Artigos - Produção Vegetal - FCAV

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Diagrammatic scale for evaluation of Bremia lactucae sporulation in lettuce seedlings
(2023-01-01) Jacinto, Ana Carolina Pires; Castoldi, Renata; Braz, Leila Trevisan [UNESP]; Universidade Federal de Uberlândia (UFU); Universidade Estadual Paulista (UNESP)
In disease assessment, the use of diagrammatic scales provides a standard reference point for comparison. There is still no precise and accurate scale for the evaluation of sporulation intensity of downy mildew in lettuce seedlings. The objective of this study was to propose a diagrammatic scale for the evaluation of downy mildew severity in lettuce seedlings. Thirty lettuce seedlings with different sporulation intensities were used to develop the proposed diagrammatic scale. Solaris lettuce cultivar was sown, and fifteen days after sowing, inoculations occurred using distilled water, the pathogen sporangia, and Tween 20. The monitoring of disease development was performed daily.When the first sporulation appeared on the cotyledonaryleaves,the proposed scale was verified to meet the minimum and maximum levels of disease severity. Two evaluators verified the accuracy, precision and performed the estimation of the sporulation and reproducibility using a scale. The images obtained are important in the standardization of a scale to identify resistant, tolerant and susceptible plants to downy mildew. Furthermore, it allows validating a diagrammatic scale of sporulation intensity of B. lactucae in lettuce seedlings. Thus, it is the diagrammatic scale developed in the work will guide future research to accelerate the detection of mildew severity in lettuce seedlings
Biometric aspects of fruits and diaspores from Mauritia flexuosa from the brazilian Cerrado
(2023-03-28) Campos, Thiago Souza [UNESP]; de Souza, Antonio Maricélio Borges [UNESP]; Vieira, Guilherme Rodrigues [UNESP]; Pivetta, Kathia Fernandes Lopes [UNESP]; Universidade Estadual Paulista (UNESP)
The buriti palm (Mauritia flexuosa L. f.) serves as a raw material for the food, pharmaceutical and biotechnological industries but it has a low germination rate and seed viability, which are directly related to the morphological characteristics of the fruits and seeds. Biometric characterization provides information necessary for the differentiation, characterization of ecological and genetic aspects of different species and populations of the same group, and can help in the conservation and propagation of species. The current work performed the biometric characterization of fruits and diaspores of Mauritia flexuosa from a cultivation environment in the Brazilian Cerrado. 100 fruits were randomly sampled, which were measured in length, width, thickness, individual weight, diaspore length, diaspore width, diaspore thickness and individual diaspore weight. Fruits were classified as red (Hue 10 R 4/8) and yellow-orange diaspores (Hue 7.5 YR 8/8). Data for each characteristic were submitted to descriptive statistical analysis. The fruits varied by 6.56% in length, 4.38% in width and 4.26% in thickness while the diaspores varied by 8.17% in length, 9.29% in width and 9.62% in thickness. The variables fruit weight and diaspore weight showed the greatest variations, 12.12% and 23.86%, respectively. There was a positive correlation between width and thickness (0.90). The small variation in biometric dimensions indicates that the species has little variability.
Fertilizer source and application method influence sugarcane production and nutritional status
(2023-01-01) Castro, Sérgio Gustavo Quassi de; Coelho, Anderson Prates [UNESP]; Castro, Saulo Augusto Quassi de; Souza Chiachia, Thais Regina de; Castro, Rosilaine Araldi de; Lemos, Leandro Borges [UNESP]; AgroQuatro-S Experimentation and Applied Agronomic Consultancy; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP); Yara Brazil Fertilizers S/A
Introduction: The contrasting weather conditions throughout the sugarcane harvest period in south-central Brazil (April to November) influence fertilization management in sugarcane ratoon. Methods: Through field studies carried out over two cropping seasons, we aimed to compare the performance of sugarcane at sites harvested in the early and late periods of the harvest season as a function of fertilizer sources associated with application methods. The design used in each site was a randomized block in a 2 x 3 factorial scheme; the first factor consisted of fertilizer sources (solid and liquid), and the second factor consisted of application methods (above the straw, under the straw, and incorporated into the middle of the sugarcane row). Results: The fertilizer source and application method interacted at the site harvested in the early period of the sugarcane harvest season. Overall, the highest sugarcane stalk and sugar yields at this site were obtained with the incorporated application applying liquid fertilizer and under straw applying solid fertilizer, with increments of up to 33%. For the site harvested in the late period of the sugarcane harvest season, the liquid fertilizer promoted a 25% higher sugarcane stalk yield compared to the solid fertilizer in the crop season with low rainfall in the spring, while in the crop season with normal rainfall, there were no differences between treatments. Discussion: This demonstrates the importance of defining fertilization management in sugarcane as a function of harvest time, thereby promoting greater sustainability in the production system.
Sowing time and substrate in the production of ipê-mirim seedlings
(2022-01-01) Ferraz, Marcos Vieira [UNESP]; de Souza, Antonio Maricélio Borges [UNESP]; Costa, Carla Rafaele Xavier [UNESP]; Muniz, Ana Carolina Corrêa [UNESP]; de Andrade Loureiro, Eduardo Akira Suzuki [UNESP]; Pivetta, Kathia Fernandes Lopes [UNESP]; Universidade Estadual Paulista (UNESP)
Tecoma stans is popularly known as ipê-mirim in Brazil. This species belongs to the Bignoniaceae family and it is native to Americas and Antilles, where it is widely used in landscaping as urban tree. The seedlings are produced from seeds and there are several factors that influences its development, such as the sowing time and the substrate. This work aimed to understand the effect of the sowing time and substrates on the production of Tecoma stans seedlings. The experiments were carried out in a nursery. The experimental design was completely randomized. The substrates were arranged in a 2 × 6 factorial scheme, two sowing times (autumn and spring) and six commercial substrates (SC1; SC2; SC3; SC4; sand and vermiculite) under four replicates and ten seedlings per plot. The means were compared to each other using the Tukey test (p < 0.05). There was a significant difference between the seasons of the year, showing that the percentage of emergence was higher in spring (89%). The seedlings of Tecoma stans were shown to be nutrient-dependent both in the emergence of the seedling and in the subsequent development of the seedlings, since the highest averages of the studied characteristics were obtained in the commercial substrates, as they have nutrients in their composition, with greater emphasis on SC1
Biofortified Rocket (Eruca sativa) with Selenium by Using the Nutrient Film Technique
(2022-11-01) Nascimento, Carolina Seno [UNESP]; Nascimento, Camila Seno [UNESP]; Lopes, Guilherme; Carrasco, Gilda; Gratão, Priscila Lupino [UNESP]; Cecílio Filho, Arthur Bernardes [UNESP]; Universidade Estadual Paulista (UNESP); Federal University of Lavras; University of Talca
Selenium (Se) is an essential micronutrient for humans, but most foods are Se deficient, mainly because of its low content in the soil. A Se-deficient diet results in increased susceptibility to cardiovascular disease, cancer, and hyperthyroidism. Agronomic biofortification is a good alternative to increase Se in food. This study investigated the effect of Se on the growth, yield, and biofortification of the rocket. Plants were grown in a hydroponic system. Seven Se concentrations (0, 10, 20, 30, 40, 50, and 60 µM) were evaluated using sodium selenate. Growth, yield, lipid peroxidation, hydrogen peroxide content, and the enzymatic activity of catalase and ascorbate peroxidase were influenced by the Se concentration. Considering the evaluated parameters, 10–30 µM Se promoted the best results, and with 20 µM, the higher yield. Rocket plants treated with Se in the nutrient solution were biofortified, showing Se contents of 598.96 to 1437.56 mg kg−1 in the dry mass, higher than plants cultivated in a nutrient solution without Se, which presented 167.84 mg kg−1 of Se. Se concentrations of 10–30 µM in the nutrient solution were beneficial for rocket plants, while concentrations above 50 µM were toxic to the plants.
Identifying crisphead lettuce genotypes for a wider range of environments
(2022-01-01) Tobar-Tosse, Dora Enith [UNESP]; dos Santos Candido, Willame [UNESP]; da Silva Santos, Lucas [UNESP]; Castoldi, Renata [UNESP]; Silva, Edgar Henrique Costa [UNESP]; Braz, Leila Trevisan [UNESP]; Universidade Estadual Paulista (UNESP)
This work aims to select crisphead lettuce (Lactuca sativa L) genotypes superior in production, stability, and adaptability using a mixed model method: restricted maximum likelihood/best linear unbiased prediction. Ten genotypes were grown in different municipalities of the State of São Paulo, Brazil, and seasons of the year, resulting in twelve different environments. The experiment has a randomized complete block design with four repetitions. Genotypes comprise eight breeding lines and two commercial cultivars, Vanda and Vera. The evaluated traits include total production in g/plant, commercial production in g/plant, and numbers of leaves/plant. Analysis of joint deviance indicated that the genotypes responded differently to the environments evaluated. The crisphead lettuce breeding lines that were most productive, stable, and adapted to the twelve lettuce-growing environments, even outperforming the commercial Vanda and Vera cultivars, were lines L8, L2, and L6.
RESPONSE OF EARLY-CYCLE COMMON BEAN CULTIVARS WITH CARIOCA, BLACK AND SPECKLED GRAINS TO TOP-DRESSING NITROGEN FERTILIZATION
(2023-01-20) DE OLIVEIRA, Neuza Helena Carvalho [UNESP]; Coelho, Anderson Prates [UNESP]; Meirelles, Flávia Constantino [UNESP]; Cazuza Neto, Ancelmo [UNESP]; Lemos, Leandro Borges [UNESP]; Universidade Estadual Paulista (UNESP)
The aim was to evaluate the agronomic and qualitative attributes of early-cycle common bean cultivars with different grains types grains in response to top-dressing nitrogen (N) doses. The experiment was carried out using a randomized block design, in a split-plot scheme, with 4 replicates. The plots consisted of the cultivars IAC Nuance, IAC 1849 Polaco and IAC Veloz, with speckled, Carioca and black grains, respectively. The subplots were formed by N doses applied as top-dressing: 0 kg ha-1, 60 kg ha-1 (applied in the stage of third trifoliate leaf), 120 kg ha-1 (1/2 applied at third trifoliate leaf stage + 1/2 applied at the floral bud stage) and 180 kg ha-1 (1/3 applied at the first trifoliate leaf stage + 1/3 applied at the third trifoliate leaf stage + 1/3 applied at the floral bud stage). IAC Veloz stood out for grain yield, showing the highest grain yield in the lowest N doses, being classified as efficient to the use of N. The cultivars IAC Nuance and IAC 1849 Polaco reached maximum yields with 155 and 163 kg ha-1 of N. The IAC Nuance was the most responsive, increasing grain yield by up to 25.3% due to nitrogen fertilization. Increasing N doses applied as top-dressing increased the sieve yield and crude protein content of the common bean cultivars, with IAC Nuance standing out. The cultivars showed good grain quality, and IAC 1849 Polaco and IAC Veloz had the shortest cooking time and IAC Veloz also had the fastest hydration.
Application of the CSM-CROPGRO-Dry bean model to optimize irrigation as a function of sowing date in common bean cultivars
(2023-03-15) Coelho, Anderson Prates [UNESP]; Faria, Rogério Teixeira de [UNESP]; Lemos, Leandro Borges [UNESP]; Cazuza Neto, Ancelmo [UNESP]; Universidade Estadual Paulista (UNESP)
Common bean is grown in tropical and subtropical regions under a wide range of pedoclimatic conditions and there is a large variation between the management practices, types of cultivars being used and the farmers' technological level. In this context, simulation models are feasible and promising alternatives for site specific management practices. This study aimed to use the CSM-CROPGRO-Dry bean model as a tool to optimize irrigation management as a function of sowing date and common bean cultivar. Two common bean cultivars IAC Imperador (determinate growth habit) and IPR Campos Gerais (indeterminate growth) were grown during two winter growing seasons in a field experiment conducted in south-eastern Brazil. The experiment included five irrigation treatments (54%, 70%, 77%, 100%, and 132% of crop evapotranspiration). After model parameterization, a long-term analysis was performed to simulate the effect of the five irrigation levels on the grain yield of common bean cultivars as a function of eight sowing dates. The results showed that irrigation may be managed under a regulated water deficit without significantly reducing common bean yields if sowing is brought forward (Mar/Apr) within the winter season. For no deficit irrigation, sowing dates in which common bean reproductive stages coincide with the period of lowest global solar radiation (GSR) should be avoided. This is because, for each unit increase in GSR after flowering, grain yields of the cultivars IAC and IPR increase by 55 and 50 kg ha−1, respectively. Therefore, the CSM-CROPGRO-Dry bean model is a powerful tool for defining more specific and sustainable irrigation management for common bean cultivars.
Nickel reduces blossom-end rot even under calcium deficiency conditions evidence from physiological responses of the NI - CA interaction
(2023-01-01) Macedo, Fernando Giovannetti; de Melo, Wanderley José [UNESP]; Cecílio Filho, Arthur Bernardes [UNESP]; Santos, Elcio Ferreira; Cruz, Renata Beatriz; Belloti, Mariana; Science and Technology of Mato Grosso do Sul; Universidade Estadual Paulista (UNESP); Brazil University; Universidade de São Paulo (USP)
The isolated study of calcium (Ca) as a cause of blossom-end rot (BER), has not demonstrated advances in the knowledge of this physiological disorder. Recent studies have shown that the Ni-Ca interaction can increase tomato yield and reduce the incidence of BER. Thus, this work aimed to evaluate the effect of nickel (Ni) and Ca interaction on the physiology of tomato plants focusing on nutrient balance, gas exchange and activity of urease and glyoxalase I and II enzymes. Tomato plants were grown in pots with substrate. A random design was used in a 2 x 4 factorial scheme. Two Ca doses (sufficient Ca - Ca S = 0.35; and deficient Ca - Ca D = 0.70 g kg−1) and four Ni doses (0.0, 0.5, 1.0 and 2.0 mg dm−3) was used. The activity of the glyoxalases I and II were used as an indicator of a stress condition. In plants grown under Ca S, the Ni application showed an increase in leaf content of nitrogen, phosphorus, Ca, iron, zinc, boron, copper and Ni, as well the gas exchange enhanced. The urease activity increased as a function of the Ni doses increase. Plants grown with Ca S and Ni doses of 0.5 and 1.0 mg dm−3 showed the lowest glyoxalase activities. The use of Ni at the mentioned doses should be considered in tomato fertilization programs focused on BER reduction.
Site-Specific Nutrient Diagnosis of Orange Groves
(2022-12-01) Yamane, Danilo Ricardo [UNESP]; Parent, Serge-Étienne; Natale, William; Cecílio Filho, Arthur Bernardes [UNESP]; Rozane, Danilo Eduardo [UNESP]; Nowaki, Rodrigo Hiyoshi Dalmazzo [UNESP]; Mattos Junior, Dirceu de; Parent, Léon Etienne; Universidade Estadual Paulista (UNESP); Université Laval; Federal University of Ceará; Centro de Citricultura Sylvio Moreira; Federal University of Santa Maria
Nutrient diagnosis of orange (Citrus sinensis) groves in Brazil relies on regional information from a limited number of studies transferred to other environments under the ceteris paribus assumption. Interpretation methods are based on crude nutrient compositions that are intrinsically biased by genetics X environment interactions. Our objective was to develop accurate and unbiased nutrient diagnosis of orange groves combining machine learning (ML) and compositional methods. Fruit yield and foliar nutrients were quantified in 551 rainfed 7–15-year-old orange groves of ‘Hamlin’, ‘Valência’, and ‘Pêra’ in the state of São Paulo, Brazil. The data set was further documented using soil classification, soil tests, and meteorological indices. Tissue compositions were log-ratio transformed to account for nutrient interactions. Ionomes differed among scions. Regression ML models showed evidence of overfitting. Binary ML classification models showed acceptable values of areas under the curve (>0.7). Regional standards delineating the multivariate elliptical hyperspace depended on the yield cutoff. A shapeless blob hyperspace was delineated using the k-nearest successful neighbors that showed comparable features and reported realistic yield goals. Regionally derived and site-specific reference compositions may lead to differential interpretation. Large-size and diversified data sets must be collected to inform ML models along the learning curve, tackle model overfitting, and evaluate the merit of blob-scale diagnosis.
Greenhouse gas emissions and carbon footprint of collard greens, spinach and chicory production systems in Southeast of Brazil
(2022-11-02) Pereira, Breno de Jesus [UNESP]; Cecílio Filho, Arthur Bernardes [UNESP]; La Scala, Newton [UNESP]; Figueiredo, Eduardo Barretto de; Universidade Estadual Paulista (UNESP); Universidade Federal de São Carlos (UFSCar)
Food production in sustainable agricultural systems is one of the main challenges of modern agriculture. Vegetable intercropping may be a strategy to mitigate greenhouse gas (GHG) emissions, replacing monoculture systems. The objective is to identify the main emissions sources and to estimate GHG emissions of intercropping and monoculture production of collard greens, New Zealand spinach and chicory. Four scenarios were evaluated: ICS – intercropping collard greens and spinach; MCS – monoculture collard greens and spinach; ICC – intercropping collard greens and chicory; MCC - monoculture collard greens and chicory. The boundaries’ reach from “cradle-to-gate” and the calculation of GHG emissions were performed using IPCC methodology and specific factors (Tier 2). The total GHG emitted was standardized as CO2 equivalent (CO2eq). The GHG emissions in ICS and ICC scenarios were approximately 31% lower than in MCS and MCC scenarios. Carbon footprint in ICS (0.030 kg CO2eq kg-1 vegetables year-1) and ICC (0.033 kg CO2eq kg-1 vegetables year-1) scenarios were also lower than in MCS (0.082 kg CO2eq kg-1 vegetables year-1) and MCC (0.071 kg CO2eq kg-1 vegetables year-1) scenarios. Fertilizers, fuel (diesel) and irrigation were the main contributing sources for total GHG emitted and carbon footprint in all evaluated scenarios. The results suggest that intercropping systems may reduce GHG emissions associated with the production of vegetables evaluated as compared with monoculture.
Phytonematode population dynamics in common bean cultivation under crop rotation and no-tillage conditions
(2022-01-01) Santos, Letícia Bernabé [UNESP]; D’Amico-Damião, Victor [UNESP]; de Souza, Vinícius Fernandes [UNESP]; Ferreira, Rivanildo [UNESP]; Lemos, Leandro Borges [UNESP]; Soares, Pedro Luiz Martins [UNESP]; Universidade Estadual Paulista (UNESP)
Strategies for conserving natural resources and reducing agricultural inputs are the great challenge for agriculture, such as sustainable alternatives to control agricultural pests of high economic impact, e.g. plant-parasitic nematodes. This work aimed to evaluate phytonematode’s population dynamics in common bean cultivation grown under crop rotations and no-tillage system. The maize was seeded under pearl millet straw and intercropped with three different crops systems: i) exclusive maize system, ii) maize intercropped with brachiaria and, iii) maize intercropped with crotalaria. The experimental design was a randomized complete block with three treatments (crops systems) and 4 blocks (5 subsamples each block). The common bean was seeded on the straw of exclusive or intercropped maize. The phytonematode population was evaluated in the soil and in the roots in seven moments: (i) fallow; (ii) pearl millet flowering; (iii) pearl millet maturity; (iv) maize flowering; (v) maize maturity; (vi) common bean flowering; and (vii) common bean maturity. The greatest control of the phytonematodes species described in the area was in the maize intercropped with crotalaria treatment, as the phytonematodes population decreased 2.49-fold in this treatment when compared to exclusive maize, resulting in an increase of 11.27% in common bean yield. Therefore, maize intercropped with crotalaria is a viable alternative to reduce phytonematodes infestation in common bean crop.
UAV Multispectral Data: A Reliable Approach for Managing Phosphate-Solubilizing Bacteria in Common Bean
(2022-10-01) de Souza, Antonia Erica Santos [UNESP]; Barbosa Júnior, Marcelo Rodrigues [UNESP]; de Almeida Moreira, Bruno Rafael [UNESP]; da Silva, Rouverson Pereira [UNESP]; Lemos, Leandro Borges [UNESP]; Universidade Estadual Paulista (UNESP)
Remote sensing can offer stakeholders opportunities to make precise and accurate decisions on agricultural activities. For instance, farmers can exploit aircraft systems to acquire survey-level, high-resolution imagery data for crop and soil management. Therefore, the objective of this study was to analyze whether an unmanned aerial vehicle (UAV) allows for the assessment and monitoring of biofertilization of the common bean upon vegetation indices (VIs). The biological treatment of the legume crop included its inoculation with phosphate-solubilizing bacteria (PSB), namely Bacillus subtilis and B. megaterium. Indicators of photosynthetic performance, such as chlorophylls (a and b) and carotenoids, were measured from actively growing leaves to determine effectiveness. In addition, images were acquired in the field, both spatially and temporally, to establish functional relationships between biometric and computational features. Microorganisms manifested as growth-promoting agents to the crop as they significantly increased its quantities of light-harvesting pigments. VIs allowed for predicting their impact on photosynthetic performance, making them on-site markers of PSB. Therefore, this research can provide insights into the remote, non-destructive mapping of spectral changes in the common bean upon the application of PSB. Imagery data from UAV would enable producers to generate information on the crop to intervene in the field at the right time and place for improved utilization of biofertilizers.
Biofortification and Quality of Collard Greens as a Function of Iron Concentration in Nutrient Solution
(2022-10-01) Mercês, Julia Karoline Rodrigues das [UNESP]; Medelo, Maria José Yañez [UNESP]; Cecílio Filho, Arthur Bernardes [UNESP]; Universidade Estadual Paulista (UNESP)
The agronomic biofortification of vegetables is a strategy for increasing the concentration of iron (Fe) in food and, consequently, the intake of this micronutrient by the population. When in deficiency, it can cause anemia—a pathology that affects millions of people. Soil-less cultivation is an important cropping system, but there are no studies on how Fe concentrations in a nutrient solution can promote biofortification and affect the quality of collard greens; this is the aim of the present study. For this purpose, five Fe concentrations (2, 4, 6, 8 and 10 mg L−1) were evaluated. Increasing the Fe concentration in the nutrient solution increased the leaf Fe content and decreased the leaf contents of cationic nutrients, without affecting yield. Photosynthetic pigment contents were positively affected by Fe concentrations, while ascorbic acid decreased. There was efficient biofortification of collard greens leaves from 4 mg L−1 Fe, and a higher nutritional quality of leaves was observed at Fe concentrations of 8 mg L−1.
SOWING DEPTH AND LIGHT INTENSITY IN THE EMERGENCE AND DEVELOPMENT OF MONOCOTYLEDONOUS WEEDS
(2022-02-16) Marques, Ricardo Fagundes [UNESP]; Souza, Guilherme Sasso Ferreira [UNESP]; Pereira, Maria Renata Rocha; Marchi, Sidnei Roberto; Martins, Cibele Chalita [UNESP]; Martins, Dagoberto [UNESP]; Universidade Estadual Paulista (UNESP); Technology College of the State of São Paulo-Capão Bonito; State University of Mato Grosso
This study aimed to evaluate the effects of different sowing depths and light intensities on the emergence and development of the monocot weed species, Urochloa decumbens and Cenchrus echinatus, under field conditions. Each species constituted an experiment, and the experimental design was completely randomized with four replicates. The treatments were arranged in a 6 x 4 factorial scheme, with six sowing depths (0.5, 1.0, 2.0, 4.0, 8.0, and 12.0 cm) associated with four solar radiation intensities (100%, 70%, 50%, and 30%) obtained through the use of shading screens. Seedling emergence capacity was evaluated daily to obtain the emergence percentage and speed index. Plant height, floral induction time, and plant dry matter at flowering were measured. Even when subjected to different solar radiation intensities, U. decumbens and C. echinatus seedlings emerged at all the sowing depths. Sowing between 2.0-and 4.0-cm depths favored the emergence of seedlings of U. decumbens and C. echinatus. However, sowing at 12-cm depth reduced the emergence of both species regardless of the solar radiation intensity. Urichloa decumbens plants grown under conditions of greater shading showed the lowest values of height and dry matter accumulation during flowering. High levels of shading facilitated only the etiolation of C. echinatus plants. Increased shading flowering time in both species compared to full sunlight.
Morpho-Agronomic Characterization, Sample Size, and Plot Size for the Evaluation of Capsicum chinense Genotypes
(2022-09-01) Alves, Silfran Rogério Marialva; Lopes, Ricardo; Meneses, Carlos; Valente, Magno Sávio Ferreira; Martins, Cibele Chalita [UNESP]; Ramos, Santiago Ferreyra; Oliveira, Izamara; de Jesus Pinto Fraxe, Therezinha; Costa, Lucifrancy; Lopes, Maria Teresa Gomes; Universidade Federal do Amazonas; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); Bairro Universitário; Instituto Federal do Amazonas; Universidade Estadual Paulista (UNESP)
The Amazon is a center of diversity for Capsicum chinense Jacq., with wide genetic and morphological variability, but little exploration has been performed there to facilitate their improvement. This study aimed to characterize and evaluate C. chinense genotypes for the development of cultivars by determining the optimal size of the experimental plot and the minimum sample size to ensure a precise estimation of yield. A total of 23 genotypes were evaluated, and in multivariate analyses, the plants were characterized by 21 morphological descriptors and eight quantitative traits related to biometry and yield. The recommended sample size for fruit evaluation was defined based on simulations with subsample resampling and evaluation of the semi-amplitudes of the confidence interval of the mean estimate. The optimal plot size was estimated by the modified maximum curvature method. The similarity coefficients among the genotypes ranged from 0.54 to 0.93, indicating that the established clusters contained important information for future crosses. According to the sample size methodologies, 25 to 40 fruits should be sampled for valid evaluations of biometric traits. Experiments with five to eight plants per plot are recommended to test progenies of the species, ensuring good experimental precision combined with high selection accuracy for yield traits.
Adaptability and yield stability of cowpea genotypes in the Mid-North region of Brazil
(2022-01-01) de Souza, Cristiane Lopes Carneiro; de Moura Rocha, Maurisrael; e Silva, Kaesel Jackson Damasceno; Coelho, Anderson Prates [UNESP]; Lemos, Leandro Borges [UNESP]; Mingotte, Fábio Luiz Checchio [UNESP]; Colégio Técnico de Floriano; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA); Universidade Estadual Paulista (UNESP)
This study aimed to evaluate the adaptability and yield stability of 20 erect/semierect cowpea genotypes in the Brazil Mid-North region through three methodologies. The experiments were carried out in 10 environments, corresponding to the Cerrado, Caatinga and Amazon biomes. The research was carried out during the period of 2010 to 2011. The experiments were arranged in a randomized block design, with four replications. The Cerrado biome and the Balsas/MA region were the most suitable locations for cowpea cultivation, comprising the environments with greater yield stability. Theil (1950) methodology showed low sensitivity in genotype discrimination, while those of Lin & Binns modified by Carneiro and AMMI were more sensitive. For unfavorable environments, Lin & Binns (1998) methodology modified by Carneiro (1998) identified the cultivar BRS Tumucumaque with greater stability, whereas the AMMI methodology identified this cultivar with greater adaptation in favorable environments. Both methodologies identified the MNC02-676F-3 strain with better adaptation to favorable environments. The association of methodologies is necessary to complement the interpretation of the adaptability and stability of cowpea genotypes in the Mid-North of Brazil.
Germination response of palm seeds on a two-way thermogradient plate
(2023-01-01) Batista, Gisele Sales [UNESP]; Ferraz, Marcos Vieira [UNESP]; Mazzini-Guedes, Renata Bachin; Pritchard, Hugh; Marks, Timothy Rex; Pivetta, Kathia Fernandes Lopes [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal do Paraná (UFPR); Wakehurst Place
Palm trees are propagated almost exclusively by seeds and each species germinates under a certain temperature range. In this sense, the two-way thermogradient plate may be used to determine temperature limits for germination and seed response to temperature. The objective was to define the alternating temperature regime promoting higher and faster seed germination of Carpentaria acuminata and Phoenix canariensis palms using a two-way thermogradient plate. This equipment allowed 64 combinations of alternating and constant temperatures, ranging from 6.97 to 36.42 ºC for C. acuminata, and 7.96 to 35.94 ºC for P. canariensis. Seeds were sown in Petri dishes (25 x 9 cm) containing 1% water agar. Linear regressions were estimated to determine cardinal temperatures. After 50 days, non-germinated seeds were transferred from the two-way thermogradient plate to a germination chamber at 30 °C. The temperature regime promoting highest seed germination percentage of C. acuminata was 30.45/33.00 °C (day/night), with minimum, optimum, and maximum temperatures of 9.13, 28.53, and 36.33 °C, respectively. For seed germination of P. canariensis, the most appropriate temperature regime was 29.77/17.93 °C (day/night), with minimum, optimum, and maximum temperatures of 9.53, 28.03, and 35.43 °C, respectively.
Cucurbit Powdery Mildew Race Identification by Triplet-Septet and Disease Progress Estimation
(2023-01-01) de Oliveira Rabelo, Hudson [UNESP]; Braz, Leila Trevisan [UNESP]; McCreight, James Donald; Universidade Estadual Paulista (UNESP); Crop Improvement and Plant Protection Research Unit
The Triplet-Septet (TS) set of melon cucurbit powdery mildew (CPM) race differentials (CPMRD) was established to provide an international means for objective and uniform identification and designation on CPM races. The Area Under Disease Progress Stairs (AUDPS) method for disease progress estimation was derived from the Area Under Disease Progress Curve (AUDPC) method, and both have been used to evaluate disease progress on other crops. We aimed to identify a melon CPM race on the TS melon CPMRD, and estimate disease progress thereon using AUDPC and AUDPS. Plants were inoculated at the 3 to 4 true leaf stage. Severity of CPM infection was evaluated on the 21 TS melon CPMRD at 15, 22, 32, and 41 days after inoculation (DAI) using a visual scale. The CPM population in the greenhouse was identified as race S based on reactions of a set of 11 commonly used melon CPMRD, and it may also be designated as 127.127.126 on the TS melon CPMRD. AUDPS identified higher levels of disease than AUDPC, and its results agreed with those obtained by the commonly used melon CPMRD conventional race identification methods (current and Triplet-Septet). AUDPS can be used to evaluate the disease progress on CPM
Effect of glyphosate in Johnsongrass submitted to different soil water potentials
(2023-01-01) Silva, Antônio C. [UNESP]; Marques, Ricardo F. [UNESP]; Gonçalves, Clebson G.; Pereira, Maria R. R.; Martins, Dagoberto [UNESP]; Universidade Estadual Paulista (UNESP); Auburn University; Faculdade de Tecnologia de Capão Bonito; Agriculture and Natural Resources - UC Cooperative Extension
This work aimed to study the efficiency of herbicide glyphosate to control Johnsongrass plants (Sorghum halepense) in different phenological stages of development and when submitted to different types of soil water potentials. The study was conducted in a completely randomized design, with four repetitions. The treatments were arranged in a triple factor scheme 3 × 3 × 2, being: three soil water conditions [no water deficit (−0.03 MPa), intermediate water deficit (−0.07 MPa), and high water deficit (−1.5 MPa)], associated with three doses of glyphosate (0.0, 270.0, and 540.0 g a.e. ha−1) applied in two phenological stages (4–6 leaves and 1–3 tillers). Visual control evaluations were conducted at 7, 14, 21, and 35 days after the herbicide application. Biometric and morphophysiological parameters were also analyzed. With the increase of water restriction, there was a decrease in Johnsongrass morphophysiological components, such as specific leaf area, stomatal conductance, and the difference between environment and leaf temperature, as well as the accumulation of aerial part and roots dry matter, independently of the phenological stage evaluated. The development stage of Johnsongrass influenced the control provided by glyphosate, independently of the dose used. The different water deficits studied reduced the control of glyphosate in the two Johnsongrass development stages evaluated. Severe water deficits reduced the control of glyphosate in Johnsongrass using the recommended dose. In conditions of moderate water deficit, the control was not affected. Thus, the control with lower doses can be the most affected by water deficit.

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