Benito Moreira de Azevedo

Irrigação e fertirrigação potássica na cultura da videira em condições semiáridas

The potassium irrigation management and fertigation adjustment may improve grape yield and quality. Aiming at evaluating the biometric and productive characteristics of the ‘Ribier’ grapevine, under five irrigation levels (50%, 75%, 100%, 125% and 150% of the class A pan evaporation - CAE) and five potassium fertilization doses (2, 4, 6, 8 and 10 days), applied by fertigation, two experiments were carried out in a randomized blocks design, with five treatments and five replications, in Limoeiro do Norte, Ceara State, Brazil. The variables bunch number, size and average weight, soluble solids and yield were evaluated for the five irrigation levels, while the bunch average weight and width, number of berries, soluble solids and yield were evaluated for the five potassium fertigation intervals. The maximum irrigation level (150% of the CAE) and the seven days interval for the potassium fertigations provided the best yield for the ‘Ribier’ grapevine, under the Ceara State semiarid conditions.

Efeito de diferentes lâminas de irrigação na cultura do mamão

The objective of this work was to study the effect of the different irrigation levels at the Carica papaya L. crop, Formosa group, variety Tainung No 1, under the edapho-climatic conditions at the Jaguaribe Apodi Irrigation District (DIJA), Limoeiro do Norte, Ceara. It was applied irrigation levels corresponding to 50; 75; 100; 125 and 150% of the Class A Pan evaporation (ECA). The experimental delineation used was randomized blocks design with three repetitions and five treatments. The analyzed attributes were: average weight of the fruit, productivity and levels of total soluble solids in the fruit. The results demonstrated that the use of bigger irrigation depths increases the productivity. However, it does not modify the average weight of the fruit and the levels of total soluble solids.

Adubação potássica aplicada por fertirrigação e pelo método convencional na cultura do amendoim

The objective of this study was to evaluate the influence of potassium doses on peanut yield, when applied by drip fertigation or conventionally. The experiment was conducted in the field, in an Alfissol in Fortaleza, Ceara. The experimental design consisted of randomized blocks in a factorial arrangement plus one additional treatment [(3 x 2) + 1] and four replications, being studied three K doses (D1 - 25, D2 - 50 and D3 -100 kg ha-1) and two application methods (F1 - Fertigation, F2 - Conventional fertilizer application), plus one additional treatment (control). At 90 days after sowing, harvesting was performed, with 5 plants being taken at random from the central line of each treatment, in each block. These plants were separated by treatment and placed in a screened greenhouse for five days, for the pods to dry. The evaluated variables were: number of fruits per plant, pod weight, yield, 100 seed weight and pod size. The fertigated potassium dose corresponding to the maximum peanut crop yield (1530.68 kg ha-1) was estimated at 69.39 kg ha-1 of K2O. As to the conventionally applied potassium dose that maximized yield was estimated at 65.80 kg ha-1 of K2O, corresponding to a maximum peanut crop yield of 1092.22 kg ha-1.

Produtividade do meloeiro fertirrigado com potássio em ambiente protegido

We studied the effects of three kalium doses applied via fertigation on the yield of melon plants (Cucumis melo L.). The experiment was carried out in a greenhouse installed in Limoeiro do Norte County, Ceara State, Brazil. Plants were irrigated from April to August, 2002 by a regular or a subsurface drip irrigation system. Seeds of the hybrid Bonus 2 were sown at 0.5 x 1.0 m. Streaks were installed to induce the vertical growth of the plants, up to 2.0 m height. The experimental design followed a 2 x 3 factorial random blocks design. The treatments consisted of the combination of three kalium doses (40; 120 and 200 kg ha-1) and tof two depths of application (0.0 m - surface and 0.20 m - subsurface) with four replications per treatment. The total dry matter, leaf dry matter, average fruit weight, soluble solid content of fruits and yield of fruits were evaluated. The subsurface drip irrigated plants produced higher total dry matter and leaf dry matter. The applied kalium levels, however, resulted in no statistic difference for all evaluated variables.

Growth, gas exchange and yield of peanut in frequency of irrigation

This study was conducted to evaluate the effect of different irrigation frequencies on growth, gas exchange and yield of the peanut (Arachis ypogea L). The experiment was conducted in the field using the experimental design of randomized blocks with five treatments, five replications with four plants per plot. The treatments were composed: F2 = (irrigation every 2 days), F4 = (irrigation every 4 days), F6 = (irrigation every 6 days), F8 = (irrigation every 2 days) and F10 = (irrigation every 10 days). At 60 days after sowing (DAS), the gas exchange variables (photosynthesis, stomatal conductance and transpiration) and growth variables (plant height, leaf number, stem diameter and shoot dry matter) were evaluated. The highest irrigation frequency tested (every two days) promoted the best results for plant growth (leaf number, plant height, shoot dry matter) e for leaf gas exchange. The highest yield of field grown peanuts at the conditions prevailing in Fortaleza, Ceara, is associated with the adoption of an irrigation frequency interval of two days.

Fertirrigation potassica in the culture of the fig in Semiárido from Ceará.

O objetivo do trabalho foi avaliar as variaveis de producao da figueira, cultivar Roxo de Valinhos, sob o efeito de diferentes doses de adubacao potassica, aplicadas via fertirrigacao, nas condicoes edafoclimaticas do Distrito de Irrigacao Jaguaribe Apodi (DIJA), Limoeiro do Norte, Ceara. O experimento foi conduzido, em uma area experimental da empresa Figood, Quadra 3, lote 41, no municipio de Limoeiro do Norte (05o20’ S, 38o5’ W, 143 m) com o delineamento experimental em blocos ao acaso, com cinco tratamentos e quatro repeticoes. Os tratamentos foram definidos em funcao da adubacao potassica: 50; 75; 100; 125 e 150% da recomendacao da analise de solo (RAS). Foram avaliadas as variaveis: peso dos frutos, numero de frutos, diâmetro de frutos e produtividade. Os resultados obtidos demonstraram que a aplicacao de doses diferenciadas de K2SO4aplicadas via fertirrigacao, nao alterou significativamente nenhuma das variaveis analisadas. Como os resultados nao foram significativos, o produtor deve aplicar a dosagem minima analisada (50% da recomendacao da analise de solo) devido a grande quantidade de potassio existente no solo da regiao, alem de reduzir os custos de producao e diminuir o risco de salinizacao do solo.

Aclimatização de mudas micropropagadas de Bastão do Imperador em diferentes volumes de recipientes

The Brazilian market of tropical flowers is in a rapid growth stage. The climate of the Brazilian northeastern region, however, tends to hamper plant acclimatization. Considering this, our study aims at determining the most appropriate container (concerning to capacity) to acclimatize micropropagated Torch Lily (cultivar Porcelana) in a greenhouse. The experimental design was randomized blocks with four treatments (container capacities) and five replications. The tested container capacities were: V1 = 50cm3 (small glass - CP); V2 = 150cm3 (small plastic tube - TP); V3 = 300 cm3 (large plastic tube - TG); V4 = 450cm3 (small vase - VP). The characteristics evaluated were: the number of leaves (NF), seedling height (AM), stem diameter (DP), fresh shoot weight (MFPA), fresh root weight (MFSR), dry shoot weight (MSPA) and dry root weight (MSSR). Data were examined by analysis of variance and the Tukey test. The results point to the 450cm3 container as the best suited for Torch Lily acclimatization, since it provided the best seedling growth.

Characterization and selection method of Venturi injectors for pressurized irrigation

Venturi-type chemigation injectors are widely used due to their advantages: they do not require electric power and are cheap to operate. However, they also generate considerable energy losses which affect the pressure in the system. The correct characterization of these systems requires pressures to be correctly set at the inlet, injector and outlet points in relation to main and injected solution flows. These analytical relationships, as described in the International Organization for Standardization’s standard ISO 15873:2002, can be obtained theoretically, although it is recommended that the manufacturer should determine the real behavior of the injector by operational tests. These relationships should also be provided graphically in the form of nomograms in order to facilitate the association of the variables involved and the subsequent selection of a specific model or class and type of assembly. In order to make the right choice, it is also necessary to have precise information on the irrigation sub-units that it feeds and the grower’s fertilization program.

Yield of strawberry crops under different irrigation levels and biofertilizer doses

Strawberry is produced and appreciated in different regions of the world, due to its productive and commercial characteristics. Biofertilizer is an organic fertilizer that is easy to prepare and effective to nourish plants. The objective of this work was to assess the effect of different irrigation levels and anaerobically fermented bovine biofertilizer doses, on biomass accumulation and strawberry crop yield. The experiment was carried out in the experimental area of the UFC, in Fortaleza, Ceara, Brazil, from August to December 2012, under a screened environment. The experimental design was randomized blocks designed into subdivided plots, in which irrigation levels were applied via drip irrigation (equivalent to 33.3, 66.6, 100, 133.3 and 166.6% of the evaporation measured in the Class A tank - ECA), corresponding to the plots. The four doses of bovine biofertilizer (125, 250, 375 and 500 mL plant-1 week-1) were the subplots, with four replications. The assessed parameters were: biomass (root, shoot and total dry matter), fruit diameter, fruit length, number of fruits per plant, average fruit mass and yield. The biofertilizer and irrigation increased strawberry shoot biomass and total biomass. The interaction between irrigation and bovine biofertilizer raised the root matter to 3.7 g. The biofertilizer was nutritionally efficient for the strawberry regarding number of fruit, fruit diameter and yield. Irrigation increased strawberry length and average mass.

FREQUÊNCIA DE IRRIGAÇÃO NO DESEMPENHO ECONÔMICO E PRODUTIVO DO TOMATEIRO NO LITORAL CEARENSE

The objective of this work was to technically and economically evaluate the productivity of tomato grown under different irrigation frequencies in the coast of Ceará, Brazil. The experiment was conducted in the experimental area of the Federal University of Ceará, Fortaleza, State of Ceará, Brazil, from August to December of 2011 and 2012. A randomized block experimental design was used in the two crop cycles, with six irrigation frequencies, consisted of 2 (F2), 3 (F3), 4 (F4), 5 (F5), 6 (F6) and 7 (F7) days of interval between irrigations, and four replications. The treatments were evaluated at twenty days after transplanting (DAT), when the plants were fully acclimated to the field. The harvesting began at seventy DAT and ended at ninety DAT. The variables analyzed were fruit length, diameter and weight, number of fruits per plant and fruit yield. The economic performance of the crop was also evaluated. Tomato producers of the coastal region of the State of Ceará, who aim to increase economic return, i.e., net income, must adopt a twoday irrigation frequency (F2).