Corn yield losses caused by weeds may reach up to 80%. Reducing the use of herbicides is one of agriculture's major goals and several alternatives are currently being investigated, including intercropping. In the Brazilian Northeast, corn intercropping with cowpea (Vigna unguiculata (L.) Walp.) is extensively practiced, and there is interest in evaluating weed control under this type of intercropping. The objective of this work was to evaluate the effects of different cowpea planting times, intercropped with corn, on green ear yield of two corn cultivars. The experiment was carried out under randomized design blocks with four replications. AG 1051 and AG 2060 corn cultivars were submitted to the following treatments: no hoeing, two hoeings (20 and 40 days after planting), and cowpea planting (BR 4 - Mulato cultivar, with indeterminate growth) at corn planting and at 5, 10, and 15 days later. Twenty-eight weed species were found in the experiment area. In all characteristics evaluated, except for plant height, ear height, and total number of green ears, where no difference occurred between treatments, the lack of weeding determined the smallest means, while weed control determined the highest. In plots where cowpea was sown, intermediate means were obtained for number and weight of marketable unhusked green ears and for number and weight of marketable husked ears. This suggests that cowpea controlled weeds to a certain extent, especially when it is planted earlier, which was, however, insufficient to avoid green ears yield loss. The corn cultivars evaluated were not different among themselves, except with regard to ear height. The cowpea grain yields were practically null in all plots.

This work had the purpose evaluate physiological quality and incidence of fungi in twelve cowpea seeds cultivars, produced in the state of Ceará, Brazil, in 2005. The physiological quality was evaluated through the germination standard and vigour tests (First germination count) and sanity quality was evaluated through the method paper filter (blotter test) being used four repetitions of 100 seeds. In relation physiological potential of cultivars, it was observed that the cultivars presented low vigour, like Galanjão (0 %), Costela de Vaca (11,49 %) and Parambú (16,6 %). The germination index were low too, except Sempre Verde with 70,33 % the germination of seedlings normal. In respect the incidence of fungi in the seeds, the Fusarium spp. was detected in 0,5 a 0,6 %, Colletotrichum only in Corujinha (0,5 %), Pingo de Ouro 3 (2 %) and Macrophomina phaseolina was detected only in Costela de vaca and Pingo de ouro (0,5 %) and Galanjão (7 %). The incidence of Aspergillus spp. was verified in all you cultivars and Penicillium sp. was detected only in Galanjão, Pingo de Ouro and Costela de Vaca (12 %). Others fungi like Curvularia sp., Phoma sp., Trichoderma sp. and Alternaria sp. were detected in low incidence. The seeds evaluated shown a low physiological quality and the most frequent fungi were those of storage.

An experiment was carried out in the vegetable garden of Plant Science Department at the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró-RN, during the period of June to August 2005, to evaluate the influence of different spacings on rocket economics performance. The experimental design used was randomized complete blocks in a 3 x 4 factorial scheme with four replications. The treatments consisted of the combination of three between row spacings (0,20; 0,25 and 0,30 m) with four within row spacings (0,05; 0,06; 0,07 and 0,10 m). The rocket cultivar grown was 'Cultivada'. Indicators of economic performance were evaluated through gross income, net income, rate of return and profit margin. The highest economics efficiencies were obtained in the following spacings: 0,20 m x 0,05 m; 0,25 m x 0,05 m and 0,30 m x 0,05 m.

This assay was conducted at the Departamento Ciências Vegetais of Universidade Federal Rural do Semi-Árido, with the objective to evaluate the tolerance of the jitirana (aegyptia Merremia L.), in saline solution. The used experimental delineation was the inteiramento casualizado with four treatments and four repetitions. The treatments had evidenced of four levels of salinity: testemunha (0,614ds/m) and the three saline solutions the 10, 20 and 30ds/m. The seeds had been incubadas in the sand esterilizada in caixotes wooden with capacity of 100 sementes.O parameter germination percentage were used as identification character of resistance. Ahead of the displayed one one concludes that the jitirana is tolerant the salinity since the same dS/m came to present reduction in the germination only in the C.E=30.

Moringa oleifera Lam is a leguminous species well adapted to arid and semi arid conditions and is largely used as ornamental for parks and gardens in the animal feeding and human diet and as medicinal. Since research informations on this plant species are scarce, the current work aimed to evaluate the production of leaves, stems and roots dry matter in Moringa oleifera Lam seedlings hidroponicaly grown under physiological conditions or not. The treatments used were the following: (1) nutrient solution containing all required macronutrients (experimental control) or lacking (2) N; (3) P; (4) K; (5) Ca; (6) Mg and (7) S. The Moringa oleifera Lam showed different responses to the imposed treatments. Nutrient solution free of N, P and Mg decreased whole dry matter production (WDM) and increased root to shoot ratios (R/S), however both parameters were not affected in plants grown under absence of K, Ca and S in the nutrient solution.

The slag represent an alternative recommended to replace the traditional source of corrective or fertilizers. This study evaluated different base saturation levels, comparing basic slag to dolomitic limestone as soil acidity corrective agents and in the availability of calcium, magnesium and phosphorus. Thus, one experiment involving soil incubation was conducted in laboratory, during 60 days. The treatments consisted of two corrective agents: dolomitic limestone and basic slag, evaluated by the base saturation method, with eight correction levels (V%) (56, 58, 60, 62, 65, 67, 69 e 71 %) and two replicates. After the incubation period the soil samples was analyzed chemically. The application of the corrective agents promoted efficient neutralization of acidity in soil, especially when basic slag was used. The Ca + Mg level increased depending on the increasing amounts of correctives, reducing the K (Ca2+ + Mg2+)-0,5 ratio. The neutralization of acidity in soil reaction was fast when the slag was used. The soil available P did not increase with increasing levels of soil acidity correctives.

The effect of the plant resistance inducer acibenzolar-S-methyl on in vitro mycelial growth and sporulation of Curvularia eragrostides was evaluated, as well as the time and dosage of its application for the pathosystem yam x C. eragrostides. Five concentrations: 250; 125; 62.50; 31.25 and 15.12 ppm were evaluated for mycelial growth and sporulation of C. eragrostides. The ASM was sprayed onto the leaves of yam plants, at a concentration of 10 g, 20 g, and 30 g of the active ingredient (i.a.) per 100 liters of water, at time intervals of 10, 15, and 30 days before pathogen inoculation. Mycelial growth and sporulation of C. eragrostides was not affect by ASM, at the concentrations of 62.5; 31.25, and 15.12 ppm. Application of ASM was most effective at the dose of 15 g a.i./100 l of water, at 15 days before pathogen inoculation, providing protection against C. eragrostides, with a decrease of up to 76.15 % in yam leaf spot severity.

The word had the aim to evaluate vegetative growing of manicoba function of two management systems, three densities and four plant cuttings. It had been used randomized blocks an sub-divided with factorial (2x3x4) with 5 repetition, being two of management systems (with/without camalhao) and 3 densities of planting (6666; 3333 and 2500 plants/ha) and to sub-parcels four heights (5, 15, 30 and 45 cm). Analyzed variable were: plant height (PLHE), broting number (BRNU), dry matter production (Kg/ha), and ratio leaf/brunch (L/B). Management system and planting density do not manicoba with medium value of 114.4 cm. BRNU increased (P<0.01) with planting cut height of 45 cm and as consequence production increasement of DM of leaves total. Ratio L/B was altered by management system, planting density, cutting height, keeping bigger than other. Among evaluated treatments, cutting height was affected vegetative growing and consequently phitomass accumulation and DM production.

The present research describes the defensive behavior of Haplostegus nigricrus Conde (Hymenoptera: Pergidae) larvae exposed to the stink bug predators Podisus nigrispinus (Dallas), Supputius cincticeps (Stal) e Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae). The main defensive strategy of H. nigricrus seems to be the regurgitation of toxic compounds and the continuous exhibition by the mouth, because all predators died until 24 hours after the direct contact. Only B. tabidus reached the adult phase with H. nigricus larvae as diet what suggests the higher tolerance and hability for detoxication of chemical compounds from that Symphyta.

The work was accomplished in Santa Luzia Farm in the municipal district of Cruz do Spirit Saint, PB. Located in the coordinates Lat 6° 56'52.21" S and Log 35° 7'57.01" O with the objective of verifying the space variability in what concerns the saturation of aluminum in Interchangeable Catiônica's Complex (ICC). the total area considered about experimental unit was of 49 ha. The area was divided in irregular mesh totaling 39 points, each collection point, besides the limits of the property, it was georreferenciado with a Geodesic GPS. The collection of the soil felt in trenches of 1 m3. The tenor of Aluminum in the first horizon of the profile of the studied soil presents characteristic of dependence fort, have seen the relationship n effect/ landing of < 25%. the saturation of aluminum is, in 61,5% of the area, normal and in the others 38,5% of the area demand correction.