In statistical analyses of seed germination experiments, it is essential to ensure that the assumptions of the chosen methods are not violated to obtain valid and reliable results. When these assumptions are violated, alternative methods should be considered, one of which is survival analysis. This study aimed to evaluate the application of this methodology, using a nonparametric approach, to assess the germination of Cecropia pachystachya and Jacaranda caroba. In the first experiment, alternating temperatures of 30/20 °C and 25/15 °C were applied under two light conditions (light and darkness). In the second, germination was assessed at constant temperatures ranging from 15 to 35 °C. Germination reached or exceeded 50% in both species under alternating temperatures and light conditions. In continuous darkness, J. caroba exhibited a higher germination speed and percentages, whereas C. pachystachya was unaffected by light conditions. The recommended alternating temperature for both species was 30/20 °C. The optimal constant temperatures were 25 °C for J. caroba and 30 °C for C. pachystachya. It is concluded that the nonparametric survival analysis technique effectively discriminates seed germination of the studied species.

Brazil is the country which has produced the most coffee for over 150 years, and to achieve high productivity, pesticides are the most common control measure for pests. Due to the need to adopt less impactful control practices, natural enemies or insecticides of botanical origin have been studied as alternatives to synthetic insecticides. However, botanical pesticides can negatively affect some natural enemies, and the effect depends on the formulation and concentration. The objective of this study was to estimate the survival of green lacewing larvae, Chrysoperla externa (Hagen), exposed to different doses of neem-based products, whose active ingredient is azadirachtin (Azamax^®: 0 (control treatment with distilled water), 12, 24, 36, 48, 60, 72, 84, 96, and 108 mg a.i. L⁻¹; Organic neem^®: 0, 3.3, 6.6, 9.9, 13.2, 16.5, 19.8, 23.1, and 26.4 mg a.i. L⁻¹; Natuneem^®: 0, 3.8, 7.5, 10.5, 15.0, 18.8, 22.5, 26.3, 30.0, and 33.8 mg a.i. L⁻¹), using a parametric approach. Predator larvae were exposed to neem-based insecticides and evaluated for 20 days. Survival curves estimated by the models—Log-logistic for Azamax^®, Weibull for Organic neem^®, and Log-normal for Natuneem^®—demonstrated an inverse relationship between increasing doses and survival time. These concluded that the application dose should be less than 84 mg a.i. L⁻¹ for Azamax^®, 19.8 mg a.i. L⁻¹ for Organic neem^®, and 26.3 mg a.i. L⁻¹ for Natuneem^® to keep 50% of the green lacewings alive for 13 days, which is the average time for the larval cycle of C. externa.

Rice (Oryza sativa L.) has been one of the most consumed foods on the planet, with economic and social importance. Diseases, mainly blast, caused by the fungus Pyricularia oryzae, are limiting factors for the production of rice. The present work aimed to select covariables that can influence resistance to rice blast, using the selection strategy proposed by Collett. Logistic regression models were adjusted to predict disease resistance, using the ROC curve to assess the predictive capacity. The data used were obtained from a population of 413 plants, with phenotypic information collected in 82 countries and classified into five subpopulations. The research found that, out of over fifteen variables embedded to assess the disease, only three revealed to be relevant for the final adjusted model, namely: width of flag leaf (V4), the mean number of primary panicle branches (V8) and the amount of amylose from ground grains (V15). The variable V4 presented the most significant influence on disease resistance. Additionally, for each unit increase in V4, V8 and V15, it is expected to obtain 279.3, 31.9 and 9.4% increases, respectively, in the probability of resistance to rice blast.

Mabea fistulifera Mart. (Euphorbiaceae) is a native tree recommended for the restoration of degraded areas. The objective was to evaluate the quality of M. fistulifera seed lots through germination and vigor tests. The germination test was conducted in a factorial design (3 x 2 x 2), involving three seed colors (red, orange, and brown), with and without elaiosome, and two substrates (paper roll - PR and top of paper - TP). The conductivity test was arranged in a factorial design (3 x 2), with three seed colors and with and without elaiosome. Survival analysis was performed, along with log-rank and Wilcoxon tests, to compare germination curves. Brown seeds exhibited the highest conductivity and lowest germination, while red seeds showed the lowest conductivity and highest germination. On the PR substrate and without elaiosome, orange seeds had higher initial germination; brown seeds germinated more, and red and orange seeds showed greater deterioration. Red and orange seeds exhibit better physiological quality. Seed color is a reliable indicator of vigor and quality in M. fistulifera seeds. Paper is an effective substrate for germination. The absence of elaiosome may influence water absorption, but its effect on germination is not evident.

O objetivo deste estudo foi avaliar a influência dos fenômenos climáticos El Niño e La Niña na produtividade simulada pelo modelo 3PG em Eucalyptus spp. Os estudos foram realizados em áreas com plantio clonais de eucalipto nos estados da Bahia (BA), Minas Gerais (MG) e Rio Grande do Sul (RS). Trabalhou-se nos anos de ocorrência dos eventos El Niño e La Niña com intensidades fraca, moderada e forte nos anos de 1980 a 2015. Foram feitas simulações das variáveis que expressam produtividade nos plantios em cada ano destes eventos climáticos, utilizando o modelo 3PG. A calibração do modelo foi feita a partir de dados de inventários dos talhões trabalhados. As idades de três, cinco e sete anos foram avaliadas ao longo do ciclo. As médias dos estados, regiões e idades foram comparadas estatisticamente pelo teste de Tukey (p ≤ 5%). O modelo foi capaz de detectar tendências atribuídas aos eventos climáticos do El Niño e La Niña, evidenciando maiores incrementos volumétricos naqueles que apresentaram maiores totais de chuvas. Os eventos em que ocorreram condições climáticas limitantes ao crescimento dos plantios verificaram menor incremento da biomassa total. A biomassa estimada apresentou maiores incrementos para os órgãos: lenho>raiz>folhas, respectivamente.