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Lantana camara (L.) is considered one of the main invasive plants, and the allelochemicals produced by this species can be defined as bioactive secondary metabolites that mediate chemical interactions between the plant and other organisms and, therefore, play an important role in its succession and establishment. The present study aimed to investigate the effect of L. camara aqueous extracts on the germination and growth behavior of Bidens pilosa (L.) by evaluating physiological parameters (germination rate, germination speed index, seedling performance and structure and membrane integrity), as well as the extract metabolic profile. The extract reduced the germination speed index and seedling growth rate and promoted abnormalities in the geotropism and root development in both populations. The third germination phase was highly affected (more than the phases I and II). Lantadene A and B are the possible compounds conferring the herbicidal properties, and the L. camara extract has a potential to be used in the development of a new environmentally-friendly herbicide.

Agrobiodiversity is essential for a sustainable food production, and the knowledge of the potential characteristics of landrace seeds may prompt farmers to adopt the habit of seed conservation for this species. This study aimed at categorizing landrace and commercial common bean (Phaseolus vulgaris L.) accessions, according to the physiological quality (viability and vigor) of seeds produced in the field, during two growing seasons, under organic and conventional farming systems. Germination percentage, field emergence, electrical conductivity, accelerated aging, cold test and seedling length were assessed. The landrace bean accessions exhibit diversity in the physiological seed quality, in terms of their viability and vigor. No differences were observed between the farming systems, in relation to the physiological quality of the seeds produced. The categorization of landrace common bean accessions allows to identify those with superior physiological seed quality.

About 1 billion people are currently suffering from chronic hunger, malnutrition, and vitamin A deficiency, while it is predicted that world food production needs to increase by 70% by 2050 to satisfy 9.9 billion predicted population in the world, relying on a natural resource base that is reaching its limits and with climate change adding further pressures on agriculture and acting as the main driver of crop diversity loss. The main goal of this chapter was to discuss the role of neglected crops (arrowroot, cassava, and cowpea) as potential sources of vitamin A with case studies of Mozambique country where the current population (30.5 million-mid-2018) is predicted to more than double by mid-2050 (67.4 million) while vitamin A deficiency and food insecurity are serious issues. Crops have an important role in rural communities and are nutrient dense and can be used in diet diversification and vitamin A alleviation. They are highly adapted to agroecological niches and marginal areas. The current research reinforces that neglected crops are potential sources of vitamin A with an extra extensive phytochemical composition that together are important in alleviating vitamin A deficiency. Their production promotion must be reinforced and incorporated in crop diversification.

Lantana camara (L.) is considered one of the main weeds of agricultural crops, and allelochemicals produced by this species may be a source for the development of natural herbicides. In this study, phytotoxic effects of L. camara aqueous extracts on seed germination and seedling growth of Avena sativa (L.) were assessed. The experimental design was completely randomized, in a 2 x 5 factorial scheme, with treatments resulting from two assays, testing five concentrations of the extract (0 %, 2.5 %, 5.0 %, 7.5 % and 10 %; vv-1). During the seed germination, physiological (e.g., seed imbibition, germination and vigor) and biochemical (e.g., catalase, ascorbate peroxidase, proline, phenols, malondialdehyde and hydrogen peroxide) proprieties were evaluated. The leaf extracts of L. camara affected the response variables on A. sativa by reducing the germination speed index (phases I and II) and seed viability (phase III of germination), thus causing a solute leakage and increasing the production of reactive oxygen forms and, finally, lipid peroxidation. Extract concentrations above 2.5 % inhibit the growth of epicotyls. Therefore, the studied allelochemicals showed potential to be exploited in the development of natural herbicides.