Biostimulants are used in cotton (Gossypium hirsutum L.) to balance vegetative and reproductive growth as well as to increase cotton seed yield and fiber quality. Therefore, in order to study the efficiency of seed treatment with biostimulants, nutrition, production and technological quality for the cotton fiber, a field experiment was installed. The study was conducted at the Alvorada farm research field, in Luis Eduardo Magalhães municipality - BA. The experiment was arranged in a completely randomized block design with four replicates and five treatments (control group, untreated group, Booster®, Stimulate®, Improver® and Biozyme®). Leaf contents of nutrients, yield and technological quality of the fiber were evaluated. The results showed that application of biostimulants in the seeds increased the N, K, S and Fe contents in the cotton leaf, but there was no influence on the crop yield. However, these products caused changes in the fiber characteristics, related to length uniformity, micronaire, length and strength of the fiber.

Com o objetivo de avaliar componentes agronômicos qualitativos e caracterizar morfologicamente variedades de mandioca em função da época de colheita, conduziu-se o experimento na Universidade Estadual do Sudoeste da Bahia, campus de Vitória da Conquista- BA. O delineamento experimental utilizado foi o de blocos ao acaso, com 3 repetições, e os tratamentos arranjados segundo o esquema de parcelas subdivididas, com cinco variedades (Sergipe, Caitité, Platinão, Roxinha e Pão da China) nas parcelas e seis épocas de colheita nas subparcelas (270, 330, 390, 450, 510 e 570 dias após o plantio). Foram avaliadas: altura de plantas, diâmetro de caule, área foliar total e índice de área foliar. Além disso, foi feita a caracterização morfológica das plantas.  Os genótipos apresentaram comportamento diferenciado para a característica altura de plantas, a variedade Roxinha foi superior até 450 dias após o plantio, sendo que aos 510 e 570 dias, a variedade Caitité foi superior. Os genótipos Pão da China, Platinão e Sergipe apresentaram maior diâmetro de caule que a variedade Caitité, sem diferenças entre épocas. Para as características índice de área foliar e área foliar total, houve redução dos índices na sexta colheita, devido a fatores climáticos no período. A variedade Sergipe apresentou a maior retenção foliar. Na caracterização morfológica dos genótipos, notou-se diferenças entre os materiais e características estudadas.

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Fertilizers can be used to change competition relationships between crop and weed by promoting crop species growth, since rival species has a differentiated response to nutrients. We aimed to evaluate weed dry mass accumulation when or not NPK (nitrogen, phosphorus and potassium) fertilizers were applied to cassava crop. Therefore, weed samples were collected every 35 days, from 35 to 525 days after cassava planting, by randomly throwing a 0.25 m 2 metal square (0.5 m × 0.5 m) within useful area of the plots with and without fertilization. After each thrown, it was removed weed shoot, separated by species, then counted and weighed to determine number of plants and shoot dry mass. Fertilization did not influenced the weed population during most part of the crop cycle; however, promoted greater weed dry mass accumulation in the second crop year, 350 days after planting. Panicum maximum, Brachiaria plantaginea, Sida rhombifolia, Pavonia cancellata, Setaria parviflora and Cynodon dactylon, which were the most abundant weeds, had different responses to fertilization. P. maximum and B. plantaginea have outstood because of their shoot dry mass increase of 41.59 and 36.25%, respectively, when comparing fertilized and non-fertilized treatments.

Phytosociological surveys are basis for weed management in agricultural crops. We aimed in this study to survey weed within a cassava cultivation field in the city of Vitória da Conquista, Southwestern Bahia, Brazil. The crop was grown for 18 months (from January 2013 to July 2014), with samples at 35, 70 and 105 days after planting (first year cultivation), and at 350, 385 and 420 days after planting (second year cultivation). Sampling was performed according to inventory square method, in which a 0.25 m 2 iron frame is thrown randomly on the cropland. Then, weed within this metal square area are cut at ground level, identified, quantified and afterwards placed into an oven at 65°C during 72 h to obtain dry mass of each species. Evaluated phytosociological parameters were frequency, relative frequency, density, relative density, abundance, relative abundance and importance value index. The main identified families in the survey were Malvaceae, Asteraceae and Poaceae. In total, it was assessed 14 families, 32 genera and 38 species of weeds. The highest importance value index was found for Sida rhombifolia, Cynodon dactylon and Brachiaria plantaginea. Regarding dry mass, Panicum maximum, B. plantaginea and S. rhombifolia had the largest values. It was concluded that weed control methods must focus on species and consider reinfestations in the second crop year.