Characteristics of emitters under low pressure are essential for designing drip irrigation systems. Low pressure data for drip emitters are not available from manufacturers. A laboratory test was conducted to evaluate the performance of five types of newly manufactured drip tapes, especially under a low pressure distribution system. The five drip products that were tested were (i) Toro Drip in PC (PCS 1810-18- 100), (ii) T-Tape (TT15-1245-0100), (iii) Mister_LS (MLD-HDT100), (iv) Mister_PS (MLD-1PC 25), and (v) Netafim (Techline CV 560 050). Drip tapes tested in this study have design discharge rates of 4.00 L/hr @ 206.84 Kpa (1.06 gph @ 30 psi), 1.02 L/hr @ 55.16 Kpa (0.27 gph @ 8 psi), 3.785 L/hr @ 172.37 Kpa (1.00 gph @ 25 psi), 3.785 L/hr @172.37 Kpa (1.00 gph @ 25 psi), and 0.984 L/hr @ 206.84 Kpa (0.26 gph @ 20psi), respectively. All of them, except T-Tape, were pressure compensating (PC) emitters; the T-Tape was non-pressure compensating (NPC). For all products, except Toro, the emitter spacing was 0.305 m (12 inches) and for Toro, it was 0.46 m (18 inches). Mister_PS (MLD-1PC 25) was the point source (PS) emitter and all others were line source emitters. Drip products were tested with 15 different operating pressures ranging from 5.97 KPa (0.87 psi) to 344.74 KPa (50.00 psi). From an evaluation of 60 emitters from each product, the Toro brand showed an average uniformity coefficient (UC) of 91.24 %, with a coefficient of variation (Cv) of 0.06, T-Tape drip products showed an average UC of 96.63 % with a Cv of 0.04, Mister_ LS showed an average UC of 93.12 % with a Cv of 0.08, Mister_PS showed an average UC of 96.33 % with a Cv of 0.04, and Netafim showed an average UC of 97.92 % with a Cv of 0.02. Flow rate vs. pressure head (Q-H) curves were also developed for each drip emitter tested. From emitter exponent values it was observed that all of the pressure compensating (PC) products behaved like NPC emitters at low pressures, although they behaved like PC emitters under normal operating pressures. From statistical analysis, it was determined that except for Netafim product, all other tested products were effective under low operating pressures as were under high operating or recommended pressures. Netafim product had no emission under low pressures. Using the measured average emission rate and developed Q-H curves, the distribution uniformities of all products except Netafim were calculated under low pressure ranges of 5.97 KPa (0.87 psi) to 23.88 KPa (3.50 psi ) for different lengths of laterals and under 0%, 1%, 2%

Doctor of Philosophy / Department of Biological & Agricultural Engineering / Aleksey Y. Sheshukov / Isaya Kisekka / The Ogallala aquifer has been important to agriculture in the U.S. High Plains for the past six decades. Groundwater from the aquifer helped turn the fertile soils of the region, large parts of which are semi-arid, into some of the most productive agricultural lands in the U.S. and the world. However, this agricultural success has come at a great cost to the aquifer. Today, as a result of drastic aquifer drawdown, well capacities in some regions of the High Plains are no longer sufficient to sustainably irrigate crops. In response to this growing problem, wide ranging efforts towards conservation of the Ogallala aquifer were formulated and implemented. One of these efforts is to further improve irrigation efficiency. Adaptation of microirrigation, an efficient method of irrigation, to center pivots is regarded by some as the next major step towards expanding the usage of microirrigation technology, and along with-it improving the efficiency in center pivot systems. Four studies were conducted as parts of this dissertation with the application of a four-span center pivot, installed at the Kansas State University’s Southwest Research and Extension Centre (SWREC) in Garden City, Kansas. The studies assessed the technical performance of Mobile Drip Irrigation (MDI) compared to Low Elevation Spray Application (LESA) and Low Energy Precision Application (LEPA). In the first study, the irrigation uniformity, application efficiency and seasonal irrigation uniformity of MDI were evaluated against those of LEPA and LESA. Two sets of MDIs, one with a dripper flow rate of 3.8 L/h, and another of 7.6 L/h, a LESA spray and LEPA bubbler were utilized. Potential differences in season-long irrigation uniformity between the devices were evaluated by analyzing a periodically acquired vegetative index data from aerial imaging. The results showed that MDI and LEPA were more efficient than LESA as indicated by their significantly higher coefficients of uniformity and higher application efficiencies. The second study evaluated soil water redistribution under MDI against those of LEPA and LESA. The effect of irrigation was found to be mostly limited to the top 60 cm of the soil profile for all the evaluated irrigation application technologies. MDI and LEPA showed the highest horizontal variation in water content, and water redistribution pattern of MDI was similar to LEPA. In the third study, the performance of MDI for corn production, in comparison to LESA and LEPA was conducted by comparing grain yield, water productivity, above ground biomass, leaf area index (LAI), and soil water content. In general, crop biophysical measurements under MDI were not significantly different from those under LEPA and LESA, and any marginal benefits of MDI were likely masked by rainfall. Hence, further evaluation of MDI is recommended under stringent water application conditions. The fourth study assessed MDI dripline spacing and length for different soil types.

Sustainable Built Environments Senior Capstone Project / This paper examines Subsurface Drip Irrigation(SDI) as a solution to water conservation in landscape irrigation. This is a problem because of the drought that the southwestern United States is experiencing, and the amount of water that landscapes utilize and which is ultimately wasted due to inefficient practices. Subsurface drip irrigation represents a potential solution due to its high efficiency and water saving ability; however, there are some problems within it as a system. Utilizing a multiple case studies approach, this paper looked at three of the top irrigation companies, Rain Bird, Toro, and Netafim, and examined how they innovated to overcome the problems with SDI. Synthesizing the best and most effective practices from each company, a model for improving SDI was generated.

Neste trabalho buscou-se avaliar a suscetibilidade dos diferentes modelos de tubos gotejadores ao processo de entupimento quando expostos ao uso de cloreto de potássio (branco e vermelho), aplicados via diferentes qualidades de água. O experimento foi realizado em três fases, por um período de doze meses, analisando o desempenho de 22 modelos de gotejadores (autocompensante e convencionais), com quatro tratamentos e dez repetições, sendo cada repetição representada por um gotejador. Na primeira fase, foram aplicados os seguintes tratamentos: (T1) água com fitoplâncton (lago) e cloreto de potássio branco; (T2) água com fitoplâncton (lago) e cloreto de potássio vermelho; (T3) água potável (laboratório) e cloreto de potássio branco; (T4) água potável (laboratório) e cloreto de potássio vermelho. Na segunda fase foram adicionadas partículas sólidas (solo) às soluções dos tratamentos 1 (T1-Lg/B) e 2 (T2-Lg/V), mantendo a mesma solução do tratamento 3 (T3-Lb/B) e adicionado sulfato de ferro à solução do tratamento 4 (T4-Lb/V). Na terceira fase acrescentou-se hidróxido de ferro às soluções referentes a T1 (T1+So) e T2 (T2+So), mais uma aplicação de uma solução concentrada diretamente nas linhas (tubos gotejadores) sem passar pelo sistema de filtragem, sendo os tratamentos: (T1) Água do lago, cloreto de potássio branco, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para baixo. (T2) água do lago, cloreto de potássio vermelho, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para cima. (T3) água do lago , cloreto de potássio branco, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para cima. (T4) água do lago, cloreto de potássio vermelho, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para baixo. Os modelos de tubos gotejadores analisados apresentaram desempenhos variáveis, tanto na suscetibilidade ao entupimento quanto no coeficiente de variação de vazão, sugerindo que a arquitetura interna dos gotejadores, foi o fator determinante na caracterização do processo de entupimento. Não foi observada diferença significativa da dinâmica de entupimento com relação à aplicação dos cloretos de potássio branco e vermelho na ausência ou presença de fitoplâncton, mostrando que é possível fazer uso do cloreto de potássio vermelho em fertirrigação, tomando o cuidado de verificar a ausência do elemento ferro no adubo (análise de laboratório). A adição de partículas sólidas e do sulfato de ferro aos tratamentos da primeira fase, passando pelo sistema de filtragem, não potencializou mudanças significativas do cenário de suscetibilidade ao entupimento, nas condições de irrigação da segunda fase. A entrada de partículas sólidas e hidróxido de ferro no sistema sem passar pelo sistema de filtragem (fase 3) e o posicionamento do orifício dos gotejadores para baixo intensificaram o processo de entupimento, onde os modelos convencionais foram os mais sensíveis e alguns modelos autocompensantes foram mais tolerantes a presença destes elementos na água de irrigação. O modelo C3 foi o que apresentou melhor desempenho entre os modelos convencionais nas três fases estudadas, sendo que os modelos A2 e A3 destacaram-se entre os modelos autocompensantes, com uma boa recuperação da vazão ao final dos ensaios. / This work aims to evaluate the susceptibility of several dripline models against clogging process when exposed to potassium chloride (white and red), applied through different water qualities (fertirrigation). The experiment was accomplished in three phases, during a period of twelve months, analyzing the performance of 22 drip models (compensating and conventional), with four treatments and ten repetitions, being each repetition a dripper. In the first phase, it was applied the following treatments: (T1) water with fitoplancton (lake) and white potassium chloride; (T2) water with fitoplancton (lake) and red potassium chloride; (T3) potable water (laboratory) and white potassium chloride; (T4) potable water (laboratory) and red potassium chloride. In the second phase, solid particles were added to the solutions of previous treatments 1 (T1-Lg/B) and 2 (T2-Lg/V), maintaining the same solution for treatment 3 (T3-Lb/B) and added iron sulfate to the solution of treatment 4 (T4-Lb/V). In the third phase iron hydroxide was added to the solutions of T1 (T1+So) and T2 (T2+So) treatments, one more application of a concentrated solution directly in drip lines without passing through the filtration system, resulting the following treatments: (T1) water with fitoplancton, white potassium chloride, solid particles and iron hydroxide, with dripper facing down. (T2) water with fitoplancton, red potassium chloride, solid particles and iron hydroxide, with drippers facing up, (T3) water with fitoplancton , white potassium chloride, solid particles and iron hydroxide, with drippers facing up, (T4) water with fitoplancton, red potassium chloride, solid particles and hydroxide of iron, with drippers facing down. Driplines presented a variable performance, regarding the original flow rate levels and variation coefficient, suggesting that internal architecture of emitters, it is a major factor related to clogging resistance to treatments imposed. Statistical differences were not observed for clogging dynamics under the application of white or red potassium chloride, under different water quality conditions, showing that it is possible to use the red potassium chloride for fertirrigation without problems. It is recommended to certify the absence of iron element in the fertilizer based on laboratory analysis. The addition of solid particles and iron sulfate to first phase treatments, going through the filtration system, did not increase the clogging rate or emitters (second phase). The application of solid particles and iron hydroxide in the system without passing through the filtration system (phase 3) and the positioning of drippers facing down, intensified the clogging process. Conventional models were more sensitive and compensating models were more tolerant of this water quality conditions. Models C3 performance better among the conventional models in all phases studied. Models A2 and A3 stood out among compensating models, presenting a good recovery flow rate at the end of the experiment.

The thesis summary is included in the 01front.pdf

The focus of this study is the economic feasibility of drip irrigation adoption using capital budgeting and quadratic programming techniques. The capital budgeting techniques used in the study are net present value (NPV) and returns above specified costs (RASC). Modified crop enterprise budgets incorporating drip irrigation are developed based on data from Texas AgriLife Extension Service crop enterprise budgets and published literature focusing on costs and returns of drip irrigation. The quadratic programming technique considers risk and incorporates the modified crop enterprise budgets to estimate a cropping pattern that maximizes the net income above specified costs for the region. The RASC per acre for drip-irrigated crops ranged from $56.34 to $1,909.03, while the RASC per acre for flood-irrigated crops ranged from $142.51 to $1,488.12. Flood-irrigated onions, cotton, and sugarcane had higher RASCs per acre, while the RASCs were greater for drip-irrigated grapefruit and oranges. Evaluating the NPV of the crops resulted in similar results; only grapefruit and oranges were economically-feasible drip-irrigated crops. The baseline results identified levels of drip irrigation adoption ranging from 52,000 acres to 64,497 acres as levels of risk were varied. The level of water available at the reservoir suggested minimal impacts on the level of drip-irrigation adoption, but serious implications for the agriculture economy. Several sensitivity scenarios concentrated on the implications of yield response and water savings that result from the adoption of drip irrigation. The greatest amounts of drip-irrigated crops were present when the yield responses were 130% of the flood-irrigated crops with a 20% water savings. As the amount of water available was reduced, the amount of drip-irrigated crops ranged from 46,111 acres to 59,724 acres. Drip irrigation appears to be an economically-viable alternative in the LRGV due to the presence of drip-irrigated crops in the entire myriad of scenarios investigated in this research. If producers are only concerned with the bottom line as provided by the RASC analysis and no other variables such as water availability, risk, and crop rotations affecting the decision making process, only drip-irrigated grapefruit and oranges are economically competitive with conventional irrigation systems.

SILVEIRA, Enio Marques de Castro. Fisiologia de plantas de meloeiro cultivadas sob diferentes níveis de irrigação. 2013. 57 f. ; Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia Agrícola, Programa de Pós-Graduação em Engenharia Agrícola, Fortaleza-CE, 2013. / Submitted by demia Maia (demiamlm@gmail.com) on 2016-06-23T13:21:26Z No. of bitstreams: 1 2013_dis_emcsilveira.pdf: 553128 bytes, checksum: ad61050bcccc7053d91abf2f8adb3ce9 (MD5) / Approved for entry into archive by demia Maia (demiamlm@gmail.com) on 2016-06-23T13:22:01Z (GMT) No. of bitstreams: 1 2013_dis_emcsilveira.pdf: 553128 bytes, checksum: ad61050bcccc7053d91abf2f8adb3ce9 (MD5) / Made available in DSpace on 2016-06-23T13:22:01Z (GMT). No. of bitstreams: 1 2013_dis_emcsilveira.pdf: 553128 bytes, checksum: ad61050bcccc7053d91abf2f8adb3ce9 (MD5) Previous issue date: 2013 / The melon is the most exports of fresh fruit produced in Brazil, especially being produced in the states of Rio Grande do Norte and Ceará. All this curcubitaceae commercial orchard in the two regions is performed under irrigated conditions. Thus, measures of efficient use of water become essential for this crop. The improvement in efficiency of water use will depend primarily on a management plan that deliver only the amount of water necessary for their full development. The study aimed to evaluate plant growth, water status, gas exchange and yield of yellow melon grown under different irrigation levels. Therefore, two experiments were conducted in the experimental field of Curu, Paraipaba, CE, using hybrid Gold Mine, with spacing of 2.0 m x 0.4 m, under drip irrigation. The first experiment consisted of weekly evaluation of plant growth in response to applying three different irrigation water levels: 100% 80% and 120% (T1, T2 and T3 respectively) of calculated levels. In the second experiment, in addition to the treatments mentioned above, was inserted another factor: the irrigation schedule of 24 to 48 hours, with four replicates. In this it, was evaluated gas exchange, water potential, the carbohydrate in different parts of the plant, yield and fruit quality. In all treatments the plants showed the lowest water potential daily between 12:00 to 2:00pm. Although stomatal conductance decreases during the day curse, it remained in amounts sufficient for photosynthetic rate nearly constant, with a slight reduction after noon and marked decrease only after 4:00pm. In turn, with the exception of transpiration, which was higher in plants irrigated every 48 hours, the irrigation water levels and the irrigation schedule did not affect gas exchange of plants. Likewise, the production, the size and quality of melon fruits were practically not influenced by treatments. Thus, under the experimental conditions used, the increase or decrease of 20% of irrigation water level calculated and recommended to the melon in the region, did not affect plant development, nor the production. Only the amount of total soluble solids was positively influenced by the addition of 20% of the water levels calculated, when applied daily / O melão representa a maior parte das exportações de frutas frescas produzidas no Brasil, sendo cultivado em larga escala nos estados do Rio Grande do Norte e Ceará. Todo o cultivo comercial desta curcubitácea nestas duas regiões é realizado sob condições de irrigação. Assim, medidas de uso eficiente da água tornam-se essenciais para esta cultura. A melhoria na eficiência do uso da água irá depender principalmente de um manejo que entregue à planta somente a quantidade de água necessária para o seu pleno desenvolvimento. Neste sentido, o presente trabalho teve por objetivo avaliar o crescimento das plantas, o estado hídrico, as trocas gasosas e a produção do meloeiro amarelo cultivado sob diferentes lâminas de irrigação. Para tanto, conduziram-se dois experimentos no Campo Experimental do Curu, no município de Paraipaba, CE, utilizando híbrido Gold Mine, com espaçamento de 2,0 m x 0,4 m e irrigado por gotejamento. O primeiro experimento consistiu na avaliação semanal do crescimento das plantas em resposta à aplicação de três diferentes lâminas diárias de irrigação: 100% 80% e 120% (T1, T2 e T3 respectivamente) da lâmina calculada. No segundo experimento, além dos tratamentos citados anteriormente, foi inserido outro fator: turno de rega de 24 e 48 horas, com quatro repetições por tratamento. Neste, se avaliou as trocas gasosas, o potencial hídrico, os teores de carboidratos nas diversas partes das plantas e a produção e qualidade dos frutos. Em todos os tratamentos, as plantas apresentaram o menor potencial hídrico diário no período de 12h00min às 14h00min. Apesar de a condutância estomática decrescer ao longo do dia, a mesma se mantinha em valores suficientes para permitir uma taxa fotossintética praticamente constante, com leve redução após o meio dia e decréscimo acentuado somente após as 16h00min. Por sua vez, com exceção da transpiração, que foi mais alta nas plantas irrigadas a cada 48 horas, o turno de rega e as lâminas hídricas aplicadas não influenciaram as trocas gasosas das plantas. Da mesma forma, a produção, o tamanho e a qualidade dos frutos de meloeiro praticamente não foram influenciados pelos tratamentos aplicados. Assim, nas condições experimentais utilizadas, o acréscimo ou diminuição de 20% da lâmina de água calculada recomendada para o melão na região, não influenciou o desenvolvimento das plantas, nem tampouco a produção. Apenas a quantidade de sólidos solúveis totais (ºBrix) foi influenciada positivamente pelo o acréscimo de 20% da lâmina calculada, quando aplicada diariamente.

Made available in DSpace on 2014-06-11T19:26:47Z (GMT). No. of bitstreams: 0 Previous issue date: 2000-04Bitstream added on 2014-06-13T19:14:05Z : No. of bitstreams: 1 leitejunior_jb_me_botfca.pdf: 548112 bytes, checksum: 3c54996aed140271001523e8eeadb99f (MD5) / Com o objetivo de encontrar uma solução para a salinização dos solos sob cultivo protegido que possibilite reduzir sua salinidade com a contínua utilização das estufas, foi realizado um experimento na Fazenda Experimental São Manuel, em São Manuel, pertencente a Faculdade de Ciências Agronômicas - UNESP/ Campus de Botucatu.O experimento foi conduzido nos meses de outubro e novembro de 1999, num solo denominado Latossolo Vermelho Amarelo textura média, e consistiu na simulação de adubação excessiva, através da adição de 645 g.m-2 de cloreto de potássio (KCl) e 51 g.m-2 de fosfato monoâmonico (MAP). A cultura utilizada foi a alface americana cultivar Tainá, transplantada no espaçamento de 35 x 35 cm e irrigada através de gotejamento. O experimento consistiu num fatorial 23, cujos fatores foram (nos níveis presença e ausência): pré-lavagem do solo antes do transplantio com uma lâmina de 101,89 mm; cobertura plástica preta do solo (mulching) e lixiviação a cada irrigação (com fração de 50% e irrigação diária, até 20 dias após o transplantio (DAT), e 30% até o final com irrigação a cada 2 dias.Com base nos resultados, pode-se concluir que a pré-lavagem não foi eficiente na redução de íons do solo, somente reduziu o pH havendo uma interação significativa entre a presença deste com a presença do mulching para os íons H++Al3+ no aumento da concentração desse, mas teve efeito na redução da condutividade elétrica na profundidade de 20cm aos 2 DAT e aos 14 DAT interagindo com a lixiviação.O mulching de cor preta foi eficiente na redução dos níveis dos elementos K, Ca e Mg a 20 cm de profundidade refletindo nas características químicas soma de bases, capacidade de troca catiônica e saturação de bases, mas reduziu o diâmetro das cabeças da alface americana. Apesar da condutividade elétrica não ter diferido significativamente, ele reduziu os sais na superfície dos canteiros...(Resumo co / With the objective of finding a solution for the salinization of the soils under protected cultivation and that it facilitates to reduce its salinity with the continuous use of the stoves, an experiment was accomplished in Experimental Farm São Manuel, in São Manuel, belonging the Faculdade de Ciências Agronômicas - UNESP/ Campus of Botucatu. The experiment was driven the months of October and November of 1999, in a soil denominated latosoil red yellow medium texture, and it consisted of the simulation of excessive fertilization through the addition of 645 g.m-2 of potassium chloride (KCl) and 51 g.m-2 of phosphate monoammmonic (MAP). THE used culture went to American lettuce to cultivate Tainá , transplanted in the spacing of 35 x 35 cm and irrigated through leak. The experiment consisted of the combination of 3 factors in 2 levels, whose factors were: pré-wash with a sheet of 101,89 mm; black plastic covering of the soil (mulching) and leaching to each irrigation (with fraction of 50% and daily irrigation, until 20 days after the transplant DAT , and 30% until the end with irrigation to every 2 days), in the levels with and without presence of the factor. With base in the results, it can be concluded that the pré-wash was not efficient in the reduction of ion of the soil, it only reduced the pH having a significant interaction among the presence of this with the presence of the mulching for the ion H++Al3+ in the increase of the concentration of that, but it had effect in the reduction of the electric conductivity in the depth of 20cm to 2 DAT and to 14 DAT combining the effects with the leaching...(Complete abstract, access undermentioned electronic address).

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / O melÃo representa a maior parte das exportaÃÃes de frutas frescas produzidas no Brasil, sendo cultivado em larga escala nos estados do Rio Grande do Norte e CearÃ. Todo o cultivo comercial desta curcubitÃcea nestas duas regiÃes à realizado sob condiÃÃes de irrigaÃÃo. Assim, medidas de uso eficiente da Ãgua tornam-se essenciais para esta cultura. A melhoria na eficiÃncia do uso da Ãgua irà depender principalmente de um manejo que entregue à planta somente a quantidade de Ãgua necessÃria para o seu pleno desenvolvimento. Neste sentido, o presente trabalho teve por objetivo avaliar o crescimento das plantas, o estado hÃdrico, as trocas gasosas e a produÃÃo do meloeiro amarelo cultivado sob diferentes lÃminas de irrigaÃÃo. Para tanto, conduziram-se dois experimentos no Campo Experimental do Curu, no municÃpio de Paraipaba, CE, utilizando hÃbrido Gold Mine, com espaÃamento de 2,0 m x 0,4 m e irrigado por gotejamento. O primeiro experimento consistiu na avaliaÃÃo semanal do crescimento das plantas em resposta à aplicaÃÃo de trÃs diferentes lÃminas diÃrias de irrigaÃÃo: 100% 80% e 120% (T1, T2 e T3 respectivamente) da lÃmina calculada. No segundo experimento, alÃm dos tratamentos citados anteriormente, foi inserido outro fator: turno de rega de 24 e 48 horas, com quatro repetiÃÃes por tratamento. Neste, se avaliou as trocas gasosas, o potencial hÃdrico, os teores de carboidratos nas diversas partes das plantas e a produÃÃo e qualidade dos frutos. Em todos os tratamentos, as plantas apresentaram o menor potencial hÃdrico diÃrio no perÃodo de 12h00min Ãs 14h00min. Apesar de a condutÃncia estomÃtica decrescer ao longo do dia, a mesma se mantinha em valores suficientes para permitir uma taxa fotossintÃtica praticamente constante, com leve reduÃÃo apÃs o meio dia e decrÃscimo acentuado somente apÃs as 16h00min. Por sua vez, com exceÃÃo da transpiraÃÃo, que foi mais alta nas plantas irrigadas a cada 48 horas, o turno de rega e as lÃminas hÃdricas aplicadas nÃo influenciaram as trocas gasosas das plantas. Da mesma forma, a produÃÃo, o tamanho e a qualidade dos frutos de meloeiro praticamente nÃo foram influenciados pelos tratamentos aplicados. Assim, nas condiÃÃes experimentais utilizadas, o acrÃscimo ou diminuiÃÃo de 20% da lÃmina de Ãgua calculada recomendada para o melÃo na regiÃo, nÃo influenciou o desenvolvimento das plantas, nem tampouco a produÃÃo. Apenas a quantidade de sÃlidos solÃveis totais (ÂBrix) foi influenciada positivamente pelo o acrÃscimo de 20% da lÃmina calculada, quando aplicada diariamente. / The melon is the most exports of fresh fruit produced in Brazil, especially being produced in the states of Rio Grande do Norte and CearÃ. All this curcubitaceae commercial orchard in the two regions is performed under irrigated conditions. Thus, measures of efficient use of water become essential for this crop. The improvement in efficiency of water use will depend primarily on a management plan that deliver only the amount of water necessary for their full development. The study aimed to evaluate plant growth, water status, gas exchange and yield of yellow melon grown under different irrigation levels. Therefore, two experiments were conducted in the experimental field of Curu, Paraipaba, CE, using hybrid Gold Mine, with spacing of 2.0 m x 0.4 m, under drip irrigation. The first experiment consisted of weekly evaluation of plant growth in response to applying three different irrigation water levels: 100% 80% and 120% (T1, T2 and T3 respectively) of calculated levels. In the second experiment, in addition to the treatments mentioned above, was inserted another factor: the irrigation schedule of 24 to 48 hours, with four replicates. In this it, was evaluated gas exchange, water potential, the carbohydrate in different parts of the plant, yield and fruit quality. In all treatments the plants showed the lowest water potential daily between 12:00 to 2:00pm. Although stomatal conductance decreases during the day curse, it remained in amounts sufficient for photosynthetic rate nearly constant, with a slight reduction after noon and marked decrease only after 4:00pm. In turn, with the exception of transpiration, which was higher in plants irrigated every 48 hours, the irrigation water levels and the irrigation schedule did not affect gas exchange of plants. Likewise, the production, the size and quality of melon fruits were practically not influenced by treatments. Thus, under the experimental conditions used, the increase or decrease of 20% of irrigation water level calculated and recommended to the melon in the region, did not affect plant development, nor the production. Only the amount of total soluble solids was positively influenced by the addition of 20% of the water levels calculated, when applied daily

Neste trabalho buscou-se avaliar a suscetibilidade dos diferentes modelos de tubos gotejadores ao processo de entupimento quando expostos ao uso de cloreto de potássio (branco e vermelho), aplicados via diferentes qualidades de água. O experimento foi realizado em três fases, por um período de doze meses, analisando o desempenho de 22 modelos de gotejadores (autocompensante e convencionais), com quatro tratamentos e dez repetições, sendo cada repetição representada por um gotejador. Na primeira fase, foram aplicados os seguintes tratamentos: (T1) água com fitoplâncton (lago) e cloreto de potássio branco; (T2) água com fitoplâncton (lago) e cloreto de potássio vermelho; (T3) água potável (laboratório) e cloreto de potássio branco; (T4) água potável (laboratório) e cloreto de potássio vermelho. Na segunda fase foram adicionadas partículas sólidas (solo) às soluções dos tratamentos 1 (T1-Lg/B) e 2 (T2-Lg/V), mantendo a mesma solução do tratamento 3 (T3-Lb/B) e adicionado sulfato de ferro à solução do tratamento 4 (T4-Lb/V). Na terceira fase acrescentou-se hidróxido de ferro às soluções referentes a T1 (T1+So) e T2 (T2+So), mais uma aplicação de uma solução concentrada diretamente nas linhas (tubos gotejadores) sem passar pelo sistema de filtragem, sendo os tratamentos: (T1) Água do lago, cloreto de potássio branco, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para baixo. (T2) água do lago, cloreto de potássio vermelho, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para cima. (T3) água do lago , cloreto de potássio branco, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para cima. (T4) água do lago, cloreto de potássio vermelho, partículas sólidas e hidróxido de ferro, com o orifício do gotejador posicionado para baixo. Os modelos de tubos gotejadores analisados apresentaram desempenhos variáveis, tanto na suscetibilidade ao entupimento quanto no coeficiente de variação de vazão, sugerindo que a arquitetura interna dos gotejadores, foi o fator determinante na caracterização do processo de entupimento. Não foi observada diferença significativa da dinâmica de entupimento com relação à aplicação dos cloretos de potássio branco e vermelho na ausência ou presença de fitoplâncton, mostrando que é possível fazer uso do cloreto de potássio vermelho em fertirrigação, tomando o cuidado de verificar a ausência do elemento ferro no adubo (análise de laboratório). A adição de partículas sólidas e do sulfato de ferro aos tratamentos da primeira fase, passando pelo sistema de filtragem, não potencializou mudanças significativas do cenário de suscetibilidade ao entupimento, nas condições de irrigação da segunda fase. A entrada de partículas sólidas e hidróxido de ferro no sistema sem passar pelo sistema de filtragem (fase 3) e o posicionamento do orifício dos gotejadores para baixo intensificaram o processo de entupimento, onde os modelos convencionais foram os mais sensíveis e alguns modelos autocompensantes foram mais tolerantes a presença destes elementos na água de irrigação. O modelo C3 foi o que apresentou melhor desempenho entre os modelos convencionais nas três fases estudadas, sendo que os modelos A2 e A3 destacaram-se entre os modelos autocompensantes, com uma boa recuperação da vazão ao final dos ensaios. / This work aims to evaluate the susceptibility of several dripline models against clogging process when exposed to potassium chloride (white and red), applied through different water qualities (fertirrigation). The experiment was accomplished in three phases, during a period of twelve months, analyzing the performance of 22 drip models (compensating and conventional), with four treatments and ten repetitions, being each repetition a dripper. In the first phase, it was applied the following treatments: (T1) water with fitoplancton (lake) and white potassium chloride; (T2) water with fitoplancton (lake) and red potassium chloride; (T3) potable water (laboratory) and white potassium chloride; (T4) potable water (laboratory) and red potassium chloride. In the second phase, solid particles were added to the solutions of previous treatments 1 (T1-Lg/B) and 2 (T2-Lg/V), maintaining the same solution for treatment 3 (T3-Lb/B) and added iron sulfate to the solution of treatment 4 (T4-Lb/V). In the third phase iron hydroxide was added to the solutions of T1 (T1+So) and T2 (T2+So) treatments, one more application of a concentrated solution directly in drip lines without passing through the filtration system, resulting the following treatments: (T1) water with fitoplancton, white potassium chloride, solid particles and iron hydroxide, with dripper facing down. (T2) water with fitoplancton, red potassium chloride, solid particles and iron hydroxide, with drippers facing up, (T3) water with fitoplancton , white potassium chloride, solid particles and iron hydroxide, with drippers facing up, (T4) water with fitoplancton, red potassium chloride, solid particles and hydroxide of iron, with drippers facing down. Driplines presented a variable performance, regarding the original flow rate levels and variation coefficient, suggesting that internal architecture of emitters, it is a major factor related to clogging resistance to treatments imposed. Statistical differences were not observed for clogging dynamics under the application of white or red potassium chloride, under different water quality conditions, showing that it is possible to use the red potassium chloride for fertirrigation without problems. It is recommended to certify the absence of iron element in the fertilizer based on laboratory analysis. The addition of solid particles and iron sulfate to first phase treatments, going through the filtration system, did not increase the clogging rate or emitters (second phase). The application of solid particles and iron hydroxide in the system without passing through the filtration system (phase 3) and the positioning of drippers facing down, intensified the clogging process. Conventional models were more sensitive and compensating models were more tolerant of this water quality conditions. Models C3 performance better among the conventional models in all phases studied. Models A2 and A3 stood out among compensating models, presenting a good recovery flow rate at the end of the experiment.