Maria da Conceição Silva

Produtividade e composição química de gramíneas tropicais na Zona da Mata de Pernambuco

This work was carried out to evaluate the productive potencial and chemical composition of five grasses (Pennisetum purpureum Schum. cv. Pioneiro, P. purpureum Schum cv. Mott; Panicum maximum Jacq. cv. Mombaca, P. maximum Jacq cv. Tanzânia, e Brachiaria brizantha (Hochst) Stapf. cv. Marandu). The cuts were performed at 35 days of intervals and 40 cm above ground. Pioneiro showed higher DM yield (7.35 t DM/ha/35 days) when compared to the Dwarf Elephantgrass (5.28 t DM/ha/35 days) and Tanzânia grass (5.23 t DM/ha/35 days), being similar to the others. Brachiaria brizantha presented the highest total tillering (538.72/m²) however the aerial tiller weight was the lowest for this species. The cultivars of P. purpureum showed higher aerial tillering and lower basal tillering, when compared to the cultivars of P. maximum. The CP concentration ranged from 6.96 to 10.20% and the cultivar Pioneiro presented the highest value. No difference was found among the forages for NDF and ADF, and the mean values were 73.83 and 39.20%, respectively. At the evaluated cut interval, the forages presented a high proportion of leaves (> 80%), showing potential to be used on livestock pasture-based operations in the Forest Zone of Pernambuco.

Relação entre características morfológicas e produtivas de clones de palma-forrageira

This research evaluated the relationship among the morphological and productive characteristics of clones of cactus forage for identification of those that directly contribute to the production. It was evaluated 50 clones of cactus forage planted five years ago and submitted to the first cut two years before the evaluation. Characteristics of the plant and of the cladode were evaluated and data were analyzed by descriptive characteristics, Pearson correlation and by path analysis of the explanatory independent variables on the dry matter production in t/ha/2 years (main dependent variable). Production varied among clones and it was the highest in clones 8, 782 e 418 whose dry matter production was of 40.8; 18.1 and 12.1 tMS/ha/2 years, respectively. There was a low correlation among almost all the explanatory variables and the production considered main variable, so, association of characteristics was needed. Characteristic height associated with plant width explained better the potential of dry matter production in t/ha/2 years because they presented a high correlation with production (r = 0.71) and the highest direct effect (0.69). Indirect and non destructive selection for production have to be based on higher and larger plants.

Variability and heritability of morphologic characters in elephant grass clones in the Forest Zone in Pernambuco

Esta pesquisa foi realizada para avaliar a variabilidade e herdabilidade de caracteres morfologicos de 54 clones de capim-elefante na Zona da Mata de Pernambuco (tres testemunhas locais e os demais provenientes da RENACE/CNPGL). Utilizou-se delineamento em blocos casualizados com testemunhas adicionais. Foram realizados tres cortes de avaliacao aos 60 dias de crescimento. Houve diferencas significativas para diâmetro de colmo, densidade de perfilhos basais e aereos, largura da folha 3, comprimento da folha 5, porcentagem de lâminas foliares, porcentagem de colmo e relacao lâmina foliar/colmo. Os clones da RENACE sao semelhantes aos tradicionalmente cultivados nas condicoes da Zona da Mata de Pernambuco quanto a maioria dos caracteres morfologicos. A cultivar Pioneiro floresceu precocemente nas condicoes ambientais deste estudo. As caracteristicas numero de perfilhos basais e aereos/metro apresentaram alta herdabilidade, o que evidenciando pouca influencia do ambiente na variabilidade entre clones. Considerando a variabilidade entre os clones da RENACE para numero de perfilhos basais e aereos/metro e relacao folha/colmo e a alta herdabilidade desses caracteres, e possivel obter ganhos geneticos para essas caracteristicas no melhoramento do capim-elefante na regiao da Zona da Mata de Pernambuco.

Recovery methods of Brachiaria decumbens Stapf. pastures in the Agreste region of Pernambuco State

In order to identify methods of recuperation of degraded pastures in the Agreste of Pernambuco, an experiment was conducted in the Fazenda Riacho do Papaguaio, municipial district of Sao Joao. It was used a split-plot feature within a confounded randomized block design. The experimental treatments were four recovery managements (deferment, deferment + harrowing, deferment + harrowing + corn as a companion crop, deferment + corn as a companion crop), two levels of nitrogen (0 and 100 kg/ha of N), two levels of phosphorus (0 and 100 kg/ha of P2O5), totalizing 16 experimental treatments with three replications. The harvesting evaluation was taken after 138 days from implementation of the experimental treatments. A significant N and P2O5 interaction was observed with marked increase in forage dry matter mass corresponding to the combination of 100 kg/ha of N and P2O5. The deferment and deferment + corn treatments resulted in higher forage mass yield as compared to the harrowing ones. After 138 days of growth, there was an increase in the percentage of uncovered soil with plow use, while the opposite was true without the use of a plow. Plowing did not demonstrate agronomic viability as a degraded pasture recuperation practice. Allowing the pasture to rest for 138 days during the rainy season promoted its recuperation, primarily with the combined application of nitrogen and phosphate fertilizers. The recovery of nitrogen and phosphate fertilized Brachiaria decumbens Stapf. was associated with decrease of other species.

Influência do fósforo e de diferentes regimes de corte na produtividade e no perfilhamento do capim-de-raiz (Chloris orthonoton Doell)

The work was carried out in a greenhouse, at the Animal Science Department/UFRPE, from October 2000 to May 2001, to evaluate the effect of phosphorus fertilization and different cut systems on the productivity and tillering of the capim-de-raiz (Chloris orthonoton, Doell). The experimental design was completely randomized, distributed in a factorial arrangement 3 x 2 x 2, being three levels of application of phosphorus fertilizer (0, 100 and 200 kg/ha of P2O5), two cut frequencies (30 and 40 days) and two cut intensities (5 and 15 cm). Significant interaction between cut frequency and cut intensity as well as phosphorus fertilization and cut frequency for the DM yield was observed. The best combination between cut frequency and cut intensity was 40 days and 5 cm, respectively, with 10.66 g/pot of DM. The phosphorus fertilization showed higher efficacy when the cut frequency was 40 days (11.70 g/pot of DM). Phosphorus fertilization, cut frequency and cut intensity showed significant effect on the tillering process.

Ensaios preliminares sobre autofecundação e cruzamentos no melhoramento do capim-elefante

The objectives of this work were to evaluate the self-pollination as a tool in the elephantgrass (Pennisetum purpureum) breeding and to compare progenies of Pennisetum purpureum origined from different breeding strategies: self-pollination, intraspecific crossbreeds, and interspecific crossbreeds with Pennisetum glaucum. The experimental treatments were represented by the three fecundation forms: intraspecific crossbreed, interspecific crossbreed and self-pollination. A total of ten families originated from intraspecific crossbreed resulting in 160 progenies; two families originated from interspecific crossbreed resulting in 38 progenies, and two families originated from self-pollination resulting in 40 progenies, was evaluated. The evaluated traits were dry matter production (kg/tussock), dry matter concentration (%), plant height (m), number of basal tillers (n./tussock) and survival index (%), in two evaluations and non-replicated plots. The intraspecific crossbreed, interspecific crossbreed and self-pollination presented average dry matter production of 0.47, 0.78, and 0.46 kg of DM/tussock, at first evaluation and 0.14, 0.23, and 0.22 kg of DM/ tussock, at second evaluation, respectively. This indicates the necessity of plot replication to separate the environmental effect from the genetic effect. The interspecific crossbreed showed potential to generate progenies with satisfactory dry matter concentration which is more appropriated for ensiling. The treatments showed potential to release variability of traits evaluated through vegetative propagation, however, the low survival index of self-pollinated progenies reduces the probability of obtaining pure lines of elephantgrass.

Avaliação de métodos para recuperação de pastagens de braquiária no agreste de Pernambuco: 1. aspectos quantitativos

The experiment was performed to evaluate the productive response of a degraded B. humidicola pasture to different pasture recovery methods. It was used a split-plot within a confounded randomized block design. The main plot was represented by the combination among managements and fertilization levels and the sub-plot by the deferred periods. The experimental treatments were four recovery managements (no-tillage, harrowing, harrowing + corn as a companion crop, no-tillage + corn as a companion crop), two levels of nitrogen (0 and 100 kg/ha of N), two levels of phosphorus (0 and 100 kg/ha of P2O5) and, different periods of deferment (113, 156, 200 and 240 days), totalizing 64 treatments with three replications each one. It was found a significant interaction between recovery managements and P fertilization. The average dry matter accumulation (DMA) was 7.52; 1.68; 1.10 and 4.43 t/ha of B. humidicola for no-tillage, harrowing, harrowing + corn as a companion crop, no-tillage + corn as a companion crop, respectively. The highest deferment period increased DMA, plant heigth and B. humidicola participation in the botanical composition, as well reducing percentage of other species in the DMA and percentage of uncovered soil. Brachiaria humidicola pastures at the initial degradation stage, grown in low available phosphorus soils, may be recovered using a deferment period associated to a phosphorus fertilization.

Estratégias para Uso de Cactáceas em Zonas Semiáridas: Novas Cultivares e Uso Sustentável das Espécies Nativas

No Semiarido brasileiro, os anos mais secos do que a media historica de precipitacao tem se agrupado em periodos de tres a quatro anos e ocorrem a cada tres ou quatro decadas. Instabilidades estas que vem se acentuando nas ultimas decadas, tornando tambem instaveis os sistemas de producao agropecuario da regiao. Fato este que aumenta a importância de cultivo de forrageiras xerofilas nestas areas, entre elas destaca-se a palma forrageira. Diante disto e dos problemas fitossanitario que vem ocorrendo na regiao com esta cultura, crescente e a demanda por genotipos produtivos e adaptados para a referida regiao. Para atender tal demanda o Instituto Agronomico de Pernambuco/IPA em parceria com a Universidade Federal Rural de Pernambuco tem buscado por meio de seu Programa de Melhoramento da Palma Forrageira. Como resultado desse esforco pode-se citar a identificacao de novas cultivares de palma resistentes a praga cochonilha do carmim, as quais foram registrados no MAPA. Neste documento encontra-se a forma de obtencao desses novos genotipos, suas principais caracteristicas morfologicas e resultados preliminares de manejo das mesmas, bem como, de forma muito sucinta, a utilizacao de cactaceas nativas na alimentacao animal. DOI:10.15528/2176-4158/rcpa.v15n2p111-121

Avaliação de métodos para recuperação de pastagens de braquiária no agreste de Pernambuco: 2. valor nutritivo da forragem

The research was carried out to evaluate qualitative aspects of a B. humidicola degraded pasture managed under different recovery methods in Bezerros-PE. A confounded split-plot randomized block design was used. The main plot was formed by the factorial arrangement between managements and fertilization levels. The splitplot model consisted of the different deferment periods. The factors were represented by four recovery managements (no-tillage, arrowing, arrowing + corn, no-tillage + corn), two N levels (0 and 100 kg/ha of N), two P levels (0 and 100 kg/ha of P2O5) and four deferment periods (113, 156, 200 and 240 days), with three replications. CP, NDF, ADF, P, ashes contents and IVDMD were determined. Significant interaction among management systems and P fertilization was observed when NDF, ADF and P concentration of braquiaria were evaluated. B. humidicola deffered for 113, 156, 200 and 240 days showed the following ADF and IVDMD values, respectively: 40.36 and 61.92%; 43.89 and 56.58%; 44.52 and 31.35%; 46.25 and 30.07%.