This study aimed to investigate the local botanical knowledge of native food plants in three rural communities, located in the semiarid region of Paraíba State, Brazil, verifying possibilities of differences of knowledge among communities and between men and women. Semi-structured interviews about native plant knowledge and use were conducted with all householders in each community, totaling 117 informants. The species similarity among the communities of Pau D’Arco, Várzea Alegre, and Barroquinha was compared with Jaccard index, and the use value index (UVgeneral, UVcurrent, UVpotential) was used to determine the most important species. The Kruskal-Wallis test was used to compare the use values among communities and genders. The consensus factor among the informants was calculated according to the uses cited, and the Wilcoxon test was used to compare the use values between men and women. We recorded 9 species belonging to 8 genera and 8 families in Várzea Alegre; 10 species, 9 genera, and 9 families in Barroquinha; and 7 species, 7 genera and 7 families in Pau D’Arco. Spondias tuberosa Arruda (Anacardiaceae) in Várzea Alegre, Spondias sp. (Anacardiaceae) in Barroquinha, and Ximenia americana L. (Olacaceae) in Pau D’Arco were the most prominent species. Preparation methods are slightly different in the three communities, and there is low similarity about species use among the communities. Regarding gender, the analysis of use value among the communities evidenced significant differences only for UVgeneral among women, specifically between Barroquinha and Pau D’Arco. For men and women within each community, there is a difference only for UVpotential in Barroquinha. This study showed that the residents of the three rural communities have limited knowledge of native food plants found in their communities, but they know where to find them, which parts they may use and how to consume them. The fact is that men know plants that are more distant from the residences and women know those that are next to them.

The use of medicinal plants is an important source of therapeutic resources in rural communities and the wide versatility of some species may attract interest for prospecting studies. The aim of this study was to record and analyze local knowledge and the use of medicinal plants in the rural community of Malícia, municipality of Araçagi, Paraíba State, Northeastern Brazil, applying quantitative methods to calculate the Relative Importance (RI) and the Informant Consensus Factor (ICF). Semistructured interviews were conducted with 46 heads of households. The interviews addressed questions about the used parts of the plants, therapeutic indications, and form of use. Therapeutic indications were classified into categories of body systems. The Relative Importance Index (RI) was calculated to verify the species versatility, and the Informant Consensus Factor (ICF) was calculated to verify the consensus of use among informants regarding the body systems. A total of 111 plant species were recorded, inside 101 genera and 47 families. Fabaceae (16 spp.), Lamiaceae, and Myrtaceae (each one with 7 spp.) were the most representative families. Mentha arvensis, Aloe vera, and Myracrodruon urundeuva had the highest RI. A high consensus of use was observed among the informants for neoplasms, nervous system diseases, and infectious and parasitic diseases. Leaves were the part most cited for medicinal use. Regarding the method of preparation, the decoction and the oral administration route stood out. Neoplasms and respiratory system diseases had the highest ICF values. The results indicate a diversified knowledge of the local pharmacopeia and the need for in-depth studies to corroborate the effectiveness of medicinal plants and to understand the dynamics of local knowledge.

Availability and Use of Woody Plant Resources in Two Areas of Caatinga in Northeastern Brazil

The ecological apparency hypothesis seeks to understand the dynamics of use that a particular species has through its availability in vegetation areas. According to this hypothesis, apparent plants are the most collected and used by humans. This hypothesis was tested in the rural community of Santa Rita, municipality of Congo, in Cariri microregion (Paraíba state, Northeast Brazil). We calculated the use value (UV) for each species. For the phytosociological inventory, we adopted the point-quadrant method, plotting 500 points distributed in the vegetation areas of the community, registering the perimeter measurements and height of 2000 plants. Interviews were conducted with householders, totaling 98 informants (41 men and 57 women), and 24 species, 21 genera, and 11 families were recorded. The cited species were grouped into 11 utility categories. The Spearman correlation coefficient was used to correlate phytosociological and ethnobotanical data. The use values of the species did not correlate with phytosociological parameters. Regarding the use categories, there were positive correlations for fuel (UV with dominance and basal area), construction (UV with all phytosociological parameters), fodder (UV with all parameters), and poison/abortion categories (UV with density and frequency). Ecological apparency significantly explained the local importance of useful plants in fuel, construction, and fodder categories, and less significantly for poison/abortion.

Given the lack of information on the use of spontaneous plants from the Caatinga biome as green manure to produce green grains, the present work aimed to agronomically and economically optimize cowpea production for green grains and their components when fertilized with equitable biomass amounts of hairy woodrose (Merremia aegyptia L.) and roostertree (Calotropis procera Ait.) in two cropping seasons in a semi-arid environment. The experiment used a randomized complete block design, with five treatments and five replicates. The treatments consisted of equitable amounts of dry M. aegyptia and C. procera biomass of 16, 29, 42, 55 and 68 t ha-1. In each experiment, an additional treatment was planted with cowpea without fertilizer (absolute control), and another was fertilized with mineral fertilizer for the purpose of comparison with the treatment of maximum physical or economic efficiency. The maximum optimized physical (agronomic) efficiencies of cowpea green pods and grain production were reached in the productivity of green pods at 3.90 t ha-1 and green grains at 4.06 t ha-1, with incorporation into the soil of 45.07 and 50.48 t ha-1 of green manure, respectively. The maximum economic efficiency of cowpea green grain production was reached at a net income of R$5826.12 ha-1 and at a rate of return of 1.29 reals for each real invested with application to the soil of 38.74 and 37.85 t ha-1 of the tested green manure biomass.