Plot size and experimental precision for sunflower production

In order for sunflower cultivation to be economically sustainable, research should be based upon suitable experimental techniques. Since this kind of information is not readily available, the aim of this study was to estimate the seed production heterogeneity index and the optimal experimental plot size, and to verify experimental precision in sunflower experiments. Sunflower seed yield figures for plots of 1-meter rows (0.4 m spacing) were collected. The experiments were carried out in the 2004/05 and 2005/06 growing seasons in a 1-ha area, by marking out 12 randomized blocks (12 uniformity trials) of two rows 48 plots long on land used for commercial production of sunflowers in Bossoroca, state of Rio Grande do Sul, Brazil. Plots of different sizes were simulated and estimates made for the mean, variance and coefficient of variance for each plot size, and the production heterogeneity index, optimal plot size and experimental precision estimated. The sunflower seed production heterogeneity index was high, the plots should be large and the rows are the blocks. The optimal plot size is two 3-meter rows (2.4 m²).Para sustentar a expressão econômica da cultura do girassol, a pesquisa deve dispor de técnicas experimentais adequadas. Pela falta desta informação, o trabalho tem como objetivo estimar o índice de heterogeneidade da produção de grãos, o tamanho ótimo de parcela experimental e verificar a precisão experimental em experimentos com girassol. Foi obtida a produção de grãos de girassol em parcelas de uma fila (espaçadas em 0,4 m) de 1 m de comprimento. Nas safras de 2004 e 2005, 2 blocos (12 ensaios em branco) constituídos por duas filas com 48 parcelas de comprimento foram casualizados, numa área de 1 ha com produção comercial de girassol em Bossoroca, RS. Foram planejadas parcelas de diferentes tamanhos, estimadas a média, variância e coeficiente de variação para cada tamanho de parcela, sendo estimados o índice de heterogeneidade da produção, o tamanho ótimo de parcela e a precisão experimental. O índice de heterogeneidade da produção de grãos de girassol é alto, as parcelas devem ser grandes e as filas devem ser os blocos. O tamanho ótimo de parcela é igual a duas filas de 3 m de comprimento (2,4 m²)

Height of cut and harvest period effects on tillering and yield of sugarcane

O objetivo deste trabalho foi avaliar a relação entre a altura do corte basal de colmos e da época de colheita da cana-de-açúcar e suas conseqüências no perfi lhamento e na produtividade da cana-soca.O delineamento experimental foi o de blocos ao acaso, em fatorial 2x3x3, constituídos de dois genótipos (IAC86-2480 e RB72454), três alturas de corte (0, 10 e 20 cm, acima do nível do solo) e três épocas decolheita (maio, julho e setembro de 2006), com quatro repetições, em Jaú, SP. O 'IAC86-2480' mostrou maior número de perfi lhos por metro linear, em relação ao 'RB72454', em todas as avaliações. No fi nal do ciclo de desenvolvimento, as alturas de cortes de 10 e 20 cm e a época de colheita em maio proporcionaram maior número de perfi lhos. Os genótipos de cana-de-açúcar responderam à altura de corte e à época de colheita dos colmos. O 'RB72454' teve maior produtividade de cana, quando a colheita foi realizada em setembro. A reserva energética acumulada na base dos colmos favoreceu a rebrota da cana-de-açúcar, em condições climáticas desfavoráveis. A época de colheita interferiu na produtividade de cana e de açúcar.The objective of this work was to evaluate the relationship of sugarcane cut height cane and harvest period, and their effects on tillering and ratoon yield. The experimental design was the randomized blocks one,in a 2x3x3 factorial arrangement, with two genotypes (IAC86-2480 and RB72454), three heights of cut (0, 10 and 20 cm, above soil level) and three harvest periods (May, July and September 2006), with four replicates, in Jaú, São Paulo State, Brazil. Tillering was signifi cantly higher in 'IAC86-2480', in comparison to 'RB72454', in all evaluations. At the end of the growth cycle, cut heights at 10 and 20 cm of fi elds harvested in May resulted in higher tillering. Sugarcane genotypes responded to heights of cut and to harvest periods. The highest caneyield was observed in 'RB72454' harvested in September. The energy stored in the base of stalks improved sugarcane sprouting under unfavorable weather conditions. Season periods affected stalk and sugar yield

Semivariogram models for estimating fig fly population density throughout the year

O objetivo deste trabalho foi selecionar modelos de semivariogramas para estimar a densidade populacional da mosca‑do‑figo (Zaprionus indianus; Diptera: Drosophilidae) ao longo do ano, com uso da krigagem ordinária. Dezenove locais de monitoramento foram demarcados em área de 8.200 m2, cultivada com seis espécies de frutíferas: caquizeiro, citros, figueira, goiabeira, macieira e pessegueiro. Durante um período de 24 meses, foram realizadas 106 avaliações semanais nesses locais. O número médio de moscas‑do‑figo capturadas semanalmente por armadilha, por mês, foi submetido aos modelos de semivariogramas circular, esférico, pentaesférico, exponencial, gaussiano, quadrático racional, seno cardinal, K‑Bessel, J‑Bessel e estável, por meio de interpolação por krigagem ordinária. Os modelos com melhor ajuste foram selecionados a partir da validação cruzada. Cada conjunto de dados (meses) tem uma estrutura de dependência espacial específica, o que torna necessário definir modelos específicos de semivariogramas para melhorar o ajuste ao semivariograma experimental. Portanto, não foi possível definir um modelo padrão de semivariograma; ao invés disso, seis modelos teóricos foram selecionados: circular, gaussiano, seno cardinal, K‑Bessel, J‑Bessel e estável.The objective of this work was to select semivariogram models to estimate the population density of fig fly (Zaprionus indianus; Diptera: Drosophilidae) throughout the year, using ordinary kriging. Nineteen monitoring sites were demarcated in an area of 8,200 m2, cropped with six fruit tree species: persimmon, citrus, fig, guava, apple, and peach. During a 24 month period, 106 weekly evaluations were done in these sites. The average number of adult fig flies captured weekly per trap, during each month, was subjected to the circular, spherical, pentaspherical, exponential, Gaussian, rational quadratic, hole effect, K‑Bessel, J‑Bessel, and stable semivariogram models, using ordinary kriging interpolation. The models with the best fit were selected by cross‑validation. Each data set (months) has a particular spatial dependence structure, which makes it necessary to define specific models of semivariograms in order to enhance the adjustment to the experimental semivariogram. Therefore, it was not possible to determine a standard semivariogram model; instead, six theoretical models were selected: circular, Gaussian, hole effect, K‑Bessel, J‑Bessel, and stable

Emergência de plântulas de trigo estimadas a partir da análise de sementes

There are various vigor tests for the evaluation of seeds physiological quality, however, few studies correlate this tests with plants emergency. This study aimed at identifying wheat (Triticum aestivum L.) seed analysis variables that best predict seedling emergence. Wheat seeds (CEP 30 cultivar) were divided into two batches, one initially subjected to the accelerated ageing process and forming the low-quality batch, and the other, without application of the accelerated ageing process, to compose a high-quality batch. The following seed test variables were evaluated: (i) percentage of normal seedlings in the germination tests, (ii) initial germination counting, (iii) accelerated ageing, (iv) cold test without soil, (v) germination speed index, and (vi) emergence of seedlings in sand after seven and 15 days. The following seedling characteristics were evaluated: root and shoot lengths, total length, and dry mass of the root and shoot. The characteristics evaluated for the seedlings were subjected to path analysis and the seed tests variables to stepwise multiple regression analysis, taking seedling emergence at seven days as the response variable. Factor analysis was also carried out on all variables. Dry mass of the shoot and root length presented the best correlation with seedling emergence for the high-quality batch, but this behavior was not observed for any variable in the low-quality batch. Accelerated ageing was the best seedling emergence estimator for both batches of the used cultivar.Existem inúmeros testes de vigor que podem ser utilizados na avaliação da qualidade fisiológica das sementes, porém, são poucos os estudos que relacionam estes testes com a emergência de plântulas das culturas. Identificaram-se variáveis da análise de sementes de trigo (Triticum aestivum L.) que mais bem predizem a emergência de plântulas dessa cultura. Um lote de sementes de trigo do cultivar CEP 30 foi dividido em dois sublotes, sendo um submetido preliminarmente ao processo de envelhecimento acelerado, compondo o sublote de baixa qualidade, e outro, sem aplicação do processo de envelhecimento acelerado, compondo o sublote de alta qualidade. Foram realizados os testes de sementes: (i) percentagem de plântulas normais nos testes de germinação, (ii) primeira contagem de germinação, (iii) envelhecimento acelerado, (iv) teste de frio sem solo, (v) índice de velocidade de germinação, e (vi) emergência de plântulas em areia aos sete e aos 15 dias. As características das plântulas foram os comprimentos de raiz, de parte aérea e total e as massas secas de raiz e de parte aérea. As características das plântulas foram submetidas à análise de trilha e as variáveis dos testes de sementes, à análise de regressão múltipla stepwise, com a emergência de plântulas aos sete dias como variável resposta. Foi realizada também a análise de fatores com todas as variáveis avaliadas. A massa seca de parte aérea e o comprimento de raiz apresentaram as melhores relações com a emergência de plântulas, para o sublote de alta qualidade, não sendo observado esse comportamento para nenhuma variável no sublote de baixa qualidade. O envelhecimento acelerado foi o melhor estimador da emergência de plântulas, para ambos os sublotes utilizados

Attractive solutions for monitoring Zaprionus indianus (Diptera: Drosophilidae) populations in fig orchard

The fig fly (Zaprionus indianus) is one of the major fig pests in Brazil, being its monitoring important for reducing the use of chemical insecticides. This study aimed at evaluating the efficiency of attractive food for Z. indianus, in fig orchard. The experiment was installed in a domestic fig ('Roxo de Valinhos' cultivar) orchard, using five treatments (fig juice at 50%, sugarcane molasses at 7% and grape juice at 30%, 40% and 50%), with five replicates, in a completely randomized design. A total of 3,284 adult fig flies (1,983 female and 1,301 male) were captured, representing 42% of the total insects and 62% of the drosophilids captured. The proportion of males and females was similar for all attractive solutions. Fig juice at 50% was effective in capturing the fig fly, being recommended for its monitoring in domestic orchards. Sugarcane molasses at 7%, despite its effectiveness, did not present regularity in fig fly capturing, being only indicated for periods of less than 28 days. At the concentrations tested, the grape juice was not effective

Production of cucumber cultivars according to the accumulated thermal sum

Cucumber is a species appreciated in cooking, in addition to providing various nutrients for health. In view of this, it is important that research on its growth is carried out, prioritizing statistical analyzes that effectively demonstrate the results. The objective was to verify the differences by analyzing of the variance and nonlinear models, in addition to characterizing the production, early production and production rate of cultivars of cucumber using of nonlinear models. An experiment was carried out in a randomized block design (RBD), with three cultivars (‘Atlantico’, ‘Caipira’ and ‘Fuyu’) in six replications. Two types of analysis of variance were performed for the variable mass of cucumber fruits. In the first the RBD design was considered with three cultivars and six replications and in the second the RBD design was considered in a split subdivided over time (cultivars x harvests). Afterwards, the Logistic growth model was adjusted for the fruit mass variable as a function of accumulated thermal sum, and determination of the critical points of the model. The use of nonlinear models to evaluate experiments with cultures of multiple harvests has advantages in relation to anova and complementary tests. The cultivar ‘Fuyu’, has higher productivity compared to the cultivars ‘Atlantico’ and ‘Caipira’, in addition to presenting greater precocity and production rate. The adjustment of the logistic model and its critical points allowed to identify the production, precocity and production rate of the evaluated cultivars of the cucumber

Agronomic performance of canola hybrids cultivated in a low altitude region in Southern Brazil

The area occupied by crops has expanded in recent years in the central region of Rio Grande do Sul, Brazil and the search for alternative winter crops to integrate the productive system is relevant given the idleness of the areas at this time and the lower risk of frost losses that occur in most grain-producing regions. In this sense, the objective of this research was to evaluate the agronomic performance of eight canola hybrids (Hyola 61, Hyola 50, Hyola 433, Hyola 571CL, Hyola 575CL, Diamond, ALHT B4, and ALHT M6), cultivated in low altitude areas, in the Central region of Rio Grande do Sul (RS). The experiment was conducted in 2017, in Santa Maria, RS, using a randomized block design with four replicates. Canola hybrids show variability regarding the morphological components and grain production. The environmental condition and low altitude of the region of Santa Maria do not compromise the productive potential of the canola crop, obtaining grain productivity superior to the state and national averages. Therefore, canola crop can be inserted in the central region of Rio Grande do Sul if adequate agronomic management is performed. The cultivars Hyola 50, Hyola 571CL, Hyola 433, Hyola 575CL, Diamond, and Hyola 61 present the highest grain productivity

Maize genetic variability and modifications on the experimental plan

Resultados experimentais seguros exigem um plano experimental apropriado, obtido através da utilização de adequado tamanho e forma de parcelas, número de repetições e de amostras. O objetivo deste trabalho foi avaliar a influência de diferentes bases genéticas de milho, híbrido simples (DAS 9560), duplo (AG 6018), triplo (AG 303) e variedade cultivada (Pampa), sobre a estimativa do tamanho de parcela experimental e do número de repetições. O delineamento experimental foi de blocos ao acaso com quatro repetições e amostragem nas parcelas. As parcelas experimentais foram constituídas por oito fileiras com 12 metros de comprimento, formando 96 unidades básicas. O tamanho de parcela e o número de repetições foram estimados por meio dos métodos de Lessman & Atkins e de Hatheway. O tamanho ótimo de parcela variou entre 4,5 m2 (híbrido simples) e 7,2 m2 (híbrido duplo). A heterogeneidade do solo e a variabilidade genética influenciam no tamanho ótimo de parcela e número de repetições necessárias.An adequate experimental plan is necessary to get high quality data. Experimental plan ensures correct plot size and shape as well as adequate number of replications and samples. The objective of this work was to verify if maize genetic variability could interfere in the size of experimental plots and number of replications. Single (DAS 9560), double (AG 6018) and triple (AG 303) crosses and the open pollinated variety (Pampa) were evaluated. The experiment was carried out in a randomized complete block design with four replications. Plot samples comprised experimental plots with eight rows of 12 m with 96 basic units. Lessman & Atkins and Hatheway methods were used to estimate optimum plot size and replication number. The best plot size varied from 4.5 m2 (simple hybrid) to 7.2 m2 (double hybrid). Soil heterogeneity and genetic variability change plot size and number of replications requested