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Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Multicollinearity must be diagnosed in multivariate analyses. Among the indicators, the condition number can be used to quantify the degree of multicollinearity. Hence, this study sought to determine the number of measurements (trials) necessary to estimate the number of condition in linear correlation matrices between rye traits. Five uniformity trials were carried out with 'BRS Progresso' rye, and eight morphological traits and eight productive traits were evaluated, forming two groups. In each group of traits, six cases (combinations of traits) were planned and the multicollinearity diagnosis was performed. Repeatability analyses were performed using the following methods: analysis of variance, principal component analysis, and structural analysis, and the number of measurements (trials) was determined for different levels of precision. A higher condition number of repeatability coefficients was obtained by the principal component methods (based on correlation and variance and covariance matrices) and structural analysis based on the variance and covariance matrix. A greater number of measurements (trials) is necessary to estimate the number of conditions in productive traits compared to morphological ones. One trial is enough to efficiently estimate the condition number with a minimum accuracy of 80% in morphological and productive traits of rye, whereas at least three trials are required for 95% accuracy. [ABSTRACT FROM AUTHOR]

Copyright of Boletim de Geografia is the property of Universidade Estadual de Maringa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Soybean is the main agricultural crop produced and exported by Brazil, and the whitefly, Bemisia tabaci (Gennadius, 1889) (Hemiptera: Aleyrodidae), is one of the main pests of this crop. Whitefly control is carried out mainly with chemical insecticides, which has led to an increase in number of applications and evolution towards resistant populations. There is a need to study alternatives for the control of this insect pest, and biological control using entomopathogenic fungi can be an effective tool, offering less risk to the environment. This study aimed to design and evaluate four management programs in two soybean cropping seasons, including two integrated management alternatives, a conventional chemical management alternative and a biological (fungal) control alternative. Two sequential sprays set 10 days apart were performed for each program, and the results of ANOVA and Scott-Knott test (P ≤ 0.05) revealed differences among treatments. The integrated management consisting of a sequential spray of chemical insecticide followed by a fungal one stood out as the best control option, presenting 60% of control efficacy for whitefly adults and 34% for whitefly nymphs in the first cropping season; 83% of control efficacy for whitefly adults and 53% for whitefly nymphs in the second cropping season. Therefore, integrating fungi-based products with chemical insecticides may provide an efficient alternative for controlling B. tabaci in soybean. • Integrating entomopathogenic fungi-based products with chemical insecticides enhances B. tabaci control in soybean. • Applying fungi-based products after two sprays of chemical insecticides provides 60–83% of control for whitefly adults. • This strategy is more effective for B. tabaci control than applying fungal products in the first spray or alone. [ABSTRACT FROM AUTHOR]

Copyright of Revista Ciência Agronômica is the property of Revista Ciencia Agronomica and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The whitefly Bemisia tabaci is the second most widespread and economically important arthropod pest in the world, with frequent population outbreaks occurring in Brazil and increasing economic damage on soybean crops. High oviposition rate, short life cycle and uneven distribution along the plants' canopy favour the dissemination of B. tabaci within soybean crops and compromise the efficacy of control measures. The objective of this work was to quantify soybean yield reduction caused by B. tabaci damage and propose an economic injury level (EIL) for this pest in soybean crops. Experimental design was randomized blocks with four replicates. Soybean grain yield and its components (number of pods, number of grains and 1000-grain weight) were quantified in relation to different levels of B. tabaci infestation in two cropping seasons, obtained through insecticide sprays carried out at different growth stages of the soybean plants. The resulting data were submitted to variance analysis, mean separation test and regression analysis. We found that a population density of one whitefly trifoliate−1 reduces from 0.88 to 1.79 grains plant−1, 0.16 ± 0.01 g plant−1 or 31.24 ± 4.21 kg ha−1of grain yield, and varies in response for pods plant−1 and 1000-grains weight. Based on this information, we suggest an economic injury level of 1.465 ± 0.195 B. tabaci trifoliate−1, considering a control cost of US$ 20.00 ha-1 and soybean crop value of US$ 400.00 tonne−1. • The number of B. tabaci soybean trifoliate−1 is decisive for the level of control. • The population peak was reached during soybean reproductive phases. • The economic injury level of B. tabaci in soybean is 1.465 ± 0.195 trifoliate−1. • One B. tabaci trifoliate−1 reduced 0.16 ± 0.01 g plant−1 or 31.24 ± 4.21 kg ha−1. • One B. tabaci trifoliate−1 reduced 0.88 to 1.79 grains plant−1. [ABSTRACT FROM AUTHOR]