-The aim of the study was to evaluate the morphological and productive characteristics of five genotypes of Desmanthus spp. submitted to two cutting intensities (20 and 40 cm), in the semi-arid region of Pernambuco. Of the genotypes studied, three were derived from ecotypes collected in municipalities of Pernambuco (7G, 31D and 50J) and two were from the state of Sergipe, coming from Australia (10AU and 13AU). Four cuttings were made with a frequency of 60 days. The treatments were randomized in blocks, with split plots and three replications. The variables studied were plant height, stem diameter, canopy diameter, the number of leaves per branch, LAI, leaf yield, stem yield, pod yield and forage yield, and leaf stem -1 ratio and pod stem -1 ratio. Genotypes 7G and 31D had higher forage yield and a larger number of leaves per branch. Forage yield was higher in the intensity of 20 cm. The cuttings reduced the total yield, stem yield, pods yield and forage yield, of the different genotypes studied. For leaf stem -1 ratio, the genotype 13AU was higher than genotypes 7G and 50J in the cutting intensity of 40 cm. Genotype 10AU had the highest pod stem -1 ratios in the three cuttings. The differences shown between genotypes of Desmanthus spp., especially 7G and 31D, in the intensity of 20 cm, indicate the possibility of selecting promising materials for cultivation in the semi-arid region of Pernambuco, with desirable morphological and productive characteristics to the forage plants.Keywords: Cutting height. Native legumes. Forage yield. Semi-arid. MORFOLOGIA E PRODUTIVIDADE DE GENÓTIPOS DE JUREMINHA (Desmanthus spp.) SOB DIFERENTES INTENSIDADES DE CORTE

The present study aimed to evaluate the chemical composition, profile and fermentative losses, microbial population and the aerobic stability of mixed silages of cactus pear and gliricidia. the treatments corresponded to the addition levels of gliricidia (Gliricidia sepium (Jacq.) Steud), in the silages of cactus pear (Opuntia ficus indica Mill.), at ratios 0%, 25%, 50%, 75% and 100% gliricidia. The data were subjected to analysis of variance and regression to evaluate the effect of the addition levels of gliricidia. the average related to the opening days were compared by the tukey's test and the average hours of exposure to air were compared by the Student's t-test. the addition of gliricidia in cactus pear silage provided a linear increasing effect for pH, crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF), acid detergent lignin (ADL), neutral detergent insoluble protein (NDIP), and increased aerobic stability (AS). The highest dry matter recovery was estimated in the silages with 58% gliricidia. Based on the fermentative, chemical composition and silage losses, all the silages tested were adequate. However, considering aerobic stability, the addition of at least 25% gliricidia is recommended to provide the animal a feed with important quality and high nutritional value.Both from the productive point of view of the palm and the conservation of the forage nutritional value, cactus pear ensilage would maximize the use of this forage resource, allowing farmers to create a new alternative for the conservation of feed rich in water and energy 1,2 . Cactus pear silage is even more valued for use in feeding ruminants in arid and semi-arid regions, that according to Souza et al. 3 and Borges et al. 4 the inclusion of cactus silage in the ruminant diet reduce water intake, and decrease human-animal competition for water in arid and semi-arid environments where water resources are limited. Furthermore, cactus pear silage allows harvesting of the entire palm planting, standardizing and increasing the regrowth capacity and hence productivity, besides reducing labour with harvest and periodic supply throughout the dry season.Despite some attributes unfavourable to silage, other characteristics of cactus pear as its bioactive compounds should be considered. The cladodes of the cactus pear are chemically modified structures, composed by chlorophyll and a large percentage of water internally, which exerts the photosynthetic functions of the leaves 5 , as well as the percentage of organic acids found in cladodes, which are oxalic, malic, citric, malonic, succinic and tartaric acid, the latter two being smaller 6 and showing great variation, especially when evaluated in relation to the planting site and cultural practices.Another aspect to be evaluated in the cactus pear ensiling process is related to its percentage of water soluble carbohydrates (WSC), since cactus pear is a forage rich in pectic polysaccharides 7 , i.e., esterified sugars with a high concentration of galactose, arabinose, xylose an...

Existem discrepâncias na literatura quanto a identificação de espécies do gênero Desmanthus. Objetivou-se caracterizar anatomicamente três genótipos que representam as espécies Desmanthus pernambucanus (7G, 50J) e D. virgatus (13AU). O material foi coletado no campo experimental da Unidade Acadêmica de Serra Talhada (UAST/UFRPE), na estação seca. Folhas de diferentes idades foram coletadas e fracionadas em pecíolo, nectário extrafloral, ráquis, peciólulo e foliólulo, seguindo-se o preparo das lâminas. A morfologia do pecíolo variou entre genótipos e folhas. O nectário extrafloral apresentou formato de cálice enquanto o peciólulo apresentou-se em aspecto de U em todos os genótipos estudados. Na ráquis, a morfologia do 7G e 50J foi semelhante, em ambas as folhas com projeções superiores, enquanto o genótipo 13AU apresentou formato cilíndrico. O foliólulo apresentou-se com uma única camada de células epidérmicas e mesofilo dorsiventral, exceto nas folhas jovens do genótipo 7G e 50J. Foram observadas cavidades secretoras no tecido floemático em todas as frações estudadas, com exceção dos foliólulos. Ocorreram cristais prismáticos em todos os genótipos e frações estudadas. Existem características anatômicas e morfológicas que permitem a distinção entre as espécies estudadas.

The effects of different management strategies on improving growth and modifying the botanical composition of C3 and C4 perennial grasses grown in a mixed canopy are underexplored. We aimed to evaluate the botanical composition and vegetation dynamics of a mixed canopy containing kikuyugrass (Pennisetum clandestinum Hochst. Ex Chiov) and tall fescue (Festuca arundinacea Schreber cv. Rizomat) subjected to four grazing management strategies over 22 mo. The experimental design was a randomized complete block in a factorial arrangement (two maintenance canopy heights: grazed to 7 cm in the autumn, or uninterrupted and maintained at 12 or 17 cm) with three replicates. The plots were sampled every month throughout the experimental period; the forage mass data were used to determine the botanical composition and leaf area index of the canopy. Although autumn grazing to 7‐cm height promoted an increase in pasture leaf proportion, it did not represent an effective augment in pasture leaf mass in the following winter–spring season. Canopies heights managed at 17 cm presented a greater proportion of tall fescue in herbage mass (81%) compared with those maintained at 12 cm (73%). Severe defoliation in the autumn delayed the regrowth to 12‐ or 17‐cm canopy heights by approximately 90–120 d in both evaluation years. From a farm‐level perspective, this result would restrict the recommendation of this grazing management strategy because this time lapse would demand that the pastures not be grazed for the 25–33% period of the year compared with the pastures that were not grazed in the autumn.

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