ABSTRACT Light is a determining factor in plant morphophysiology, as it influences the growth and development of agricultural crops. Thus, the objective was to investigate the effects of light sources on the growth and development of “biquinho” pepper cultivars. The experiment was performed in two stages (Exp1 and Exp2), evaluating two cultivars (BRS Moema; Airetama biquinho) in five light sources (white LEDs, red LEDs, blue LEDs, red/blue LEDs, and fluorescent lamps). In Exp1 the plants were kept in a controlled condition, with a completely randomized design, in a 2x5 factorial scheme (cultivars x light sources) until 76 days after emergence (DAE), in which growth variables and photosynthetic pigments were evaluated. In Exp2, the plants were removed from the above conditions and transplanted in pots, being kept in greenhouse for more 76 DAE. At 152 DAE, the same variables as Exp1 were evaluated, as well as gain of shoot fresh and dry mass, and gain of root fresh and dry mass. In both experiments, growth variables were affected by cultivar and the light sources, however, the behavior did not follow the same trend for all variables, indicating that the light quality influences the growth of the crops, and impacting during greenhouse conditions.

ABSTRACT The aim of this study was to evaluate, using logistic model, the differences in early production, production rate and total productivity of two strawberry cultivars with transplants from different origins grown in substrate. The experiment was carried out in a randomized block design (RBD), with two strawberry cultivars (Albion and Camarosa) and two origins of transplants (National and Imported), with four repetitions consisting of eight plants. For the variable fruit mass, the logistic model was adjusted as a function of the accumulated thermal sum, and from the partial derivatives of the adjusted function, the critical points of the model were estimated. The use of the Logistic model allows evaluating precocity and rate of fruit production efficiently and accurately. The cultivar Camarosa was the most productive compared to the Albion cultivar, presenting a shorter production cycle, with a high production peak. The Albion cultivar was earlier, presenting more constant production during the evaluated production cycle. The transplant's origin did not show significantly different results for the cultivars evaluated. The producer must choose the cultivar that will be used based on its performance and also based on consumer preferences and fruit demand.

Abstract The objective of this work was to evaluate the influence of colored shade mesh and plant density on the morphological characteristics of Corymbia citriodora seedlings. The highest radiation efficiency was found in the blue mesh, 7.01 g MJ-1 and 5.72 g MJ-1 for average and high density respectively. For dry matter and leaf area index at high density, the treatment without mesh followed by the red mesh was the best. The chlorophyll index did not differ between treatments, with mean values of 206.4, 59.1 and 262.0 for chlorophyll a, b and total, respectively. Using principal component analysis, we found the total variance to be 70%. The use of colored shade mesh and plant density altered the radiation use efficiency and dry matter accumulation. Leaf area index was affected only by plant density. The red mesh resulted in the most similar values to the treatment without mesh.

ABSTRACT. Strawberry is an economically and socially important crop in several regions worldwide. Thus, studies that provide information on topics in strawberry growth are important and must be constantly updated. The aims of this study were to fit a logistic growth model to describe strawberry fruit production and to estimate the partial derivatives of the fitted model in order to estimate and interpret the critical points, in addition to using multivariate analyses. To do this, data on 16 treatments [combinations of two cultivars (Albion and Camarosa), two origins (national and imported), and four mixed organic substrates (70% crushed sugar cane residue + 30% organic compost, 70% crushed sugar cane residue + 30% commercial substrate, 70% burnt rice husk + 30% organic compost, and 70% burnt rice husk + 30% commercial substrate)] conducted in a randomized complete block design (RCBD) with four replicates were used. A logistic model was fitted to the accumulated fruit production stratified by treatment and replication. Partial derivatives related to the accumulated thermal sum were estimated in order to quantify the critical points of the model. Subsequently, a principal component analysis was performed. The results show that the use of growth models substantially increases the inferences that can be made about crop growth, and the multivariate analysis summarizes this information, simplifying its interpretation. Approaches such as those carried out in this study are still rarely used, but, compared to simpler models, they increase the amount of inferences that can be made and provide greater elucidation of the results.

Abstract The aim of this work was to evaluate the effect of five light qualities [fluorescent lamps (FL); white (WL), red (RL), blue (BL), or red/blue LEDs (RBL)] and two types of flask sealing (with or without porous membranes) in the in vitro germination and growth of two Capsicum frutescens cultivars (Espaguetinho and Cayenne). For this, two seeds were inoculated per flask (350 mL) containing 50 mL of MS medium with 100 mg L-1 myo-inositol, 30 g L-1 sucrose, 6.0 g L-1 agar, and pH 5.8 ± 0.1. The plants were kept under culture room conditions (16-h photoperiod, 25 ± 2°C and irradiance of 40 μmol m-2 s-1). The experiment was arranged in CRD, 2x5x2 factorial scheme (Cultivar X Light qualities X Sealing type). At 42 days, the following traits were evaluated: percentage of germination; root and shoot length; number of green leaves, senescent leaves and nodal segments; and fresh and dry weight. Plants grown under RL and BRL, showed greater number of green leaves, and longer shoots and roots. The use of porous membranes remarkably reduced the number of senescent leaves. Thus, the use of porous membranes, RL and BRL are recommended since they improve growth and development of pepper in vitro.

RESUMO: O objetivo deste trabalho foi determinar a variável meteorológica com maior contribuição na produtividade de colmos de cana-de-açúcar na região noroeste e central do Rio Grande do Sul. Os genótipos de cana-de-açúcar utilizados foram: UFSM XIKA FW, UFSM LUCI FW, UFSM PRETA FW, UFSM DINA FW, UFSM MARI FW, IAC87-3396. As cultivares UFSM são provenientes do processo de mutação do programa de melhoramento da Universidade Federal de Santa Maria, campus de Frederico Westphalen, e possuem tolerância a baixas temperaturas. Os caracteres morfológicos responsáveis pela produtividade utilizados nos modelos foram diâmetro médio de colmo, número médio de colmos por metro de sulco e estatura média de colmos. As variáveis meteorológicas utilizadas foram a temperatura mínima do ar, precipitação pluviométrica, radiação solar incidente e soma térmica acumulada. Foi realizada a correlação de Pearson, correlações canônicas e regressão de Stepwise entre os caracteres morfológicos e as variáveis meteorológicas, nos quais foi constado que a temperatura mínima do ar é a variável com maior influência na produtividade da cana-de-açúcar nas regiões estudadas e, que a soma térmica acumulada é a variável com maior correlação e contribuição no diâmetro de colmo e estatura média dos colmos. Desse modo, os modelos indicam que o crescimento da cana-de-açúcar responde de forma positiva a soma térmica acumulada, e as regiões em estudo apresentam potencial para o cultivo da cana-de-açúcar.

ABSTRACT: This study determined the meteorological variable that most contribute to the productivity of sugarcane stalks in the northwest and central regions of Rio Grande do Sul. The following sugarcane genotypes were used: UFSM XIKA FW, UFSM LUCI FW, UFSM PRETA FW, UFSM DINA FW, UFSM MARI FW, and IAC87-3396. The UFSM cultivars originate from a mutation process in the breeding program conducted at the Federal University of Santa Maria, Frederico Westphalen campus, and have low temperature tolerance. The productivity-associated morphological characters included in the models were average stem diameter, average stem number per meter of furrow, and average stem height. The following meteorological variables were used: minimum air temperature, precipitation, incident solar radiation, and accumulated thermal sum. Pearson’s correlation, canonical correlations, and Stepwise regression were performed between morphological characters and meteorological variables: minimum air temperature had the greatest influence on sugarcane productivity in the studied regions, and accumulated thermal sum showed the highest correlation and contributed most to stem diameter and average stem height. Thus, the models indicated that the growth of sugarcane is positively associated with the accumulated thermal sum, and sugarcane can be cultivated at the studied regions.

RESUMO O uso de pesticidas com alta toxicidade para controlar patógenos do solo, como Fusarium spp. e Sclerotinia sclerotiorum, tem gerado preocupação, devido aos impactos irreversíveis causados no meio ambiente, além de selecionar isolados resistentes. Dessa forma, os óleos essenciais surgem como uma alternativa eficiente no controle de doenças. Diante da problemática de controle de patógenos do solo e alto potencial antimicrobiano que os óleos essenciais possuem, este trabalho teve como objetivo avaliar o potencial fungicida de óleos essenciais no controle de Fusarium spp. e S. sclerotiorum, in vitro. Utilizou-se um delineamento inteiramente randomizado, esquema fatorial 2×4×8, com dois isolados (Fusarium spp. e S. sclerotiorum), quatro óleos essenciais (Aloysia citriodora, Cymbopogon winterianus, Lippia alba e Ocimum americanum) e oito concentrações de óleo essencial (0,0; 0,2; 0,4; 0,6; 0,8; 1,0; 1,2 e 1,4 ?L·mL-1), com dez repetições. Os óleos essenciais inibiram o crescimento micelial dos fungos em diferentes concentrações, sendo seu potencial justificado pela presença de compostos químicos antifúngicos. Os óleos essenciais de A. citriodora, C. winterianus, L. alba e O. americanum apresentam alto potencial fungicida, sendo alternativas viáveis para formulação de produtos comerciais, impulsionando a indústria de agrotóxicos.

ABSTRACT The use of highly toxic pesticides to control soil pathogens, such as Fusarium spp. and Sclerotinia sclerotiorum has generated concern, due to the irreversible impacts caused on the environment, in addition to selecting resistant isolates. In this way, essential oils appear as an efficient alternative in control of diseases. Facing the problem of soil pathogens control and high antimicrobial fungicide that essential oils present, this work aimed to evaluate the in vitro fungicidal potential of essential oils in control of Fusarium spp. and S. sclerotiorum. A completely randomized design, factorial scheme 2×4×8 was used, with two isolates (Fusarium spp. and S. sclerotiorum), four essential oils (Aloysia citriodora, Cymbopogon winterianus, Lippia alba and Ocimum americanum), eight essential oil concentrations (0.0; 0.2; 0.4; 0.6; 0.8; 1.0; 1.2 and 1.4 ?L·mL-1), and ten replicates. The essential oils inhibited mycelial growth of the fungi in different concentrations, being their potential justified by the presence of antifungal chemical compounds. Essential oils of A. citriodora, C. winterianus, L. alba and O. americanum present high fungicidal potential, being viable alternatives for formulation of commercial products, boosting the pesticides industry.

RESUMO: O objetivo deste estudo foi caracterizar a produção de pimenta biquinho através da interpretação dos parâmetros do modelo Logístico e seus pontos críticos obtidos pelas derivadas parciais da função, bem como indicar qual a melhor cultivar e a melhor época de cultivo para locais de clima subtropical. Conduziu-se um experimento em esquema fatorial 2x3 sendo duas cultivares de pimenta biquinho (BRS Moema e Airetama biquinho), em três épocas de cultivo (E1: outubro de 2015, E2: 01 de novembro 2015 e E3: janeiro de 2016). Ajustou-se o modelo logístico para massa de frutos em função da soma térmica acumulada, e calculou-se os pontos críticos através das derivadas parciais do modelo com a finalidade de caracterizar o desempenho produtivo da cultura através da interpretação biológica destes parâmetros. Temperaturas próximas a 0 ºC durante o experimento foram letais às plantas, e por isso, para a época 3, ajustou-se um modelo de regressão linear. A interpretação dos parâmetros do modelo Logístico e seus pontos críticos permitiram que a produção das cultivares nas épocas 1 e 2 fossem caracterizadas, sendo que a cultivar mais produtiva é Airetama biquinho em todas as épocas de transplante. Essa cultivar também apresenta maior concentração de produção no período. Quanto a precocidade produtiva as duas cultivares não diferiram significativamente. Sobre a época 3, não foi possível interpretar da mesma forma, pois o ajuste do modelo linear não permite as mesmas interpretações realizadas para o modelo não linear, reafirmando a sua aplicabilidade em cultura olerícolas de múltiplas colheitas.

ABSTRACT: The objective of this study was to characterize the production of biquinho pepper through the interpretation of parameter estimates from the logistic model and its critical points obtained by the partial derivatives of the function, and to indicate the best cultivar and growing season for subtropical climate sites. For this, a 2x3 factorial experiment was conducted with two cultivars of biquinho pepper (BRS Moema and Airetama biquinho) in three growing seasons (E1: October 2015, E2: November 2015, E3: January 2016). The logistic non-linear model for fruit mass was specified as a function of the accumulated thermal sum, and the critical points were calculated through the partial derivatives of the model, in order to characterize the productive performance of the crop by the biological interpretation of the estimates of the three set parameters. In E3, temperatures close to 0 ºC during the experiment were lethal to the plants, and a linear regression model was used in this case. The production of the cultivars in E1 and E2 were well characterized by the estimated logistic models, and the most productive cultivar was Airetama biquinho in all evaluated seasons. This cultivar also presented higher concentration of production. The two cultivars did not differ significantly with regards to productive precocity. For E3, it was not possible to interpret the parameters in the same way as for E1 and E2, since the use of the linear model did not allow the same interpretations performed for the nonlinear model, reaffirming its applicability horticultural crops of multiple harvests.

ABSTRACT. The objective of this study was to estimate the coefficient of repeatability and the number of measurements required for production and quality variables in a strawberry crop. An experiment was conducted with two strawberry cultivars from two origins grown in four substrate mixtures, totaling 16 treatments, evaluated in a randomized block design with four replications. Mass (MF) and number (NF) of fruits per plant were evaluated as measures of production, and total soluble solids (SST), titratable acidity (AT) and firmness (FIR) of fruits during the crop cycle were evaluated as measures of quality. Subsequently, the repeatability coefficient was estimated by the following methods: analysis of variance (ANOVA), principal component analysis using a correlation matrix (PCcor), principal component analysis using a variance-covariance matrix (PCcov) and structural analysis (SA). The number of measurements was adjusted for each studied variable based on determination coefficients of 0.80, 0.85, 0.90, and 0.95. The repeatability coefficients ranged from low to medium. The ANOVA method gave the lowest r values, while the PCcov method presented the highest values of r. When using the PCcov method, 3.6, 2.9, 6.2, 3.2, and 3.8 measurements were needed to reach 80% confidence for the variables MF, NF, SST, AT, and FIR, respectively, and this increased to 7.3, 14.0, 29.6, 15.4, and 18.1 for 95% confidence in the results for MF, NF, SST, AT, and FIR, respectively.

RESUMEN Los metabolitos secundarios son producidos por ciertas especies de plantas, y pueden influir en el desarrollo de algunas especies, debido a la acción de los efectos alelopáticos. Por lo tanto, el objetivo del trabajo fue evaluar el efecto alelopático del aceite esencial de Lippia alba en la germinación, emergencia y vigor de las plántulas de diferentes lotes de semillas de lechuga. El experimento se realizó en un diseño completamente al azar, en un esquema factorial 3x5, que consta de tres lotes de semillas del cultivar Grand Rapids® y cinco dosis de aceite esencial de L. alba (0; 0,25; 0,50; 0,75 y 1,00%) diluido en agua destilada y homogeneizado en Tween® 80. Se evaluó la germinación y el vigor de la semilla en el laboratorio (experimento I) y la emergencia en un ambiente protegido (experimento II). Los resultados obtenidos mostraron que hubo un efecto inhibitorio con una reducción significativa de la germinación, el vigor y la emergencia de la semilla cuando se añadió aceite esencial de L. alba a partir de concentraciones de 0.25%. El aceite esencial mostró potencial alelopático sobre diferentes lotes de semillas de lechuga, afectando la germinación, el vigor y la emergencia de las semillas.

ABSTRACT Secondary metabolites are produced by certain plant species and may influence the development of some species through the action of allelopathic effects. Thus, the objective of this study was to evaluate the allelopathic effect of Lippia alba essential oil on the germination, emergence and vigor of seedlings of different batches of lettuce seeds. This experiment was conducted in a completely randomized design with a 3x5 factorial scheme consisting of three batches of seeds of the cultivar Grand Rapids® and five doses of L. alba essential oil (0, 0.25, 0.50, 0.75 and 1.00%) diluted in distilled water and homogenized in Tween® 80. Seed germination and vigor, in the laboratory (experiment I), and emergence, in a protected environment (experiment II), were evaluated. The results demonstrated that there was an inhibitory effect with a significant reduction of germination, vigor and seed emergence when L. alba essential oil was added starting at concentrations of 0.25%. The essential oil showed allelopathic potential over different lettuce seed lots, affecting germination, vigor and seed emergence.

Resumo Devido a sua relevante importância econômica, tanto para o setor alimentício quanto farmacêutico, a oliveira vem sendo cada vez mais cultivada em todo o mundo. Para isso, a obtenção de mudas de qualidade com uniformidade e idoneidade varietal surge como fator altamente relevante na implantação dos pomares de oliveiras. Dessa forma, o objetivo deste trabalho foi desenvolver protocolo de estabelecimento in vitro a partir de segmentos nodais de duas cultivares de oliveira sob diferentes concentrações de hipoclorito de sódio e concentrações de BAP. O experimento foi conduzido no delineamento inteiramente casualizado, em esquema fatorial triplo (2x3x3), sendo duas cultivares de oliveira (Arbequina e Koroneiki), três concentrações de BAP (0,00; 2,22 e 4,44 µM) e três concentrações de hipoclorito de sódio (0,6; 0,8 e 1,0% de cloro ativo) para a descontaminação dos explantes. Cada tratamento contou com três repetições e a unidade experimental constituída por cinco tubos de ensaio com um explante cada. Após 28 dias, foi possível observar que os tratamentos testados não promoveram o estabelecimento in vitro de Olea europaea cv. Arbequina. A concentração de 2,22 µM de BAP adicionada ao meio WPM e a concentração de 1,0% de hipoclorito de sódio, utilizada na desinfestação dos explantes, apresentaram resultados promissores no estabelecimento in vitro de Olea europaea cv. Koroneiki.

Abstract Due to its relevant economic importance, both for the food and pharmaceutical sectors, the olive tree is being increasingly cultivated around the world. For this, obtaining quality seedlings with uniformity and varietal suitability emerges as a highly relevant factor at the implantation of olive orchards. Thus, the objective of this work was to develop in vitro establishment protocol from nodal segments of two olive cultivars under different concentrations of sodium hypochlorite and different concentrations of BAP. The experiment was conducted on completely randomized design, in a triple factorial scheme (2x3x3), two olive cultivars (Arbequina and Koroneiki), three BAP concentrations (0,00; 2,22 e 4,44 µM) and three concentrations of sodium hypochlorite (0,6; 0,8 and 1,0% active chlorine) for the decontamination of the explants. Each treatment had three replicates and the experimental unit consisted of five test tubes with one explant each. After 28 days, it was possible to observe that the treatments tested did not promote in vitro establishment of Olea europaea cv. Arbequina. The concentration of 2,22 µM of BAP added to the WPM and the 1,0% concentration of sodium hypochlorite used in disinfestation of the explants, presented promising results in the in vitro establishment of Olea europaea cv. Koroneiki.

RESUMEN El objetivo de este trabajo fue identificar y estimar las relaciones entre variables componentes de producción y rendi miento de frutos en tomate. El experimento se realizó con diseño de bloques al azar con un arreglo factorial 2x3x3, correspondiendo a dos híbridos de tomate (Netuno y San Vito), tres dosis de boro (H3BO3 - 0, 2, 4 g/sitio) y calcio (si aplicación, aplicación cada 7 días y aplicación cada 14 días), para un total de 18 tratamientos, cuatro repeticiones y 20 plantas por parcela. Se estimaron los coeficientes de correlación de Pearson entre las variables medidas, poste riormente, se seleccionaron aquellos con mayor significancia para la productividad mediante el método Stepwise y la verificación de la multicolinealidad por el número de condiciones y el factor de inflación de la varianza. Las correla ciones de las variables seleccionadas fueron descompuestas en efectos directos e indirectos sobre la productividad de los frutos mediante el análisis de coeficientes de trayectoria. Se encontró una fuerte correlación entre las variables, excluyendo las variables altura, diámetro y masa promedio de los frutos. Por lo tanto, existen relaciones de causa y efecto entre la variable independiente la masa total de frutos y la variable principal de productividad total de frutos, y las variables diámetro y número total de frutos no contribuyeron a aumentar la productividad de tomate.

ABSTRACT The objective of this study was to identify and estimate the relationships between production component variables and fruit yields in tomatoes. This experiment was conducted in a randomized block design with a 2x3x3 factorial arrangement, with two tomato hybrids (Netuno and San Vito), three doses of boron (H3BO3 - 0, 2, 4 g/pit) and three calcium floral applications (no application; application every 7 days; and application every 14 days), totaling 18 treatments with four replications and 20 plants per plot. Pearson correlation coef ficients were estimated between the measured variables and, after that, those with greater significance were selected for productivity with the Stepwise method and verification of multicollinearity using the number of condition and inflation factor of the variance. The correlations of the selected variables were decomposed into direct and indirect effects on fruit productivity with path analysis. There was a strong correlation be tween the variables, excluding the variables height, diameter and average mass of the fruits. Thus, there were cause and effect relationships between the independent variable total mass of the fruits and the principal variable total fruit yield. The variables diameter and total number of fruits did not contribute to an increased tomato production.

ABSTRACT Aloysia triphylla is an aromatic plant used in several industrial sectors, owing to the chemical properties of its essential oil. Biosynthesis of organic compounds is influenced by the growth conditions. As such, temporal and spatial variation affect the chemical composition of essential oils. We hypothesized that: i) the chemical composition of A. triphylla essential oil is influenced by differences in irrigation and season; and ii) the major components of A. triphylla essential oil do not vary between treatment conditions. To test these hypotheses, we determined the chemical composition of A. triphylla essential oil as a function of four seasons crossed with four irrigation levels. A completely randomized experimental design with a randomized block in a 4 × 4 factorial scheme, representing the four seasons of the year (summer, autumn, winter, and spring) and four irrigation levels (50%, 75%, 100%, and 125% of the reference evapotranspiration), was used with four replicates. Our results show that the chemical composition of A. triphylla essential oil varied with the two study factors, of which season was the major factor. The highest concentrations of constituents classified as monoterpene and sesquiterpene were observed in the summer season, and the highest constituents of the other group of compounds were observed in winter. In addition, the major components of the essential oil were α-citral, limonene, and β-citral, and their levels were the highest during winter.

Resumo A fonte de luz na cultura de tecidos muitas vezes é um dos fatores pontuais para a adequação da produção de plantas, para isso, vêm se utilizando os diodos emissores de luz (LEDs) no intuito de aumentar o crescimento e desenvolvimento das plantas propagadas in vitro. O objetivo do trabalho foi avaliar a propagação in vitro de cultivares de Alpinia purpurata ‘Red Ginger’ e ‘Pink Ginger’ em duas diferentes fontes de luz (lâmpadas tubulares fluorescentes ou LED Branco). O experimento foi conduzido em delineamento inteiramente casualizado, esquema fatorial (2x2), totalizando quatro tratamentos com dez repetições, e a unidade experimental composta por um frasco contendo cinco explantes. Após 55 dias, foi possível observar que lâmpadas LED branco e a cultivar Red Ginger proporcionaram o maior número de brotos. Já para o número de folhas, a cultivar Red Ginger e lâmpadas LED branco proporcionaram resultados superiores. Para comprimento da parte aérea, a cultivar Red Ginger mantida sob lâmpadas fluorescentes foi superior, e a Pink Ginger apresentou superioridade quando cultivada sob luzes LED. Assim, mesmo com respostas diferenciadas entre genótipos, sugere-se o uso de lâmpadas LED branco na propagação in vitro das cultivares de Alpinia purpurata ‘Red Ginger’ e ‘Pink Ginger’.

Abstract The light source in tissue culture is often one of the punctual factors for the adequacy of plant production. For this, light emitting diodes (LEDs) have been used in order to increase the growth and development of the plants propagated in vitro. The objective was to evaluate the in vitro propagation of cultivars of Alpinia purpurata ‘Red Ginger’ and ‘Pink Ginger’ in two different light sources (fluorescent or LEDs tubes). The experiment was conducted in a completely randomized design, factorial scheme (2x2), totaling four treatments with ten replicates, and the experimental unit composed of one flask containing five explants. After 55 days, white LED and the ‘Red Ginger’ provided the highest number of shoots. For the number of leaves, the cultivar ‘Red Ginger’ and white LED lamps provided superior results. For shoot length (cm), the cultivar ‘Red Ginger’ kept under fluorescent lamps was superior, and ‘Pink Ginger’ presented superiority when cultivated under LED lights. Thus, even with differentiated responses among genotypes, the use of white LED lamps in the in vitro propagation of Alpinia purpurata ‘Red Ginger’ and ‘Pink Ginger’ cultivars is suggested.

RESUMO O objetivo deste trabalho foi determinar a temperatura base da chicória e aplicá-la na análise fenológica da cultura, durante quatro períodos de cultivo. O trabalho foi realizado com a cultura da chicória (Chicorium endivia) cultivar Escarola Lisa, na Universidade Federal de Santa Maria, campus Frederico Westphalen-RS. O experimento foi conduzido em delineamento de blocos ao acaso com quatro períodos de cultivo (P1: 15/2/2015; P2: 29/04/2015, P3: 22/07/2015, P4: 16/10/2015) em 10 repetições, com uma planta por repetição. As avaliações consistiram da contagem do número de folhas, realizada três vezes por semana após transplante até o ponto de colheita. Para determinação de temperatura base utilizaram-se os métodos desvio padrão em graus dias (DPgd), desvio padrão em dias (DPd), coeficiente da variação em graus dias (CVgd), coeficiente de variação em dias (CVd), coeficiente de regressão (CR), X-intercepto. Desta forma, a temperatura base para emissão de duas folhas sucessivas na escarola é de 4,7°C, obtida através dos valores de 4,0 e 5,5°C, observados nos métodos DPgd e CR. Para a emissão de duas folhas é necessário entre 16,6 e 27,8°C dia folha-1.

ABSTRACT The objective of this study was to determine the base temperature of escarole and to apply in the phenological analysis of crop during four growing periods. The study was carried out with escarole (Chicorium endivia) ‘Escarola Lisa’ cultivar, at the Federal University of Santa Maria, campus Frederico Westphalen-RS. The experiment was performed in a randomized block design with four sowing periods (P1: 2/15/2015; P2: 04/29/2015, P3: 07/22/2015, P4: 10/16/2015) and 10 replicates, each replicate being one plant. The evaluations consisted of counting the number of leaves, performed three times a week after transplanting date until the harvesting point. To determine the base temperature, the following methods were used: standard deviation in degree-days (SDgd), standard deviation in days (SDd), coefficient of variation in degree-days (CVgd), coefficient of variation in days (CVd), regression coefficient (RC) and X-intercept. The base temperature for emission of two successive leaves in the escarole is 4.7°C, obtained by values of 4.0 and 5.5°C, observed in the SDgd and RC methods. For two leaves emission, the temperature between 16.6 and 27.8°C day leaf-1 is necessary.