The interrill erosion can be the most harmful form water erosion, due it drags of the superficial layer of the soil, where it essential elements to the crop development. This work had the objective of evaluating the soil losses for different slopes and doses of residue of sugar-cane straw. The experiment was led at Soil Conservation laboratory of UFRPE, it was constituted in the evaluation of the water erosion obtained under simulate rains in experimental portions (1,0 m x 0,5 m x 0,1 m). It was observed that there was difference for the applied doses of 0,4 and 0,6 kg m-2 of soil cover, in relation to the bare soil, so much for the soil losses as for it rates them of soil detachment, demonstrating the effectiveness of the cover of the soil in the reduction of the erosion rates. With relationship to the applied slopes, therewas an increase of the soil losses and of the rates of soil detachment, with the elevation of the slopes among all the cover doses. The residues in the surface of the soil reduce the rates of soil detachment and they increase the resistance to the surface water, provoking decrease of the Numbers of Reynolds and of Froude, evidencing the interrill erosion. The laminar slow regime of surface water to attest the interrill erosion.

To evaluate the utilization of the biofetilizer substituting nutrient solution in hydroponic lettuce was carried out the study in greenhouse at Environmental Science Departament of the UFERSA, located in Mossoró, Rio Grande do Norte State, Brazil. The statistical test was realized in randomized blocks, with thee repetitions. Treatments were composed of five nutrient solution (Biofertilizer - T1; Biofertilizer + 25% of the mineral nutrient solution - T2; Biofertilizer + 50% of the mineral nutrient solution - T3; Biofertilizer + 75% of the mineral nutrient solution - T4 and mineral nutrient solution - T5). The fresh and matter biomes, leaf area, diameter of caulis and number of leaf was analyzed. The T5 treatment showed better response in relation to growth parameters and production of hydroponic lettuce, demonstrating that in a hydroponic requires high levels of nutrients readily available to meet the rapid and high nutrient demand.

This work was carried in commercial areas cultivate with muskmelon (Cucumis melo L.), variety AF- 646, in the municipal district of Acaraú, state of Ceará, Brazil. The investigation was split in four treatments: hand cross pollination, open pollination in presence of the honey bee hives, open pollination and resricted pollination. The observed variables were: rate of fruit set, fruit weight and seed number of fruits. The hand cross pollination showed the best effect to number of fruit set, fruit weight and seed number of fruits, following to open pollination in presence of the honey bee hives, open pollination and resricted pollination, without fruit set. Considering the melon cultivated at open fields and during the dry season in NE Brazil, it is possible to conclude that it depends on biotic pollinators and that honeybees promote efficientily the pollination.

O presente estudo teve como objetivo avaliar o efeito dos componentes dos substratos em diferentes misturas submetidos à adubação fosfatada sobre a composição mineral de mudas de mangabeira. Este experimento foi executado no Centro de Ciências Agrárias, UFPB, localizado no município de Areia-PB. O delineamento experimental foi em blocos casualizados, com 17 tratamentos, três repetições, e unidade experimental constando de quatro mudas. Os substratos testados foram acondicionados em sacos de polietileno preto, composto de fibra de coco, com valores variando de 0 a 40 %, esterco bovino de 0 a 25,5 %, terra vegetal de 25 a 70 %, 15 % de areia e superfosfato triplo, nas doses de 0,0; 5,5 e 11,0 g L-1. Foi avaliada a composição mineral dos sistemas radiculares e na parte aérea das mudas aos 150 dias após a germinação das sementes, para os teores de macronutrientes e cobre. Aadição de esterco bovino e de superfosfato triplo provocaram o incremento dos teores de macronutrientes no sistema radicular e na parte aérea das mudas de mangabeira, ao contrário do efeito da adição de terra vegetal e fibra de coco. O teor de cobre na parte aérea das mudas aumentou com o incremento da concentração de terra vegetal e da fibra de coco no substrato. Recomenda-se a utilização das concentrações de 24 % de esterco, 51 % de terra vegetal, 10 % de fibra de coco, 15 % de areia e 8 g dm- 3 de superfosfato triplo, para obtenção dos máximos teores estimados de macronutrientes e de cobre no sistema radicular e na parte aérea de mudas de mangabeira.

It was studied vegetal remainders into four mountain areas: Serra de Bodopitá (Area1), Serra de Bodocongó (Area 2), Serra do Monte (Area 3) and Serra do Canoió (Area 4) located in paraiban Cariri. The study aimed at determines the phytossociolical parameters and for this was used the program Mata Nativa 2. It was also calculated the indexes of Shannon, Pielou equability, diversity of species and families. From the 2972 sampled individuals, 633 belonged to Area 1, 602 to Area 2, 908 to Area 3 and 829 to Area 4. All of them were distributed in 54 species belonged to 25 botanic families. It was observed that the families Fabaceae and Euphorbiaceae had the largest number of species and individuals and after them Cactaceae, Anacardiaceae and Apocynaceae. The Shannon indexes values in Areas 1, 2, 3 and 4 were respectively 2.65; 2.93; 2.35 e 2.59 nats.esp.-1 . The founded densities were 3165 individuals.ha-1 in Area 1, 3010 individuals.ha-1 in Area 2, 4540 individuals.ha-1 in Area 3 and 4145 individuals.ha-1 in Area 4. The four areas had the same species with the most importance values being them: Caesalpinia pyramidalis, Aspidosperma pyrifolium, Bauhinia cheilantha, Piptadenia stipulacea.

The study propagation of non-cultivated plants aims the species domestication, and its propagation can be carried out by seeds. However exist factors that affect the germination, among them there are the size, the weight of seed and the use of chemical substances. The present work was carried out with the objective to evaluate the influence of the weight of seeds and chemical promoters on the seed germination of Hyptis pectinata. It was used seeds collected and classified of sambacaitá in blower machine, which had been placed to germinate on Petri dishes, and kept in germination chamber at 27ºC under constant light. The experimental design was the completely randomized in factorial scheme 2x4, referring two chemical seeds classification llow and heavy seeds) and three substances (GA3, KNO3 and PEG) and the control, with four replications of 50 seeds each. The variables analized were percentage, speed germination index and mean square for time of germination. The statistical analysis was carried out using the software Sanest, and the average values compared by the Test of Tukey 5%. The different classification of seeds by weight present influence on the physiological quality of sambacaitá's seeds. Heavy seeds germinate in higher percentage, and faster speed, and short time. The chemical treatment with KNO3 and GA3 increases the germination percentage, but for the speed germination index and germination do not present significant difference. The use of PEG increases the mean square time of germination of sambacaitá's seeds.

The experiment was carried out at a greenhouse of Plant Science Department of the Universidade Federal Rural do Semi-Árido (UFERSA), Mossoró-RN, with the objective of determing the best treatment with scarlet starglory to with soil on rocket performance cv. Cultivated. A completely randomized desing with six treatments and four replications. The treatments consist of: T1 (scarlet starglory in coverage 35 days) T2 (scarlet starglory in coverage 28 days); T3 (scarlet starglory in coverage 21 days); T4 (scarlet starglory in coverage 14 days); T5 (scarlet starglory in coverage 7 days); T6 - Control (no fertilized soil). The evaluated traits were: plant height, number of leaves per pot, dry mass and yield of grains. The different times of jitirana significantly in coverage plant height, number of leaves per pot, dry mass and yield. The time of 35 days was what provided the greatest increases in plant height, leaf number, yield of green mass and dry.

With the objective to determine the influence of the dehydration and of the size and/or weight on germination percentage and the vigor of jussara palm seeds (Euterpe edulis Mart.), 10 individuals' ripe fruits, picked in the Experimental Station of Ubatuba (IAC) they were classified by size in 5 sieves of circular sieve: 26/64¿ (10,31mm), 28/64" (11,11mm), 30/64" (11,90mm), 32/64" (12,69mm) and 34/64" (13,49mm). It was determined, the medium weight of the classified seeds. The quality of the seeds was evaluated through the following parameters: water content of the seeds; germination and vigor (first germination counting). It was evaluated the drying speed of different seed sizes for 48 hours, in dry chamber. The sizes of 28/64", 30/64" and 32/64" represented 98,7% of the total weight of the harvested seeds and showed similar drying speed, percentage of germination and vigor. With the increase of the drying period, the smaller seeds (28/64") had their germination less affected them the intermediate (30/64") and bigger sized seeds (32/64").

Aiming on estimating the evapotranspiration (ETc) and crop coefficient (Kc) of passion fruit, an experiment was carried out at the Federal University of Ceará - UFC, The field experiment was carried out at the Curu Valley Experiment Station (FEVC) of the Federal University of Ceará, in Pentecoste - CE, during the period of May, 2004 to February, 2005. The evapotranspiration of the crop was estimated trough the law of conservation of masses using the water balance in a controlled volume of soil with a depth of 0.60 m. The period of the water balance was 296 days after transplanting (DAT). The results showed a variable increase of the accumulated the evapotranspiration during the cycle of the passion fruit plant went to the tension of 1,489.3 mm for 35 kPa. The evapotranspiration daily average in the tension was 35 kPa of 5.81mm day-1. The medium values in the crop coefficient were study for the 1.09Penman - Monteith - FAO and 0.88 Class A pan.

The objective of this research was to evaluate the effect two hybrids of maize, cultivated on "safrinha" conditions, in different rates of 08-28-16 formula. The treatments consisted of two hybrids of maize (DKB747 e CO32) cultivated in no-tillage system (SPD) and five rates of fertilizer 08-28-16 (100, 200, 300, 400 e 500 kg ha-1). The randomized block design was used, with subdivided splots and four replications. The maize was sowed on 02/03/2006 using seeder pneumatic of mechanics traction, with four individual lines, spaced of 0.45 m During maize flowering period, morphologic components were evaluated; the harvest occurred on 150 days after the sowing, when the production components were evaluated. The hybrid of maize DKB747 showed greater efficiency, while the hybrid of maize CO32 was more responsive to rates used. NPK rates on 08-28-16 formula above 300 kg ha-1 are not necessary to the hybrid CO32 cultivated on "safrinha" conditions, in Botucatu region, state of São Paulo.