Studies related to the absorptions and nutrient partitioning in organs of irrigated beans are scarce and very important for the improvement of different fertilization models. This study aimed to evaluate the growth of irrigated common bean in winter, through biomass production and nutrients uptake to organs and shoots. We used a randomized block design with three replications and seven composed of time periods of plant collection (10, 20, 30, 40, 50, 60 and 70 days after plant emergence) with separation in leaves, stem, flower+pod and grains. After determination of dry matter, the content of N, P, K, Ca, Mg and S absorbed by shoots and components of bean was estimated. Nonlinear sigmoid and gaussian models were fitted to characterize biomassa production and nutrient uptake during bean growth. The absorption of by bean decreasing in the following order, in kg ha-1: 138 K, 112 N, 66 Ca, 16 P, 11 S and 7 Mg, indicating the high absorption of K and N and demand of K replacement by top dressing. During the initial growth stage, leaves were responsible for 80% of macronutrients accumulation in shoots. In the final growth stage, grains exported 90, 75 and 65% of P, N and Mg absorbed, showing its high export rate.

Growing cover crops preceding planting common beans and corn may influence the yield of these cash crops. This study aimed to evaluate the biomass production and decomposition of crop residue cover and yield of maize and beans grown on these soils as coverings of plants. The experiment was conducted under field conditions in the 2011/12 harvest in Uberaba. With a randomized block designed in a split - plot scheme, seven cover crops were used : sunn hemp ( Crotalaria spectabilis ), jack bean ( Canavalia ensiformis DC.), mil- let ADR300, ADR500 and ENA2 ( Pennisetum glaucum L.), Sorgo (S orghum bicolor L.) and brachiária ( Urochloa brizantha cv Marandú), and subplots in annual succession crops (maize and bean). The millets ADR300, ADR500 and ENA2 among Poaceae and jack beans between Fabaceae produced more dry biomass (9.8, 8.9, 8.6 and 3.8 t ha - 1 ), respectively; after 150 days of decomposition of plant residues of sunn hemp, jack bean, sorghum, brachiaria, millet ADR500, millet ENA2 and millet ADR300 were in the order of 67.9; 71.7; 53.8; 61.7; 49.9; 45.5 and 46.7%, respectively; the maize yield was higher when the culture was grown on resi- dues of millet ENA2 (7.2 t ha - 1 ) and jack bean (6.8 t ha - 1 ), while the bean was higher when grown on millet ADR300 (1.3 t ha - 1 ) and sunn hemp (1.2 t ha - 1 ).

The silicon fertilization has a beneficial effect in enhancing the resistance of plants to diseases, however, this effect can be reduced in the presence of high levels of nitrogen. Given the above, this study aimed to investigate the effect of silicated and nitrogen fertilization in control of rice blast in irrigated system. Plants were grown in an area of tropical lowland and evaluated as to the severity of leaf blast incidence on pan-1 of calcium and magnesium silicate associated with 45 kg ha - 1 of nitrogen topdressing on had lower severity of leaf blast and higher grain yield compared to plants not supplemented with silicon. The combination of silicated fertilization with 90 kg ha - 1 of nitrogen topdressing resulted in a greater incidence of panicle rice blast. After analyzing the results, it was concluded that supple- mentation with silicon and nitrogen promoted reduction in the severity of blast in rice plants in irrigation sys- tem without affecting the yield.

The objective of this work was to evaluate the effect of desalination wastewater on the post harvest quality and conservation of lettuce, cultivars Verônica and Quatro Estações, produced in hydroponic system with coconut fiber. The test was developed in an protected environment from the Department of Environmental Sciences of Universidade Federal Rural do Semi-Árido, located in Mossoró/RN, installed in an experimental design of randomized blocks, in factorial scheme 2 x 2 x 5, with three replicates, the treatments consisted of two lettuce cultivars (Verônica and Quatro Estações), two times of evaluation (at the time of harvest and after three days of conservation) and five levels of salinity of the nutrient solution with or without a further dilution of the tailing desalination of brackish water (1.1; 2.4; 3.6; 4.7 and 5.7 dS m-1). Quatro Estações cultivar showed lower weight loss during the conservation period and higher total value of chlorophyll and pH. The matter of vitamin C and soluble solids were influenced by the reuse of tailing from desalination in nutrient solution, presenting higher level in the highest salt content studied. The cultivated lettuce on coconut fiber irrigated with reuse of the tailing nutrient solution in desalination presented, in general, good appearance both at harvest and after three days of conservation.

The bovine biofertilizer applied through irrigation water in the soil (bio fertigation), can be a viable organic source to maintain fertility levels in agricultural production systems. So, this work was aimed at evaluating the effects of different concentrations of bovine biofertilizer applied by fertigation on corn growth, gas exchange and yield. The experiment was conducted under full sun exposure, in Fortaleza, Ceara, in 100 liter (100 L) vessels. The experimental design was that of randomized blocks with five treatments and five repetitions. Treatments consisted of 0.5 L doses (per plant) of a fertigating solution (biofertilizer + water) weekly applied, with a different biofertilizer concentration to each treatment, as follows: C0 = 0% biofertilizer (control), C1 = 12.5%, C2 = 25% biofertilizer, C3=50% biofertilizer, C4 = 100% biofertilizer. We analyzed the effects on the following variables: plant height, stem diameter, leaf number, shoot dry weight, photosynthesis, stomatal conductance, transpiration and yield. The biofertilizer was the most efficient considering the initial growth and gas exchange. Also, the bovine biofertilizer treatments (as a whole) favored the increase in the weight of 1000 seeds and grain yield.

The trial was developed under greenhouse conditions in the experimental area of IFGoiano - Campus Rio Verde. The research aimed to evaluate the growth of physic nut irrigated with subsurface drip sys- tem. The experimental design was completely randomized, using two irrigation depths (100% and 50% of irri- gation depth) and two models of driplines (M1 and M2) with five replicates (containers) each treatment. Data was submitted to analysis of variance by F test, and in cases of significance, regression analysis was performed. For the data flow of the drippers, we used descriptive statistics. The application of irrigation equal to 100% using the dripper model presented a major development when compared to other treatments.

Allelopathy can be defined as any effect , direct or indirect, beneficial or harmful, a plant on the other, through the release of chemical compounds into the environment. Thus, this study aimed at evaluat- ing, in the laboratory, allelopathic effects of aqueous extracts from cover crops as canola (Brassica napus L. var), crambe (Crambe abyssinica Hochst), sunn hemp (Crotalaria juncea), linseed (Linum usitatissimum L.) and forage turnip (Raphanus sativus L.) at 0, 12.5, 25, 50 and 100% concentrations. The plants used in aqueous extracts were collected during their flowering period of each studied species. Germination tests were performed on seeds gerbox, fresh and dry seedlings biomass, root and shoots seedlings length. The experimental design was completely randomized (CRD) in factorial (5x5) with four replicates per treatment. According to these results, it can be concluded that the tested extracts showed allelopathic effect on seedlings of lettuce, cucumber and soybean on almost all parameters, but for soybean germination and dry mass percentage, this effect was not significant. The sunn hemp extract, despite concentration, contributed the most to increased germination and seedling growth. However, linseed extract showed opposite effect for these parameters in 100% concentrations.

The present work studied the productivity of plant and ratoon cane in soils with different physical, chemical and mineralogical particulars submitted to phosphate fertilization. Randomized block field experi- ments were located at Japungu Distillery (Paraíba State), at Sugar Cane Experimental Station of Carpina (Pernambuco State) and at Bom Jesus Sugar Cane plant (Pernambuco State), from where Argisoils of sandy, mid and clayey textures were selected respectively. The doses of 0, 40, 80, 120, 160 and 200 kg ha - 1 P 2 O 5 were applied at the bottom of the furrow (fertilization foundation). In the subsequent ratoon cane were applied 0 and 40 kg ha - 1 P 2 O 5 (topdressing) for each of the doses applied at the planting. It was concluded in this study that the productivity of sugarcane plant was positively influenced by phosphorus fertilization planting. The ratoon cane only responded nicely to phosphorus coverage in the less weathered medium texture Argisoils; Phospho- rus fertilization of ratoon sugarcane coverage in clay and weathered Argissolos did not promote increased productivity, restricting its recommendation in Argissolos with these characteristics.

It characterization of the variability of soil attributes is necessary so that we can interpret the possible causes of variations in crop yields, because the soil has, naturally, heterogeneity its attributes. Thus, the objective of this study was analyze the spatial variability and dependecy, through the tool GS+, the physical attributes of a typic fluvia underwent two systems use and management of soil: disking and mowing lines. The area managed by disking for over 10 years has 0.5 ha and the area mowing between the lines 13 years ago has 2.3 ha both located on the systematic plan of Experimental Farm in the Valley Curu, Pentecoste. Soil samples were taken in both disturbed and undisturbed areas obeying the spacing of 15 x 15 m, 21 in the area with har- rowing and 78 in the area by mowing between the rows. The density was the only attribute which there wasn’t spatial dependence structure. The other attributes (sand, clay, silt, micro and macroporosity and gravimetric soil moisture and the mechanical resistance to penetration) showed spatial dependence of medium until high. It was observed in the mowing area is made between the lines showed lower values macroporosity and high penetra- tion resistance, the constraint condition for the growth of roots.

This paper describes the composition of fatty acids in oil extracted from seeds of carnaúba ( Copernicia prunifera (Miller) H. E. Moore), an important palm species native to Northeastern Brazil. After extracting the crude oil, the physico - chemical characteristics (density, refraction index, pH, acidity and saponi- fication index) were registered and the chemical composition of the fatty acids was determined by gas chroma- tography (GC - FID). The predominance of saturated fatty acids does not make carnaúba seed oil a promising alternative for the food industry, and the small yield obtained (approx. 5%) may constitute a limiting factor for commercial exploitation, but carnauba seed oil could potentially be used in the production of biofuels, cosmet- ics and detergents.