Submitted by Mario BC (mario@bc.ufrpe.br) on 2016-05-25T13:26:37Z No. of bitstreams: 1 Cinthya Mirella Pacheco.pdf: 1295032 bytes, checksum: 994d8bd5db7ce0b37100b5eecda0f820 (MD5) / Made available in DSpace on 2016-05-25T13:26:37Z (GMT). No. of bitstreams: 1 Cinthya Mirella Pacheco.pdf: 1295032 bytes, checksum: 994d8bd5db7ce0b37100b5eecda0f820 (MD5) Previous issue date: 2016-02-24 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / The aim of this work was to select promising varieties to water stress based on physiological parameters, biochemical and productivity. To this end, two experiments were conducted, one in greenhouse condition and another in field conditions. The experiment, the greenhouse experiment was completely randomized in a factorial 6 x 2 corresponding to six varieties of sugarcane (RB98710, RB962962, RB92579, C90-176, C90-178 and RB72454) and two treatments , daily irrigation (control) and suspension of irrigation (no irrigation). As for the field experiment, the experimental design was a randomized block consisting of eight installments, corresponding to the eight varieties (RB92579, RB867515, RB863129, RB962962, RB972631, RB002504, RB992506 and C90-176), grown in conditions irrigation rescue and dry. the physiological variables of gas exchange were evaluated, photosynthetic pigments and water relations, biochemical analysis to determine the carbohydrate content, proline and total amino acids for the greenhouse experiment, besides the growth analysis, total soluble protein and productivity for the field experiment. The collections for the analyzes were carried out after 24 h and 72 h after stopping irrigation for home experiment of vegetation and after 3, 6 and 10 months of cultivation in the field experiment, in addition to productivity after 11 months. The physiological variables were overall quite heavily in varieties of sugarcane at home conditions of vegetation, and in the field. However, the C90-176 variety stood out among those studied in a greenhouse, not to present changes in its gas exchange, water relations and efficiency of water use, and present significant accumulations of carbohydrate concentration in leaves and proline, roots after 24 h of stress, indicating greater tolerance to water deficit of short duration. And RB962962 variety was considered the most sensitive to water deficit by reducing gas exchange early in the stress, and presents reduction in leaf water potential and efficiency of water use after 72 h. In addition, this strain showed significant reductions of the proline content in leaves and roots after 24 h of water removal, which can lead to an oxidative damage plants in greater exposure to stress. As for the experiment conducted under rainfed conditions in the field, it observed a possible osmotic adjustment of RB92579 varieties RB867515, RB962962 and RB972631, with the accumulation of amino acids and proline, which linked to the partial closing of the stomata indicated RB92579 variety as more tolerant to drought, since even with all varieties representing a reduction in their productivity, this variety showed lower reduction (20%) compared to RB972631 not presented stomatal closure and reduced their productivity by 38%, and is considered, therefore, the most sensitive. The contrast of the responses to dryland farming through irrigation suspension, short or long term, presented in varieties indicated as tolerant and sensitive to drought is promising to assist in breeding programs. Therefore it presents the way of more efficient responses in order to provide greater tolerance of sugarcane drought and contributes to expanding the potential of already cultivated varieties or the development of new varieties recommended for regional crops. / O objetivo desse trabalho foi selecionar variedades promissoras para o estresse hídrico com base em parâmetros fisiológicos, bioquímicos e de produtividade. Para tal, foram realizados dois experimentos, um em condição de casa de vegetação e outro em condições de campo. O delineamento experimental, do experimento de casa de vegetação foi inteiramente casualizado, em arranjo fatorial 6 x 2 correspondendo a seis variedades de cana-de-açúcar (RB98710, RB962962, RB92579, C90-176, RB72454 e C90-178) e dois tratamentos, rega diária (controle) e suspensão da rega (sem rega). Já para o experimento de campo, o delineamento experimental foi em blocos ao acaso, compostos por oito parcelas, que corresponderam às oito variedades (RB92579, RB867515, RB863129, RB962962, RB972631, RB002504, RB992506 e C90-176), cultivadas em condições de irrigação de salvamento e de sequeiro. Foram avaliadas as variáveis fisiológicas das trocas gasosas, pigmentos fotossintéticos e relações hídricas, as análises bioquímicas de determinação dos teores de carboidratos, prolina e aminoácidos totais, para o experimento de casa de vegetação, além da análise de crescimento, concentração de proteínas solúveis totais e produtividade para o experimento de campo. As coletas para a realização das análises foram realizadas após 24 h e 72 h após a suspensão da rega para o experimento de casa de vegetação e após 3, 6 e 10 meses de cultivo no experimento de campo, além da produtividade após 11 meses. As variáveis fisiológicas no geral foram afetadas negativamente nas variedades de cana-de-açúcar tanto em condições de casa de vegetação, como no campo. No entanto, a variedade C90-176 se destacou dentre as estudadas em casa de vegetação, por não apresentar alterações nas suas trocas gasosas, relações hídricas e eficiência do uso da água, além de apresentar acúmulos significativos de teores de carboidratos nas folhas e prolina, nas raízes, após 24 h de estresse, indicando maior tolerância ao déficit hídrico de curta duração. A variedade RB962962 foi considerada a mais sensível ao déficit hídrico por reduzir as trocas gasosas logo no início do estresse, além de apresentar redução no potencial hídrico foliar e eficiência do uso da água após 72 h. Em adição, esta variedade apresentou reduções significativas do teor de prolina nas folhas e raízes, após 24 h de suspensão da rega, o que pode levar as plantas a um dano oxidativo numa maior exposição ao estresse. Já para o experimento realizado em condições de sequeiro, no campo, foi observado um possível ajustamento osmótico das variedades RB92579, RB867515, RB962962 e RB972631, com o acúmulo de aminoácidos e prolina, que atrelado ao fechamento parcial dos estômatos indicou a variedade RB92579 como a mais tolerante a seca, visto que mesmo com todas as variedades apresentando redução em suas produtividades, essa variedade apresentou menor redução (20%) em comparação a RB972631 que não apresentou fechamento estomático e reduziu a sua produtividade em 38%, sendo considerada, portanto, a mais sensível. O contraste das respostas ao cultivo de sequeiro, por meio da suspensão de rega, de curta ou longa duração, apresentado nas variedades indicadas como tolerantes e sensíveis à seca é bastante promissor para auxiliar nos programas de melhoramento genético. Pois, apresenta as vias de respostas mais eficientes, a fim de conferir maior tolerância da cana-de-açúcar a seca e contribui para ampliação do potencial das variedades já cultivadas ou o desenvolvimento de novas variedades recomendadas para cultivos regionais.

The Mediterranean basin is widely recognized as a climate change hotspot, with climate models projecting increasingly warmer and drier conditions that will impact local ecosystems, communities, and economies. Agriculture will be among the most affected sectors, with harsher conditions for crops’ growth, greater water needs, and lower yields. One of the most resilient crops to limiting and stressful conditions is barley, which is often sown in areas where other crops and cereals would struggle. This work analyzed the impacts of climate change on rainfed barley using the province of Almeria as a case study. This is one of the most arid areas of the Mediterranean basin, where agriculture is among the main economic resources, and where barley is the main crop produced outside greenhouses. Barley growth was modeled using the AquaCrop model in its Python implementation, AquaCrop-OSPy. Setting the model up to avoid local re-calibration of the barley parameters and to capture multi-year trends in productivity change, rather than its interannual variability. The study focused on two 30-year time periods: mid-century (2041-2070), and end-century (2071-2100); and on Shared Socioeconomic Pathways scenarios SSP1-2.6, SSP2-4.5, and SSP5-8.5. For each time period and SSP scenario, the research also evaluated three sub-scenarios of soil water content at sowing: with the parameter set respectively at 10%, 20%, and 30% of the Total Available Water (the water present in the soil available for the crop to sustain its life). Having estimated climate change impact, the research analyzed different adaptation pathways (irrigation, the application of mulches, and the change in sowing date), to evaluate their performances for climate change adaptation in the area.  The results indicate the importance of soil water content for maintaining good yields, or reducing losses, and indicate the possible average yield change to be between +14% and -45% at mid-century, and between +12% and -55% at end-century. The greater variability in productivity is associated with the soil water content at sowing rather than on the SSP scenario, with SSP5-8.5 being the only one showing a marked difference compared to the others. Regarding irrigation, the results show how with a soil water content at sowing of 10% of the Total Available Water, irrigation up to 100 m³/ha might not be sufficient to avoid productivity losses. Also, the study indicates that an optimal threshold to trigger irrigation for adaptation purposes might be found between 0% and 20% of the Total Available Water. Overall, it indicates how adaptation through irrigation can be viable in the province. The work moreover suggests the effectiveness of mulches as an adaptation strategy to partially limit irrigation water needs in the future and improve the yield performance of the crop. However, the research does not indicate a clear benefit linked to changing the sowing date to earlier or later sowing dates but suggests the importance of correctly seizing the sowing window to reach optimum yield in the future. Lastly, the work shows that the approach used to carry out this research is suitable to assess trends in yield change at multi-year scale, if the analyzed time window is indicatively larger or equal to 10 years, and if an error of around 10% on the results is accepted. / Medelhavsområdet är allmänt erkänt som en hotspot för klimatförändringar, och klimatmodellerna förutspår allt varmare och torrare förhållanden som kommer att påverka lokala ekosystem, samhällen och ekonomier. Jordbruket kommer att vara en av de mest drabbade sektorerna, med tuffare förhållanden för grödornas tillväxt, större vattenbehov och lägre avkastning. En av de grödor som är mest motståndskraftiga mot begränsande och stressande förhållanden är korn, som ofta sås i områden där andra grödor och spannmål skulle ha svårt att klara sig. I det här arbetet analyserades klimatförändringarnas inverkan på regnkorn med provinsen Almeria som fallstudie. Detta är ett av de torraste områdena i Medelhavsområdet, där jordbruket är en av de viktigaste ekonomiska resurserna, och där korn är den viktigaste grödan som produceras utanför växthus. Kornets tillväxt modellerades med hjälp av AquaCrop-modellen i dess Python-implementering, AquaCrop-OSPy. Modellen ställdes in för att undvika lokal omkalibrering av kornparametrarna och för att fånga fleråriga trender i produktivitetsförändringar, snarare än den mellanårliga variationen. Studien fokuserade på två 30-årsperioder: mitten av århundradet (2041-2070) och slutet av århundradet (2071-2100), och på scenarierna SSP1-2,6, SSP2-4,5 och SSP5-8,5 för de gemensamma socioekonomiska vägarna. För varje tidsperiod och SSP-scenario utvärderade forskningen också tre underscenarier av markvatteninnehåll vid sådd: med parametern inställd på 10%, 20% respektive 30% av det totala tillgängliga vattnet (det vatten som finns i jorden som är tillgängligt för grödan för att upprätthålla sitt liv). Efter att ha uppskattat effekterna av klimatförändringarna analyserade forskningen olika anpassningsvägar (bevattning, applicering av mulcher och förändring av sådatum) för att utvärdera deras prestanda för anpassning till klimatförändringar i området.  Resultaten visar att markvattenhalten är viktig för att upprätthålla god avkastning eller minska förlusterna, och visar att den möjliga genomsnittliga avkastningsförändringen är mellan +14% och -45% vid mitten av århundradet och mellan +12% och -55% vid slutet av århundradet. Den större variationen i produktivitet är förknippad med markvatteninnehållet vid sådd, snarare än på SSP-scenariot, med SSP5-8.5 som det enda som visar en markant skillnad jämfört med de andra. När det gäller bevattning visar resultaten att med en markvattenhalt vid sådd på 10% av det totala tillgängliga vattnet, kan bevattning upp till 100 m³ / ha inte vara tillräcklig för att undvika produktivitetsförluster. Studien visar också att en optimal tröskel för att utlösa bevattning i anpassningssyfte kan hittas mellan 0% och 20% av det totala tillgängliga vattnet. Sammantaget visar studien hur anpassning genom bevattning kan vara genomförbar i provinsen. Arbetet tyder dessutom på att mulcher är effektiva som en anpassningsstrategi för att delvis begränsa bevattningsvattenbehovet i framtiden och förbättra grödans avkastning. Forskningen visar dock inte på någon tydlig fördel med att ändra sådatumet till tidigare eller senare sådatum, men antyder vikten av att korrekt utnyttja såfönstret för att nå optimal avkastning i framtiden. Dessutom visar arbetet att den metod som används för att genomföra denna forskning är lämplig för att bedöma trender i avkastningsförändringar på flerårig skala, om det analyserade tidsfönstret är större eller lika med 10 år, och om ett fel på cirka 10% på resultaten accepteras.

Lack of sufficient water for irrigation is a major problem in and around the valleys surrounding the town of Aiquile, Cochabamba Bolivia. In addition, much of the region is undergoing desertification compounded by drought, deforestation, bad traditional agricultural practices, over grazing and a "torrential" rainfall pattern leading to severe soil erosion and low agricultural production. Between 1992 and 1994, the author constructed a network of 24 small, mostly rainfed farm ponds to increase agricultural production and alleviate soil erosion and land-use problems by improving cover conditions. A 5-year post-impoundment analysis was carried out in 1998. The analysis examined current pond conditions, design criteria, irrigation water / crop production increases and the alleviation of land-use problems. Current pond conditions fell into four distinct categories with only 25 percent of the ponds being deemed as "functioning well." The project increased irrigation in the region and improved cover conditions in 66 percent of the pond sites.

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniv., 2003. / Härtill 5 uppsatser.