Revista Raízes e Amidos Tropicais

9

Authors: Sônia Maria Forti Broglio, Roseane Cristina Prédes Trindade, Marcelo Cavalcante, Paulo Vanderlei Ferreira

Damage assessment of caterpillars in the crop of sweet potatoes was studied with the aim of identifying whether the attack of these pests affect the crop yield. It was used clones obtained from CECA / UFAL from botanical seeds of open pollinated populations: CL - 01, CL - 03, CL - 04, CL - 10, CL - 11 e CL - 12 (Co Copinha); CL - 09 (Paulistinha Branca); CL - 13 e CL - 14 (Roxa de Rama Fina); CL - 02 (Co Branca); CL - 06 (60 Dias); and CL - 08 (Pixaim I). It was used randomized blocks designs with 12 treatments and 3 replicates. For identification of caterpillars, different samples were collected manually and sent to the Entomology Laboratory of the CECA/ UFAL and were maintained until adult emergence, which were killed, mounted, photographed and sent for identification. The damage rating was conducted in two periods: before application of a chemical insecticide (deltamethrin) and the second 15 days after treatment. For classification of the notes was used a scale notes from 1 to 5 (1 = 1-20 %; 2= >20-40 %; 3= >40-60 %; 4 = >60-80 %; 5 = >80-100 %). The notes were given by four people, in the central two meters floor area of each plot. After taxonomic identification, the species proved to be involved: Spodoptera dolichos (Fabr., 1794), S. cosmioides (Walk., 1858) and S. albula (Walk., 1857) (Noctuidae); Pseudoplusia includens (Walk., 1857) (Noctuidae) and Agrius cingulatus (Fabr., 1775) (Sphingidae). The damage caused by caterpillars, when not applied insecticide was significant, and it was a clone with the highest average, the highest preference for feeding by the caterpillars. Clones 2, 3, 4 and 10 did not differ from one clone, noting also low yield. Clones 6, 9 and 13 showed the lowest average infestation of caterpillars, followed by higher yield. The insecticide deltamethrin was efficient in controlling the caterpillars because the occurrences of damage decreased after application, with no statistically significant difference between treatments. The averages ranged from 0.90 to 1.46. This is the first record of the occurrence of S. dolichos, S. cosmioides, S. albula, P. includens and A. cingulatus sweet potato in the State of Alagoas. The injuries caused by defoliating caterpillars affected productivity.

11

Authors: Amauri Siviero, Bianca Schott

The knowledge of botanical and agronomic characteristics of cassava germplasm is of paramount importance for the selection of promising cultivars, elimination of duplicates and to obtain genetic parameters useful in breeding programs. This study aimed to characterize the botanical and agronomic cultivars of cassava collection at Embrapa Acre (CMEA). The study was conducted at the Experimental Field of Embrapa Acre being evaluated 103 cultivars of cassava. The experiment was evaluated as a sample in the field using ten plants per cultivar. The botanical and agronomic characterization of cassava cultivars was performed using 24 descriptors, 17 eight qualitative and quantitative. The genetic diversity of cultivars was estimated by the Euclidean distance and the clustering was done by the method of nearest neighbor. Genetic studies have enabled the division of the cultivars into three groups consisting of one, seven and 95 cultivars. The agronomic traits such as number of days to flowering and root rot were most influenced the division into groups.The results show that there is similarity between the cassava genotypes of CMEA and the existence of genetic variability among the accessions evaluated. It can be concluded that there are genetic materials that have potential for selection and breeding prospect with good recommendation of cassava cultivars to Acre.

12

Authors: Moisés de Souza Modesto Júnior, Raimundo Nonato Brabo Alves, Enilson Solano Albuquerque Silva

This study aimed to evaluate cassava productivity of smallholder farmers from the managed coppice of different ages in the Settlements of PA Minas Pará and PA Progresso in Ipixuna do Pará city, State of Pará, Brazil. The research consisted of application of questionnaires to gather information about coppice age, ground preparation systems and cultural practices used by farmers. The parameters were: selection of “maniva-seed”, cropping spacing of 1m x 1m, manual weed control and cassava harvesting for obtaining root yield . The average yield in t/ha and number of plants/ha were measured by four samples of 2m x 10m, randomly selected in the farmers property. The average yield of Settlement PA Minas Pará farmers was 13.3 t/ha of root while the productivity of the Settlement PA Progresso farmers was 21.47 t/ha, therefore 61.43 % higher. Farmers who applied the Trio Productivity practices achieved the highest root yields.