Australian Journal of Crop Science   AJCS

August 2021 | 15(08):2021 | ERALY VIEW | 10.21475/ajcs.21.15.08

Fertilizing model for Djulis (Chenopodium formosanum Koidz.) using mixture design approaches

Chien-Chang Chiu*, Hung-Sheng Peng, Ching-Ying Liao, Yu-Chu Chen, Chong-Ho Wang*

Department of Plant Industry, National Pintung University of Science and Technology. Pintung County, Neipu Township, 1 Shueifu Road, 912 Taiwan
Department of Horticulture, National Taitung College. Taitung City, 889 ChengChi North Road, 950 Taiwan
Taitung District Agricultural Research and Extension Station, Council of Agriculture, Executive Yuan. Taitung city 675 Chunghua Road Sec1, 950 Taiwan


Abstract
Djulis (Chenopodium formosanum Koidz.), a cereal plant native to Taiwan, was used for wine making, insect repellant, and health promotion. Therefore, using appropriate experimental design and modeling approach is of importance to predict the effect of the interaction among nitrogen (N), phosphorus (P), and potassium (K) on djulis yields. In this study, a mixture design approach was applied to investigate the effects of interactions among nitrogen, phosphorus and potassium on the grain yields of djulis plants. Based on a three-variable including N, P, and K with each maximum of them was of 200 g (6 m2)-1, a mixture design approach was employed by 42 experiments in 14 study plots to obtain an optimal combination of N : P : K= 100 : 200 : 100 (g / 6 m2)-1) to predict an optimal dry djulis yield of 52.80 g / plant in this study. This study revealed that the linear mixture of N, P, and K and the interaction of P and K had marked effects on the yields of djulis. Moreover, the results were fitted to a quadratic polynomial equation using a multiple regression analysis. Our data showed this mixture design is a reliable approach to develop a model that can be used to predict the djulis yields.

Pages 1089-1094 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p2638
.........................................................................................................................................................................................................................................

Treated municipal wastewater reuse for eggplant irrigation

Marie Therese Abi Saab*, Claude Daou, Isam Bashour, Antoun Maacaron, Salim Fahed, Dany Romanos, Yara Khairallah, Nada Lebbous, Celine Hajjar, Roula Abi Saad, Caroline Ojeil, Mohamed Houssemeddine Sellami, Salim Roukoz, Maher Salman

Lebanese Agricultural Research Institute, P.O. Box 90-1965, Fanar, Lebanon
Lebanese University, Faculty of Sciences, Fanar, Lebanon
American University of Beirut, Beirut, Lebanon
Food and Agriculture Organization (FAO), Beirut, Lebanon
National Research Council of Italy, Institute for Agricultural and Forestry Systems in the Mediterranean (CNR–I.S.A.FO.M.), Via Patacca, 85, – 80056 – Ercolano (NA) Italy
Ministry of Agriculture, Beirut, Lebanon; (7) Food and Agricultural Organization (FAO), Rome, Italy


Abstract
In the Bekaa Valley of Lebanon, the availability of freshwater is limited and therefore farmers must start using alternative water sources such as treated wastewater for irrigating crops. The present study is of great importance, since it provides evidence of some on-farm options that farmers can adopt when irrigating with treated effluent, in order to minimize the health risks. Eggplant was grown under two water quality regimes (Freshwater (FW) and treated wastewater (TW)) and two agronomic practices (no mulch (N_Mu) and use of plastic mulch (Mu)). Treatments were arranged in a split plot design with four replicates. Water quality regime was the main plot factor, while agronomic practices were the subplot factors. Water quality, soil, the marketable yield and other parameters were measured. Fruit samples were evaluated for bacterial contamination. The drip line performance was monitored. The study results revealed that the treatment with treated effluent gave more fruits.m-2, yield and mean fruit weight than the treatment using fresh water irrigation, with an increase of 3.98%, 10.74% and 5.63%, respectively. In addition, the use of mulch (Mu) resulted in an increase in yield (24.23%) and number of fruits (14.11%). Concerning the emitters’ performance and sensitivity to clogging, discharge reduction rate (Rd = 6.75%) for drippers delivering TW was lower than the admissible value of 20% discharge variation, indicating that the quality of water has little effect on emitter performance. Concerning bacterial contamination of fruits, irrigation with treated wastewater showed no contamination in terms of fecal streptococci, salmonella or E. coli. However, the fruits were contaminated with fecal coliforms that were present at a concentration less than 200 CFU.100 g-1. Following the World Health Organization Guidelines, pathogens could be reduced through post treatment health-protection control measures such as drip irrigation, product washing, disinfection and produce peeling.

Pages 1095-1101 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p2711
.........................................................................................................................................................................................................................................


Agricultural and livestock production in the Amazon: a reflection on the necessity of adoption of integrated production strategies in the western region of the state of Pará

Lucieta Guerreiro Martorano*, José Reinaldo da Silva Cabral de Moraes, Lílian Kátia Ximenes Silva, Paulo Campos Christo Fernandes, João Maria do Amaral Júnior, Leila Sheila Lisboa, Kedson Alessandri Lobo Neves, Aline Pacheco, Troy Patrick Beldini, Lucas Eduardo de Oliveira Aparecido, Welligton Conceição da Silva, Vicente de Paulo Campos Godinho

EMBRAPA Eastern Amazon / NAPT Middle Amazon, Santarém, PA, Brazil
São Paulo State University (Unesp), School of Agricultural and Veterinarian Sciences, Jaboticabal, SP, Brazil
University of the Amazon-(UNAMA), Belém, PA, Brazil
EMBRAPA Cerrados, Brasília, DF, Brazil
Federal Institute of Amapá, Campus Porto Grande, Brazil
Municipal Secretariat of Belém – SEMEC, PA, Brazil
Federal University of Western Pará (UFOPA), Santarém, Brazil
Federal Institute of Education, Science and Technology of South of MinasGerais – IFSULDEMINAS – Campus of Muzambinho, Muzambinho, Brazil
University of the Amazon-(UNAMA), Santarém-PA, Brazil
EMBRAPA Rondônia, Vilhena, RO, Brazil


Abstract
The Brazilian Amazon has a large bovine herd and is an important exporter of meat from cattle and is also one of the most competitive regions for exportation of animal protein. Conventional extensive cattle ranching management has been a strategy promoted by public policies and has contributed to the processes of occupation of the region through modification of public lands with native forests. The objective of this study was to analyze the fundamental elements that have sustained conventional extensive cattle ranching in the Amazon and to demonstrate new strategies to change this paradigm, with a focus on western Pará. Data from the Brazilian Institute of Geography and Statistics (IBGE) on cattle ranching production between 1990 and 2019 were analyzed and separated into two periods, 1990-2000, and 2001-2019. Meteorological data from western Pará were analyzed to describe the agrometeorological conditions (1989 -2012) with respect to the hydrological regime and its controls on the soil-plant-atmosphere system. Results show that the largest greenhouse gas emissions (GGE) from ruminants occurs during the dry season due to pasture forage grasses that are highly lignified. In contrast, lower emissions occur from diets rich in proteins and lipids, with subsequent gains in productivity, thus indicating the benefits of pastures with well-managed grasses. It is believed that cattle ranchers will adopt integrated systems such as integration of crop-livestock-forest (ICLF) when they are able to understand that climate conditions can be allied with sustainability indicators of the production chain. This paradigm shift in production systems applies not only to environmental and economic aspects, but especially to social ones such as opportunities to hire qualified workers coming from regional agrarian science schools.

Pages 1102-1109 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p2908
......................................................................................................................................................................................................................................

Responses of different varieties of sugarcane to irrigation levels in the Cerrado

Elson de Jesus Antunes Júnior, José Alves Júnior*, Carolina Carvalho Rocha Sena, Derblai Casaroli, Adão Wagner Pêgo Evangelista, Rafael Battisti

School of Agronomy, Department of Biosystems Engineering, Federal University of Goiás (UFG), Zip code 74.690.900, Goiânia, Goiás, Brazil

Abstract
The Cerrado is under full expansion of sugarcane cultivation. However, the climate of this biome limits the production of sugarcane due to a marked water deficit. Therefore, the objective of this study is to evaluate different varieties of sugarcane in two cultivation cycles in response to irrigation levels in the Cerrado. The experiment was conducted in Goiânia-GO, Brazil, from March 2016 to March 2018, during the cycles of plant-cane and ratoon cane in pots. The experiment was completely randomized in a 5 x 6 factorial design. The treatments were five varieties of sugarcane (RB867515, CTC11, SP860042, IAC873396, and IAC911099) and six levels of supplementary irrigation (100, 80, 60, 40, 20 and 0% of the ETc determined by weighing lysimeter), and four replications. Eight biometric analyses were performed 45 days apart. At the end of each cycle, the quality of the raw material was determined through technological analysis. At the initial development phase (between March and August), when growth is low, we found that it is better to use an irrigation level that provides at least 40% of ETc, since the Cerrado environment does not increase sugarcane height. At the growth phase (between September and March), there is active growth corresponding to 74% of the cane's height. Therefore, the ideal irrigation is that at least 80% of the ETc be provided at the growth stage to support the sugarcane to reach a maximum growth and consequently favorable technological indexes. The supplementary irrigation level of 60% of ETc accelearted the process of maturation of sugarcane for a 12-month cycle. We conclude that the level of supplementary irrigation using greater technical viability for the cultivation of sugarcane in the Cerrado is 60% of the ETc. The varieties most adapted to this production environment are RB867515 and IAC873396.

Pages 1110-1118 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p2978
.................................................................................................................................................................................................................................

Either embryogenesis or indirect organogenesis in sugarcane: Are we missing the key points?

Manoel Viana Linhares-Neto, Letícia Rios Vieira, Pedro Vitor Schumacher, Mariele Rossato, Luciano Coutinho Silva, Fabrício Jose Pereira, Renato Paiva, Antonio Chalfun-Junior*

Department of Biology, Plant Physiology Sector, Federal University of Lavras, Brazil
Department of Cellular and Molecular Biology, CBIOTEC, Federal University of Paraíba, Brazil
Department of Biology, Institute of Natural Sciences, Federal University of Alfenas, Brazil

Abstract
Both in vitro establishment and callogenesis of sugarcane allow a production of quality regenerative material, which is necessary for in vitro clonal propagation and for genetic transformation. In this study, we establish the efficient production of calli from the RB855156, RB92579 and RB867515 cultivars and characterize their regenerative potential in relation to either an embryogenic or an organogenic origin both by morphology and by anatomy. Callogenesis was induced in MS medium with 3.0 mg L-1 2.4-D. Three antioxidants were tested: polyvinylpyrrolidone (150; 300; 600 mg L-1), citric acid (7.5; 15; 30; 60 mg L-1), and ascorbic acid (7.5; 15; 30; 60 mg L-1). The morphological characterization of the calli was performed by visual classification, and the anatomical analyses by light microscopy. The experimental design was completely randomized, containing 150 explants by cultivar to antioxidant evaluations and potential regenerative evaluation within three times of subcultures (84; 112; 140 days). We have attained the key points of our in vitro research. Calli regeneration depended on the oxidation level and genotype. Antioxidants only in the culture medium were not enough to prevent oxidation. However, citric acid (7.5 mg L-1) as a pretreatment of the explant minimized this problem. Bacterial contamination was developed for the three cultivars, inhibiting the establishment to RB867515. The disinfestation protocol was efficient for RB855156 and for RB92579 cultivars. Three varieties of calli differed in the regeneration potential. In addition, histological analysis of the calli unfolded not only that there were structural differences but also that their buds had an organogenic origin.

Pages 1119-1129 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3082
..............................................................................................................................................................................................................................

Ecophysiology and production of red pitaya under different light conditions

Edmilson Igor Bernardo Almeida*, Márcio Cleber de Medeiros Corrêa, Rosilene Oliveira Mesquita, Maria Izabel Galão, Júlio César DoVale, Marcelo de Sousa Silva, João Paulo Cajazeira, Ronialison Fernandes Queiroz

Universidade Federal do Maranhão, 65500-000, Chapadinha-MA, Brazil
Univeridade Federal do Ceará, 60440-900, Fortaleza-CE, Brazil
Faculdade IEducare-FIED, 62320-000, Tianguá-CE, Brazil


Abstract
In commercial orchards of red pitaya fruit, yellowish cladodes frequently occur, mainly in the warmest months of the year. The measurement of probable interferences on the ecophysiology and production of red pitaya and their correlations are unprecedented and may present a basis for commercial producers. This study aimed to analyze the effect of different light conditions on growth, anatomy, photosynthetic pigments, gas exchanges, and the production of red pitaya in Fortaleza (CE). The experimental design was carried out in randomized blocks (RDB), with five treatments, five replications, and two plants per plot. The treatments consisted of five levels of luminosity: full sunlight, 35, 50, 65, and 80% shading, with the use of PVC shade screens. At 365 days, morphological, biochemical, physiological, and anatomical characters were analyzed. The fruit production was estimated from the first fruit emission, which occurred 186 days after the experiment installation. It is concluded that the luminosity conditions interfere with a variably in the growth, anatomical structures, photosynthetic pigments, gas exchanges, and production, as well as on their correlations. The crop presented high phenotypic plasticity and adequately acclimated to cultivation in full sunlight, obtaining the highest production. Moreover, this study recommended cultivating in full sunlight and at 35% shading, which showed the greatest performances in terms of ecophysiological variables and productive yield.

Pages 1130-1138 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3099
...................................................................................................................................................................................................................................

Grain sorghum under pre- and post-flowering drought stress in a semiarid environment

Andrey Antunes de Souza, Abner José de Carvalho, Edson Alves Bastos, Milton José Cardoso, Marcos Paulo Mingote Júlio, Paulo Sérgio Cardoso Batista, Bruno Henrique Mingote Julio, Carmela Vaz Campolina, Arley Figueiredo Portugal, Cícero Beserra de Menezes, Simônica Maria de Oliveira

State University of Montes Claros - Campus Janaúba, Janaúba, MG, Brazil
Embrapa Mid-North, Teresina, PI, Brazil
Federal University of São João del-Rei - Campus Sete Lagoas, Sete Lagoas, MG, Brazil
Embrapa Maize and Sorghum, Sete Lagoas, MG, Brazil


Abstract
Sorghum is one of the most drought-tolerant cereals. However, strong water stress, especially during the reproductive phase, causes significant grain yield reduction. Drought events are common in second crops planted after soybean harvest in Brazil. The objective of the present study was to assess grain sorghum hybrids grown under pre- and post-flowering drought stress. Twenty-five hybrids were subjected to two water stress environments (pre- and post-flowering) and one environment with non-water stress. The experimental design was a split plot based on a randomized complete block with three replicates. Water stress pre-flowering reduced plant height, accelerated flowering, and increased panicle index compared with water stress post-flowering. Both pre- and post-flowering stress reduced yield, by 45% and 48%, respectively. Grain mass was greatly affected by stress occurring post-flowering but not by that occurring pre-flowering. Therefore, the reduction in yield caused by pre-flowering stress is due more to the reduction of grain number in the panicle, whereas the reduction when stress occurs post-flowering is due more to reduction in grain size. The plant chlorophyll index decreased when stress occurred pre-flowering and reverted after irrigation had resumed, demonstrating recovery in the photosynthetic capacity of the sorghum plant. With post-flowering stress, the chlorophyll index decreased significantly 30 days after the stress, affecting grain filling, with consequent yield loss.

Pages 1139-1145 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3162
..................................................................................................................................................................................................................................

Silicon as mitigator of salt stress in mango tree seedlings

Mário Leno Martins Véras*, Lunara de Sousa Alves, Toshik Iarley da Silva, Iana Nogueira da Silva, Amanda Stefanne do Nascimento da Costa, Edinete Nunes de Melo, Hellen Patricia Lemos Cordovil, Adriana Pricilla Jales Dantas, Nelto Almeida de Sousa, Thiago Jardelino Dias

Federal Institute of Amapá, Highway BR 210 – km 103, 68997-000, Porto Grande, AP, Brazil
Federal University of Paraíba, Department of Phytotechnics and Environmental Sciences, Highway BR 079 – km 12, 58397-000, Areia, PB, Brazil
Federal University of Viçosa, Department of Phytotechnics, Avenue Peter Henry Rolfs, University Campus, 36570-900, Viçosa, MG, Brazil
Federal University of Santa Maria, Building 77, Room 05, Roraima nº 1000, Camobi Neighborhood, 97105-900, Santa Maria, RS, Brazil


Abstract
The use of saline water dramatically reduces the growth and development of plants. Thus, salt stress mitigation can be important to allow the use of this water in the agriculture. This study aimed to evaluate the effect of silicon as attenuators of effects caused by salt stress on seedlings of “Espada” mango tree variety. An experiment was conducted under completely randomized experimental design in a factorial scheme (5 x 2). The factors studied consisted of silicon concentrations (0, 50, 100, 150 and 200 mg L-1) and irrigation with low water (0.8 dS m-1) and high (6 dS m-1) electrical conductivity and the growth of mango tree seedlings was assessed 70 days after sowing (DAS) by the height, number of leaves, stem diameter, dry matter of root, aerial part and total, dry matter content, Dickson Quality Index and Index of tolerance to salinity. The application of silicon via leaf mitigates the deleterious effects of salt stress in mango seedlings. Silicon 200 mg L-1 promotes higher growth, dry matter accumulation and 100 mg L-1 concentration provides higher salt tolerance in mango seedlings. Electrical conductivity in the irrigation water at 6 dS m-1 reduce the growth and quality the of mango tree seedlings.

Pages 1146-1150 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3190
................................................................................................................................................................................................................................

Structural change in an oxisol under dynamic loads and different tillage systems

Patrícia Freitas Candine*, Paulo Márcio Fernandes Viana, Elton Fialho dos Reis

Universidade Estadual de Goiás, Campus Central Henrique Santillo, Br 153, Nº 3105, Cep 75132-400, Anápolis, GO, Brasil

Abstract
This study aimed to analyse the structural changes of an oxisol under different loads using no-tillage (NT) and conventional till (CT) conditions. Experiments were conducted using a randomised design with a 2 x 5 factorial scheme, areas of oxisol under no tillage and conventional tillage and five loads (0, 50, 100, 150, and 200 kg), with 4 repetitions, totally 40 experimental units. Loads were applied by a traffic simulator to determinate the surface tamping and the variables (cohesive intercept and friction angle), which obtained through shear-force equipment. The tillage systems and loads of traffic influenced the soil structure based on the variables analyzed. The highest values for surface tamping and compaction degree were observed in no tillage condition, while cohesive intercept and friction angle were higher on conventional tillage. The use of the above-stated load, which the soil can support, causes structural rearrangement. After the structural rearrangement, the soil tends to return to its initial state. The variation in friction angle associated with different applied loads is less in soil under no-tillage conditions.

Pages 1151-1156 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3191
......................................................................................................................................................................................................................................

Growth, foliar gas exchange and biomass accumulation in passion fruit seedlings irrigated with saline waters and due to the applications of salt stress attenuators

Gilton Bezerra Goés, Aylson Jackson de Araujo Dantas, Thiago Jardelino Dias, Mário Leno Martins Véras*, Toshik Iarley da Silva, Lunara de Sousa Alves, Ana Carolina Bezerra, Márcia Paloma da Silva Leal, Alvaro Carlos Gonçalves Neto, Valéria Fernandes de Oliveira Sousa

Federal University of Paraíba – Agricultural Sciences Center – Campus II, Highway PB 079 – Km 12, Caixa Postal 66, 58397-000, Areia-PB, Brazil
Federal Institute of Amapá, Highway BR 210 – km 103, 68997-000, Porto Grande, AP, Brazil
Federal University of Viçosa – Campus Viçosa, University Campus, 36570-900, Viçosa-MG, Brazil
Federal University of Paraíba, Department of Phytotechnics and Environmental Sciences, Highway BR 079 – km 12, 58397-000, Areia, PB, Brazil
Rural Federal University of Pernambuco, Dois Irmãos, 52171900 - Recife, PE, Brazil


Abstract
The use of substances attenuating the harmful effects of salts on plants is an important strategy for the use of salt water in agriculture. The objective of this work was to evaluate the growth, gas exchange and biomass accumulation of passion fruit seedlings (Passiflora edulis Sims) irrigated with salt water due to the application of salt stress attenuators. The experiment was carried out in a randomized complete block design, in a 5 x 3 x 2 factorial scheme, with three replications, referring to the electrical conductivities of the irrigation water (1.5, 2.5, 3.5, 4.5 and 5.5 dS m-1), three doses of humic acids (0, 10 and 20 mL) and two doses of citric acid (0 and 10 mL) as attenuators, respectively. Increased salinity of irrigation water reduced growth, accumulation of dry shoot biomass and gas exchange (stomatal conductance, transpiration, net photosynthesis, CO2 internal concentration) of passion fruit sourced seedlings. Citric acid did not attenuate the negative effects of the salts and negatively interfered in the growth and accumulation of dry biomass of the shoots of passion fruit, mainly to the seedlings irrigated with water of low salinity. Humic substances at a dose of 20 mL promoted higher growth of passion fruit sprouts but were not sufficient to attenuate the negative effects of irrigation water salts. Therefore, citric acid and humic substances, under the conditions of the study, are not an option to use saline water in the production of passion fruit seedlings.

Pages 1157-1163 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3198
................................................................................................................................................................................................................................

Linear relationships between grain yield and tassel traits in maize

Daniela Lixinski Silveira*, Alberto Cargnelutti Filho, Cleiton Antônio Wartha, Fernanda Carini, Cirineu Tolfo Bandeira, Rafael Vieira Pezzini, Felipe Manfio Somavilla

Graduate Program in Agronomy, Federal University of Santa Maria, UFSM, Santa Maria, RS, Brazil
Department of Plant Sciences, Center of Rural Sciences (CCR), Federal University of Santa Maria, UFSM, 97105-900, Santa Maria, RS, Brazil
Graduate Program in Applied Plant Sciences, University of Minnesota, Saint Paul, United States of America
Undergraduate Agronomy, Federal University of Santa Maria, Santa Maria, RS, Brazil


Abstract
This study aimed to verify the linear relationships between maize grain yield and tassel traits, identifying traits for selection through direct and indirect effects over three crop years. Three experiments were performed with 20 maize genotypes in a randomized complete block design with three replicates. Individual variance analysis showed significant genotype effects for all traits in the three crop years. However, a joint analysis demonstrated a significant genotype effect at 5% error probability for all traits, but branching space length. Furthermore, only the number of secondary branches and tassel branch number did not show significant genotype × crop year interaction. These results revealed a genotype differentiated behavior over the evaluated years, emphasizing the need to evaluate genotypes in more than one crop year. Based on phenotypic and genotypic correlation matrices and path analyses, the number of secondary tassel branches showed a positive linear relationship with grain yield; therefore, it can be used for the indirect selection of maize plants in breeding programs.

Pages 1164-1171 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3228
...................................................................................................................................................................................................................................

Resistance levels of Arabica coffee cultivars to bacterial-halo-blight under field conditions and planting spacings within the rows

Fernando Cesar Carducci, Willian Gabriel dos Santos, Carlos Theodoro Motta Pereira, Lucas Mateus Rivero Rodrigues, Luís Otávio Saggion Beriam, Luciana Harumi Shigueoka, Valdir Mariucci Junior, Gustavo Hiroshi Sera*

Instituto de Desenvolvimento Rural do Paraná – IAPAR-EMATER (IDR-Paraná), Plant Breeding Department, Rodovia Celso Garcia Cid, km 375, Zip Code 86047-902, Londrina-PR, Brazil
Universidade Estadual de Londrina (UEL), Agronomy Department, Rodovia Celso Garcia Cid, km 380, Zip Code 86057-970, Londrina-PR, Brazil
Instituto Agronômico (IAC) Centro de Café Alcides Carvalho, CP 28, Zip Code 13001-970, Campinas-SP, Brazil
Instituto Biológico, CP 70, Zip Code 13012-970, Campinas-SP, Brazil


Abstract
Bacterial-halo-blight (BHB) is an important coffee disease caused by the Pseudomonas syringae pv. garcae. To date, there are few studies reporting resistance to BHB in adult plants of Arabica coffee cultivars under field conditions. The aim of this study was to assess the levels of resistance to BHB in Arabica coffee cultivars under field conditions and different planting spacings within the rows (SWR). The field trial was assessed for BHB severity in natural infection condition by using a grade scale, ranging from 1 to 5 in Londrina (Paraná state, Brazil) in December 2016 (36 months after planting). The experiment was planted at the 2.50m spacing inter-row, using randomized blocks design in a 4 x 15 factorial scheme with three replications and five plants per plot. The factors consisted of four SWR (0.40m, 0.50m, 0.60m and 0.70m) and 15 Arabica coffee cultivars. The resistance levels were based on the mean BHB severity grades, where the cultivars were classified as highly resistant (HR), resistant (R), moderately resistant (MR), slightly resistant (SR) and susceptible (S). Adult plants of IPR 102 and IPR 106 were HR and MR to BHB, respectively, under natural field conditions. IAPAR 59, IPR 103, IPR 104, IPR 107 and IPR 108 showed a lower level of resistance than the cultivars IPR 102 and IPR 106. Some HdT-derived cultivars such as IPR 97, IPR 98, IPR 99 and Tupi IAC 1669-33, besides cultivars IPR 100, IPR 101 and IPR 105, derived from IAC 1110-8 were susceptible. In the two SWR more densely, the BHB severity was higher, and some cultivars behaved as more susceptible in these spacings.

Pages 1172-1176 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3229
................................................................................................................................................................................................................................

Soft computational techniques to identify cotton leaf damage


Rafael Faria Caldeira*, Wesley Esdras Santiago, Bárbara Teruel

Faculty of Agricultural Engineering of the University of Campinas– FEAGRI/UNICAMP
Institute of Agricultural Sciences of the Federal University of the Jequitinhonha and Mucuri Valleys– ICA/UFVJM

Abstract
The principal objective of agriculture is the production of a high yield of healthy crops. This yield may be improved by the automatic detection of diseases and the consequent reduction in the use of pesticides. A digital processing system for images was thus developed and used to identify lesions on the leaves of cotton plants. A collection of 60,659 images of sub-metric resolution showing samples of soil and both healthy and damaged leaves was obtained and processed with an algorithm for the extraction of texture from 102x102-pixel samples. Then they analyzed with a neuro-fuzzy classifier trained to discriminate the three types of regions (soil, healthy leaf, and lesioned leaf). The algorithm developed was able to recognize the three classes. It generated a great amount of information on recognition of background which was more consistent than leaf damage areas. Therefore, it surpassed the performance of areas of healthy leaves. A similar trend was found for sensitivity. The overall accuracy of the system was 71.2%, suggesting that the unbalanced data of the different classes had skewed the results of the algorithm, as the number of false positives for the less well represented classes was greater. The analysis of unbalance (F-Score) showed that, independent of the volume of data, the attributes of texture utilized yielded better results for the images containing areas of damage in relation to overall accuracy. Therefore, given the challenges involved in the automatic identification of lesions in agricultural crops, such as variations in illumination, color, and texture, as well as obstruction, overlapping, and complexity of the region of which the image was taken, the behavior of the model was deemed satisfactory. Given the hybrid nature of the model, it should contribute to the state of the art in the use of intelligent systems in agriculture. This algorithm is available at https://github.com/rafaeufg/Cotton-diseases

Pages 1177-1185 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3256
..............................................................................................................................................................................................................................

Fruit development of groundcherry (Physalis angulata L.) in dryland

Diana Nurus Sholehah, Sucipto Hariyanto, Hery Purnobasuki*

Program of Mathematics and Natural Science, Faculty of Science and Technology, Airlangga University, Surabaya, Indonesia
Department of Biology, Faculty of Sciences and Technology, Airlangga University, Surabaya, Indonesia
Program of Agroecotechnology, Faculty of Agriculture, University of Trunojoyo Madura, Bangkalan, Indonesia


Abstract
Physalis angulata are widespread in the tropics with high bioactive compounds and pharmacological effects. This paper aims to identify the stages of fruit development and changes in physicochemical properties to provide comprehensive data on optimal fruit utilization. This study used CM 1 accession found in Madura Island with purplish stems and fruit peels. After 30 days of cultivation, the plant was transplanted into a polybag containing red Mediterranean soil and manure (5:1). It is grown in a greenhouse for 90 days to observe. The experimental design was completely randomized. The stages were selected as treatments: 1, 3, 6, 9, 12, 15, 18, and 21 Day After Anthesis. The study used 15 replications with a total of 15 plants used, except for chemical analysis which used five replication with three plants for each replication. Observations were carried out during the reproductive phase and the parameters included fruit phenology, physical character, and chemical characteristics. The result showed that the growth stage of P. angulata consists of fully opened flower, fruit development (fruit set and fruit expansion), and ripening fruit (starting ripe, advanced ripe, and eating ripe). The optimal fruit stage for consumption is 21 days after anthesis, which has a diameter of 13.58 mm, a weight of 1.69 g and firmness of 3.40 N, total soluble solids of 14.96 Brix, total titratable acid of 0.0011%, and vitamin C 20.91 mg/100 g.

Pages 1186-1191 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3318
...............................................................................................................................................................................................................................

Propagation and control of Anredera cordifolia (Ten.) Stennis (madeira vine)

João Paulo R. San Gregorio, Nicolas Moreira Pioto, Victor Augusto Forti, Josiane Rodrigues, Paulo Vinicius da Silva, Patricia Andrea Monquero*

Graduate Program in Agriculture and Environment, São Carlos University, Araras, São Paulo State, Brazil
Center of Agrarian Sciences, São Carlos University, Araras, São Paulo State, Brazil
Federal University of Grande Dourados, Dourados, MS, Brazil 


Abstract
Anredera cordifolia (Ten.) Stennis, commonly known as the madeira vine, is a succulent vine that produces vegetative structures on stems and invades agricultural areas in Brazil. This plant has become a possible invader in Brazilian agriculture with records of losses in coffee crops. The objective of this study was to study the influence of dimensional variation and different depths of planting aerial bulbils on the growth and development of A. cordifolia plants, as well as to study the influence of the effect of herbicides on postemergence control. All experiments were carried out in a greenhouse. In the propagation experiment, a completely randomized design with six replications was used. Aerial tubers of four weight categories (C) (C1, 0–0.59 g; C2, 0.60–1.49 g; C3, 1.50–2.99 g; C4, 3.0–12.0 g) were evaluated regarding the percentage of viable tubers, number of stems per tuber (ST), average stem length, shoot dry matter, and emergence speed index (ESI). ST and ESI were evaluated at seven soil depths (0, 3, 6, 10, 15, 20, and 30 cm). For experiments with herbicides, a completely randomized design with four replications was used. Six herbicides (chlorimuron-ethyl, flumioxazin, glyphosate, metsulfuron-methyl, saflufenacil, and glyphosate + saflufenacil) at the recommended doses and a control (without herbicide) were used to evaluate the postemergence control. Plants from larger tubers had a higher sprouting rate and faster growth and establishment, and tubers grown on the soil surface produced plants with faster development. Glyphosate + saflufenacil was more effective in controlling this plant species, with 79.50% control. All other herbicide treatments caused only chlorosis and poor control.

Pages 1192-1197 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3320
.................................................................................................................................................................................................................................

Natural resistance of two mango Mangifera indica L. commercial cultivars to anthracnose caused by Colletotrichum gloeosporioides Penz. Penz. & Sacc

A. Sánchez-Arizpe, Ma. E. Galindo-Cepeda, J. L. Arispe-Vázquez*, R. Genis-Velázquez, M. E. Vázquez-Badillo, A. Antonio-Bautista

Departamento de Parasitología, Universidad Autónoma Agraria Antonio Narro, Calzada Antonio Narro #1923, C.P. 25315, Buenavista, Saltillo, Coahuila, México
Departamento de Fitomejoramiento, Universidad Autónoma Agraria Antonio Narro, Calzada Antonio Narro #1923, C.P. 25315, Buenavista, Saltillo, Coahuila, México


Abstract
Mexico ranks first worldwide as the largest mango exporter and Mango is one of the more produced tropical fruits worldwide. The need for strategies for the protection of crops, environment and people leads us to investigate disease control methods. The use of resistant cultivars is the most important. In addition, it is advantageous for the producer because it will reduce the cost for disease control. The objective of this research was to evaluate the natural resistance of two mango cultivars against anthracnose, using different spore doses and times of evaluation. The sampling was performed on April 15th, 2018 at an open market placed south of Saltillo, Coahuila, Mexico. Pathogen was isolated from fruits of Tommy Atkins and Ataulfo mango cultivars showing advanced degrees of black spots collected out from at open markets in Saltillo, Coahuila, Mexico. The pathogen purification was done by monoconidial cultures and identification was done with morphocultural criteria. Spore suspension was prepared and inoculated on ripe mango fruits using different doses and disease severity was evaluated 6 and 10 days after inoculation using millimetric sheets. A complete random factorial design of three factors was used, where: factor A stands for mango cultivars (Tommy Atkins and Ataulfo), factor B is treatments and factor C stands for times of evaluation. The results are shown as percentage and data was analyzed with factorial analysis using the SAS® 9.1 software. C. gloeosporioides was identified in mango cultivars; with hyaline conidia of 16.90 to 25.12 µm length and 4.33 to 5.18 µm width. The results show cultivars resistant to anthracnose in the study area. Natural resistance against anthracnose was as 80.00 to 93.67 %, thus, mango cultivars showed a certain resistant degree.

Pages 1198-1203 | Full Text PDF| doi: 10.21475/ajcs.21.15.08.p3347
....................................................................................................................................................................................................................................

Taxonomic significances of seed morphology in some tribes of subfamily Malvoideae (Malvaceae) in Saudi Arabia

Kadry Abdel khalik*, Suad Al-Ruzayza, Ahmed Farid

Biology Department, Faculty of Applied Science, Umm-Al-Qura University, Makkah, Saudi Arabia
Botany and Microbiology Department, Faculty of Science, Sohag University, Sohag, Egypt
Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut, Egypt

Abstract
In this study, we evaluated the taxonomic significance and seed macro and micromorphological characteristics of 28 species belong to eight genera of subfamily Malvoideae (Malvaceae) from Saudi Arabia. The genotypes were studied using light and scanning electron microscope (SEM). Macro- and micromorphological characters of the seeds are presented, including shape, color, size, hairs, surface pattern, epidermal cell shape, anticlinal boundaries, and periclinal cell wall. The taxonomic and phylogenetic implications of seed coat micromorphology were compared with those of the available gross morphological and molecular data (ISSR and SCOT). Seed character analysis offered useful data for evaluating the taxonomy of Malvoideae on both intrageneric and tribal levels. Monophyly of the genera Abutilon, Malva and Pavonia was supported. Moreover, these analyses supported previous phylogenetic data, indicating that distinct lines are present within the genus Hibiscus and Sida, indicating that these genera are not monophyletic. A key is provided for identifying the investigated taxa based on seed characters.

Pages 1204-1216 | Full Text PDF| Supplementary Data PDF| doi: 10.21475/ajcs.21.15.08.p3360