The scarcity of good quality water in semiarid region has been the main limiting factor for in- creasing the irrigated area. However, due to greater availability of saline water, and reduced costs, when man- aged carefully, can be a viable alternative. The objective of this research was to study the effects of water use with low (S1 = 0,5 dS m-1) and high (S2 = 4,3 dS m-1) salt concentration on growth of melon plant. Melon (Cucumis melo L., cv Sancho) crop was irrigated with water of low and high salinity water under different management strategies: S1S2S2S2 – T1, S1S1S2S2 – T2, S1S1S1S2 – T3, S2S1S2S2 – T4, S2S1S1S2 – T5, S2S2S1S2 – T6 (the 1st, 2nd , 3rd and 4th term of these sequences correspond to different phases of crop – initial growth, flowering, fruit maturation and harvest, respectively), irrigation with S1 water throughout the crop cycle – T7 (control), varying the type of water every two days throughout the cycle (irrigation with S1 during 2 days fol- lowed by S2 1 day – T8 and with S2 during 2 days and followed by S1 1 day – T9) and irrigation with S2 water throughout the cycle - T10. The experiment was conducted in a completely randomized design with four replica- tions. The use of low and high salinity water applied in different phases of plant growth under different man- agement strategies did not affect the characteristics of melon cultivar Sancho. The cultivar Sancho tolerates irrigation water salinity up to 4,3 dS m-1, without any loss in growth and development.

One of the characteristics of maize cultivation in the Northeast region of Brazil is the diversity of production systems. One can find from large companies, which adopt modern cultivars and relatively high sowing densities, to small properties, with traditional cultivars grown at low sowing densities (cultivation in pits spaced more than 1.0 m). The objective with this work was to evaluate the effects of sowing density (30, 40, 50, 60, or 70 thousand plants ha-1) on green ear yield and grain yield of maize cultivars (AG 405 and BR 106). Green ears and grain are assessed and marketed differently. Consequently the optimum densities for ob- taining each product may be different. In addition, maize cultivars may respond differently to increased density. Densities were achieved by maintaining a constant spacing between rows (1.0 m) and varying the spacing be- tween pits within the same row. Cultivars and sowing densities were combined in a factorial scheme, arranged in a random block design with five replications. The maximum yield of marketable husked green ears of culti- vars AG BR 405 and 106 were obtained with densities of 59 and 62 thousand plants ha-1, respectively. The maximum grain yield of cultivars AG 405 and BR 106 were obtained with densities of 61 and 70 thousand plants ha-1, respectively. In general, to produce marketable green ears, cultivar BR 106 was better in terms of number of ears, but the other cultivar was better in terms of ear weight. Cultivar AG 405 responds better to increased density for grain production.

This study aimed to evaluate the potential for milk production (MP), lactation length (LL) and calv- ing interval (CI), analyze the environmental component affecting these traits, and to estimate the heritability and repeatability for milk production in crossbreds of Murrah buffalo cows in the state of Alagoas, Brazil. Data was composed of 487 observations of MP from 136 lactations recorded between the years of 2000 and 2010. In the analysis of variance for PL, the fixed effects were season (1- October to March, 2 -April to September) and year of the beginning of lactation, calving order and the LL (covariate). For the analysis of LL only the fixed effect of year of the beginning of lactation was included, and finally for the CI analysis, year of the beginning of lactation and calving order. The estimates of covariance were obtained using unicharacteristic analysis by Bayesian inference method, applyingan animal model, through Gibbs sampling. The additive genetic, perma- nent environment and residual effects were included as random effects in the model. The averages (sd) of MP, LL and CI were 2,218.03 kg (408.18), 282.59 days (39.48) e 422.49 days (91.05), respectively. All the effects included in the models were important (P<0.01). The estimates of heritability and repeatability for PL were 0.29 and 0.69, respectively. The results suggest that there is a moderate genetic variability among individuals for PL, indicating the possibility to obtain gain using selection.

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 ).

Over the past few years, the increased use of fossil fuels as well as the unsustainable use of land, through the reduction of native forests has increased the greenhouse gas emissions, contributing defini- tively to the rise in temperature on earth. In this scenario, two environmental factors, directly related to the physiology of crop production, are constantly being changed. The first change is the increase in the partial pres- sure of carbon dioxide (CO2), which directly affects photosynthetic efficiency and the associated metabolic processes. The other change is the temperature increase which affects all the physiological and metabolic proc- esses mediated by enzymes, especially photosynthesis and respiration. Therefore, this review aims to discuss the main effects caused by increased CO2 pressure and the temperature rise in the physiology, productivity and post-harvest quality of plants with photosynthetic metabolism C3, C4 and CAM. Based on physiological evi- dence, the increased atmospheric CO2 concentration will benefit net photosynthesis, stomatal conductance and the transpiration of C3 plants, however in hot, dry and saline environments, the C4 and CAM species present an advantage by having low photorespiration. Studies show controversial conclusions about the productivity of C3 and C4 plants, and the quality of their fruits or grains under different CO2 concentrations or high tempera- tures. Thus, there is a need for more testing with C3 and C4 plants, besides of more researches with CAM plants, in view of the low number of experiments carried out in this type of plants.

The aim of this study was to analyze the physical characteristics of the fruits of cocoa and co- coa producing clonal CCN - 51 submitted to irrigation and nitrogen fertigation applied in semi - arid of Bahia in an experiment conducted in the field on the property in Vale do Sol, Jequié, BA. The statistical experimental design was randomized blocks in a 4x4 factorial with treatments consisting of the sheets of water (L1 = 1146.35 mm, L2 = 1335.66 mm 1525.58 mm = L3, L4 = 1717.58 mm) and the nitrogen (N1 = 249.3 kg ha - 1 , N2 = 307.2 kg ha - 1 , N3 = 365.0 kg ha - 1 , N4 = 422.9 kg ha - 1 ), with four replications. Nitrogen doses and the in- teraction between them with water slides positively influenced the number of seeds per fruit, number of fruits per plant and weight of almonds per fruit; water slides influenced the number of fruits per plant clonal cacao CCN - 51. The water slides, nitrogen and the interaction between these positively influenced the production of dry almonds of cocoa clonal CCN - 51. Treatment L3 N3 showed higher productivity of cocoa almonds for sale with 1025.69 kg ha - 1 .

The objective of this study was to evaluate the reaction of soybean (Glycine max) cultivars to brown spot (Septoria glycines) under different crop management methods. In this study the effects of the following crop management techniques were evaluated on five soybean cultivars (Msoy9001; Msoy8411; Conquista; Emgopa313; A7002): (a) fungicides and hormones, and; (b) time of planting (October, November and December). The experiment was set in Cristalina, GO, Brazil, in a randomized complete block design with eight replications in a factorial scheme (5 x 3 x 4). The chemical control of brown spot was tested as following: 1) Tetraconazol (T) (0.35 L ha-1) Thiophanate methyl + (TM) (0.4 L ha-1); 2) Stimulate ® [indolbutiric acid 0.005%, kinetin 0009% and giberelic acid (GA3 0.005%) (0.10 L ha-1)] + T (0.35 L / ha) + TM (0.4 L ha-1); 3) T (0.5 L ha-1), and; 4) control without any product. For each plot was evaluated the disease severity and incidence, and yield of seeds. Msoy8411 and Emgopa-313 planted in November presented the lowest amount of disease, and the highest seed yield. Considering the analysis of all cultivars, the chemical treatments that significantly reduced disease were Tetraconazol (0.5 L ha-1) and the chemical combination [Stimulate ® (0.10 L ha-1) + Tetraconazol (0.35 L ha-1) + Thiophanate methyl (0.4 L ha-1)].

This study aims to provide doses of P 2 O 5 rates in Regolithic Neossoil, and evaluate the phos- phorus waste (P) in the soil and leaf content in three successive cowpea - beans crops. The experiment was car- ried out at field conditions, in Areia city – PB, in the period January to December 2007 in a randomized block with six treatments (0, 100, 200, 300, 400 and 500 kg ha - 1 P 2 O 5 ) and four replications. The first crop production variables (green beans per plant (PGVP), productivity of pods (PV) and dry beans (PGS) as a function of the above treatments, and in the last two harvests, the same variables in the production function were evaluated residual phosphorus in the soil. Phosphorus content after the first crop (49.53 mg dm - 3 ), corresponding to a residue (38.33 mg dm - 3 ) was higher initially to that in soil (11.2 mg dm - 3 ) before the first crop. Foliar - P for the highest values were observed for the first crop. Already the third crop, introduced himself as one of lower con- centration of P in the leaves, 1.56 g kg - 1 . The dose of 280 kg ha - 1 P 2 O 5 gave residue in P sufficient for the maxi- mum production of green beans per plant of 252 g, the second crop soil's estimated maximum yield of pods, 6.3 to 7.3 t ha - 1 at the first and second crops were obtained with Keywords : Vigna unguiculata . Phosphorus waste. yield.

The reuse of waters served in industries is winning space in the current days, in face of possibility of its use in agriculture. It was aimed with this work to evaluate the effect of levels of available water in the soil and of effluents of industries of supply Campina Grande, Paraíba state, Brazil, on the chemical attributes of the soil and on the phytomass and production variables of the castor oil plant, variety BRS Nordestina. The experiment was in greenhouse in entirely randomized design in factorial scheme 5 x 3 with 3 repetitions, with 5 water types and 3 available soil water levels. The studied treatments promoted increase in all soil chemical attributes at the end of the experiment. The interaction types of water and levels of available water in the soil was significant for all phytomass and production variables, except for the length of the root. The largest value for the phytomass and production variables was obtained for the treatment with 100% of available water in the soil and wastewater of COTEMINAS. however, the number of male flowers didn't suffer significant effect of the levels of available water of the soil with the wastewater of COTEMINAS.

The rio Doce river basin has great silvicultural potential, areas cultivated with pasture are con- verted to forest plantations. Physical processes in the soil, especially the infiltration water, are very dependent on the type and management of its coverage. The objective of the present study was to evaluate the differences between rates of water infiltration in soils submitted to eucalyptus plantations and pasture and adjust empirical models of infiltration. The experiment was conducted at four sites in the Rio Doce river basin, MG, Brazil, where two were planted with eucalyptus and two with pasture. Five infiltration tests using the concentric rings method were performed in each area. Results show that the soils infiltration rate with eucalyptus plantations were higher than those found in soils from pasture areas, with stable infiltration rates of 78 and 165 mm h-1 in eucalyptus and 47 and 50 mm h-1 in pasture. The model of Horton indicated the highest adjusted confidence index for the four sites analyzed.