-In pineapple fields, weed competition is exacerbated by the fact that the crop is small and has a very slow vegetative development. The objective of this study was to determine the effects of herbicides on growth, yield and quality of pineapple, cultivar 'Pérola'. The experimental design was in randomized blocks with four treatments and four replications. Treatments consisted of weeding by hoe and the herbicides diuron; fluazifop-p-butyl and atrazine + S-metolachlor applied in post-emergence. The characteristics evaluated monthly during the vegetative stage were stem diameter, D-leaf length, number of leaves, number of emitted leaves and percentage of natural floral induction. In the reproductive phase, evaluations were made of average fruit weight (g) with and without crown, fruits length and diameter, number of slip, slip-sucker and sucker type seedlings, determination of soluble solids and pH in the pulp. There was no effect of herbicide treatment on the vegetative growth characteristics. Stem diameter increased until 330 days after planting, showing a decrease after this period. The D-leaf grew over time in all treatments, although phytotoxicity symptoms were observed after the first application of herbicides. The traits evaluated on the reproductive phase showed no significant differences in response to treatments. Therefore, the use of diuron fluazifop-p-butyl and atrazine + S-metolachlor did not affect growth, yield and fruit quality of pineapple, cultivar 'Pérola'. Index terms: Ananas comosus var. comosus, weeds, herbicides, 'Pérola'. CRESCIMENTO, PRODUÇÃO E QUALIDADE DO ABACAXIZEIRO EM RESPOSTA AO USO DE HERBICIDASRESUMO -No cultivo do abacaxizeiro, a competição com plantas daninhas é agravada pelo fato de a cultura apresentar pequeno porte e ter o desenvolvimento vegetativo muito lento. O objetivo do trabalho foi determinar os efeitos de herbicidas sobre o crescimento, a produtividade e a qualidade do abacaxizeiro 'Pérola'. O delineamento experimental foi em blocos casualizados com quatro tratamentos e quatro repetições. Os tratamentos foram constituídos de capina manual através de enxada e herbicidas diuron, fluazifpo-Pbutílico e Atrazina + S-Metalacloro em pós-emergência. As características avaliadas mensalmente na fase vegetativa foram diâmetro do talo, comprimento da folha "D", número de folhas, número de folhas emitidas e porcentagem de indução floral natural. Na fase reprodutiva, foram avaliados peso médio dos frutos (g) com e sem coroa, comprimento e diâmetro dos frutos, número de mudas do tipo filhote, filhote-rebentão e rebentão, determinação dos sólidos solúveis e ph da polpa. Não houve efeito dos tratamentos de aplicação de herbicidas sobre as características de crescimento vegetativo. o diâmetro do talo apresentou aumento até 330 dias após o plantio, evidenciando diminuição após esta época. A folha "D" apresentou crescimento ao longo do tempo em todos os tratamentos embora tenham sido observados sintomas de fitotoxidez após a primeira aplicação dos herbicidas. As características a...

ABSTRACT. This study evaluated the nutritional characteristics of hay of nineteen hybrids between sorghum and Sudan grass. The experimental design was a randomized block with nineteen treatments and three replications. The chemical characteristics of the respective hays were analyzed 52 days after sowing and 45 and 49 regrowth days. Data were analyzed by analysis of variance, and when the F test was significant, the treatment means were compared by the Scott and Knott test at 5%. Genotypes 1013026 and 1014020 showed similar dry matter content. As for ether extract content, the highest values ranged from 2.20 to 2.66%. Higher values of minerals were observed in hybrids 1013026 and 1011005. In relation to crude protein, higher content values were reported for hybrids 1013021 and 1013020 (14.59 and 15.47% CP). When evaluating the neutral detergent fiber content, lower values varied between 56.05 and 57.07% for hybrids 1013016 and 1011009. Considering the content of acid detergent fiber, values ranged from 32.70 to 35.78%. Values of dry matter digestibility were higher than 50%. All hybrids provide quality hay, however the hybrid 1014019 showed the best nutritional value.

The objective was to evaluate agronomically nine sorghum-sudangrass hybrids (Sorghum bicolor × Sorghum sudanense) and the nutritive value of their respective hays. The experimental design used was randomized blocks in a 3 × 9 factorial scheme, with three replications. Three cuts were made: 42 days after germination, 29 days after regrowth, and 28 days after the second regrowth. All hybrids showed a higher number of plants ha–1 (P < 0.05) in the second cut. For the green matter and dry matter production of the hays, the values ranged from 49.16 to 62.07 t ha–1 and 9.07 to 11.43 t ha–1, respectively. There were no differences (P > 0.05) in dry matter, mineral matter, or ether extract. The hybrids 1013020, BRS 810, 1013016, and 1624F016 showed higher values of crude protein (CP) of 16.49, 16.17, 16.08, and 15.88%, respectively. Differences were observed (P < 0.05) in neutral detergent fiber (NDF) content. The hybrids 1013020, BRS 802, 1013021, 1013016, BRS 810, and 1624F006 presented lower levels of NDF (60.57, 60.74, 62.15, 62.37, 62.58, and 64.70%, respectively). The hybrids BRS 802, 1013016, BRS 810, and 1624F006, stood out above the others, presenting high forage yield and adequate nutritive value (CP content >13% and NDF content <65%).

Nutritive value of hay from sorghum-sudangrass hybrids (Sorghum sudanense vs. Sorghum bicolor) Valor nutritivo do feno de híbridos de sorgo com capim-sudão (Sorghum sudanense vs. Sorghum bicolor