Bitter' and 'sweet' cassava are normally distinguished based on the hydrocyanic acid (HCN) content of their roots. Moreover, Brazilian farmers tend to select 'sweet' cassava based on the taste and cooking aspects. The aim of this study was to characterize chemical traits of 'bitter' and 'sweet' cassava roots of the Amazon region and to find genetic relations among accessions based on these traits. Considerable phenotypic variation was detected among the evaluated traits moisture, ashes, total soluble solids, total titratable acidity, pH, total carotenoids, free and total cyanide, crude protein, glucose, fructose, sucrose and starch. Aside from free and total cyanide, the trait means of sugars and moisture differed in 'bitter' and 'sweet' cassava and also differentiated these in different clusters in the dendrogram using the unweighted pair-group method based on arithmetic averages (UPGMA) and in the results of principal component analysis.

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Cassava (Manihot esculenta Crantz) is a plant from the Brazilian Amazonia which presents wide genetic variability. Since it is one of the most consumed foods in the world, efforts to generate more nutritive cultivars are necessary. The objective of the present study was to characterize twenty genotypes of cassava from an Active Germplasm Bank (AGB) in Pará state, Brazil, according to physicochemical characteristics of the root: moisture, ashes, total soluble solids, total titratable acidity, pH, total carotenoids, free and total cyanide, total protein, glucose, fructose, sucrose and starch. The values of moisture, ashes and soluble solids ranged from 60.53 to 71.96%, 1.22 to 1.80%, and 2.33 to 3.78%, respectively. Total titratable acidity ranged from 1.83 to 3.35% and pH from 5.68 to 6.50. The concentration of total carotenoids ranged from 2.34 to 9.76 μg g -1 , and total and free cyanide from 177.98 to 691.71 mg kg -1 and 20.29 to 135.19 mg kg -1, respectively. The protein concentration varied between 0.18 and 0.73%, which was considered low. The sugar figures ranged from 0.17 to 0.53%; 0.03 to 0.39%, and 0.14 to 0.40% for glucose, fructose and sucrose, respectively, and starch ranged from 18.65 to 36.01%. These results indicate a high phenotypic variation for chemical traits in samples of bitter cassava collected in Pará state, as well as potential for gains in genetic breeding. RESUMO: A mandioca (Manihot esculenta Crantz) é uma planta de origem na Amazônia brasileira que apresenta ampla variabilidade genética. Por ser um dos alimentos mais consumidos do mundo, esforços para geração de cultivares mais nutritivas são necessários. O objetivo foi caracterizar 20 genótipos de mandioca mantidos em um Banco Ativo de Germoplasma

The objective of this work was to conduct a study on the cultivation of black pepper by small farmers in the city of Capitão Poço / PA. The research was developed based on the application of semi-structured questionnaires, in order to identify the form of cultivation of black pepper in the municipality carried out by family farmers, where a total of 50 producers were interviewed, and this sample was defined based on amount of small producers in the municipality. In addition, other resources were used, such as photographic records, audio recording, notes in field notebooks and direct and indirect observations, which also supported the research. Most respondents (46%) have been producing black pepper for over ten years, and 38% have reported growing the crop between five and ten years, 54% of producers said that the cultivation practice of the crop was adhered to. income supplementation and 32% said it was a passed on activity from father to son and the main variety cultivated by farmers (56%) is kotanadan. Thus, it was found that the main factor of cultivation of black pepper, is the complementation of income of small producers, using the variety kotanadan, because it is easily accessible in family farming of the studied region. Highlighted ConclusionThe main factor for cultivation of black pepper var. kotanadan is the supplementation of income of familiar producers.

The objective of the study was to identify the main obstacles faced by nurserymen in the production of citrus seedlings in Santa Luzia do Induá, municipality of Capitão Poço / PA. The research was developed based on the application of semistructured questionnaires, where 50 active seedling producers were interviewed on a random basis, out of a total of 100 nurseries. Finally, the information obtained was analyzed. The producers had difficulty in accepting the importance of applying one of the items of normative instruction No 48, which deals with the need of protected environment for the production of the Basic Plant, Matrix, Certified Bubble and Certified Mute, considered essential for obtaining material seedlings and certified seedlings. Stated that the way of acquiring the seeds for the production of the rootstock acquired from his property and bought in the trade. According to nurserymen, 90% of the seeds come from plants that are not registered with an inspection body and are used for the production of the rootstock (known as a horse). The local producers have little knowledge and understanding of current regulations, thus being one of the main difficulties. In addition, the producers stated that the main obstacles they face in the production and marketing of seedlings are: Lack of technical assistance and public policies; phytosanitary attack and compliance with Normative Instruction No. 48. These factors together cause major limitations in the production system. Thus, among the aforementioned the main problem experienced by the producers, it is worth noting the adequacy to IN 48 that entails in great changes in the way of production of seedlings of the nurserymen.