Soil is an important water compartment into a watershed scale, mainly due to its role in providing water to plants and to the influence of antecedent moisture on the runoff initiation. The aim of this research is to assess the permanence of water effectiveness in the soil under preserved-vegetation constraints in the Caatinga biome, in the semiarid northeastern Brazil. For this purpose, hourly soil moisture measurements were collected with TDR and analyzed between 2003 and 2010 for three soil-vegetation associations in the Aiuaba Experimental Basin. The results showed that in nine months per year soil moisture was below wilting point for two associations, whose soils are Chromic Luvisol and Haplic Lixisol (Abruptic). In the third association, where the shallow soil Lithic Leptosol prevails, water was found non-effective four months per year. A possible reason for the high water permanence in the shallowest soil is the percolation process, generating sub-surface flow, which barely occurs in the deeper soils. In situ observations indicates that the long period of soil moisture below the wilting point was not enough to avoid the blooming season of the Caatinga vegetation during the rainy periods. Indeed, after the beginning of each rainy season, there is a growth of dense green vegetation, regardless of the long period under water shortage.

Rural communities located in the Brazilian Northeast, especially in the semiarid zone, live with water shortages resulting from erratic rainfall. This work proposes the cultivation of saltbush ( Atriplex nummularia ) in the Rural Settlement Project of Boa Fé, Mossoró/RN as alternative to the disposal of reject brine from desalination plant on yield of forage. The statistical design was a split - plot design, being four treatments at the plots, related to irrigation with reject brine water, at different levels of soil moisture by moisture from Field Capacity (FC) (100, 85, 70 and 50% of FC) and in subplots and two levels of organic manure (without fertilized and fertilized) with four replications. The variables of yield and forage quality of saltbush were analyzed. It was observed that saltbush has a great production capacity in terms of fresh matter and drought for saltbush under a level of 85% soil moisture in relation to the field capacity of soil, presenting minimal loss of yield; however, this proved to be productive even with the dry soil. The total yield was satisfactory, showing its viability for forage production.

This study evaluated the growth and agro - industrial productivity of sugarcane varieties subjected to different irrigation levels in the county of Penápolis - São Paulo, Brazil. The experimental design was a randomized block with a factorial arrangement of 2 × 7 (two cultivars of sugarcane: RB965902 and RB855453, at seven irrigation levels: L0 = 0%, L1 = 25%, L2 = 50%, L3 = 75%, L4 = 100%, L5 = 125%, and L6 = 150% of crop evapotranspiration - ETc) with four replicates. The irrigation system was a subsurface drip at a flow rate of 1.4 L h - 1 . The variables evaluated were tillering, culm length, leaf area index (LAI), dry matter, and industrial productivity. The maximum number of plants per linear meter was 30 for variety RB965902 at 100% ETc, and 29 for variety RB855453 at 125% of ETc. Maximum tillering occurred at 120 and 150 days after planting (DAP) for RB965902 and RB855453, respectively. The maximum LAI of BR965902 was 9.57 at 210 DAP and 9.81 at 201 DAP for the RB855453 variety. The RB855453 variety produced an average of 178.93 t ha - 1 with irrigation and 164.81 t ha - 1 without, while the variety RB965902 produced 164.08 t ha - 1 and 154.61 t ha - 1 with and without irrigation, respectively. At harvest, the total recoverable sugars (TRS) were 129.62 kg t - 1 for RB965902 and 131.63 kg t - 1 for RB855443. The RB855453 variety produced on average 14.19 t ha - 1 more than the RB965902 variety.

Studies have shown that some plant species exhibit satisfactory production levels when grown under high salinity levels, whereas others exhibit decreased production due to sodium sensitivity even at low sodium concentrations. The castor bean is moderately sensitive to salinity. The aim of the present study was to evaluate the early growth of three castor bean varieties (BRS Energia, MPA 34 and MPB 01) grown in nutrient solution with increasing sodium concentrations (control, 25, 50, 75 and 100 mmol L - 1 ). A completely randomized split - plot experimental design was used, with a 5x3 factorial scheme and three replicates per treatment. Salinity resulted in decreased dry weight of all castor bean varieties grown for 31 days under hydroponic conditions. The dry weight accumulation was less affected at the root than at the shoot level. Nevertheless, the shoot dry weight decreased with the increasing salinity. MPA 34 exhibited higher early growth than the remaining tested varieties. Salinity affected the early development of the tested castor bean varieties, and this effect was more pronounced at the shoot than at the root. Variety MPA 34 is promising for cultivation under moderate salinity levels.

The great diversity of plants in the Brazilian Semiarid environment represents a vital natural resource for the human populations of these areas. Many of these plants have been subject to extractivism and among these, the species of the genus Stylosanthes , which have occurrence in this region, show great potential, however, studies on this topic are limited, and little is known about the existing variability among these plants. Therefore, further study is necessary, to facilitate the development of cultivars. This might reduce the scarcity of fodder supply in this region, but to commence a plant breeding programme, it is essential to identify genetic variability. Therefore, this study evaluated 25 accessions of Stylosanthes spp., to identify the most suitable candidates to be parents in a plant breeding programme for the semiarid region of the state of Bahia. Two experiments were carried out in different sites in an experimental design of randomized blocks with four replicates, with a spacing of 3.0 × 8.0 m. A large amount of genetic diversity was observed among accessions and the genotypes BGF 08 - 007, BGF 08 - 016, BGF 08 - 015 and BGF 08 - 021 were the most divergent in the overall evaluation. For the structuring of segregating populations, it is recommended to combine the genotypes BGF 08 - 016, BGF 08 - 015, BGF 08 - 007 and BGF 08 - 006, and for the interspecific crosses, a hybrid from the accession BGF - 024 with the accessions BGF 08 - 016 or BGF 08 - 015. This might generate superior individuals for mass descriptors, which are the most important for animal forage breeding.

The aim of this study was to evaluate different organic substrates and phosphorus doses on the growth and leaf content of nitrogen, phosphorus and potassium in rootstocks of Tamarindus indica L. The experiment was performed in a greenhouse nursery located on the campus of the Universidade Federal Rural do Semi-Árido (UFERSA), from March to October 2013. The treatments consisted of three organic sources at a concentration of 40% (v/v) (bovine manure, goat manure and a commercial organic compound) and four doses of simple superphosphate (0, 0 kg m-3, 2.5 kg m-3, 5.0 kg m-3 and 7.5 kg m-3). The experiment was conducted in a randomized block design (RBD), with 12 treatments (substrates), four replications and 10 plants per plot, totaling 480 plants. The goat manure and the organic compound were the most suitable treatments for the production of rootstocks of the tamarind tree. The maximum dose of 7.5 g kg-1 of simple superphosphate caused the highest levels of phosphorus and potassium in the dry mass of shoots. The nutrients in the dry matter of shoots accumulated in the following order: N > K > P.

The potential economic and environmental benefits brought by bromeliads production are significant. It is noteworthy that the high degree of degradation of some ecosystems as the Atlantic forest involve reduction of these species. This factor has been worsened by the elevated degree of endemism of these plants, e.g. Aechmea costantinii (Mez) L. B. Sm., which is a high ornamental potential bromeliad but understudied. Thus, the present research aimed to characterize physical and morphological features of A. costantinii fruit and seeds, describing the different stages of post - seminal development, as well as evaluating seed germination behavior with respect to temperature and light. For this purpose, we used fruit and seeds freshly harvested from an Atlantic Forest fragment, located in the city of Maceió, Alagoas State, Brazil. Tests were carried out under a completely randomized design, in a 6x4 factorial scheme (temperature x light) with four replications of 25 seeds. The polyspermic fruit are of tricarpellate/triloculate type and originated from inferior ovary, containing an average of 73 elliptical and mucilaginous seeds with basal embryo. The germination is epigeal - type and occurs in a great intensity and high speed at 35 °C, regardless light presence or quality.

Seedling production for reforestation aims to achieve the best plant growth in a minimal amount of time, to provide good survival and growth levels after transplantation. During cultivation, it is necessary to know the shading levels that lead to the best growth. The objective of this study was to assess the growth of young Mimosa caesalpiniifolia Benth. plants provided with various amounts of shade in the northeast semi-arid region of Brazil. Four types of shade cloth were tested (0, 30, 50 and 70%). Shoot length, stem diameter, stem dry matter, leaf dry matter, total dry matter and leaf area were assessed. Leaf area ratio, specific leaf area, absolute growth rate, relative growth rate and net assimilation rate were also calculated. The different shading levels affected M. caesalpinifolia growth, with the best growth indicators observed in plants grown under 50% shade, with increases in plant height, leaf area and total dry matter observed compared to the full sun condition.

The use of medicinal plants in the herbal medicine of Brazilian Health System has intensified production and the need for developing efficient agricultural techniques that promote greater productivity of these species. The objective of this work was to evaluate the chamomile production at field conditions as a function of irrigation depths and organic fertilizer rates. The experiment was conducted in the Universidade do Oeste Paulista (Campus II experimental area), in Presidente Prudente, São Paulo State, Brazil. A triple factorial experimental design was used, consisting of irrigation rates (150, 100, 75, 50, 25 and 0% of the reference evapotranspiration - ETo), organic manure types (poultry and cattle manure) and manure rates (0, 3 and 5 kg m-2), with four replications. The capitula production per plant, capitula dry weight and yield per water input (water use efficiency) were evaluated. The supplementary irrigation combined with organic manure fertilization provided the highest capitula yield for chamomile crop in the Presidente Prudente region. The combination of poultry manure at rate of 5 kg m-2 with water depth equal to 150% of the ETo resulted in higher average values of capitula fresh and dry weight and water use efficiency.

In two simultaneous experiments, we evaluated the impact of brackish irrigation water and nitrogen (N) fertilization on the production of citrus (scion-rootstock combinations) and its associated gas exchanges. These experiments were conducted at the Campus of Federal University of Campina Grande, Brazil in a protected environment (shade screens on the sides) using drainage lysimeters. Experiment I used a randomized block design (3 replicates), in a 5 × 3 factorial arrangement, corresponding to five water salinity levels (0.6, 1.2, 1.8, 2.4, and 3.0 dS m-1) and three scion-rootstock combinations: RS1– Common Sunki mandarin (TSKC) × Poncirus trifoliata English (TRENG) - 256; RS2– Common Rangpur lime (LCRSTC); and RS3– TSKC × (Rangpur lime (LCR) × P. trifoliata (TR)) - 059; with Mimo do Céu orange as the scion variety. Experiment II used a randomized block design (3 replicates), in a 3 × 2 factorial arrangement, corresponding to the three scion/rootstock combinations and two nitrogen (N) doses (100 and 200 mg kg-1 of soil). Plants were irrigated with water of 3.0 dS m-1. For both experiments, gas exchanges and mean mass of fruits were evaluated at harvest. Gas exchanges were inhibited in plants under saline stress. Plants grafted with Common Rangpur lime showed greater production potential than did the other genotypes studied, even under brackish water conditions.