The cowpea (Vigna unguiculata (L.) Walp.) is one of the most cultivated leguminous in the world. In spite of being a very studied species, there are theoretical models for the development for different habits of culture. The concept of thermal time, replacing the chronological time, has been used frequently, with the advantage to be independent of location and time of sowing. Considering the relevance of the activity for the State of Piauí, this work had the purpose of describing fenology of the variety BR 17 - Gurguéia, relating the number of day-degrees necessary to the development of each fenological state. An experiment was realized in the Departamento de Fitotecnia of Centro de Ciências Agrárias of Universidade Federal do Píauí, Teresina- Piauí. It was found that the number of vegetative stages is indefinite and that the variety shows at least six reproductive stages. The vegetative stage V1 (2º in the main branch with leaflets fully open) was the longest and from the stadium V10 (11º in the main branch with leaflets fully open) was overlap of vegetative and reproductive stages. The cultivar BR 17 - Gurguéia in rainfed crop, requires 818.2 degree-days from sowing until the early reproductive stage and 1103.5 degree days from planting to the end of the reproductive cycle, with wide adaptability for the State of Piauí; the cultivar BR 17 - Gurguéia presents six reproductive stages, LV the stadium is the longest among the vegetative and reproductive stages, individually, need a greater number of degree- days that the vegetation

This paper aimed to evaluate the use of cactus pear as the main substrate for the production of amiloglucosidase by solid state fermentation with the aid of the filamentous fungus Aspergillus niger. The experiments were conducted at the Laboratory of Agro-industrial wastes at the State University of Southwest Bahia - UESB. The cactus pear was dried up to about 2% moisture. The variables in the fermentation process were water activity (0.891, 0.964, 0.976 and 0.983) and fermentation time (24 h, 48 h, 72 h, 96 h and 120 h). The results showed high enzyme production by the third day of fermentation, irrespective of water activity in all trials, after the fermentation time reduction of enzyme activity was observed, with the highest activity was 60.32 U/g in 72 hours and the water activity of 0.891. During the fermentation process the fungus synthesized and excreted the enzyme without the need for any other inducer addition to forage cactus and water, thus demonstrating the viability of using the palm as raw materials for bioprocesses.

The objective of this work was to evaluate the chemical composition and microbial of biofertilizers at different decompositions times. For this, we used biofertilizers two. The experimental designused was entirely randomized in factorial scheme 2x7 two sources of manure (cattle and chicken) and seven times of decomposition (0, 5, 10, 15, 20, 25 and 30 days), with three replications. We evaluated the chemical parameters (pH, CE, dry mass, N, P, K, Ca and Mg) and microbiological (bacteria, fungi and actinomycetes total). The chicken manure gave significant increase of nitrogen, phosphorus and potassium, dry mass and electrical conductivity. The highest concentration was within 15 to 20 days of decomposition, with the exception of nitrogen, with the highest concentration on the preparation of biofertilizer. In the microbiological analysis, the chicken manure resulted in higher total population of microorganisms (bacteria, fungi and actinomycetes total) compared to beef. The decomposition periods of biofertilizers influence on nutrient levels, diversity and populations of microorganisms.

This paper aimed to characterize the main agricultural productive systems of the county of Ibimirim in the semi-arid region of the state of Pernambuco, Brazil, in order to obtain data that can serve as subsidy to the implementation of agroforestry systems. Different productive unities were characterized through semi-structured interviews with local agriculturists selected through a stratified sampling. Each layer was composed by the main activity executed by the family which correspondent to: group 1: irrigated agricultural systems; group 2: traditional systems and forest extractivism; group 3: apiculture; group 4: handicraft fishing. The sample was composed by 5% of the small agriculturist in the groups 1, 2 and 3 and 2% in the group 4, due to this group being more homogeneous. The irrigated agriculture stood out in economic terms, althought it has demonstrated limited autonomy due to external raw materials dependence in addition to contribute to soil and hydric resource degradation. The traditional systems high adaptability and the apiculture conservationist character have generated a low impact under the local ecosystems. Fishing, forest extractivism and forest management are activities that allow the agriculturist maintenance in the rural environment and constitute a source of revenue during the dry season. The activities diversification and the integration of different productive systems has been a concrete possibility for income generation and improvement in the life quality of the families in the region. This way, the agroforestry systems of multiple use must be priority in rural development programs for the region sustainability.

This paper presents the results of a taxonomic study of the family Poaceae held in Parque Nacional Serra de Itabaiana, with the objective of contributing to the knowledge of species richest of the Park. The PARNA Serra de Itabaiana (10 45'15''S and 37 25'15''O) is located in the state of Sergipe and covers an area of 7966 ha which includes three units, the serra do Cajueiro, Comprida and de Itabaiana. Collections were made between April 2006 and April 2008 and deposited in UFP, ASE, MO, and RB. Information on distribution have been raised from herbaria, literature and databases available on the Internet. We identified 40 species in the PARNA classified into 19 genera, the richest of which is Paspalum L., with eight species. Five species had their distribution extended in this work. A key to identify the species is presented, as well as comments on distribution and ecology.

The blossom-end rot of tomato is characterized by the appearance of a necrotic tissue in the distal part of the fruit. This disorder is not caused directly by the calcium deficiency, but it results from the expression of some genes in stress conditions. Interactions between temperature, water availability, high saline or ammonium concentration, etc., control the appearance of the blossom-end rot in the fruits. The aim of this paper was to evaluate the influence calcium and ammonium on the productivity and blossom-end of tomatoes grown hydroponically. The experiment was carried out in the green house of the Department of Agronomy of the Federal Rural University of Pernambuco, and consisted of factorial arrangement between six levels of calcium and two levels of ammonium in the nutrient solution (6 x 2), with six replications in experimental design of randomized blocks. Calcium treatments were the concentrations of 120, 140, 170, 200, 240 and 280 mg L-1, and ammonium treatments were the absence of this cation in the nutrient solution and the addition of 28.4 mg L-1, corresponding to 15% of total-N of the nutrient solution. The blossom-end rot, productivity, fruit diameter and number of fruits were evaluated. The data were submitted to the analysis of the variance and regression. The calcium addition caused a reduction in the tomato productivity, and the treatments with ammonium caused a lesser incidence of blossom-end rot.

Aiming to evaluate the nodulation and grain yield by cowpea inoculated with rhizobia isolates obtained of soil samples from Brazilian Northeast region, an experiment was carried out in Leonard jars under greenhouse conditions. The experiment was performed on a randomized block design with five replicates and five sampling times, performed at 15, 30, 45, 60 and 75 days after emergence (DAE). Nine rhizobia isolates and the recommended strain (BR 2001) were inoculated on cowpea. Besides, it were used two control treatment: mineral nitrogen (TN, applying 150 mg N plant-1) and an absolute control (T0). Evaluating the number of nodules per plant (NN), nodule dry mass (NDM), plant dry matter (PDM), Accumulated N (Nac), grain dry mass (GDM) and straw dry mass of pods (DMP). Results showed that the NN, NDM, PDM and Nac content increased until 45 DAE. Although variations had been occurred after 60 DAE for these parameters, significant difference was only found for Nac content at 75 DAE. Evaluated parameters (NN, NDM, PDM and Nac) showed a high correlation with GDM. Although no statistical difference had been observed to the strain BR 2001, five of the nine Bradyrhizobia isolates provided GDM production from 1.6 to 2.4 times more than the recommended strain, indicating high potential of use of these isolates as inoculant. However, further experiments are needed, mostly under field conditions to confirm these results.

The effects of thermal gradients on stem add one methodological constraint for estimating sap flow through the Granier method (thermal dissipation probe). The present work studied the effect of natural thermal gradients on estimates of sap flow by using thermal dissipation probe in mango plants. The study was carried by using mango plants of the cultivar Tommy Atkins during two development stages: (a) during the initial development phase of plants with leaf area of 0.66, 0.73, 1.78 m2 , planted in 15 and 50 liters pots. The study was carried in a greenhouse environment and in the field. Different thermal shields were used around the stem of plants in pots in order to minimize the effects of thermal natural gradients. The measurements of thermal differences were obtained from an adult plant with high leaf density and small exposition of branches to solar radiation. Sensors placed in stems of adult plant with high leaf density provided smaller thermal gradients compared to those inserted in young plant stems. It is necessary to cover the whole branch with neoprene and a shield (skirt type) of aluminum paper above and below the location of probe insertion for exposed branches. The air temperature at 2 m height may be used efficiently to correct thermal gradients. It is indispensable the correction of natural thermal gradients in the stem for adequate estimating sap flow density by the Granier method.

The Serra de Itabaiana is located near the coast of Sergipe, in the municipalities of Areia Branca and Itabaiana. It is part of the Parque Nacional Serra de Itabaiaba, which is characterized as being an ecotone. Orchidaceae Juss. is one of the most diverse families in the world and is the fourth richest in the study area. This paper presents a taxonomic survey of the orchids from the area. The fieldwork was carried out during july 2006 to january 2009 in several habitats of the study area and during the dry and rainy seasons. The vouchers are at UFP Herbarium, with duplicates at ASE, BHCB, HUEFS and RB. The current work registered 25 species belonging to 17 genera. Habenaria (5 spp.) and Epidendrum (3 spp.) were the most diverse. It represents around 70% of the total orchid species recorded for the State of which 14 are new records (see Flora of Brazil, www.jbrj.gov.br). The large number of orchid species, which five of them are endemic to Brazil supports the area as a Conservation Site and reinforces the needs for floristic-taxonomic inventories for a better knowledge of the real diversity of the family in the Brazilian Northeastern.

This paper aimed to evaluate the initial growth of castor bean (Ricinus cummunis L.) in response to fertilization with sewage sludge and calcium and magnesium silicate. The experiment was conducted from July to August 2010 at the Institute of Agricultural Sciences (ICA) in Montes Claros, UFMG - MG. The cultivation was carried out on a Cambisol, using as indicator plant castor bean (Ricinus communis) variety BRS Energy. The treatments, in factorial 2 x 4, in randomized block design with three replicates, were: two doses of calcium and magnesium silicate (0 and 1 t ha-1) and four doses of sewage sludge compost (0; 23,81; 47,62 and 71,43 t ha-1, in dry basis). In the experiment, plant height, crown diameter, stem diameter and leaf number were measurement. Calcium and magnesium silicate did not influence the growth characteristics of plant. On the other hand, the castor bean showed response to sewage sludge compost, expressing the maximum value of the growth characteristics at a dosage of 71.43 t ha-1, except for the number of leaves, which did not respond to any treatment.