Irrigation Blades Research Articles

Morphological Behavior of Green Onion (Allium fistulosum L.) Irrigated with Saline Water in a Protected Environment

To elucidate the tolerance of green onion to high salinity, this study aimed to evaluate the effect of the application of saline water on the irrigation of green onion grown in a protected environment in the Agreste de Alagoas region. The experiment was developed in a protected environment at the Federal University of Alagoas - Arapiraca Campus. The experimental design was entirely randomized, and the treatments were composed of five irrigation blades: one level of salinity and four repetitions. Irrigation occurred daily via drainage lysimeters. Two cultivation cycles of 30 days each were carried out. At the end of each cycle, the following parameters were analyzed: plant height (PH), number of tillers (NT), root length (RT), fresh mass of the aerial part (FMAP), dry mass of the aerial part (DMAP), fresh mass of the root (FMR) and dry mass of the root (DMR). The data were subjected to analysis of variance (ANOVA) via SISVAR 5.6. A statistically significant difference was found, and the Tukey test was applied (p < 0.05). In the first cycle, the variables PH, FMAP and DMR had significant effects on the number of irrigation slides. In the second cycle, only the PH was significant, highlighting the influence of saline irrigation on the increase in this variable. Thus, in both cycles, the PH was the only variable with a significant effect on the number of saline irrigation blades. FMAP and DMR were influenced by the saline water used. Saline irrigation is an alternative for the management of green onion in a protected environment under the conditions of Agreste in the state of Alagoas.

Production and Post-Harvest of Yellow Melon Under Irrigation Blades and Use of Biostimulant

Production and Post-Harvest of Yellow Melon Under Irrigation Blades and Use of Biostimulant

Use of microlysimeters to determine soil water evaporation as a function of drainage

The aim of this study was to test two models and two sizes of microlysimeters to determine soil water evaporation as a function of the removal of water by drainage at the bottom of the units. The experiment was conducted at the experimental field of the State University of Mato Grosso (UNEMAT) in Tangará da Serra, Mato Grosso, Brazil. Soil water evaporation was determined using microlysimeters constructed from rigid PVC tubes, of which two models and two sizes were tested. The four microlysimeter treatments were: 100 mm diameter without drainage (ML100WD), 100 mm diameter with drainage (ML100D), 150 mm diameter without drainage (ML150WD), and 150 mm diameter with drainage (ML150D). The microlysimeters were fitted to an irrigation blade of 60 mm and compared to applications with four irrigation blade sizes (15, 30, 45, and 60 mm). Water evaporation from the soil was obtained from the mass variation of the microlysimeters, and was then compared to the soil water evaporation determined using weighing lysimeters. The obtained data were analyzed using descriptive statistical techniques, tests of means, and regression analysis. The soil water evaporation values present significant differences between the two microlysimeter sizes (100 and 150 mm diameter) and the two models (with and without water drainage). Soil water evaporation is affected by the water drainage that occurs at the bottom of the microlysimeters. There was no difference in soil water evaporation between irrigation rates within the same microlysimeter size and model. The two models and the two microlysimeter sizes tested can be used for the quantification of soil water evaporation, due to the high determination coefficients observed when compared to the evaporation observed with the weighing lysimeters.

Soil susceptibility to salinity and sodicity in sorghum areas under abiotic stress

Sorghum is a C4 grass adapted to saline and water stress, common in semiarid regions. Therefore, deficit irrigation is an alternative for rural producers, since productivity is not considerably affected. However, the use of brackish water can lead to salinization and/or sodification of the soil. Based on this, the objective was to evaluate the effect of irrigation water salinity and deficient irrigation depth on the soil sodification and salinization process. Two different experiments were carried out, designed in randomized blocks, under four irrigation blades (IB1 = 53%, IB2 = 67%, IB3 = 85% and IB4 = 94% of Culture evapotranspiration (ETc)) and four salinities, expressed in electrical conductivity (ECw) - 1.5; 3.0; 4.5 and 6.0 dS m-1. The variables analyzed were conductivity of the saturation extract (ECse) and the Sodium Adsorption Ratio of the extract (SARse), estimated by soil-water suspension 1:2.5 in layers 0 - 20 and 20 - 40 cm of the soil, considering their average.

Water stress mitigation by silicon in sweet-potato

The objective was to evaluate the effect of the reduction in the irrigation blades under silicate fertilization via soil on growth, branch emission, production of fresh phytomass of aerial part, yield of marketable tuberous roots, and agricultural water use efficiency by plants of the sweet-potato variety Campina, with purple skin. The treatments were arranged in subdivided plots, distributed into randomized blocks, using a 2x5 factorial scheme with three repetitions, totaling 30 experimental units. The plots were two irrigation blades of 100 and 50% of the crop evapotranspiration – (ETc) and the subplots corresponded to the silicon doses of 0.0, 0.5, 1.0, 1.5, and 2.0 g plant-1. At the end of the experiment, the following variables were evaluated: stem diameter, branch emission, fresh phytomass of aerial part, phytomass of marketable tuberous roots, yield, and water use efficiency by plants. According to the results, the reduction from 100 to 50% of the ETc caused inhibition of growth, production of fresh phytomass of aerial part, and yield of marketable tuberous roots. The crop revealed to be more sensitive to water stress regarding yield than regarding growth or biomass formation by the aerial part and marketable tuberous roots.

THE PRODUCTION PERFORMANCE OF FODDER SORGHUM ACCORDING TO IRRIGATION SHEETS AND LAND COVER

The objective of the present work was to evaluate the productivity and efficiency of the use of the water in the culture of sorghum forager (BRS Black Tip) under different blades of irrigation (50; 75; 100; 125 and 150% of the evapotranspiration of the culture, ETc) associates the different levels of covering deceased (mulch) (0.00; 2.50; 3.75; 5.00 and 6.25 cm). The experimental delineation was made use in subdivided parcels, 5 x 5 with 5 repetitions, having totalized 125 experimental units. It was analyzed: productivity of cool mass, productivity of dry substance, productivity of seed, weight of 100 seed, weight of the seed for panicle, efficiency of use of the water in the production of cool mass in (kg m-3 and R$ m-3). For the results it was possible to conclude that, the factors of production in irrigation blades and in bagana coverage had been promising for the productivity of the culture of sorgo; The significant effect for efficiency in the use of the water in the 0 variable of productivity of cool biomass and dry substance in kg m-3 and R$ m-3, indicate this being a promising culture for the region, associated with the adopted techniques of culture in the present work.

Produtividade da alface cultivada em campo e ambiente protegido em resposta às lâminas de irrigação e níveis salinos

Objetivou-se avaliar, por meio da biometria e da produtividade, a resposta da alface a lâminas de irrigação e níveis salinos em condições de campo e em ambiente protegido. O delineamento foi em blocos ao acaso, 5 blocos, em esquema fatorial 5x5. Utilizou-se lâminas de irrigação: L1= 50; L2= 75; L3= 100; L4= 125 e L5= 150% da ETc e níveis de água salina: S1= 0,12; S2= 1,12; S3= 2,12; S4= 3,12 e S5= 4,12 mS cm-1. As variáveis avaliadas foram: altura de planta (AP), diâmetro da copa (DC), índice de área foliar (IAF), índice de número de folhas (INF), matéria fresca total (MFT), matéria seca total (MST), produtividade da alface (PA) e produtividade do uso da água na alface (PAA). Os dados obtidos foram submetidos à análise de variância e análise de regressão em superfície de resposta, utilizando o software estatístico R. Para a biometria, os melhores resultados foram observados para a variável AP em ambiente protegido e o DC em campo. O IAF tiveram melhores resultados em campo e a variável INF, em ambiente protegido. Para a PA, o cultivo em campo obteve os melhores resultados atingindo uma produtividade de 13,52 t ha-1. Para as variáveis AP, DC, IAF, INF, MFT, MST e PA os melhores resultados foram obtidos para lâminas iguais ou superiores a 100% da ETc e a salinidade entre 0,12 e 1,12 mS cm-1. Já a variável PAA teve comportamento decrescente com o aumento da lâmina de irrigação nos dois ambientes de cultivo.

Gas exchange and putrescine content as drought stress indicators in corn cultivars fertilized with silicon

The effects of drought stress on maize have been extensively reported in tropical and subtropical areas, including morphological changes in plants and reductions in the grain yield. The development of sustainable alternatives that help mitigate the negative impacts of water stress is indispensable for the development of agricultural crops. This study evaluates the effect of silicon fertilization in two irrigation blades, on gas exchange, putrescine content, quantification of Ca, K, Zn, and Fe by neutron activation and grain yield in two maize cultivars, tolerant and sensitive to drought stress. Two experiments were conducted, the first using BR-1010 (sensitive to drought stress) and the second using DKB-390 (tolerant to drought stress), in 19 dm-3 pots with one plant in each pot. The experiment was organized in randomized blocks, in a factorial scheme, combining two irrigation blades (30 percent and 100 percent of necessary water replacement) and two silicon conditions per pots: control (-Si), and 27g Si (+Si) using calcium silicate (10.5 percent Si) with four replicates. The contents of putrescine, Ca, K, Zn, and Fe, as well as transpiration rate, stomatal conductance, and net photosynthetic contents were quantified. Maize yield was measured at the end of the study. It was concluded that supplementation with Si contributes to a 12 percent increase in yield for BR-1010 (drought sensitive) and 14 percent for DKB-390 (drought tolerant). Si increased the net photosynthetic rate, transpiration rate, and stomatal conductance in DKB-390. The content of putrescine increased in plants submitted to drought stress and can be considered as an indicator of drought stress. The leaf contents of Ca, K, Zn, and Fe varied according to the cultivars and water blade studied.

PRODUÇÃO FORRAGEIRA E EFICIÊNCIA DE UTILIZAÇÃO DA ÁGUA DO CAPIM SUDÃO SUBMETIDO A DIFERENTES LÂMINAS DE IRRIGAÇÃO1

PRODUÇÃO FORRAGEIRA E EFICIÊNCIA DE UTILIZAÇÃO DA ÁGUA DO CAPIM SUDÃO SUBMETIDO A DIFERENTES LÂMINAS DE IRRIGAÇÃO1
 
 WELLINGTON MEZZOMO2; MARCIA XAVIER PEITER3; ADROALDO DIAS ROBAINA4; JARDEL HENRIQUE KIRCHNER5; ROGÉRIO RICALDE TORRES6 e BRUNA DALCIN PIMENTA7
 
 1 Trabalho retirado da tese intitulada: “Viabilidade técnica e econômica da produção de forragem do capim sudão irrigado por aspersão convencional”, do autor Wellington Mezzomo2 
 2 Eng. Agrônomo, Mestre, Doutorando no Programa de Pós-Graduação em Engenharia Agrícola, UFSM, Avenida Roraima, nº 1000, bairro Camobi, Santa Maria, RS, Brasil, CEP: 97195-000, wellingtonmezzomo@gmail.com.
 3 Eng. Agrônoma, Doutora, Professora Associada do Departamento de Engenharia Rural, UFSM, Avenida Roraima, nº 1000, bairro Camobi, Santa Maria, RS, Brasil, CEP: 97195-000, mpeiter@gmail.com.
 4 Eng. Agrônomo, Doutor, Professor Titular do Departamento de Engenharia Rural, UFSM, Avenida Roraima, nº 1000, bairro Camobi, Santa Maria, RS, Brasil, CEP: 97195-000, diasrobaina@gmail.com.
 5 Eng. Agrônomo, Doutor, Professor do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Rua Nelsi Ribas Fritsch, nº 1111, bairro Esperança, Ibirubá, RS, Brasil, CEP: 98200-000, jardel.kirchner@ibiruba.ifrs.edu.br
 6 Eng. Agrônomo, Doutor, Professor do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Rua Eng. João Viterbo de Oliveira, nº 3061, Zona Rural, Vacaria, RS, Brasil, CEP: 95219-899, rogerio.torres@vacaria.ifrs.edu.br.
 7 Eng. Agrônoma, Mestre, Professora do Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Sul, Rua Nelsi Ribas Fritsch, nº 1111, bairro Esperança, Ibirubá, RS, Brasil, CEP: 98200-000, bruna.pimenta@ibiruba.ifrs.edu.br.
 
 
 1 RESUMO
 
 As pastagens cultivadas são a forma mais prática e viável economicamente para alimentação bovina, entretanto, na região sul do Brasil no período de primavera-verão a qualidade e a disponibilidade forrageira decaem em razão da irregularidade pluvial, fazendo-se necessária a utilização da irrigação. O capim Sudão (Sorghum sudanense (Piper) Stapf), cultivar BRS Estribo vem se destacando em relação as demais gramíneas de verão, porém o suprimento hídrico ótimo ainda é desconhecido, pois as pesquisas divergem sobre os resultados. O objetivo, foi avaliar a produtividade do capim Sudão sob diferentes lâminas e determinar a eficiência na utilização da água em dois anos de cultivo (2015/2016 e 2016/2017). Os experimentos foram conduzidos na Universidade Federal de Santa Maria, baixo o delineamento experimental em blocos ao acaso com cinco lâminas de água, 25, 50, 75, 100 e 125% da evapotranspiração de referência (ETo) e tratamento testemunha sem irrigação, todos com quatro repetições. Houve diferença estatisticamente significativa para os distintos tratamentos, sendo determinado a máxima eficiência técnica para produção de massa seca e eficiência de utilização da água, no Ano 1 as lâminas de água foram 103,1% e 73,6% da ETo respectivamente e no Ano 2 foram as lâminas com 120,8% e 95,6% da ETo.
 
 Keywords: evapotranspiração de referência, massa seca, BRS Estribo.
 
 
 
 
 
 MEZZOMO, W.; PEITER, M. X.; ROBAINA, A. D.; KIRCHNER, J. H.; TORRES, R. R.; PIMENTA, B. D.
 FORAGE PRODUCTION AND EFFICIENCY IN THE UTILIZATION OF WATER IN SUDAN GRASS SUBMITTED TO DIFFERENT IRRIGATION DEPTHS
 
 
 2 ABSTRACT
 
 Cultivated pastures are the most practical and economically viable way to feed cattle, however, in southern Brazil, during spring-summer, forage quality and availability decline due to rainfall irregularity, irrigation is required. Sudan grass (Sorghum sudanense (Piper) Stapf), cultivar BRS Estribo has been outstanding in relation to the other summer grasses, however the optimal water supply is still unknown, as research diverges about the results. The objective was to evaluate the yield of Sudan grass under different depths and to determine the efficiency in the utilization of water, in two years of cultivation (2015/2016 and 2016/2017). The experiments were conducted at the Federal University of Santa Maria, under a randomized block design with five water depths, 25, 50, 75, 100 and 125% of reference evapotranspiration and control treatment without irrigation, all with four repetitions. There was a statistically significant difference for the different treatments, being determined the maximum efficiency technique for dry mass production and efficiency in the utilization of water, in Year 1 the water depths were 103.1% and 73.6% of ETo respectively, and in Year 2 depths were 120.8% and 95.6% of ETo.
 
 Keywords: reference evapotranspiration, dry mass, BRS Estribo.

Performance of two lettuce cultivars under different amounts of irrigation in protected environment

The scarcity of information on the demand of water for the cultivation of vegetables, such as lettuce, in protected environment, especially with regard to the adequate management of irrigation, limits productive performance. The objective of this study was to evaluate the effect of different irrigation slides on two cultivars of lettuce in protected environment. The experiment was conducted in Chapadinha - MA, from March to May 2017. The cultivars of lettuces used were Brava and cv. Grand Rapids-TBR, in a completely randomized experimental design with 5 treatments consisting of irrigation blades: 6,0, 12,0, 16,5, 19,5 e 31,8 mm corresponding to the tensions 6, 10, 15, 30, e 50 kPa, respectively, and five replications, totaling twenty five plots per cultivar. The following variables were analyzed: plant height, stem diameter, number of leaves, root volume, fresh shoot mass, shoot dry weight, fresh root mass, root dry mass and root length. For the cultivar Brava, the irrigation blade for tension of 50kPa, recorded the highest absolute yield of fresh and dry mass of the shoot, with averages of 65.99 g and 7.68 g, respectively. Likewise, for the cultivar cv. Grand Rapids-TBR, the 50 kPa strain also provided the highest numerical estimate for fresh and dry shoot mass, 129.09 g and 51.03 g, respectively. The blades corresponding to the tensions of 6 and 10kPa, consumed about 18 mm per plant more than the tension of 50 kPa, for both cultivars. In an equivalent way, the fresh mass of the aerial part had greater increase in the tension of 50 kPa (65.99 g).

DESENVOLVIMENTO DA CULTURA E PRESENÇA DE E. COLI NA SALSA IRRIGADA COM ÁGUA RESIDUÁRIA TRATADA POR RADIAÇÃO SOLAR

DESENVOLVIMENTO DA CULTURA E PRESENÇA DE E. COLI NA SALSA IRRIGADA COM ÁGUA RESIDUÁRIA TRATADA POR RADIAÇÃO SOLAR
 
 
 MARIANA ALEXANDRE DE LIMA SALES1 E RODRIGO MÁXIMO SÁNCHEZ ROMÁN2
 
 1 Doutora em Agronomia: Irrigação e Drenagem. Rua Heleni de Souza Costa, 41 – Jardim Ypê, 18.608-710, Botucatu-SP, Brasil. mal_sales@hotmail.com
 2 Departamento de Engenharia Rural, Faculdade de Ciências Agronômicas, Universidade Estadual Paulista (UNESP) Campus de Botucatu. Fazenda Experimental Lageado, Avenida Universitária, nº 3780, Altos do Paraíso, CEP: 18610-034, Botucatu – SP. Brasil. rodrigo.roman@unesp.br
 
 
 1 RESUMO
 
 O objetivo deste trabalho foi avaliar a influência da água residuária doméstica tratada por radiação solar (ARD-TRS) no desenvolvimento da salsa (graúda portuguesa), além de verificar e quantificar a presença de Escherichia coli na cultura. O experimento foi realizado na FCA/UNESP no município de Botucatu - São Paulo, o qual consistiu na aplicação de diferentes porcentagens (0, 25, 50, 75 e 100%) de ARD-TRS na lâmina total de irrigação. Os resultados obtidos foram satisfatórios, visto que no geral houve um aumento nos valores de altura da planta, número de talos, diâmetro do maior talo, diâmetro da touceira e massa da matéria fresca e seca, observando-se diferenças significativas em função da porcentagem de ARD-TRS na lâmina total de irrigação. Assim conclui-se que, a utilização de diferentes porcentagens de ARD-TRS na lâmina total de irrigação influenciou positivamente no desenvolvimento da cultura estudada, apresentando uma população de E. coli na água de irrigação < 100 NMP 100 mL-1 e nas culturas ≤ 1.000 NMP 100 mL-1.
 
 Palavras-chave: reuso da água, SODIS, Petroselinum Crispum, coliformes, produtividade.
 
 SALES, M. A. L.; SÁNCHEZ-ROMÁN, R. M.
 DEVELOPMENT AND PRESENCE OF E. COLI IN PARSLEY IRRIGATED WITH DOMESTIC WASTE WATER TREATED WITH SOLAR RADIATION 
 
 
 2 ABSTRACT
 
 The objective of this study was to evaluate the influence of solar-treated domestic wastewater (ARD-TRS) on the development of parsley (Portuguese coarse), and to verify and quantify the presence of Escherichia coli in the crop. The experiment, carried out at FCA / UNESP, in Botucatu - São Paulo, consisted of the application of different percentages (0, 25, 50, 75 and 100%) of ARD-TRS in the total irrigation depth. The results obtained were satisfactory, since in general there was an increase in values ​​of plant height, number of stalks, diameter of the largest stalk, clump diameter and mass of fresh and dry matter, and significant differences were observed as function of the percent of ARD-TRS in the total irrigation depth. Thus, it was concluded that the use of different percentages of ARD-TRS in the total irrigation depth had a positive influence on the development of the studied culture, presenting a population of E. coli in irrigation water <100 NMP 100 mL-1 and in cultures ≤ 1,000 NMP 100 mL -1.
 
 Keywords: water reuse, SODIS, Petroselinum crispum, coliforms, productivity.

Sources of Potassic Fertilization in Soybean Production under Different Irrigation Blades

Aims: The objective of this research was to evaluate the physiological and biometric parameters of the soybean crop in potassic fertilization sources under different irrigation blades. Two potassium sources (ground rock, “phonolite”, with 9% K2O and potassium chloride with 60% K2O) and five irrigation blades (30, 70, 100, 130 and 160% of the recommended blade) were used.
 Study Design: The experimental design was in randomized blocks, with ten treatments and four replications, in a 2 x 5 factorial scheme, totaling 40 vessels.
 Place and Duration of Study: Sample: Department of Agronomy, UNIFENAS, between March 2018 and November 2018.
 Methodology: Soil moisture was determined through tensiometers, using a water potential of -30kPa, considered adequate for the soybean crop. At the end of the crop cycle, the weight of shoot dry matter, weight of 1000 seeds, weight of seeds standardized to 13% moisture, total chlorophyll, chlorophyll a, chlorophyll b and carotenoids, besides nutrient content of the leaf tissue, were evaluated.
 Conclusion: KCl favors the accumulation of dry matter, weight of 1000 grains and grain production in the soybean crop in the different irrigation blades. Phonolite increases calcium and magnesium contents in the leaves, independently of the irrigation blade used, also favoring the increase in phosphorus and sulfur contents when soil moisture increases.

Crescimento do milheto (Pennisetum glaucum) irrigado com água residuária no Seridó Paraibano

The use of wastewater can be an irrigation alternative for millet, especially in areas with low availability of water, such as the Seridó Paraibano Region. The objective of this work was to evaluate the growth and production of millet irrigated with wastewater under a consortium with lab-lab beans. The experiment was conducted at the Caboré site, in the municipality of Frei Martinho-PB. The experimental design was a randomized complete block design with five plots (40, 60, 80, 100 and 120% of available water) in a consortium with lab-lab bean in the subplot. The treated wastewater came from the Sewage Treatment Plant of the municipality. The variables measured were: height of the plant; leaf area; number of leaves; diameters and SPAD (chlorophyll meter). There was a significant difference in relation to plant growth, leaf area and number of leaves. The stem diameter and SPAD had no significant effect, an average of 11.197 mm / plant and an average of 60.952 units were observed. The millet plants presented high number of leaves and high leaf area when applied to the irrigation blade of 300 mm of wastewater. The consortium of millet X-lab-lab beans did not interfere interfere with the growth of millet.

MAXIMIZAÇÃO DA PRODUÇÃO DO CACAUEIRO CCN-51 ATRAVÉS DE MODELOS DE REGRESSÃO

The objective of this research was to study the production and physical characteristics of CCN-51 clonal cacao fruits through linear regression models, submitted to irrigation slides and nitrogen doses. For the data collection, four irrigation slides were applied, using the crude irrigation blade (LB), being 0,6 LB; 0,8 LB; 1 LB and 1,2 LB. The crude lamina measured through the water evaporation readings in a class "A" tank installed in the rural property. The fertilizer doses applied were 70, 100, 130 and 160% of the nitrogen (N) recommended for the cocoa crop in traditional regions. The experimental design was a 4 x 4 factorial, resulting in 16 treatments. The proposed regression models estimated 39, 85 Un. Fruit-1; 56, 25 g.fruit-1 and 1649, 23 kg ha-1 for the number of seeds (Un), Average weight (g) and productivity (kg ha-1) respectively.

Agronomic efficiency of ‘Cantaloupe’ melon under different water blades and organic fertilization

The objective of this study was to evaluate the effect of different irrigation blades on the presence and absence of biofertilizer on the agronomic performance of the ‘Cantaloupe’ melon in the Paraíba backwoods. The work was conducted under field conditions in the Agroecology Sector, belonging to the State University of Paraíba (UEPB), Campus IV. The experimental design was a randomized block using four irrigation blades (60, 80, 100 and 120% - ET0, (mm day-1)) with presence and absence of biofertilizer replicated six times. The following variables were evaluated: main branch length, leaf area, number of leaves, phytomass aerial part, pulp diameter, soluble solids, bark diameter, number of seeds per fruit, seed weight per fruit and weight of 100 seeds. The irrigation blade of 120% of ET0 promoted greater growth and development since biofertilizer application provided a greater number of seeds per fruit and weight of 100 seeds, there was no interaction between the factors studied in both variables evaluated in the Cantaloupe melon.

English

The aim of the present study is to assess the effects of different irrigation blades on the growth and yield of cauliflower cv. Verona CMS. The plants were cultivated in Red-yellow Latosol during the dry period (winter-spring 2014 and 2015), in the Cerrado-Amazon transition region, Middle-Northern of Mato Grasso State, Brazil. The reference evapotranspiration (ETo) was recorded through the Class A pan method by using tank coefficient of (Kp) 0.7795. We assessed the blades of 40, 60, 80, 100 and 120% evapotranspiration of the culture (ETc) by taking into account the cultivation coefficients (Kc) of 0.70 and 0.95 in the vegetative and reproductive phases. With regard to the morphometric variables of the plants (height, stem diameter and number of leaves) there were no significant interactions between assessment time (days after planting) and irrigation blades throughout the crop years. The hydric response functions presented higher yield at repositions from 80% to 100% of ETc. Variations in the irrigation blade did not influence the thermal demands for the inflorescence differentiation period or the inflorescence shape. Increased irrigated blade reduced water use efficiency: 7.4 and 12.4 kg of fresh mass per m³ of irrigated water. Key words: Irrigation management, water response function, degree-days, evapotranspiration.

PRODUCTIVE-ECONOMIC BENEFIT OF FORAGE CACTUS-SORGHUM INTERCROPPING SYSTEMS IRRIGATED WITH SALINE WATER

ABSTRACT The objective of this study was to evaluate the productive and economic performance of a forage cactus and sorghum intercropping system in relation to a forage cactus single cropping system under different irrigation blades with saline water. The study was conducted in Serra Talhada, State of Pernambuco, in a randomized block design, consisting of a factorial arrangement with split-plot parcels (5×2) and four replications. The five plots were the irrigation depths based on the reference evapotranspiration (ETo) (0, 8.75, 17.5, 26.25, and 35% ETo) and the two cropping systems were single forage cactus cropping and cactus intercropped with sorghum. The experiment was conducted for one year, with one forage cactus cycle and two cycles of sorghum. Yields were obtained at the end of the cycles. Economic profitability was analyzed by means of net revenue (NR) and the benefit/cost ratio (B/C), with cactus forage sold as forage or as "seed" and sorghum as forage. Net revenue and B/C simulations were carried out over an eight-year useful life span of the irrigation system. Increasing irrigation depth increased the dry matter yield of the intercropping system because of higher sorghum yield. Based on the NR and B/C ratio values, forage cactus and sorghum produced as forage produced higher economic outcomes in the intercropping system and showed a higher profitability from the 2nd year of implementation of the irrigation system. Forage cactus and sorghum intercropping irrigated with saline water is therefore recommended for forage production in the Brazilian semi-arid region.

The Effect of Different Irrigation Levels in Cowpea Production in the Mid-Northern Region of Tocantins—Brazil

The objective of this study was to evaluate the effects of the application of irrigation levels in the productivity and water use efficiency, in the soil and climatic conditions of the municipality of Colinas do Tocantins, located in the Mid-Northern region of the State of Tocantins. The cowpea cultivation system was submitted to the application of five irrigation blades, based on ET0—Reference Evapotranspiration: Blade 0% of ET0, Blade 50% of ET0, Blade 75% of ET0, Blade 100% of ET0 and Blade 125% of ET0 (B0, B50, B75, B100 and B125% of ET0). The descriptive statistics were used to analyze the data, applying the 95% confidence interval to discriminate the differences between the treatments, since the replicates were constituted of 100 plants harvested at random within the plot for each treatment and no design method was performed. A significant effect of the different levels was found on all evaluated components, with the exception of the length of the pod, which did not differ in the irrigation levels. The increase in irrigation contributed to the increase of the results of the components that compete directly for higher productivity, such as number of pods per plant, weight of pods and number of seeds per pod. In these results, it was found that higher irrigation levels confer higher yields. Water-use efficiency—WUE behaved as per productivity trend, that is, it decreased with the reduction of irrigation levels.

Produtividade de grãos verdes do feijão-caupi sob diferentes regimes hídricos

O objetivo deste trabalho foi avaliar a produtividade de grãos verdes, os componentes de produção e a eficiência do uso da água do feijão-caupi, sob regimes hídricos. O experimento foi conduzido na Embrapa Meio-Norte, em Teresina - PI, entre setembro e novembro de 2009. Foram avaliadas cinco lâminas de irrigação, estabelecidas com base em frações da evapotranspiração de referência (25; 50; 75; 100 e 125% da ETo), e as cultivares BRS Guariba e BRSParaguaçudefeijão-caupi. Aplicou-se a irrigação por sistema de aspersão convencional fixo. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições e parcelas subdivididas (cultivares). As máximas produtividades de grãos verdes, 2.937,3 kg ha-1 (BRS Guariba) e 2.492,9 kg ha-1 (BRS Paraguaçu), foram estimadas com as lâminas de irrigação de 354 mm e 423 mm, respectivamente. A máxima eficiência de uso da água para a produtividade de grãos verdes foi observada com as lâminas de 275 mm e 231 mm, para as cultivares BRS Paraguaçu e BRS Guariba, respectivamente. A cultivar BRS Guariba demonstrou melhor desempenho produtivo quando comparada com a cultivar BRS Paraguaçu.

Crescimento vegetativo, produção de fitomassa e de óleo essencial de Melissa officinalis L. sob diferentes lâminas de irrigação

O objetivo deste estudo foi avaliar a produção de fitomassa e óleo essencial da M. officinalis L. com lâminas de irrigação no Norte de Minas Gerais como medidas de uso racional da água. O delineamento experimental utilizado foi o inteiramente ao acaso em parcelas subdivididas no tempo, com seis tratamentos definidos pelas lâminas de irrigação (T1=0,50xET0; T2=0,75xET0; T3=1,0xET0; T4=1,25xET0; T5=1,5xET0 e T6=1,75xETO), e quatro repetições. O estudo foi conduzido em microlisímetros. Com base na análise de regressão, observou-se que o crescimento e a produção de fitomassa foram influenciados pela disponibilidade hídrica. Maior produção e teor de óleo essencial foram conseguidos na menor lâmina e a época de avaliação não influenciou na aplicação das lâminas.