Plant-growth-promoting rhizobacteria (PGPR) influence soil fertility, plant growth, tolerance to abiotic stress, resistance to herbivorous insects, and plant interactions with other organisms. While the effects of PGPR on plant growth, fruit yield, and induced defense responses have been extensively studied, the consistent positive outcomes have fueled rapid expansion in this research field. To evaluate PGPR impacts on plant growth and interactions with phytophagous insects, we conducted a systematic meta-analysis using publications from electronic databases (e.g., PubMed, Web of Science) that reported PGPR effects on plants and insects. Effects were categorized by plant family, PGPR genus, insect feeding guild, and insect–host specialization. Our analysis revealed that PGPR generally enhanced plant growth across most plant families; however, the magnitude and direction of these effects varied significantly among PGPR genera, indicating genus-specific interactions with host plants. When assessing PGPR-mediated reductions in phytophagous insects, we found that Pseudomonas, Rhizobium, and Bacillus exhibited the weakest negative effects on insect populations. PGPR significantly reduced both monophagous and polyphagous insects, with the most pronounced negative impacts on sucking insects (e.g., aphids, whiteflies). This study highlights critical patterns in PGPR-mediated plant growth promotion across taxa and the related differential effects on phytophagous insect activity. These insights advance our understanding of PGPR applications in agroecological production systems, particularly for integrated pest management and sustainable crop productivity.

Capsicum annuum L. var. glabriusculum is a semi-domesticated species of economic importance; however, its establishment in commercial plantations has been hampered by the low germination and emergence rates of its seeds. The aim of this study was to evaluate the effect of the fruit ripening stage on seed germination and seedling emergence in C. annuum var. glabriusculum. Seeds were extracted from fruits with six different ripening stages. The evaluated traits were the germination and emergence percentages, germination and emergence rates, and 17 physical traits of the seeds. According to the results, seeds extracted from red, orange, and pinto fruits presented better germination and seedling emergence percentages (85, 86, and 82% and 95, 93, and 94%, respectively). A principal component analysis showed that some differences in the physical traits of the seed were associated with the fruit ripening stages and seed development. A canonical discriminant analysis showed a high correlation between the fruit ripening stages and the physical and physiological characteristics of the seed, allowing the formation of four groups. The fruit ripening stages (pinto, orange, and red) influence the germination of the seeds and the emergence of the seedlings of C. annuum L. var. glabriusculum, so obtaining seeds from physiologically ripe fruits allows for obtaining seeds of better quality.

Background. The fall armyworm Spodoptera frugiperda is one of the most damaging pests of maize in tropical areas. Objective. To evaluate the damage caused by S. frugiperda and the leaf morphological traits in 15 populations of maize landrace. Methodology. The leaf damage caused by S. frugiperda and four-leaf morphological traits (leaf blade thickness, leaf blade hardness, specific leaf area and trichome density) were evaluated at 20, 30 and 40 days after emergence (DAE) in two seasons, dry (March and April) and rainy (June and July). Spearman correlation between the degree of leaf damage and each leaf morphological trait was also evaluated. Results. Maize populations showed differential response to the damage caused by S. frugiperda among seasons and evaluating date. The leaf morphological traits were different between seasons and among evaluating dates. The trichome density had intermediate negative correlation with the level of leaf damage in rainy season (rs = − 0.32, p < 0.001). Implications. The lower leaf damage may be indicator of resistance against S. frugiperda. Conclusion. The population 2020−M62 had low susceptibility to S. frugiperda, this population may be candidate for maize breeding program.

Background. Cascading effects through tritrophic interactions (microorganisms, plants, herbivores) are basic components in ecosystems that are often influenced by force from bottom up or top down. One of the most important cases is the fixation of nitrogen through growth promoting bacteria of PGPR plants, which can alter the cascading effects in superior trophic interactions, through physical and chemical changes in the plants. Bacteria as growth promoters not only participate in growth, they are also considered the best biological control agents since they have the potential to suppress pathogenic microorganisms and induce systemic resistance against pest insects. Objective. This study aims to evaluate the contribution of the inoculation of the Rhizobium etli nitrogen fixing bacteria in the growth of Phaseolus vulgaris and the oviposition and preference of Bemisia tabaci. Methodology. Bean plants were established on sterilized soil, two batches of plants were formed: plants inoculated with R. etli and non-inoculated (control) plants. In the first experiment, were measured plant growth and characteristics related to defense against phytophages. In the second experiment, the preference and oviposition of Bemisia tabaci was evaluated by free choice and non-choice tests. Results. Inoculation with R. etli favored some specific growth characteristics, such as leaf area and root length. Phytophagous defense variables, as well as adult preference and oviposition of B. tabaci were not different between inoculated and non-inoculated plants. Implications. The main limitation of the use of PGPR depends on the type of soil and the variety of beans, so this inoculant could also be tested in cases where it has been proven that there is low natural colonization of Rhizobium in Phaseolus lunatus L. during its growth. Conclusion. Inoculation increased some growth variables; however, it did not affect the oviposition and preference of Bemisia tabaci. Additional work is required to assess the effects of factors, such as bean variety, synergy among rhizobacteria species, natural resistance of the host plant, environmental conditions and soil types.