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 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 use of natural coagulants and organic filters locally produced and low financial cost can provide attenuation problems in discharge of wastew aters, without treatment, into watercourses. Was ev aluated in this study the efficiency of the coagulation pro cess, using the Ca(OH) 2 in the preparation of Moringa seed extract, followed by filtration sawdust in the trea tment of sewage. In the tank of 150 L containing se wage was added a solution of the moringa seed extract prepar ed with Ca(OH) 2 0.011 mol L -1 at a concentration of 2.2 grams of seed per liter of wastewater to be treated . The coagulated effluent was applied to organic fi lter and the filtrate volume was converted in pore volume. Physi cal and chemical analyses were carried out in the i nfluent and effluent of the two treatment structure for the evaluation of treatment efficiency. The treatments by coagu- lation followed by filtration provided removals of 98.0, 75.3, 75.8, 75.0, 79, 7, 59.0 and 88.3% of tu rbidity, Total Solids, Total Fixed Solids, Total Volatile So lids, Total Suspended Solids, Suspended Solids Fixe d and Volatile Suspended Solids and of 51.2, 88.7, 72.6; 33.5 and 38.5% of Biochemical Oxygen Demand, Chemic al Oxygen Demand, Phosphorus, Nitrogen and Sodium.

The aim of this study was to evaluate the relative expression of three candidate genes, CHIA1, SGF14c and CHS8 * possibly involved in seed quality, in contrasting seed coats from four soybean genotypes. Two genotypes with yellow seed coats, BMX Potência RR and CD 202, and two genotypes with black seed coats, TP and IAC were studied to determine the relative gene expression through the qPCR technique, in sev- en stages of seed coat development for all four genotypes, at 25, 30, 35, 40, 45, 50 and 55 days after anthesis. The CHIA1 and SGF14c genes showed higher expression in cultivar CD 202; the former in the final stages of seed coat development, at 55 days after anthesis, the latter gene at earlier stages, specifically at 25 days after anthesis. The CHS8* gene showed higher expression in CD 202 seed coats at 50 days after anthesis. All three genes expressed at higher levels on genotypes of yellow seed coats, and are considered relevant to new areas of research based on the expression of genes related to seed quality.

Glyphosate is one of best known agrochemicals and i s used to prevent the spread of weeds. However, little is known about the impact of this c hemical on non-target organisms such as the soil mi crobial community. Therefore, the objective of this study w as to evaluate the effect of glyphosate on the micr oorgan- ism population and the microbial attributes of soil s cultivated with yellow and sweet passion fruits. The experi- mental design used was complete randomized blocks i n a 3 x 2 factorial scheme with the times of soil s ample collection (0, 5 and 47 days after herbicide applic ation- DAH) and the two species of passion fruit ye llow ( Passiflorae dulis f. flavicarpa O. Deg.) and sweet ( Passiflora alata Dryand) as the factors,with three replica- tions. No impact of the glyphosate herbicide was fo undon the bacterial communities of soil. However, a mild and transitory impact was observedon the fungal pop ulations, encouraging these populationsat 47 DHA. G ly- phosate changed the carbon microbial biomass and so il microbial attributes, except for total organic c arbon. Multivariate, principal component analysis revealed that the total bacteria, endospore-forming bacteri a, total fungi, carbon microbial biomass and metabolic quoti ent attributes of soil are the most sensitive facto rs for pre- dicting the impact of glyphosate on biological indi cators of soil planted with two species of passion fruit yellow ( P. edulis f. Flavicarpa ) and sweet ( P. alata ).

In order to evaluate the sensitivity of citrus g enotypes: ‘Santa Cruz Rangpur’ lime, ‘Sunki Tropical’ mandarin, ‘Troyer’ citrange, ‘Volkamer’ l emon, and HTR-051 and HTR-069 trifoliate hybrids to salinity during the rootstock formation period in g reenhouse. The genotypes were subjected to five lev els of irrigation water salinity: control, tap water with electrical conductivity (EC w ) of 0.41 dS m -1 and water with EC w of 1.0, 2.0, 3.0 and 4.0 dS m -1 , made from salts NaCl, CaCl 2 .2H 2 O e MgCl 2 .6H 2 O, using the 7:2:1 propor- tion, respectively. The ‘genotypes’ and ‘salinity’ factors were arranged in factorial design (6x5), us ing a ran- domized block, with five blocks and four plants per parcel. The growth and physiological variables wer e evalu- ated registering the most significant effects to sa linity on total dry matter at all genotypes, highli ghting total dry matter accumulation in 'Volkamer' lemon and the hig hest decrease from increasing salinity it is observ ed in 'Troyer' citrange. The 'Volkamer' lemon and HTR – 0 69 can be recommended to formation of seedlings of cit- rus rootstocks under salinity due to its less sensi tivity in the formation of biomass.

The P critical levels in plants depend from soil characteristics which reflect phosphate buffer power. In Pernambuco, soils mineralogical characteristics change at different regions where corn is cultivated. To evaluate P critical levels in corn plants in soil cultivated in different soils and contact periods of this element in the soil, aiming to study the relationships between these critical levels and P adsorption, it was realized an experiment using subsuperficial samples of a Vertissolo Ebânico órtico (VEo) (Mollisol), clay textured with predominance of 2:1 clay mineral and a Nitossolo Vermelho distroférrico (NVdf) (Nitosol), high clay content, predominantly hematitic, colleted at the semi - arid and humid regions of Pernambuco State, Brazil, respectively. The P doses were defined in function of the levels 0; 0.2; 0.4; 0.8 and 1.0 from the P Maximum Capacity of Adsorption (CMAP) of each soil and were incubated by 90; 60; 30; 15; and 0.5 days. The experiment was real- ized into a greenhouse in a factorial scheme (5x5x2), five P levels, five incubation periods and two soils, in randomized blocks delineation with three replicates each. Corn plants were more efficient to utilize P in NVdf, the soil with higher CMAP. The corn shoot critical levels decreased in accordance to the period of incubation in VEo, the soil with lower CMAP.

The objective of this work was to evaluate management systems for the control of Black Siga- toka in the cultivation of banana D'Angola cultivar. The experiment was installed and carried out at Embrapa Acre, Rio Branco - AC with the treatments distributed in randomized complete blocks with six replications consisting of different planting densities, corresponding to T1 - (1.111 plants ha-1; T2 - 1.666 plants ha-1; T3 - 2.000 plants ha-1; T4 - 1.333 plants ha-1; T5 - 2.500 plants ha-1 and; T6 - 1.111 plants ha-1 under rubber trees. The evaluations were carried out during two cycles of production. Plants of cv. D'Angola (AAB) cultivated in 3.0 x 3.0 m, shaded by the rubber trees, presented higher plant height, higher number of functional leaves at flowering and harvest, higher average bunch weight, greater weight of the bunches, longer cycle production and reduced severity of black sigatoka. Highest yields were obtained when we adopted higher densities. The banana intercropping with rubber trees proved to be a good alternative to permit cultivation of cv. D'Angola (long banana).

The present study verified the consumption capacity of Ceraeochrysa cubana when fed nymphs of Aleurocanthus woglumi. The experiments were conducted at the Laboratory of Entomology, Departamento de Fitotecnia e Ciências Ambientais, Universidade Federal da Paraíba – Areia/PB. Was used a completely randomized design in a factorial arrangement. The research was conducted in climatic chamber, regulated to 26 ± 2ºC, 70 ± 10% relative humidity and 12 hours photophase. The predation of C. cubana was evaluated for the three larval instars (1st, 2nd and 3rd), and as prey, nymphs of 1st, 2nd, 3rd or 4th instars of A. woglumi, with 10 repetitions per treatment. The larvae were individualized in Petri dishes (9.0 x 1.5 cm), with as standard food (control) Sitotroga cerealella eggs. The consumption among the predator instar among nymphs was higher and increasing for the first instar nymphs of A. woglumi. The total predation among the predator instar was higher when fed with nymphs of first instar of A. woglumi. The predator when fed with second instar nymphs of A. woglumi had higher intake in the 3rd larval stage. The green lacewing C. cubana is promising as a control agent of A. woglumi in biological control program, considering the infestations with nymphs of first instar of A. woglumi.

Three castor ( Ricinus communis ) genotypes were studied regarding tolerance to high exchange factorial distribution of five doses of exchangeable aluminum added to the soil (0, 0.15, 0.30, 0.60, and 1.20 cmol c dm - 3 ) and three castor genotypes (BRS Nordestina, BRS Paraguaçu, and Lyra). The plants were raised in pots in a greenhouse. At 53 days after emergence, data were taken on plant height, leaf area, dry mass of shoot and root, and leaf tissue content of macronutrients. The most sensitive genotype was the cv. BRS Nordestina, in which the shoot and root dry weight in the highest aluminum content were reduced to 12.9% and 16.2% of the control treatment, respectively. The most tolerant genotype was the hybrid Lyra, in which the shoot and root dry weight in the maximum content of aluminum were reduced to 43.5% and 42.7% of the control treatment, respectively.The increased exchangeable aluminum affected the leaf nutrient content, and the intensity of the response was different among cultivars. The aluminum toxicity increased N, Ca, and Mg contents and reduced on P, K, and S contents. The cv. BRS Nordestina had a drastic shoot dry weight reduction associated with an intense increment in the N leaf content. Thus, the N increment was caused by a concentration effect caused by the limited growth.