Search

Simultaneous cultivation of agricultural and forest species may result in changes in plant community interactions, generating microclimatic changes within the understory and then modifying growth and yield characteristics of the intercropping systems. Thus, this study aimed to assess the radiation use efficiency, growth and yield of bean and soybean cultivated in succession under two arrangements of agroforestry and full sun. To these ends, two field experiments were conducted in Southern Brazil: bean in‐season and soybean off‐season. Absolute and relative growth rates, net assimilation rate, leaf weight ratio, leaf area ratio, specific leaf area, radiation use efficiency and yield of bean and soybean were assessed. The solar radiation flux was modified by plant arrangement and tree canopy characteristics. Shading affected growth and yield characteristics and the radiation use efficiency of the studied crops. From the results obtained in this study, it is possible to recommend crop bean cultivation in agroforestry systems. However, for soybean, due to the reduced yields obtained in agroforestry systems, further research should be conducted in order to study more spaced arrangements and crop insertion in the early years of agroforestry, in order to enable its insertion in agroforestry systems in Southern Brazil. [ABSTRACT FROM AUTHOR]

The central-north of Brazil is a region with strong presence of concrectionary soil, whose supposed disadvantages from the agronomic point of view, do not prevent their use in agriculture. However, more in-depth information about the behavior of crops of agricultural interest cultivated in this type of soil is few. Due to the observation of agricultural stands in this type of soil, it was hypothesized that plinthite ironstones concretions negatively interfere in the development of crops of agro-economic interest. The objective was to verify the growth and development of soybean cultivated in soil with the presence and absence of plinthite ironstones. Concretionary Petric Plinthosol were collected in the 0-0,20 m layer and part of the soil was sieved so that concretions larger than 3.10 mm in diameter were removed, thus leaving two treatments, soil with and without plinthite ironstones. Morphological evaluations were performed during their phenological phase. Soybean grown in soil without ironstones showed higher growth at 32 and 48 DAE and more leaflets when compared to soy crop grown in soil with ironstones. As for dry matter, soybean grown in soil without ironstones showed more values for aerial, root and total mass as well for aerial root rate when compared to soybean grown in soil with ironstones. Plinthite ironstones interfere with the growth and/or vegetative development of soybeans. Soybean has less vegetative development when grown in soil with plinthite ironstone concretions. [ABSTRACT FROM AUTHOR]

Trichogramma pretiosum is one of the main egg parasitoids used in the control of lepidopteran pests in Brazil. This natural enemy can be negatively affected by the use of insecticides, herbicides, and fungicides. The present work used a systematic review and meta-analysis to group information from multiple studies on the selectivity of pesticides (279 commercial products) in rice, corn, soybean, apple and peach crops for immature stages (egg-larva, pre-pupa, and pupa) and adult parasitoids. The selected studies used the International Organization for Biological and Integrated Control (IOBC) methodology with the same adaptations for T. pretiosum. The meta-analysis found that corn crops had the highest frequency of tests (2 0 7). The most frequently tested active ingredients (a.i.) were glyphosate, glyphosate isopropylamine salt, and sulfur at frequencies of 41, 32 and 24 tests, respectively. The pesticides registered for rice crops showed the greatest sublethal effects on T. pretiosum, with an approximately 47% reduction in parasitism (RP) or emergence (RE). The adult stage of the parasitoid showed greater sensitivity to the tested pesticides (65% RP), in comparison to the immature stages. In general, insecticides showed superior toxicity for all development stages of T. pretiosum , compared to herbicides and fungicides, regardless of the recommended dosage for the crop. The present study aggregates information related to selectivity for the four life stages of T. pretiosum , contributing significantly to the integration of biological control and chemical control in rice, corn, soybean, apple and peach crops in Brazil. • Data summarized the selectivity of 279 pesticides to Trichogramma pretiosum. • Apple and peach had the high number of harmless pesticides. • Pesticides used in rice showed the greatest sublethal effects. • Adult stage showed greater sensitivity to pesticides compared to the immature stages. • Insecticides showed superior toxicity compared to herbicides and fungicides. [ABSTRACT FROM AUTHOR]

Feltia submontana (Köhler, 1961) is redescribed based on specimens from Northwestern Argentina and Central and Southeastern Brazil. Taxonomic comments, photographs of the adults, characters of taxonomic importance, and illustrations of structures of the labial palpus, legs, and male and female genitalia are provided. The species is compared with similar-looking and supposedly closely related species, such as F. hispidula (Guenée, 1852) and F. lilacina (Zerny, 1916). The species, originally described for Argentina, is reported for Brazil for the first time. Most Brazilian specimens come from the "Cerrado" but also from Southeastern Atlantic Forests. The life cycle of F. submontana specimens collected in Planaltina, Distrito Federal, Brazil, is described; the species probably has only a single generation per year and imagines are on the wing in the late autumn and early winter months; the last instar prepupa and pupa pass through aestival diapause. The abundance of F. submontana relative to other species of Agrotis Ochsenheimer, 1816, and Feltia Walker, 1856, in the above-cited locality is accessed through 4 years of standardized collecting with light trap; the species is the second most abundant species of these genera in the area, with about one fifth of the captures, second only to A. ipsilon (Hufnagel, 1766), with about two thirds of the captures, and about two times more abundant than F. subterranea (Fabricius, 1794); the latter two are regarded as important pest species in South America.