round Cabbage, Americana Great Lakes, Great Lakes 659, Lucy Brown, and Crisp Cabbage) was evaluated under five levels of salt stress (0, 50, 100, 150 and 200 mM). In the second, two lettuce cultivars, one sensitive and one tolerant to salinity, submitted to six different combinations of NaCl and Na2SiO3. The germination (G), first germination count, germination speed index, mean germination time, and root and shoot length and dry weight were evaluated. A reduction in G was seen from 100 mM for all cultivars, with 'Lucy Brown' being the most tolerant, even under higher levels of NaCl. The 'Americana Great Lakes’ and 'Great Lakes 659' were the most sensitive to salinity. When silicon was added to the NaCl treatments, it was found that the effects of the salt stress were reduced, resulting in higher values for germination and the growth variables. Silicon reduced the detrimental effects of salt stress on the physiological quality of the seeds and the initial growth phase of the lettuce.

Pages 1410-1418 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1074
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Plant growth and nutrient accumulation in two tomato hybrids under tropical conditions

Carolina Cinto de Moraes*, Thiago Leandro Factor, Humberto Sampaio de Araújo, Luis Felipe Villani Purquerio

Centro de Horticultura, Instituto Agronômico, CEP: 13012-970, Campinas, SP, Brazil
Polo Regional de Desenvolvimento Tecnológico dos Agronegócios do Nordeste Paulista, CEP: 13730-970, Mococa, SP, Brazil
Polo Regional de Desenvolvimento Tecnológico dos Agronegócios Extremo Oeste, CEP: 16900-970, Andradina, SP, Brazil

Abstract
An adequate nutrient supply can reduce production costs, improve tomato quality, and increase yield. Understanding the nutritional needs of tomato plants is thus fundamental to its successful cultivation. This study characterised plant growth and nutrient accumulation and export in ‘Gault’ and ‘Pomerano’ hybrid tomatoes cultivated under tropical conditions in Brazil. The experimental design was randomised blocks with four replicates. Leaf number, tissue dry weights, and nutrient accumulation were evaluated throughout the growing cycle. Plant growth was slow at the beginning of the cycle, but total accumulation of dry matter began to increase faster when ‘Gault’ and ‘Pomerano’ had 29 and 28 leaves, peaking at 767.6 and 712.5 g plant-1, respectively, by the end of the cycle. Fruit yields were 148.5 and 122.6 t ha-1 for ‘Gault’ and ‘Pomerano’, respectively. The maximum nutrient accumulation for both hybrids at the end of the cycle was in the order K > N > Ca > S > Mg > P > Mn > Fe > Cu > Zn > B. The amounts of N, P, and K were highest in the fruit, and the amounts of Ca, Mg, and S were highest in the vegetative tissues, for both hybrids.

Pages 1419-1425 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1076
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The 24-epibrassinolide induces rice tolerance to water stress overcoming losses in grain yield

Lucas Baiochi Riboldi*, Julian Alejandro Giraldo Murcia, Sabrina Helena da Cruz Araújo, Paulo Roberto de Camargo e Castro

Biological Sciences Department, “Luiz de Queiroz” College of Agriculture, University of Sao Paulo, Piracicaba, SP, Brazil

Abstract
Water stress leads to large productivity losses in rice cultivation, and plant hormones play a key role in the plant strategies to prevent the harmful effects of water stress in crop development. The objective of this work was to investigate the effects of brassinosteroids (BRs) in rice development and yield under irrigation and under water deficit conditions applied during the pre-anthesis period. Exogenous applications of bioregulators were performed through leaf spray. Two dosages of 24-epibrassinolide (EBL) were applied (0.01 μM and 0.1 μM), in addition to two dosages of ABA (2.27 mM and 4.54 mM ABA) in order to compare the effects, considering its already known beneficial effects in response to drought adaptation. Plants of the cultivar IRGA 424RI grown under greenhouse conditions were submitted to water deficit from V13 stage until reaching a leaf water potential of -2 MPa. Physiological, growth and biochemical parameters were measured. Even though the water stress reduced plant growth, 0.01µM EBL-treated plants presented unchanged initial dry weight, height and tillering after the stress imposition. The 0.1 µM EBL-treated plants maintained the total dry weight of grains even after water stress imposition, while control and ABA-treated plants showed a 63.9% and 28.1-58.6% reduction, respectively. The 0.01 µM EBL treatment doubled the contents of chlorophyll a, b and total and decreased stomatal conductance under stress in 41.1%. EBL treatments were able to maintain similar peroxidation levels between stressed and non-stressed plants. When analyzed together, these results indicate that EBL shows a promising perspective for improving rice tolerance to controlled water stress.

Pages 1426-1433 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1101
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Effects of NaCl salinity on leaf water status, proline and mineral ion content of four Cucurbitaceae species

Muhammad Najib Othman Ghani, Yahya Awang*, Mohd Firdaus Ismail

Genebank and Seed Centre, MARDI Headquarters, Persiaran MARDI-UPM 43400 Serdang, Selangor, Malaysia
Department of Crop Science, Faculty of Agriculture, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia

Abstract
Members of Cucurbitaceae are salt-sensitive plants and continuous fertilization without sufficient leaching may create saline environment that consequently reduce their growth and yield. A study was carried out to evaluate the physiological responses of four selected Cucurbitaceae species to NaCl salinity stress. Four types of Cucurbitaceae viz. cucumber (Cucumis sativa), squash (Cucurbita moschata), bitter gourd (Momordica charantia) and bottle gourd (Lagenaria siceraria) were subjected to four levels of NaCl (0, 25, 50, 75 mM) and data on leaf relative water content, proline content and concentration of Na+ and Cl- for leaf, stem and root were collected. Given that the dominant salt in saline soils is NaCl, both Na+ and Cl- ions will occur naturally in high concentrations. However, degree of increment was different between species. As salinity levels increased from 0 to 75 mM, Na+ concentrations in roots in bitter gourd had the highest increase; while in leaf had the lowest increase compared to other species. Increment of Cl- in leaf, stem and roots was the lowest in bitter gourd and highest in cucumber. Increase of proline content in cucumber was 3.55 times higher compared to control whereas in squash, bottle gourd and bitter gourd, the increase were respectively 2.00, 1.47 and 2.03 higher compared to their respective control. Proline content in cucumber was negatively correlated with relative water content, RWC (r = - 0.83, p ≤ 0.01), whereas in other species no correlation was recorded. In conclusion, based on Na and Cl ion concentration, RWC and proline content, bitter gourd was least salt-sensitive while cucumber was most salt-sensitive Cucurbitaceae species.

Pages 1434-1439 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1113
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Abscisic acid (ABA) and 24-epibrassinolide regulate blossom-end rot (BER) development in tomato fruit under Ca2+ deficiency

Lucas Baiochi Riboldi*, Sabrina Helena da Cruz Araújo, Julian Alejandro Giraldo Murcia, Sérgio Tonetto de Freitas, Paulo Roberto de Camargo e Castro

Biological Sciences Department, “Luiz de Queiroz” College of Agriculture, University of Sao Paulo, Piracicaba, SP, Brazil
Postharvest Biology and Technology, Brazilian Agricultural Research Corporation, Embrapa Semi-arid, Petrolina, Pernambuco, Brazil

Abstract
Calcium (Ca2+) is an essential macronutrient in plants, and low concentrations of this nutrient may result in development of a physiological disorder known as blossom-end rot (BER) in tomato. Hormones can regulate the accumulation of Ca2+ and, consequently, fruit susceptibilities to BER. The objective of this study was to evaluate the effect of gibberellin (GA), abscisic acid (ABA), and 24-epibrassinolide (EBL) on Ca2+ accumulation and BER incidence in tomato. The ‘Tyna c.v’ tomato plants were sprayed biweekly, during anthesis, with water (control), GA (28.9 µmol L-1), ABA (90.8 µmol L-1and 136.2 µmol L-1), EBL (0.01 µmol L-1 and 0.1 µmol L-1). Treatments were applied until the physiological maturity of fruits of the first raceme in a completely randomized design and then, the following evaluations were performed: percentage of BER, growth evaluations, Ca2+ contents, physical-chemical parameters in fruits, stomatal conductance and transpiration. ABA and EBL treatments reduced BER incidence in a range of 6.6 to 9.0 %. The bioregulators used had no effect on plant growth, fruit diameter, length, or color. However, application of GA and EBL reduced titratable acidity and, the first also reduced soluble solids content in the fruit. All treatments, except GA treatment, increased Ca2+ contents in the fruits, when compared with the control. The highest fruit Ca2+ content was observed in plants treated with 0.01 µmol L-1 of EBL. According to our results, ABA and EBL increased Ca2+ concentrations and decreased BER incidence and thus there is a great potential for their use in agriculture in tomato fruit.

Pages 1440-1446 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1106
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Grafting relations in atemoya (Annona x atemoya Mabb.) plants: peroxidase and phenolic compounds

Daniel Baron*, Amanda Cristina Esteves Amaro, Ana Claudia Macedo, Samanta Jaqueline Dalanhol, Carmen Sílvia Fernandes Boaro, and Gisela Ferreira

Centro de Ciências da Natureza, Universidade Federal de São Carlos (UFSCar), campus Lagoa do Sino, Rod. Lauri Simões de Barros, km 12, SP-189, CEP 18290-000, PO. Box 094, Buri, SP, Brazil
Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (Unesp), campus Botucatu, Departamento de Horticultura, PO. Box-237, 18603-970, Botucatu-SP, Brazil
Instituto de Biociências, Universidade Estadual Paulista (Unesp), campus Botucatu, Departamento de Botânica, PO. Box-510, 18618-970, Botucatu-SP, Brazil

Abstract
The aim of this study was to evaluate if variations in the peroxidase activity (PRX) and the phenolic compounds (PC) concentration in atemoya scion (Annona x atemoya Mabb.) grafted onto different rootstocks are related to incompatibility. The experiment was conducted in a greenhouse, with atemoya scion grafted onto Annona species rootstocks [A. emarginata ‘var. terra-fria’; A. emarginata ‘var. mirim; A. mucosa and atemoya (homograft)] and these species ungrafted. The evaluations were performed at 30 and 60 days after grafting (DAG) in the hypocotyl region, where the grafting was performed, in each grafting combination and the same region corresponding to the stem tissue in ungrafted plants. The atemoya scion grafted onto A. mucosa showed higher PRX than A. mucosa ungrafted, although smaller than A. emarginata ‘var. mirim’ rootstock. In atemoya grafted onto A. emarginata ‘var. fria’ rootstock, no significant change in PRX compared to A. emarginata ‘var. fria’, atemoya ungrafted and homograft. The PC concentration at 30 DAG showed no significant differences in the grafted plants, although higher than in their respective ungrafted. At 60 DAG, no differences between grafted plants were observed, however, the PC concentrations in atemoya grafted onto A. emarginata ‘var. terra-fria’ and ‘var. mirim’ rootstocks were higher than those observed in A. emarginata ‘var. terra-fria’ and ‘var. mirim’ ungrafted, respectively. We concluded that variations in PRX and the PC are not related or triggered to incompatibility between atemoya scion grafted onto A. emarginata ‘var. terra-fria’, ‘var. mirim’ and A. mucosa.

Pages 1447-1453 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1123
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Immediate and latent effect of drying air on Chinese capsicum seed quality

Isneider Luiz Silva*, Hellismar Wakson da Silva, Renato Souza Rodovalho, Lucinda Maria Espíndola Lima, Lucinda Helena Fragoso Monfort, Daniel Pereira da Silva, Luís Sérgio Rodrigues Vale, Itamar Rosa Teixeira

Universidade Estadual de Goiás, Anápolis, Goiás, Brazil
Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
Instituto Federal Goiano, Ceres, Goiás, Brazil

Abstract
Pepper is usually propagated by seeds. Therefore, seeds must have high physiological quality along with other factors to ensure strong stabilization of the crop. The Brazilian market for this aromatic plant is predominant in family agriculture. Brazil encounters problems regarding the use of pepper seeds, as there are high losses in the post-harvest phase of the product. In this project, the objective was to evaluate the quality of pepper seeds subjected to drying at temperatures of 30, 35 and 40 °C in different storage periods to minimize the risk of damage to seeds due to inadequate drying. The study was conducted in a completely randomized design with three drying temperatures and seven periods of storage (180 days) with four replicates. The germination test, electrical conductivity, water content, tetrazolium test and field emergence were performed. It was concluded that drying air temperatures of 30, 35 and 40 °C significantly influenced the quality of the seeds. After drying, pepper seeds can be stored for up to 120 days without their quality being affected dramatically.

Pages 1454-1458 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1123
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Initial development and nutrition of Eugenia dysenterica DC. on substrates formulated with sugarcane bagasse and filter cake

Paulo Dornelles, Fabiano Guimarães Silva, Mariângela Brito Freiberger*, Eduardo da Costa Severiano and Germanna Gouveia Tavares

Goiano Federal Institute. Rio Verde, GO, Brazil

Abstract
The Eugenia dysenterica DC. is a species native to Brazilian Cerrado (popularly known as cagaita), which presents many medicinal and nutritional properties. There is little informationon about the propagation of this plant using seedlings. The sugarcane bagasse (SB) and filter cake (FC) can be an alternative for low-cost substrates formulation in regions with sugarcane production like the Cerrado region. This study aimed to investigate the use of SB and FC as substrates in the proportions of 100% SB, 75:25% SB:FC, 50:50% SB:FC, 25:75% SB:FC and 100% FC, along with a comercial subtrate (Trimix®) for the initial development of E. dysenterica. The variables such particle density (PD), water availability (WA), remaining water (WR), aeration space (AS) and total porosity (TP) of the substrates were studied. The E. dysenterica seeds were sown in appropriate plastic containers filled with 288 cm3 of respective substrates. The seedlings were evaluated for plant height (H), stem diameter (Ø), leaf area (A), shoot, root and total dry matter, and Dickson Quality Index (DQI), along with macronutrients accumulation, 120 days after sowing. The treatment with combination of 25:75% SB:FC seemed to be a very appropriate substrate for production of E. dysenterica seedlings. This combination has shown adequate values for physical quality parameters. The reduction of SB proportion and increasing the FC caused increases in PD, WR and TP parameters and contrarily reduction in WA and AS. They promoted higher values for development of H, Ø, A, plant dry mass and DQI as well as the highest accumulation of N, P, K and Ca.

Pages 1459-1464 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1133
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Morphological development and yield of wheat irrigated under nitrogen and potassium fertilization in Cerrado Oxisol

Edna Maria Bonfim-Silva, Danityelle Chaves de Freitas, Tonny José Araújo da Silva, William Fenner, Helon Hébano de Freitas Sousa

Federal University of Mato Grosso - UFMT, Institute of Agricultural and Technological Sciences - ICAT, 5055 Students Avenue Rondonópolis, 78.735-901, Brazil
Federal University of Mato Grosso - UFMT, Faculty of Agronomy and Zootechnic - FAAZ, 2367, Fernando Corrêa da Costa Avenue, 78060-900, Cuiabá, Brazil

Abstract
This study aimed at assessing the effects of nitrogen-potassium interaction on dry matter and grain yield of irrigated wheat (Triticum aestivum L.) grown in the Brazilian Cerrado. The experiment was conducted for two consecutive cropping seasons (2014 and 2015), between March and August. The experiment was arranged in a randomized block design. Treatments consisted of five nitrogen and five potassium doses in a factorial scheme (5×5). The analyzed variables consisted of the shoot and spike dry weights, and grain yield. In both years (2014 and 2015), isolated effects of nitrogen and potassium doses were observed on the assessed traits. In 2014, the highest results were achieved by the respective nitrogen and potassium doses: 145.02 and 148.32 kg ha-1 for shoot dry weight, 133.79 and 139.85 kg ha-1 for spikes, and 119.14 and 138.83 kg ha-1 for grain yield. Yet in 2015, no significant results were identified, while nitrogen doses showed a linear effect on shoot and spike dry weights, potassium rates revealed such effect on grain yield. Although nitrogen showed a higher response in terms of dry weight for shoot and spikes, potassium induced the largest increases in productivity. Thus, for greater efficiency of fertilization, a careful analysis of the level of soil fertility, the expected productivity and the technological level employed is necessary. It should be emphasized that the management of fertilization has specificities every year, requiring constant adaptation.

Pages 1465-1471 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1142
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Rehydration of dry corn grain as an alternative for conservation purposes

Mircéia Angele Mombach*, Dalton Henrique Pereira, Douglas do Santos Pina, Odilon Gomes Pereira, Dheyme Cristina Bolson, Bruno Carneiro e Pedreira

Universidade Federal de Mato Grosso – FAAZ – Av. Fernando Côrrea, 78060-900 -Cuiabá, MT, Brazil
Universidade Federal de Mato Grosso – ICAA -Av. Alexandre Ferronato, 78557-970 - Sinop, MT, Brazil
Universidade Federal da Bahia, Av. Ademar de Barros, 40170-110 - Salvador, BA, Brazil
Universidade Federal de Viçosa, Av. Peter Henry Rolfs, 36570-000 - Viçosa, MG, Brazil
Universidade Estadual de Maringá, Av. Colombo, 87020-900 - Maringá, PR, Brazil
Embrapa Agrossilvipastoril, Rod. Pioneiros, 78550-970 - Sinop, MT, Brazil

Abstract
Glycerol, the main constituent of crude glycerin, has high energy efficiency and may provide energy to microorganisms in silage. Therefore, we evaluated the effect of including crude glycerin (CG) and a bacterial inoculant on the chemical composition, losses, fermentation profile, microbial population and aerobic stability of rehydrated corn grain silage. The dry corn grain (800 g kg-1 dry matter (DM)) was milled to 5 mm and rehydrated with water and glycerin to achieve 32.5% moisture content. Crude glycerin was added at 0, 75, 150 and 225 g kg-1 (natural matter (NM)), with or without bacterial inoculant. The experiment was randomized, and included three replicates in a factorial scheme, with or without bacterial inoculant, four crude glycerin levels and five fermentation periods. CG inclusion in silage decreased the nitrogenous and fibrous fractions, gas losses, DM recovery, and microbial growth. However, CG addition increased effluent and total DM losses. Treatment with 0 and 75 g kg-1 CG (NM) resulted in lower pH (4.6; 4.28) at 64 days of fermentation. Silage without CG remained stable to oxygen after 12 days. The bacterial inoculant did not influence the variables analyzed. We conclude that CG inclusion, bacterial inoculant or a combination of these additives is not recommended for this type of material. Nevertheless, rehydration with water (125 g kg-1 DM) is an alternative for storage of corn grain silage through the ensiling process.

Pages 1472-1478 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1155
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Morpho-agronomic characterization of genotypes of Conilon coffee intercropped with dwarf coconut palms

Bruno Fardim Christo, Wagner Nunes Rodrigues*, Abraão Carlos Verdin Filho, Tafarel Victor Colodetti, Dionicio Belisario Luis Olivas, Lima Deleon Martins, Fábio Luiz de Oliveira, Marcelo Antonio Tomaz

Universidade Federal do Espírito Santo, Centro de Ciências Agrárias e Engenharias, Alegre-ES, Brazil
Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural, Fazenda Experimental de Marilândia, Marilândia-ES, Brazil
Universidad Nacional José Faustino Sánchez Carrión, Lima, Peru

Abstract
The study of Coffea canephora genotypes at different environments, and the various edaphoclimatic characteristics and techniques used in the cropping systems is an important tool in the process of identifying those with higher adaptability to a particular scenario. The objective of this study was to characterize the development of Conilon coffee genotypes in an intercropping system with dwarf coconut palms. The experiment was carried out in the municipality of Colatina (Espírito Santo, Brazil), studying agronomic traits of genotypes of Conilon coffee in a completely randomized design and six repetitions. The eight treatments were composed by eight Brazilian improved genotypes of Conilon coffee and traits of growth, leafiness and fruit bearing were measured. It was possible to verify different behaviors among genotypes regarding tree architecture and fruit production. The genotypes 83 and 48 presented higher number of fruits per branch, besides vigorous growth, along with genotype 153 which presented larger leaves and higher content of chlorophyll b. Genotype 02 also had higher chlorophyll b content, but did not develop large leaves. The genotypes 16 and 100 presented lower levels of chlorophyll b but greater leaf development. Genotypes 03 and 76 are characterized by lower harvest yield. The biomass and the number of fruits per plagiotropic branch seem to be especially useful to study the variability and may ease future studies of variability among genotypes in intercropping systems.

Pages 1479-1485 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1161
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Chemical properties of the soil fertilized with potassium and calcium in guava cultivation cv. 'Paluma'

Alian Cássio Pereira Cavalcante*, Lourival Ferreira Cavalcante, Adailza Guilherme Cavalcante, Antonio Michael Pereira Bertino, Antonio Missiemario Pereira Bertino, Nubia Marisa Ferreira

Doutorado no Programa de Pós-Graduação em Fitotecnia na Universidade Federal de Viçosa, Viçosa, Minas Gerais, Brasil
Professor do Programa de Pós-Graduação em Agronomia da Universidade Federal da Paraíba, Areia, Paraíba, Brasil
Doutoranda no Programa de Pós-Graduação em Agronomia (Produção Vegetal), da Universidade Estadual Paulista – FCAV/UNESP. Jaboticabal, São Paulo, Brasil
Doutorando no Programa de Pós-Graduação em Agronomia (Produção Vegetal), da Universidade Estadual Paulista – FCAV/UNESP. Jaboticabal, São Paulo, Brasil
Mestre em Agronomia no Programa de Pós-Graduação em Agronomia, da Universidade Federal da Paraíba, Areia, Paraíba, Brasil
Doutoranda no Programa de Pós-Graduação em Fitotecnia da Universidade Federal Rural do Semi-Árido. Mossoró, Rio Grande do Norte, Brazil

Abstract
Soil fertility gradually declines over time and under continuous cultivation. It negatively reflects on the yield and quality of crop production, including guava, which is a perennial fruit of high economic potential. Therefore, the objective of this study is to evaluate the effect of potassium doses with and without the application of calcium in soil cultivated with guava “Paluma.” The experimental design was a randomized block with factorial arrangement of 2 × 5, relative to the soil with and without 120 g plant-1 year-1 calcium (using calcium nitrate) and five doses of K2O from 0, 45, 90, 135, and 180 g plant-1year-1 in the form of potassium chloride. The variables analyzed in soil were potential hydrogen, organic matter, phosphorus, potassium, calcium, magnesium, sodium, sum of bases, hydrogen plus aluminum, aluminum, cation exchange capacity, and soil base saturation. The soil fertility was higher in the treatments with potassium (K) fertilizer which has recommended doses between 90 and 135 g plant-1 year-1 without application of calcium in the soil.

Pages 1486-1491 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1222
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Physicochemical characteristics and phytochemical contents of peach trees (Prunus persica Maicel var.) grafted on different rootstocks during cold storage

Caroline Farias Barreto*, Marines Batalha Moreno Kirinus, Pricila Santos da Silva, Cesar Valmor Rombaldi, Marcelo Barbosa Malgarim, José Carlos Fachinello

Departamento de Fitotecnia, Universidade Federal de Pelotas, Capão do Leão, RS, Brasil
Departamento de Biotecnologia, Universidade Estadual de Santa Catarina, Lages, SC, Brasil
Departamento de Ciência e Tecnologia Agroindustrial, Universidade Federal de Pelotas, Capão do Leão, RS, Brasil

Abstract
Peach is highly perishable and need cold storage to have their preservation period extended. Rootstocks may affect both phenology and the development of plant, interfering with the potential of fruit preservation. Therefore, this study aimed at evaluating physicochemical characteristics and phytochemical contents of grafted Maciel var. peaches, on eight rootstocks in an orchard and in cold storage and commercialization simulation conditions. The measurements were carried out after 7, 14 and 21 days of cold storage at 1±0.5ºC, followed by a 3-day commercialization simulation period at 22±1ºC. The experimental design was a completely randomized design in factorial scheme 8x3 (8 rootstocks and 3 storage periods) with 4 repetitions of 20 fruits. Peaches were analyzed for pulp browning, total phenol content and antioxidant activity, mass loss, rot, firmness, ripening index, color, total soluble solids and titratable acidity. Lower total phenol content and lighter browning were observed in fruits harvested from trees grafted on both ‘Seleção Viamão’ and ‘Umezeiro’ rootstocks. Regardless of their rootstocks, peaches fruits retain their quality up to 14+3 days. After that, there was high mass loss, occurrence of rot, browning and softening. However, rootstocks interfered in the variables of peach quality throughout the cold storage period followed by commercialization simulation.

Pages 1492-1498 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1235
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Competitiveness of wood pulp in the international market

Philipe Ricardo Casemiro Soares, Gustavo Silva Oliveira*, Julio Peretti da Silva, Luis Henrique Ferrari, Erone dos Santos, Maria Raquel Kanieski, Jean Alberto Sampietro

Department of Forest Engineering, Centro de Ciências Agroveterinárias – CAV, University of the State of Santa Catarina – UDESC, Lages, Santa Catarina, Brazil

Abstract
Currently, Brazil is the third largest exporter of wood pulp. The objective of present study is to analyze the market competition in the international market of wood pulp in terms of concentration and inequality during the period from 2002 to 2014. Monetary values of exports were collected on the UNCONTRADE database and deflated afterwards, considering 2012 as the base year. The Hirschman-Herfindahl Index (HHI) was used for measuring market concentration, while inequality was measured by the Gini Index (G). The world market for pulp showed a low concentration with HHI varying from 0.0918 to 0.1327, indicating an increasing participation of countries in the studied market. However, results showed that United States, Canada, Brazil, Sweden and Chile dominate the market as the Gini index number varied from 0.8874 to 0.9349.

Pages 1499-1503 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1243
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Nutritional status and technological quality of sugarcane due to increasing gypsum doses

Paulo Ricardo Aprígio Clemente, Vinicius Santos Gomes da Silva*, Vilma Marques Ferreira, José Vieira Silva, Geraldo Veríssimo de Souza Barbosa, Laurício Endres

Centro de Ciências Agrárias, Universidade Federal de Alagoas, Rio Largo, Alagoas, Brazil

Abstract
The sugar-energy sector is highlighted in Brazilian agribusiness; however, poor water distribution and soil acidity have limited the yield and quality of cane fields. Gypsum improves the physical and chemical properties of the soil, attenuating the effects of water shortage and acidity in the edaphic environment. The aim of this study was to determine the effect of gypsum doses on the nutritional status, photochemical efficiency and technological quality of sugarcane. The experiment was conducted under field conditions using a randomized block design in a 3 x 5 factorial scheme with four replications. The treatments consisted of the combination of three sugarcane varieties (RB011941, RB92579, and RB991536) with five doses of gypsum (0 Mg ha-1; 2.5 Mg ha-1; 5.0 Mg ha-1; 10 Mg ha-1; and 20.0 Mg ha-1). The results showed that gypsum did not influence the evaluated variables. A varietal effect for leaf contents of P, K, Mg and S was observed. The RB92579 presented the highest levels of P (1.65 g kg-1) and K (14.55 g kg-1), while RB011941 showed the highest concentrations of Mg and S, 1.25 and 1.05 g kg-1, respectively. The mean values of the macronutrients presented the following concentration order: N > K > Ca > Mg > P > S. Genotypes were similar in terms of photochemical efficiency, which in turn, was not influenced by gypsum application. The best technological quality was verified in RB92579, which showed the highest Brix percentage (22.35%), Pol (19.75%), and the highest levels of TRS (151.3 kg t-1) of sugarcane.

Pages 1504-1511 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1256
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Ecophysiological aspects of Tachigali vulgaris seedlings using different sources and doses of nitrogen

Pedro H. O. Simões, Lenilson F. Palheta, Thays C. Costa, Glauco A. S. Nogueira*, Vitor R. Nascimento, Áurea I. A. F. e Souza, Denmora G. de Araújo, Manoel T. de Paula, Monique R. Rodrigues, Cândido F. de Oliveira Neto, Ana E. de A. Brito, Ricardo S. Okumura

Universidade Federal Rural da Amazônia, Departamento de Ciências Florestais, campus Belém – PA, Brazil
Discente em Agronomia, Universidade Federal Rural da Amazônia, Brazil
Universidade Estadual Norte Fluminense, Departamento de Agronomia em Produção Vegetal, Brazil
4Universidade Federal Rural da Amazônia, Instituto de Ciências Agrárias, campus Belém – PA, Brazil
Universidade do Estado do Pará - UEPA, Centro de Ciências Naturais e Tecnologia - CCNT, Brazil
Universidade Federal do Sul e Sudeste do Pará, Instituto de Estudos de Desenvolvimento Agrário e Regional, campus de Marabá – PA, Brazil
Universidade Federal Rural da Amazônia, Departamento de agronomia Programa de Pós-Graduação em Agronomia, campus Belém - PA, Brazil

Abstract
This study aimed to evaluate the effects of sources and increasing doses of nitrogen on growth and gas exchange in plants of Tachigali vulgaris. The experiment was conducted in a greenhouse in the period from April to July 2015. The experimental design was randomized blocks in a factorial scheme (4 x 5), corresponding to 4 sources and 5 doses with four replications. The seedlings were grown in pots containing 3 dm3 of soil. Nitrogen sources such as urea [(NH₂)₂CO], ammonium nitrate (NH4NO3), ammonium sulfate [(NH4) 2SO4] and calcium nitrate [Ca (NO3)2] were tested in five doses of 0, 75, 150, 225 and 300 mg/dm³. They were applied as a solution in four portions, 25, 50, 75 and 100 days after transplanting. The lower growth of cultivated plants may be associated with N-NH4+ and lower photosynthetic activity, especially due to negative action of this ion on stomatal conductance. The occurrence of this ion resulted in lower growth and biomass production. Based on the results, for the production of tachi-branco seedlings (Tachigali vulgaris) dose of 150 mg dm-3 of N applied in installments, 25, 50, 75 and 100 days, by applying ammonium nitrate is recommended.

Pages 1512-1518 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1266
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Yield of upland rice as affected by nitrogen application and seed inoculation with diazotrophic bacteria

Adriano Stephan Nascente*, Maria da Conceição Santana Carvalho

Brazilian Agricultural Research Corporation (EMBRAPA), Rice and Beans Research Center, P.O. Box 179, Highway 462, km 12, Santo Antônio de Goiás, State of Goiás, 75.375-000, Brazil

Abstract
The use of nitrogen-fixing diazotrophic bacteria such as Azospirillum spp. could be an important alternative to reduce nitrogen fertilization in upland rice field. The objective of this study was to determine the effect of nitrogen application at topdressing and seed inoculation with strains of Azospirillum spp. on the plant biomass, foliar nutrient concentration, yield components, grain yield and nutrient concentration of grains in upland rice under a no-tillage system. The field experiments were conducted for two growing seasons 2015/2016 and 2016/2017 in the Cerrado Region of Brazil. The experimental design was a complete randomized block in a factorial 4x4 scheme with three replications. The treatments consisted of inoculated seeds of rice with peat containing the strains of Azospirillum spp. [Azospirillum brasilense 245, Hernaspirillum seropedicae Z94, commercial Azospirillum brasilense (Ab V5 and Ab V6 strains), and without Azospirillum] with four doses of N (0, 40, 80 and 120 kg ha-1) applied as urea at topdressing. The use of diazotrophic bacteria in high level of soil organic matter did not increase yield components, grain yield and nutrients in the leaves and grains of upland rice. Increasing rates of N increased N, P, K, Ca, Mg, S, Cu and Mn in leaves; N, P, Ca, Cu and Fe in the grains, biomass, panicle per meter, grain per panicle and grain yield of upland rice. In this sense, the rate of 120 kg ha-1 of N provided the highest rice grain yield (4,413 kg ha-1).

Pages 1519-1527 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1290
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Growth and physical characterization of fruits of bell pepper (Capsicum annuum L.) cv. ‘All Big’ subjected to saline stress and exogenous application of proline

Lauriane Almeida dos Anjos Soares*, Geovani Soares de Lima, João Batista dos Santos, Hans Raj Gheyi, Reginaldo Gomes Nobre, Saulo Soares da Silva, Adaan Sudário Dias, Leandro de Pádua Souza

Federal University of Campina Grande, Academic Unit of Agricultural Engineering, Campina Grande, 58.109-970, Paraíba, Brazil
Federal University of Campina Grande, Academic Unit of Agricultural Science, Pombal, 58.840-000, Paraíba, Brazil
Federal University of Recôncavo of Bahia, Nucleus of Soil and Water Engineering, Cruz das Almas, 44.380-000, Bahia, Brazil

Abstract
Salinity is considered as one of the main abiotic stresses affecting the growth and development of various solanaceous crops such as bell pepper. To reduce the adverse effects induced by saline stress, it is necessary to apply exogenous osmoprotectants such as proline. In this context, this study aimed to evaluate the growth and physical characteristics of fruits of ‘All Big’ bell pepper under saline stress and foliar application of proline, in an experiment conducted in pots using drainage lysimeters under greenhouse conditions. The study was carried out in randomized blocks, testing two levels of irrigation with low (control) and high water salinity (EC= 0.6 and 3.0 dS m-1) associated with four doses of proline (0; 10; 20 and 30 mmol L-1). Treatment effects on plant growth and phytomass accumulation were evaluated by measuring the following variables: plant height, stem diameter and number of leaves at 85 DAT, shoot and total dry phytomass at 95 DAT. At the end of the cycle, 100 DAT, bell pepper fruits were characterized based on transverse and longitudinal diameter and pulp thickness. Increasing irrigation water salinity reduced bell pepper growth and dry matter accumulation, and pulp thickness is more sensitive to irrigation water salinity. Proline doses did not inhibit the deleterious effect of irrigation water salinity on bell pepper development; increasing proline doses led to reduction in bell pepper growth and dry matter accumulation. The bell pepper cv. ‘All Big’ demonstrated sensitivity to irrigation water salinity with 3.8 dS m-1.

Pages 1528-1535 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1306
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Effects of Boron (B) doses and forms on boron use efficiency efficiency of wheat

Fernando Shintate Galindo*, Marcelo Carvalho Minhoto Teixeira Filho, Salatiér Buzetti, Willian Lima Rodrigues, Eduardo Henrique Marcandalli Boleta, José Mateus Kondo Santini, Maikon Richer de Azambuja Pereira

Department of Plant Health, Rural Engineering, and Soils, Faculdade de Engenharia de Ilha Solteira, Universidade Estadual Paulista “Júlio de Mesquita Filho”, Ilha Solteira, Sao Paulo State, Zip Code 15385-000, Brazil
Higher Education Institute of Rio Verde, College Objetivo, Rio Verde, State of Goiás, Brazil

Abstract
Boron is one of the most limiting micronutrients in the grain production system in Brazil, mainly due to its complex dynamics in the soil-plant system. In this way, the objective of this study was to evaluate the efficiency of application forms and doses of boron with emphasis on wheat grain yield. The experiment was conducted in no-tillage system in an Oxisol with clay texture in Selvíria, MS. The experimental design was a randomized block design with four replicates arranged in a 4 x 3 factorial scheme, using four doses of boron (0, 1, 2 and 4 kg ha-1) with boric acid source (B = 17%); and three apllication forms: (A1) in desiccation of the predecessor straw, along with herbicide; (A2) at the time of sowing, in soil along with the formulated fertilization seeding and (A3) foliar application along with the syrup of the herbicide (with the application of post emergent herbicide). The increase in boron doses reduced the recovery of apparent boron (RAB), boron uptake efficiency (BUpE) and agronomic efficiency (AE), but the application of 2 kg ha-1 provided the highest boron utilization efficiency (BUtE) and wheat grain yield. We recommend application of 2 kg ha-1 of B in the soil at sowing to obtain approximately 4311 kg ha-1 of wheat.

Pages 1536-1542 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE1382
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Physiological and proteomic analysis of two contrasting Sorghum bicolor genotypes in response to drought stress

Hind Emad Fadoul*, Marmar A. El Siddig, Abdel Wahab H. Abdalla, Adil Ali El Hussein

Department of Botany, Faculty of Science, University of Khartoum, Sudan
Department of Agronomy, Faculty of Agriculture, University of Khartoum, Sudan

Abstract
Understanding the response of a crop to drought is the first step in the breeding of tolerant genotypes. In this study, two sorghum (Sorghum bicolor L.) genotypes with contrasting sensitivity to drought were subjected drought stress by withholding water for 7 days at seedling stage; physiological and protein analyses were made. Reduction percentage was recorded on leaf water content, chlorophyll a and b and total chlorophyll. Shoot and root lengths reductions were observed in the drought-sensitive Cultivar (Tabat) while the drought-tolerant line (EL9) showed an increase in shoot and root lengths under drought conditions. Drought tolerant sorghum line EL9 accumulated higher proline (26% increase) when compared to the sensitive cultivar Tabat (5% increase). Mass spectrometry analysis coupled with nanoflow UPLC was used to compare daily-watered with drought stressed (7 days) seedlings. A total of 36 protein spots were detected, of which 23 were recorded for one or both accessions under drought stress conditions only. These proteins were identified using MASCOT database search in accordance with sequence similarity with previously characterized proteins from the Uniprot database. The identified proteins were assigned to different functional categories as follows: Response to stress (35%); metabolic processes (26%); photosynthetic (13%); fatty acid biosynthesis (4%) and cell wall biogenesis/degradation (4%). Seven of the identified proteins under stress condition were unique to El9, in contrast to 4 proteins were unique to Tabat. This study showed a differential protein expression pattern of two sorghum accessions under drought stress, which will be valuable for studying the molecular mechanisms underlying drought tolerance in the future. Also, these proteins could be potential candidates for development of markers to be used in markers assisted selection.

Pages 1543-1551 | Full Text PDF| doi: 10.21475/ajcs.18.12.09.PNE134

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