Envelhecimento acelerado em sementes de melão

Accelerated aging is one of the most useful tests used for the evaluation of seed vigor but it is seldomly used to test melon (Cucumis melo L.) seeds. The objective this research was to compare different procedures of the accelerated aging test to evaluate the physiological quality of melon seeds and the efficiency of using saturated salt solution for the control of water uptake by seeds. Five seed lots each of the hybrids AF-646 and AF-682 were tested for germination, seedling emergence, traditional accelerated aging (periods 0f 48, 72 and 96 hours, at 38 or 41°C) and salt saturated accelerated aging. The accelerated aging test (traditional procedure and with salt solution) for 72h and 96h, at 38 or 41°C was sensitive to detect differences in the physiological quality of the seeds. It was also observed that the seed water content after salt saturated accelerated aging was lower and more uniform, thus presenting advantagens in relation to the traditional procedure.O teste de envelhecimento acelerado é um dos mais utilizados para a avaliação do potencial fisiológico das sementes de várias espécies. Entretanto, estudos com sementes de melão ainda são escassos. Avaliou-se procedimentos para a condução do teste de envelhecimento acelerado para avaliação do potencial fisiológico de sementes de melão (Cucumis melo L.), incluindo o uso de solução saturada de sal em substituição à água. Cinco lotes de sementes, dos híbridos AF-646 e AF-682, foram submetidos aos testes de germinação, emergência de plântulas em casa de vegetação e envelhecimento acelerado (períodos de 48, 72 ou 96 horas, a 38 ou 41°C), com e sem o uso de solução saturada de NaCl. O teste de envelhecimento acelerado (procedimento tradicional e com solução salina), conduzido com períodos de exposição de 72h e 96h a 38 ou 41°C, apresentou sensibilidade suficiente para detectar diferenças no potencial fisiológico de lotes de sementes de melão. A utilização de solução saturada de NaCl contribui para reduzir a absorção de água pelas sementes durante o teste de envelhecimento acelerado, permitiu obter resultados menos drásticos e mais uniformes, sem afetar a eficiência do teste

Avaliação do potencial fisiológico de sementes de tomate pelo teste de estresse hídrico

This work had the objective to test the efficiency of the hydric stress test on the evaluation of the physiological quality of tomato (Lycopersicon esculentum Mill.) seeds. Five seed lots of the cultivar IPA-5 were analysed by the following tests: germination, first count, cold without soil test, accelerated aging, electrical conductivity, field emergence, and seedling length under hydric stress at 0, -0.2, -0.4 and -0.6 MPa potentials. The trials were carried out at the Seed Lab and experimental fields of CPATSA, Petrolina, PE, Brazil, in a completely randomized design with four replications. The results showed that the germination test conducted at the -0.4 MPa level can be used to estimate the performance of tomato seeds under unfavourable water stress conditions.Com o objetivo de estudar a eficiência do teste de estresse hídrico na avaliação da qualidade fisiológica de sementes de tomate industrial (Lycopersicon esculentum Mill.), cinco lotes da cultivar IPA-5 foram analisados pelos testes de germinação, primeira contagem, de frio sem solo, envelhecimento acelerado, condutividade elétrica, emergência em campo e comprimento das plântulas sob estresse hídrico nos potenciais de 0, -0,2, -0,4 e -0,6 MPa. Os trabalhos foram realizados no Laboratório de Análise de Sementes e no campo experimental do CPATSA, em Petrolina, PE. As determinações foram conduzidas com quatro repetições, em delineamento experimental inteiramente casualizado. Os resultados indicam que o teste de germinação sob estresse hídrico de -0,4 MPa pode ser usado para estimar o desempenho das sementes de tomate em situações desfavoráveis de disponibilidade hídrica no solo

Phenotypic Identification of Landraces of Phaseolus lunatus L. from the Northeastern Region of Brazil Using Morpho-Colorimetric Analysis of Seeds

Phaseolus lunatus L. is a species of landrace bean widely cultivated in Northeast Brazil. The integration of new technologies in the agricultural sector has highlighted the significance of seed images analysis as a valuable asset in the characterization process. The objective was to assess the morphology of 18 P. lunatus varieties gathered from four states in the Brazilian Northeast. To achieve this, 100 seeds from each variety were utilized, and their images were acquired using a flatbed scanner with a digital resolution of 400 dpi. Subsequently, the images were processed using the ImageJ software package for analyzing seed size, shape and color characteristics. Statistical analyses were performed with SPSS software applying stepwise Linear Discriminant Analysis (LDA). The overall accuracy rate for correct identification was 80.5%. Among the varieties, the lowest classification percentage was attributed to the ‘Coquinho Vermelha’ variety (39%), while the highest rates were observed for ‘Fava Roxa’ and ‘Fava de Moita’ (98%). The morpho-colorimetric classification system successfully discriminated the varieties of P. lunatus produced in the northeastern region of Brazil, highlighting the -+*/high degree of diversity within them. In particular, seeds with uniform coloring or clearly defined secondary color patterns were easier to classify. The varieties showed low correlation, forming distinct groups based on background color, secondary color, or seed size

Effect of temperature on disease severity of charcoal rot of melons caused byMacrophomina phaseolina: implications for selection of resistance sources

[EN] Macrophomina phaseolinais the causal agent of charcoal rot disease of melons causing significant losses worldwide. Use of resistant cultivars is a desirable method for controlling this disease, but there is no information about the influence of temperature on the resistant behavior found in melon accessions. The purpose of the present study was to assess the effect of temperature on the reaction of six melon accessions selected previously for their resistant response toM. phaseolina. Accessions were inoculated withM. phaseolinaisolate CMM-1531 and grown under accurately controlled environmental conditions at different temperature regimes (25, 28, 31, and 34 degrees C) in a replicated experiment. The increase in temperature increased the severity of symptoms in most genotypes, but this effect was less pronounced in the highly susceptible control, the cultivar 'Piel de sapo', and in the most resistant accession, the wild AfricanagrestisAg-15591Ghana, that remained resistant even at 34 degrees C. The use of several screening temperatures allowed a better characterization of accessions that behaved similarly as highly resistant at 25 degrees C (Con-Pat81Ko, Dud-QMPAfg, Can-NYIsr and Ag-C38Nig), but in which resistance breaking was observed with temperature rises. Temperatures of 28 degrees C and 31 degrees C were sufficient to make Dud-QMPAfg, Ag-C38Nig and Can-NYIsr moderately resistant, whereas Con-Pat81Ko remained highly resistant. All these genotypes were susceptible at 34 degrees C, which suggest that are not suitable for hot-climate growing areas. The most promising accession was Ag-15591Ghana, whose resistance was confirmed in two greenhouse experiments under stressful temperatures (>34 degrees C). The behavior of these sources should be confirmed in naturally infested fields, but the controlled screening methods presented here are essential to characterize new resistance sources and to conduct genetic studies when a high number of plants must be managed under controlled environmental conditions.This work was supported by Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior CAPES (Brazil). This study was also partially supported by the Spanish Ministerio de Economia y Competitividad project AGL2014-53398-C2-2-R, by the Spanish Ministerio de Ciencia, Innovacion y Universidades project AGL2017-85563-C2-1-R and by the Conselleria d'Educacio, Investigacio, Cultura i Esports de la Generalitat Valenciana PROMETEO project para grupos de excelencia/2017/078 (cofunded with FEDER funds).Linhares, CMDS.; Ambrosio, MMQ.; Castro, G.; Barros Torres, S.; Esteras Gómez, C.; Nunes, GHDS.; Picó Sirvent, MB. (2020). Effect of temperature on disease severity of charcoal rot of melons caused byMacrophomina phaseolina: implications for selection of resistance sources. European Journal of Plant Pathology. 158(2):431-441. https://doi.org/10.1007/s10658-020-02083-wS4314411582Akhtar, K. P., Sarwar, G., & Arshad, H. M. I. (2011). Temperature response, pathogenicity, seed infection and mutant evaluation against Macrophomina phaseolina causing charcoal rot disease of sesame. 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Effect of irrigation on susceptibility of sunflower to Macrophomina phaseoli. Plant Disease, 67, 1214–1217.Bruton, B. D., & Miller, M. E. (1997). Occurrence of vine decline diseases of melons in Honduras. Plant Disease, 81(6), 696–696.Bruton, B. D., & Wann, E. V. (1996). Charcoal rot. In T. A. Zitter, D. L. Hopkins, & C. E. Thomas (Eds.), Compendium of cucurbit diseases (pp. 49–50). St. Paul, USA: APS Press.Chung, B. N., Lee, J. H., Kang, B., Koh, S. W., Joa, J. H., Choi, K. S., & Ahn, J. J. (2018). HR-mediated defense response is overcome at high temperatures in Capsicum species. The Plant Pathology Journal, 34(1), 71–77.Cohen, R., Elkabetz, M., & Edelstein, M. (2016). Variation in the responses of melon and watermelon to Macrophomina phaseolina. Crop Protection, 85, 46–51.Cohen, R., Omari, N., Porat, A., & Edelstein, M. (2012). Management of Macrophomina wilt in melons using grafting or fungicide soil application: Pathological, horticultural and economical aspects. Crop Protection, 35, 58–63.Cohen, R., Tyutyunik, J., Fallik, E., Oka, Y., Tadmor, Y., & Edelstein, M. (2016). Phytopathological evaluation of exotic watermelon germplasm as a basis for rootstock breeding. Scientia Horticulturae, 165, 203–210.Dantas, A. M. M., Ambrósio, M. M. Q., Nascimento, S. R. C., Senhor, R. F., Cézar, M. A., & Lima, J. S. S. (2013). Incorporation of plant materials in the control of root pathogens in muskmelon. Revista Agro@ambiente On-line, 7(3), 338–344.Durner, E. (2019). Effective analysis of interactive effects with non-normal data using the aligned rank transform, ARTool and SAS® university edition. Horticulturae, 5, 57.Edraki, V., & Banihashemi, Z. (2010). Phenotypic diversity among isolates of Macrophomina phaseolina and its relation to pathogenicity. Iranian Journal of Plant Pathology, 46(4), 93–100.El-Kolaly, G. A. A., & Abdel-Sattar, M. A. (2013). The etiology of sudden wilt disease syndrome on melon in Egypt. Nature and Science, 11(11), 79–87.El-Sappah, A. H., Islam, M. M., El-Awady, H. H., Yan, S., Qi, S., Liu, J., et al. (2019). Tomato natural resistance genes in controlling the root-knot nematode. Genes, 10, 925.FAO. (2019). FAOSTAT: Food and Agriculture Organization Corporate Statistical Database. Available at: http://faostat3.fao.org/home/S. Accessed July 8, 2019.García-Jiménez, J., Armengol, J., Sales, R., Jordá, C., & Bruton, B. D. (2000). Fungal pathogens associated with melon collapse in Spain. EPPO Bull, 30(2), 169–173.Garrett, K. A., Dendy, S. P., Frank, E. E., Rouse, M. N., & Travers, S. E. (2006). Climate change effects on plant disease: Genomes to ecosystems. Annual Review of Phytopathology, 44, 489–509.Groenewald, J. Z., & Crous, P. W. (2014). Genetic diversity in Macrophomina phaseolina, the causal agent of charcoal rot. Phytopathologia Mediterranea, 53, 250–268.Islam, S., Haque, S., Islam, M. M., Emdad, E. M., Halim, A., Hossen, Q. M., et al. (2012). Tools to kill: Genome of one of the most destructive plant pathogenic fungi Macrophomina phaseolina. BMC Genomics, 13, 493–509.Jacob, C. J., Krarup, C., Díaz, G. A., & Latorre, B. A. (2013). A severe outbreak of charcoal rot in cantaloupe melon caused by Macrophomina phaseolina in Chile. Plant Disease, 97, 141.Machado, A. R., Pinho, D. B., Soares, D. J., Medeiros-Gomes, A. A., & Pereira, O. L. (2018). Bayesian analyses of five gene regions reveal a new phylogenetic species of Macrophomina associated with charcoal rot on oilseed crops in Brazil. European Journal of Plant Pathology, 153(1), 89–100.Manici, L. M., Caputo, F., & Cerato, C. (1995). Temperature responses of isolates of Macrophomina phaseolina from different climatic regions of sunflower production in Italy. Plant Disease, 79(8), 834–838.Marinho, R. E. M., Sales Jr., R., Maracajá, P. B., Silva, G. F., Costa, F. M., & Silva, E. C. (2002). Identificação da microflora associada a raízes de meloeiro nos estados do Rio Grande do Norte e Ceará. Revista Caatinga, 15(1), 25–28.Medeiros, A. C., Melo, D. R. M., Ambrósio, M. M. Q., Nunes, G. H. S., & Costa, J. M. (2015). Métodos de inoculação de Rhizoctonia solani e Macrophomina phaseolina em meloeiro (Cucumis melo). Summa Phytopathologica, 41(4), 281–286.Miyasaka, S. (2008). Manejo da biomassa e do solo visando à sustentabilidade da agricultura brasileira. São Paulo: Navegar.Nascimento, P. G. M. L., Ambrósio, M. M. Q., Freitas, F. C. L., Cruz, B. L. S., Dantas, A. M. M., Junior, R. S., et al. (2018). Incidence of root rot of muskmelon in different soil management practices. European Journal of Plant Pathology, 152(2), 433–446.Negreiros, A. M. P., Sales, R., Leon, M., Melo, N. J. D., Michereff, S. J., Ambrósio, M. M. D., et al. (2019). Identification and pathogenicity of Macrophomina species collected from weeds in melon fields in northeastern Brazil. Journal of Phytopathology, 167(6), 326–337.Nunes, G. H. S., Aragão, F. A. S., Nunes, E. W. L. P., Costa, J. M., & Ricarte, A. O. (2016). Melhoramento de Melão. In C. Nick & A. Borém (Eds.), Melhoramento de Hortaliças (pp. 331–363). Viçosa, Brazil: Universidade Federal de Viçosa.Pitrat, M. (2017). Melon genetic resources: Phenotypic diversity and horticultural taxonomy. In R. Grumet, N. Katzir, & J. Garcia-Mas (Eds.), Genetics and genomics of Cucurbitaceae (pp. 25–59). Cham, Switzerland: Springer Nature.Pivonia, S., Cohen, R., Kigel, J., & Katan, J. (2002). Effect of soil temperature on disease development in melon plants infected by Monosporascus cannonballus. Plant Pathology, 51(4), 472–479.Reuveni, R., Krikun, J., Nachmias, A., & Shlevin, E. (1982). The role of Macrophomina phaseolina in a collapse of melon plants in Israel. Phytoparasitica, 10(1), 51–56.Salari, M., Panjehkeh, N., Nasirpoor, Z., & Abkhoo, J. (2012). Reaction of melon (Cucumis melo L.) cultivars to soil-borne plant pathogenic fungi in Iran. African Journal of Biotechnology, 11(87), 15324–15329.Sales-Júnior, R., Oliveira, O. F., Medeiros, E. V., Guimarães, I. M., & Correia, K. C. (2012). Ervas daninhas como hospedeiras alternativas de patógenos causadores do colapso do meloeiro. Revista Ciência Agronômica, 43(1), 195–198.Sales-Júnior, R., Senhor, R. F., Michereff, S. J., & Negreiros, A. M. P. (2019). Reaction of melon genotypes to the root’s rot caused by Monosporascus. Revista Caatinga, 32(1), 288–294.Sarr, M. P., Ndiaye, M., Groenewald, J. Z., & Crous, P. W. (2014). Genetic diversity in Macrophomina phaseolina, the causal agent of charcoal rot. Phytopathologia Mediterranea, 53, 250–268.Scott, A. J., & Knott, M. A. (1974). Cluster analysis method for grouping means in the analysis of variance. Biometrics, 30(3), 507–512.Siegel, S., & Castellani Jr., N. J. (1988). Nonparametric statistics for the behavioral sciences. 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Crescimento e metabolismo de mudas de Pityrocarpa moniliformis Benth. sob deficit hídrico

Pityrocarpa moniliformis Benth. has medicinal properties, forage potential, besides showing rusticity and rapid growth, which confer potential to recover degraded areas. In this context, the objective was to evaluate the growth and biochemical components of Pityrocarpa moniliformis seedlings under water deficit conditions. The design used was randomized blocks, with five treatments and four replicates, with the experimental plot consisting of twenty plants. Treatments were characterized by different periods of water deficit (0; 4; 8; 12 and 16 days without irrigation). At 44 days after sowing (DAS), when the seedlings had two pairs of fully formed true leaves, the treatments began to be applied. The development of the seedlings was evaluated until 60 DAS when they were collected for biometric and biochemical analyses. The variables analyzed were shoot height; collar diameter; number of leaves; shoot dry mass; root dry mass; root/shoot ratio; and Dickson’s quality index. Contents of total chlorophyll, chlorophyll a, chlorophyll b, total free amino acids, total soluble sugar, and proline contents in the leaves were also determined. The treatment most affected by the lack of irrigation was 16 days of water deficit, which resulted in the death of 38.8% of the seedlings. This condition caused a decrease in shoot length, reducing it by approximately 29.2% compared to the control treatment. There was also a reduction in the production of new leaves from the eighth day after the differentiation of treatments. Pityrocarpa moniliformis seedlings can develop under the condition of water deficit for up to 8 days, even with chlorophyll degradation due to stress. Pityrocarpa moniliformis maintains its vegetative development by performing osmotic adjustment through the accumulation of biomolecules (sugars, proline, and amino acids).Pityrocarpa moniliformis Benth. possui propriedades medicinais, potencial forrageiro, além de apresentar rusticidade e rápido crescimento, o que lhe confere potencialidade de uso para recuperação de áreas degradadas. Nesse contexto, objetivou-se avaliar o crescimento e os componentes bioquímicos de mudas de Pityrocarpa moniliformis em condições de deficit hídrico. O delineamento foi em blocos casualizados, com cinco tratamentos e quatro repetições, sendo a parcela experimental composta por vinte plantas. Os tratamentos foram caracterizados por diferentes períodos de deficit hídrico (0; 4; 8; 12 e 16 dias sem irrigação). Aos 44 dias após a semeadura (DAS), quando as mudas apresentaram dois pares de folhas verdadeiras totalmente formadas, iniciou-se a aplicação dos tratamentos. O desenvolvimento das mudas foi avaliado até os 60 DAS, período em que ocorreu a coleta destas para as análises biométricas e bioquímicas. As variáveis analisadas foram: altura da parte aérea; diâmetro do colo; número de folhas; massa seca de parte aérea e raiz; relação entre raiz e parte aérea; e índice de qualidade de Dickson. Também foram determinados nas folhas os teores de clorofilas totais, a e b; aminoácidos livres totais; teor de açúcares solúveis totais; e teor de prolina. O tratamento mais afetado pela falta de irrigação foi o de 16 dias, o qual acarretou a morte de 38,8% das mudas. Essa condição ocasionou a diminuição no comprimento da parte aérea das mudas, com redução de aproximadamente 29,2%, quando comparado ao tratamento-controle. Houve também redução da emissão de novas folhas a partir do oitavo dia após a diferenciação dos tratamentos. Mudas de Pityrocarpa moniliformis conseguem se desenvolver em condição de deficit hídrico por até 8 dias, mesmo ocorrendo a degradação de clorofilas devido ao estresse. A manutenção do desenvolvimento vegetativo de Pityrocarpa moniliformis ocorre devido à realização de ajustamento osmótico pelo acúmulo de biomoléculas (açúcares, prolina e aminoácidos)

Validação de testes de vigor para sementes de rúcula (Eruca sativa L.)

The limitations of the germination test, which is not efficient in detecting differences in batches with high percentage of twinning, are a major factor that favors the gain space increasing vigor tests. The objective of this study was to evaluate the comparative effectiveness of different tests for evaluating seed vigor rocket (Eruca sativa L.). The experiment was conducted in the Laboratory of Seed Analysis and Experimental Horta in the Department of Plant Sciences, Universidade Federal Rural do Semi-Árido (UFERSA) in Mossoró, RN, during the period from May to August 2011. We used rocket seed, Folha Larga and Cultivada varieties, each represented by four and five lots, respectively. The seeds were evaluated by germination, first count, electrical conductivity, potassium leaching, accelerated aging with saturated and seedling emergence in the field. The experimental design was completely randomized with four replications. The means were submitted to Tukey test at 5% probability and later analysis Pearson correlation at 5% probability. It is found that the electrical conductivity is the most suitable for evaluating the physiological seed rocket.As limitações do teste de germinação, que não é eficiente em detectar diferenças em lotes com alta percentagem de geminação, são um dos principais fatores que favorece o ganho de espaço cada vez maior dos testes de vigor. Objetivou-se com este trabalho avaliar a eficiência comparativa de diferentes testes para a avaliação de vigor de sementes de rúcula (Eruca sativa L.). O experimento foi conduzido no Laboratório de Análise de Sementes e na Horta Experimental do Departamento de Ciências Vegetais da Universidade Federal Rural do Semi-Árido (UFERSA), em Mossoró-RN, durante o período de maio a agosto de 2011. Utilizaram-se sementes de rúcula, cultivares Cultivada e Folha Larga, representadas por quatro e cinco lotes, respectivamente. As sementes foram avaliadas pelos testes de germinação, primeira contagem do teste de germinação, condutividade elétrica, lixiviação de potássio, envelhecimento acelerado com solução saturada e emergência de plântulas em campo. O delineamento experimental foi o inteiramente casualizado com quatro repetições. As médias foram submetidas ao teste Tukey a 5% de probabilidade e posteriormente à análise de correlação de Pearson a 5% de probabilidade. Verifica-se que o teste de condutividade elétrica é o mais indicado para avaliar o potencial fisiológico de sementes de rúcula

Qualidade fisiológica e tamanho de sementes de cenoura

A maturação de sementes de cenoura ocorre escalonadamente nas umbelas de diferentes ordens e, sendo a colheita realizada em uma única etapa, pode ocorrer desuniformidade de tamanho, dentro de um mesmo lote de sementes. Desta forma, este trabalho foi realizado visando determinar o efeito do tamanho da semente na sua qualidade fisiológica. Quatro lotes de sementes comerciais de cenoura cv. Brasília, provenientes da região de Bagé-RS, foram separados em três frações: grande (retenção em peneira de perfuração redonda 2 mm); média (retenção em peneira de perfuração redonda 1,5 mm) e a mistura entre grande e média (em porções iguais). Foram conduzidos os seguintes testes: germinação, tetrazólio, condutividade elétrica, envelhecimento acelerado e emergência de plântulas em casa de vegetação. Não houve diferenças significativas quanto aos diferentes tamanhos de sementes em todos os testes realizados, com exceção do teste de emergência de plântulas em casa de vegetação com avaliação aos 14 dias após a semeadura. Porém, este teste não mostrou consistência na separação das frações em diferentes níveis de qualidade, para os diferentes lotes.Maturation of carrot seeds occurs in a sequence based on the different orders of the umbel. Since harvest is carried out only at one stage, nonuniform seed sizes within the same seed lot may occur. The effect of seed size on physiological quality was determined. Four lots of commercial carrot seeds (cv. Brasília) were separated in three fractions: large (retention at 2 mm diameter); medium (retention at 1.5 mm diameter) and a mixture of large and medium seeds (1:1 proportion). These fractions were tested for germination, tetrazolium reduction, electrical conductivity, accelerated aging and seedling emergence. Only seedling emergence, evaluated after 14 days, showed statistical difference. However this test did, not show consistency for the separation of the fractions into different quality levels, for different lots

Correlação entre testes de vigor em sementes de maxixe

This work was carried out with the objective of comparing the efficiency of different tests in the physiological quality of gherkin seeds (Cucumis anguria L.), looking for information for a better utilization of these quality control tests, as well as verifying their relation at field emergency. Seven lots of gherkin seeds were evaluated by the germination test, first count, electrical conductivity at 4 and 24 hours, accelerated aging, controlled damage, cold without soil, and field emergency. The trials were carried out at the Seed Lab and at an experimental field of Embrapa-CPATSA, at Petrolina, PE, Brazil, from January to May 1996. In the lab tests, a completely randomized design was used, and in the field tests, a randomized block design was used - both of them with four repetitions of fifty seeds, being the means compared by the Tukey test, at 1% of probability. The germination and vigor tests were effective to detect differences of physiological quality among gherkin seed lots. The damage control and cold without soil tests were more stable on the division of the lots by the vigor levels and, at the same time, showed the highest correlation with field emergency.O objetivo deste trabalho foi comparar a eficiência de diferentes testes para determinação da qualidade fisiológica de sementes de maxixe (Cucumis anguria L.), visando melhorar sua utilização como testes de qualidade e verificar suas relações com a emergência de plântulas em campo. Foram avaliadas sementes de sete lotes, pelos testes de germinação, primeira contagem de germinação, condutividade elétrica a 4 e 24 horas, envelhecimento acelerado, deterioração controlada, teste de frio sem solo e emergência de plântulas em campo. O trabalho foi desenvolvido no Laboratório de Análise de Sementes e em um campo experimental da Embrapa-CPATSA, em Petrolina, PE, no período de janeiro a maio de 1996. Nos testes de laboratório, o delineamento experimental foi inteiramente casualizado, e nos testes de campo foi usado o delineamento em blocos casualizados - ambos com quatro repetições de cinqüenta sementes, sendo as médias comparadas pelo teste de Tukey a 1% de probabilidade. Os testes de germinação e vigor foram eficientes para detectar diferenças de qualidade fisiológica entre lotes de sementes de maxixe. Os testes de deterioração controlada e de frio sem solo foram mais consistentes na separação dos lotes em diferentes níveis de vigor, e ao mesmo tempo apresentaram os maiores níveis de correlação com a emergência de plântulas em campo