Australian Journal of Crop Science   AJCS

Nicotiana protein kinase 1 (NPK1) in sugarcane: effects on plant development and productivity in Oxisol

Gisele Silva de Aquino*, Julia Tufino Silva Guerzoni, Eduardo Fermino Carlos

Department of Agronomy, State University of Maringá (UEM), Av. Colombo, 5790, ZIP 223, Maringá, PR, Brazil
Laboratory of Biotechnology, Paraná Rural Development Institute (Instituto de Desenvolvimento Rural do Paraná - IDR-IAPAR); Celso Garcia Cid Road, Km 375, ZIP 95700-00 Londrina, PR, Brazil

Abstract
Losses in sugarcane crops due to water deficiencies have been increasing in Brazil and worldwide. NPK1 (Nicotiana protein kinase1) is naturally found in tobacco plants and provides tolerance to cold, heat, and salt stress, with positive results in corn, tobacco, and Arabidopsis. This study aimed to evaluate the development and productivity of transgenic sugarcane with the insertion of the tobacco NPK1 gene. Sugarcane plants cv. RB855536 were genetically transformed with the insertion of the NPK1 gene by biolistic (transgenic event obtained by biolistic) and agrobacteria (transgenic event obtained by Agrobacterium infection). These transgenic sugarcane plants were evaluated in relation to the control (non-genetically transformed sugarcane plants). The growth and productivity of the plants were evaluated in a greenhouse, at four periods: 60, 120, 180, and 270 days after planting (DAP). The measurements recorded included the average number, length, and diameter of the stems, number of green leaves, leaf area, and leaf area index. The fresh stalk mass was evaluated at 270 DAP. The insertion of the gene NPK1 significantly contributed to sugarcane development. There was a significant difference improvement on tillering across all the evaluated periods. At the end of the cycle, plants transformed using the Agrobacterium maintained a higher number of tillers, with 68 % more tillers than the other plants (control and biolistic). The fresh stalk mass was 48 % higher in productivity (than the control and biolistic). Transgenic sugarcane did not show any delay or decrease in growth compared to the conventional non-transformed sugarcane. Therefore, the results suggest that the insertion of the NPK1 gene into sugarcane is a promising alternative for increasing crop productivity.

Pages 1-7 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3332
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Change in soil chemical attributes and yield of a common-bean crop in response to steel slag application

Alessandra Vieira da Silva*, Angélica Cristina Fernandes Deus, Mara Lúcia Cruz de Souza, Fernando Broetto, Leonardo Theodoro Büll

Departament of Soil and Environmental Resources, College of Agronomic Sciences, São Paulo State University, Botucatu, SP, Brazil
Rural Engineering Department, College of Agronomic Sciences, São Paulo State University, Botucatu, SP, Brazil

Abstract
Most agricultural soils in Brazil are classified as acid, which limits agricultural production in the country, warranting the application of acidity correctives. The present study examined the effect of steel slag application on chemical characteristics of the soil as well as on the metabolic responses and yield of common-bean plants in a no-till system. The experiment was laid out in a randomized-block design with 42-m2 subplots in a 7×2 factorial arrangement, with four replicates. Treatments consisted of two factors, namely, acidity correctives and application forms. The following correctives were tested: steel slag (T1), wollastonite (T2), ladle furnace slag (T3), stainless steel slag (T4), calcined agricultural limestone (T5), agricultural limestone (T6), and a control without correctives (C). The application forms were surface application and incorporation (20 cm). Ten months after the last reapplication of the acidity correctives, a soil probe sampler was used to collect samples from the 0–10 cm, 10–20 cm, and 20–40 cm layers for chemical analysis. The common-bean crop was established after 16 months of the applications, and the following parameters were evaluated 40 days after germination: plant height; leaf dry weight; relative water content; electrolyte losses; pigment content (Clo a, Clo b, and carotenoids); leaf macronutrient and micronutrient content; total soluble protein content; leaf silicon content; enzyme activities of superoxide dismutase, peroxidase, and catalase; and gas exchange. At the end of the crop cycle, grain production and yield components were evaluated. Phosphorus, pH, base saturation, and Si increased with the application of silicates, influencing the number of plants m-1 and 100-grain weight; however, grain yield did not change.

Pages 8-13 | Full Text PDF| Supplementary Data| 10.21475/ajcs.23.17.01.p3530
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Legal provision on the use of exotic species in forest restoration: eucalyptus leaf decomposition in different Brazilian savannah formations

Sarah C. Silva, Marco B. X. Valadão, Jonas Inkotte, Fabiana P. Ribeiro, Eder P. Miguel, Alcides Gatto

National Research Institute of the Amazon – INPA, AM, Brazil
Department of Forestry Engeneering, University of Brasília (UnB), DF, Brazil

Abstract
The Brazilian federal law has established norms for vegetation protection in 2012 for the planting of exotic species for the restoration of altered areas. Given the large number of areas to be recovered in the savannah biome in Brazil (e.g., Cerrado), the use of fast-growing species and high biomass production (e.g., Eucalyptus spp.) has been earnestly considered. However, the recommendation of this exotic species must be scientifically supported. This work aimed to evaluate the decomposition process of eucalyptus leaf litter in three different phytophysiognomies in the Cerrado biome (Brazilian Savannah) with three different formation type: Typical Cerrado, Savannah Forest, and Gallery Forest. The leaf decomposition was evaluated by the litter bags that were collected from October 2017 to October 2018. The difference between the initial mass and the masses was evaluated at the different collection periods. After one year, we determined the decomposition rate and the constant k using the exponential equation proposed by Olson. The decomposition rate of eucalyptus leaves was high in the three Cerrado formations. The shortest decomposition time was observed in Gallery Forest. The results showed that the main types of Cerrado formation effectively assimilate the organic material to be deposited in the soil. Thus, the study demonstrated the feasibility and legal provision of using exotic species, e.g., eucalyptus in the arduous mission of recovering degraded forest environments.

Pages 14-19 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3711
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Bivariate spatial correlation between soil attributes and soybean productivity in an agricultural area with Dystroferric Red Latosol

Letícia Ellen Dal’ Canton*, Tamara Cantú Maltauro, Luciana Pagliosa Carvalho Guedes, Miguel Angel Uribe-Opazo, Elizabeth Giron Cima

Western Paraná State University (UNIOESTE), Cascavel, Paraná, Brazil

Abstract
In agricultural soils with low cation exchange capacity, it is essential to analyze the bivariate spatial correlation of soybean productivity and organic matter with the soil chemical attributes. Using bivariate spatial correlation makes it possible to identify patterns and behaviors that suggest a spatial association between two soil attributes, thus enabling better soil management and more efficient use of resources. The main objective of this study was to analyze bivariate spatial correlation considering variables with different spatial dependence structures. The bivariate Lee index was also calculated for this purpose. To model and describe the spatial pattern of two spatially correlated variables, the Bivariate Gaussian Common Component Model was used. In addition to calculating the bivariate spatial correlation of soil chemical attributes with soybean productivity and organic matter, the Lee index was also calculated for pairs of simulated variables with different weight matrices and geographic distance functions. It was observed that the greater the common practical range, the higher the Lee index value, indicating a higher bivariate spatial correlation. Furthermore, shorter distances between neighboring point pairs caused higher Lee index values. The distance function to calculate the distance between the point pairs was more relevant than the weight matrix in estimating the spatial dependence radius and the Lee index value. Soybean productivity showed a direct spatial correlation with the sum of bases, as well as with the calcium and magnesium contents. Organic matter had a direct spatial correlation with the sum of bases and an inverse one with the phosphorus content.

Pages 20-27 | Full Text PDF| Supplementary Data| doi: 10.21475/ajcs.23.17.01.p3714
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Physiological quality of oat seeds produced by plants treated with mesotrione or tembotrione

Gesieli Priscila Buba, Clovis Arruda Souza*, Camila Cigel, Franciele Fátima Fernandes, Cileide Maria Medeiros Coelho

Universidade do Estado de Santa Catarina, Lages - SC, Brazil

Abstract
Selective herbicides may cause plant stresses as a result of changes in plant physiology or seed formation and development processes, thus affecting the quality of seeds. Thus, the aim of this study was to assess the effect of application of increasing doses of mesotrione or tembotrione on the physiological quality of white oat seeds from different cultivars. It is a field experiment carried out in two crop years (2019 and 2020), in a split split-plot randomized block design. The main plots consisted of the cultivars: FAEM 007, IPR Afrodite, UPFA Fuerza and URS Monarca. The subplots were mesotrione and tembotrione; and sub-subplots were doses of each herbicide: 0x;1/4x; 1/2x, 1x and 2 x (x= recommended commercial doses for maize, equivalent to 168.0 g a.i. ha-1 for mesotrione and 88.2 g a.i. ha-1 for tembotrione). Seed germination was 1% lower after application of the 2x dose of the herbicides, compared with control, i.e., there was a slight reduction in the germination of seeds produced in 2019. There was a significant effect of cultivar on germination and vigor. The cultivar UPFA Fuerza showed better performance than the other cultivars, with 96% germination index (GI) and 94% accelerated aging (AA) in 2019, while the best performance in 2020 was achieved by URS Monarca, with 98% GI and 97% AA. It was concluded that the oat seeds had high physiological quality in all treatments tested. The germination and vigor of oat seeds depended on the genotype being used, especially UPFA Fuerza (2019) and URS Monarca (2020), but they were not affected by the herbicides and doses tested.

Pages 28-36 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3719
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Efficacy of growth regulators in a lodging-sensitive wheat cultivar: grain yield, crop economic profitability and flour industrial quality

Camila Cigel, Clovis Arruda Souza*, Gesieli Priscila Buba, Guilherme Kender Drösemeyer, Lucas Grillo Oliveira

Universidade do Estado de Santa Catarina, Lages - SC, Brazil

Abstract
Growth regulators in annual crops such as wheat are being used for reducing plant lodging. Thus, this study aimed to assess the effects of applying different growth regulators on grain yield, industrial quality of flour, and the economic viability of a lodging-sensitive wheat cultivar, namely TBIO-Pioneiro. The RDB experimental design consisted of five treatments and nine replicates. The treatments used the following regulators: trinexapac-ethyl (T1), ethephon (T2), prohexadione calcium (T3), chlormequat chloride (T4) and a control (untreated) (T5). The rates were determined according to the manufacturer’s recommendations for other crops. Plant height was reduced with application of regulators, for example, trinexapac (93.1 cm), and control (100.7 cm). This same growth regulator tested increased TGW (36.2 g) over the control (33.6 g) making plant lodging lowest (from 34%-control to about 10%-treated). Grain yields with application of growth regulators were higher than control (3.1 t ha-1), ranging from 148.9 to 158.9% (means regulator-treated of 4.8 t ha-1). Regarding grain alveograph indices, there was an increase in gluten strength (W) with the use of ethephon (309 10-4J), prohexadione (309.3 10-4J), and chlormequat (309 10-4J), compared with control (240.3 10-4J). The economic return on investment was higher than the control, of up to 35.7%. It is concluded that application of prohexadione, ethephon and chlormequat changes the gluten strength of wheat grains and that the growth regulators tested are efficient in controlling lodging, reducing plant height and increasing grain yields, thus providing productive stability and higher financial returns in wheat cropping.

Pages 37-43 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3723
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Orbital remote sensing to estimate evapotranspiration in a cotton cropping system irrigated by a centre pivot

Wendel Kaian Mendonça Oliveira*, Marcio Furlan Maggi, Luan Peroni Venancio, Claudio Leones Bazzi, Lúcia Helena Pereira Nóbrega, Erivelto Mercante

Universidade Estadual do Oeste do Paraná, Programa de Pós-Graduação em Engenharia Agrícola, Rua Universitária, 2069, JD. Universitário - Prédio de Desenvolvimento de Protótipos, CEP 85819-110, Cascavel, Paraná, Brazil
Universidade Federal de Viçosa, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, CEP 36570-900, Viçosa, Minas Gerais, Brazil
Universidade Tecnológica Federal do Paraná, Departamento de Ciência da Computação, Avenida Brasil, 4232, CEP 85884-000, Medianeira, Paraná, Brazil

Abstract
Evapotranspiration (ET) estimation is essential for adequate management of water resources. The main ways to quantify ET are based on the use of field sensors, class A tanks, Bowen's ratio method, turbulent vortex correlation analysis, use of lysimeters, and through Remote Sensing (RS), which allows estimating biophysical parameters based on satellite images. The objective of the research was to determine the effective evapotranspiration (ETe) of cotton plantations irrigated with a centre pivot, using the Surface Energy Balance Algorithm for Land (SEBAL), Mapping Evapotranspiration at High Resolution and with Internalized Calibration (METRIC) and Simple Algorithm for Evapotranspiration Retrieving (SAFER) methods. Comparisons were made for three agricultural years, using the R², RMSE, MAE, MBE and R statistics. The best performances in the crops were obtained with the SEBAL vs. SAFER models, which presented mean values of 0.54, -0.30 and 0.31 mm d-1 in RMSE, MBE and MAE, respectively. The data obtained by all three models can be applied to estimate ETe in irrigated cotton plantations and, consequently, their results can assist in irrigation management and in crop treatments.

Pages 44-51 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3727
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Basic economics on deficit irrigation and water quality dynamics for horticulture production in a greenhouse environment

Jeet Bahadur Chand, Guna Hewa, Ali Hassanli, Baden Myers

Prime Minister Agriculture Modernization Project, Government of Nepal, Singhdarbar, Kathmandu, Nepal
Senior Lecturer, UniSA STEM, Mawson Lakes Campus, University of South Australia, Mawson Lakes, 5095, Australia
Adjunct Professor, UniSA STEM, Mawson Lakes Campus, University of South Australia, Mawson Lakes, 5095, Australia
Research Fellow, UniSA STEM, Mawson Lakes Campus, University of South Australia, Mawson Lakes, 5095, Australia

Abstract
The objective of this paper is to examine the impact of varying deficit irrigation level and water quality scenarios on economic responses of tomatoes (Solanum lycopersicum cv. Izmir) produced in a greenhouse environment. Groundwater, recycled wastewater and a blend of both were selected as water qualities. Four irrigation scenarios were maintained including soil moisture at 60%, 70%, 80% and 100% of field capacity. The treatment maintaining soil moisture at 100% field capacity was control in this study for each water quality. The selected irrigation method and the soil texture were the drip and loamy sand respectively. The effects of deficit irrigation and water quality on the benefit-cost ratio, revenue generated per m3 of water usage, cost function and net financial return were examined. Benefit-cost ratio was a maximum of 1.37 for the control treatment of recycled wastewater. All the selected deficit irrigation treatments produced the benefit-cost ratio more than one except 60% field capacity level. Revenue generation per m3 of water usage was found the highest in treatments maintaining soil moisture content at 80% field capacity despite of water quality. Based on the benefit-cost ratio, cost function and revenue generated per cubic meter of water use, this study recommended the deficit irrigation level at 80% field capacity as the most cost-effective and water efficient strategy for greenhouse grown tomatoes.

Pages 52-60 | Full Text PDF| Supplementary Data| doi: 10.21475/ajcs.23.17.01.p3755
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Sustainable agricultural practices to improve soil quality and productivity of soybean and upland rice

Mariana Aguiar Silva*, Adriano Stephan Nascente, Marta Cristina Corsi de Filippi, Laylla Luanna de Mello Frasca, Cássia Cristina Rezende

Universidade Federal de Goiás, Brazil
Embrapa Arroz e Feijão, Brazil

Abstract
Combining cover crops with multifunctional microorganisms provides significant increments in the grain productivity of soybean and upland rice crops. However, there are still few studies that aimed to evaluate the effect of this combination on the productivity of agricultural systems. The objective of this study was to determine the effect of the mix of cover crops and the co-inoculation of multifunctional rhizobacteria on the quality of the soil, yield components, and on the grain yield of soybean and upland rice. The experimental design was in random blocks with 24 treatments in a 6x2x2 factorial scheme. Treatments were the combination of 6 (5 mix of cover crops (mixture of seeds of different cover crops species) and the control (fallow), 2 (upland rice and soybeans), 2 (co-inoculated (inoculation with two microorganisms) or not (no microorganisms), with four replications. Combination of cover crops provided an increase in Ca and Mn levels in the soil, increased activity of soil quality indicator enzymes (phosphatase and arylsulfatase), higher soybean yield, and higher number of upland rice panicles. The co-inoculation with multifunctional rhizobacteria led to an increase in phosphorus levels in the soil, the number of pods per plant, the mass of 100 grains for soybean cultivation, the number of grains per panicle, and productivity of upland rice. Therefore, a mix of cover crops, combined with the co-inoculation with multifunctional rhizobacteria are sustainable agricultural practices that can contribute to the improvement of soil quality and the increase of the productivity of soybean and upland rice crops.

Pages 61-68 | Full Text PDF| Supplementary Data| doi: 10.21475/ajcs.23.17.01.p3761
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Yield and physiological quality of corn seeds after application of detasseling techniques in two cropping seasons

Márcio Antonio Nicoletti, Thiago Alberto Ortiz*, Lúcia Sadayo Assari Takahashi

Sementes BALU – Rua Águia, 167 – 86707-190 – Arapongas (PR), Brazil
Universidade Estadual de Londrina – Departamento de Agronomia, 6001 – 86051-990 – Londrina (PR), Brazil 3Universidade Estadual de Londrina – Departamento de Agronomia 6001 – 86051-990 – Londrina (PR), Brazil

Abstract
Detasseling is an essential practice in maize seed production to obtain hybrids. Due the difficulty in carrying out the detasseling in a standardized way, the objective of this study was to evaluate the yield and physiological quality of maize seeds after using detasseling techniques in two cropping seasons. The experiment was carried out in Pitangueiras - PR, using corn progenitors of the commercial hybrid Balu 761. The experimental design was randomized blocks with 4 replications. The factorial scheme was 6 × 2, with 6 detasseling techniques: removal of the tassel only (D0); tassel removal + 1 sheet (D1); tassel removal + 2 leaves (D2); tassel removal + 3 leaves (D3); tassel removal + 4 leaves (D4); and tassel removal + 5 leaves (D5), and 2 cropping seasons: cropping season 1 (2014) and cropping season 2 (2015). The variables analyzed were: seed yield (kg ha-1), germination (%) and seed vigor from the accelerated aging (%) and cold test (%). The results showed that detasseling of maize progenitors of the Balu 761 hybrid must be carried out with the removal of the tassel only, considering that the removal of leaves during this practice is capable of reducing seed yield by up to 25%. The removal of the tassel with up to five leaves does not affect the physiological quality of the maize seeds. The cropping season influenced the seed yield, as well as seed germination and vigor from the cold test.

Pages 69-73 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3788
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Cotton, bean, and soybean yield and nutrient redistribution in leaf sap in response to organic molecules complexed fertilizers

Adriano S. Nascente*, Tarcísio Cobucci, Viviane Brasil, Roberto dos A. Reis Jr

Brazilian Agricultural Research Corporation (EMBRAPA), Embrapa Arroz e Feijão, PO Box 179, Zipcode 75375-000, Santo Antônio de Goiás, State of Goiás, Brazil
Integração Agrícola Ltda, Rua Amorinópolis Quadra Q2, Zipcode 74884-540, Lote 3, Goiânia, State of Goiás, Brazil
Graduation Student, Instituto Federal do Mato Grosso (IFMT), Campo Novo dos Parecis, State of Mato Grosso, Brazil
Harvest Agro, Londrina, State of Paraná, Brazil

Abstract
The self-shading of plants is usually caused by the advance of their growth and development. This reduces transpiration and, consequently, nutrients uptake via xylem in lower half of plants, resulting in yield losses. Strategies should be developed to promote greater nutrient input in these regions with low-plant transpiration. The objective of this work was to study the effect of foliar application of boron (B), copper (Cu), manganese (Mn), and zinc (Zn) complexed with organic molecules on the translocation of these micronutrients to the plant’s lower half (region of low transpiration) and its relationship with soybean, common bean, and cotton yield. Two field trials were carried out on soybean, common bean, and cotton crops. The first trial evaluated foliar B, Cu, Mn, and Zn sap content in the plant's upper and lower halves along with its development. While the second trial evaluated foliar B, Cu, Mn, and Zn sap content in the plant's upper and lower-halves and crop yield in response to micronutrients complexed with organic molecules (Xiflon Technology). The results show that in lower-half plant’s sap the B, Cu, Mn, and Zn contents were reduced with development of soybean, common bean, and cotton crops. Organic molecular complex application (Xiflon Technology) increased the micronutrient translocation in the lower-half of soybean, common bean, and cotton crops and their yields. Application of micronutrients along with organic molecules is a strategic tool to improve the plant's lower-half nutrition and promote crop yield. It may be used by the farmers to increase the crop’s grain yield.

Pages 74-82 | Full Text PDF| Supplementary Data| doi: 10.21475/ajcs.23.17.01.p3790
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In vitro callus and shoot initiation of Black cohosh (Actaea racemosa L.) pre-incubated in darkness treatments

Julia Robinson, Guochen Yang*, Zhongge (Cindy) Lu

North Carolina A&T State University, United States

Abstract
A medicinal plant that is commonly overharvested in its native habitat, Black cohosh (Actaea racemosa L.) rhizomes are used to mitigate symptoms of menopause and are a common alternative to hormone replacement therapy. Developing an accurate protocol for initiation of Black cohosh in tissue culture is becoming a necessity. Wild harvesting practices are the main source of Black cohosh rhizomes processed by pharmaceutical companies and are causing a significant decrease of these wild plants, leading to an At-Risk status. Growing these plants in a plant tissue culture laboratory is more sustainable than current practices, and having an accurate protocol for initiation of these plants is crucial to this. Our lab has previously developed a protocol for initiation of Black cohosh and this research was meant to optimize this protocol. Leaf explants of Black cohosh were cultured in vitro to determine the optimal duration of time for initiation of callus and/or shoot under darkness, and appropriate plant growth regulators (PGR) for shoot growth. Leaf explants incubated under darkness for increasing amount of time (0 to 6 weeks of darkness) were analyzed at two stages of tissue development. Stage 1 involved initiation of leaf explant material under darkness (treatment) and measured the callus development in leaf explants; Stage 2 was induction of adventitious shoot growth and cell division and compared the effect of two PGRs, KT and BA, on shoot growth for each darkness treatment. Leaf explants were given a score using a culture chart that assigns a numerical score to leaf explants based on their physiological characteristics. These numerical scores took into account color of leaf explant, callus development, shoot growth, and presence of dead leaf tissue. Stage 2 measured the number of shoots produced per explant within culture containers between PGRs and the number of weeks in darkness. Overall trends indicated that mortality of leaf explants decreased as the duration of incubation under darkness increased with mortality of explants decreasing from 63.9% (T0 darkness treatment) to 2.8% (T6 darkness treatment). Culture scores of explants (including dead explants) was highest for T6 weeks of darkness (culture score 2.96 on average), and for culture scores without dead explants (culture score of 3.05). During the adventitious shoot growth stage, however, T5 weeks of darkness performed significantly higher (KT: 28 shoots/ BA: 17.3 shoots) than T6 weeks of darkness (KT: 12.9 shoots/ BA: 9.4) in Replication 2 for both plant growth regulators KT PGR performed better, on average, than BA PGR.

Pages 83-89 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3808
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Natural ventilation and sucrose concentrations in the in vitro culture system affect the acclimatization of "Pérola" pineapple plants under different substrates

Hidelbrando Pimenta Pires, Sérgio Heitor Sousa Felipe, Marcos Vinícius Marques Pinheiro, Juliana de Paula Alves, Givago Lopes Alves, Paulo Henrique Aragão Catunda, Fábio Afonso Mazzei Moura de Assis Figueiredo, Fabrício de Oliveira Reis, Tiago Massi Ferraz, Thais Roseli Corrêa*

Universidade Estadual do Maranhão, São Luís, MA, Brazil
Programa de Pós-Graduação em Agroecologia, Universidade Estadual do Maranhão, São Luís, MA, Brazil
Programa de Pós-Graduação em Agricultura e Ambiente, Universidade Estadual do Maranhão, São Luís, MA, Brazil

Abstract
Plant tissue cultures represent a powerful set of tools that can be used in the production of pineapple seedlings. However, few studies have assessed the morphophysiological performance during the ex vitro acclimatization stage. Here, we evaluated the effect of different in vitro cultivation systems with sucrose reduction and types of flask sealing (without or with natural ventilation), as well as contrasting substrates on the growth and development of pineapple plants (Ananas comosus cv. Pérola) during ex vitro acclimatization. A randomized design in a 3 × 2 factorial was used with three in vitro cultivation systems [photomixotrophic (PM) + 30 g L-1 sucrose; photomixotrophic with natural ventilation (PNV) + 10 g L-1 sucrose; and PNV + 30 g L-1 sucrose)] and two ex vitro substrates (non-commercial and commercial). Our results showed that the commercial ex vitro substrate increased the height, stem diameter, and dry mass of aerial parts of plants by 25%, 14%, and 40%, respectively. Plants in PNV + 10 g L-1 sucrose and PNV + 30 g L-1 sucrose culture systems displayed reductions of 31% and 44% in respiratory rate, respectively. Notably, plants in a PNV + 10 g L-1 sucrose culture system displayed significant reductions of 36% and 41% for stomatal conductance to water vapor and transpiration rate, respectively. Thus, "Pérola" pineapple plants grown in a PNV + 10 g L-1 sucrose culture system using a commercial substrate exhibited improved gas exchange, with greater plant growth and development during acclimatization.

Pages 90-98 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3812
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Effect of grafting and number of stems on plant growth, yield and fruit quality of soilless tomatoes

Lais Perin*, Roberta Marins Nogueira Peil, Chaiane Signorini, Paulo Roberto Grolli, Eduardo Anibele Streck, Douglas Schulz Bergmann da Rosa, Cristiane Neutzling, Gabriel Nachtigall Marques, Albertina Radtke Wieth

Universidade Federal de Pelotas, Capão do Leão, RS, Brazil
Instituto Federal de Educação, Ciência e Tecnologia Farroupilha, São Vicente do Sul, RS, Brazil
Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Vacaria, RS, Brazil
Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil

Abstract
Vegetable grafting has grown considerably and has been a management alternative to overcome adverse soil cultivation conditions. However, many growers have used grafted tomato plants in substrate cultivation, claiming greater plant vigor, fruit yield, and longevity. Thus, the work objective is to evaluate the effect of grafting and the number of stems on plant growth, fruit yield, and quality of the Italian tomato, cultivated in a system of troughs filled with raw rice husk substrate. The experiments were conducted in southern Brazil, in the 2017/18 (long cycle) and 2019/20 (short cycle) crop seasons. The cleft grafting was used. The analyzed variables were the number of leaves, leaf area index, vegetative and fruit dry matter production, plant total dry matter, number of fruits, fruit yield, mean fruit weight, and total soluble solids content (ºBrix). The grafted plants had higher LAI, fruit dry matter production, fruit number, and yield (17 and 19%, respectively, in the first and second crop seasons). The quality of the fruits, concerning the concentration of sugars, was not affected by grafting, and the mean fruit size was increased by 7.9 and 8.1 grams (long and short cycle, respectively). In a long cycle, both for grafted and non-grafted plants, single-stem plant cultivation promotes 13.54% more plant growth and is 4.86% more fruit yield than double-stem plants. In a short cycle, from the point of view of reproductive growth and fruit yield, for both types of plants, cultivation with two stems is like that of single-stem plants.

Pages 99-106 | Full Text PDF| doi: 10.21475/ajcs.23.17.01.p3813