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Junhong Qin David A. Ramírez Kaiyun Xie Wenjuan Li Wendy Yactayo Liping Jin Roberto Quiroz 《Potato Research》2018,61(4):391-406
China is the largest worldwide potato producer where around half of the crops is planted in the semi-arid region frequently affected by water restriction. While innovative methods are needed for water-saving irrigation methods, the use of low-cost and environmental-friendly technology must be prioritised. In this study, potato production under drip irrigation (DI, commonly adopted to save water) was compared with partial root-zone drying furrow irrigation (PRD) using the same water volume per irrigation, in both methods. Two initiation timings (early and late) were tested under shelter and field conditions, the water supplied during every irrigation being 50% of the crop water demand calculated for furrow full irrigation (FI, as control). The comparison of both methods was done through the assessment of tuber fresh-yield and estimated economic and environmental (carbon footprint and irrigation water use efficiency, WUEi) benefits. Late PRD and DI produced the highest WUEi without significant yield reduction. PRD produced 3.1% higher net benefit than DI with an estimated CO2 emission of 3659 kg ha?1 CO2 (14% lower than DI). The input-output ratio (total input costs/yield output) for PRD was 0.4, which was 10% lower than DI. The study’s results suggested that PRD, with no less than 50% of the water applied in FI per application, not only maintained yield but could also increase revenues while saving water and reducing CO2 emissions, compared to DI. Such results might help reduce the pressure on the water reserves in semi-arid potato-producing areas in China. Notwithstanding, a scaling-up of PRD technology must be tested in those regions to substantiate the findings of this preliminary study. 相似文献
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F. Quiroz A. Corro Molas R. Rojo J. Prez Fernndez A. Escande 《Soil & Tillage Research》2008,99(1):66-75
From 2001 to 2006 crop seasons three field experiments were run to compare the effect of no tillage (NT) vs. conventional tillage (CT) on Verticillium wilt of sunflower. One experiment had sunflower monocropping (SM) and the others the sequence wheat–sunflower (WS) with 6 years of fescue pasture or seven WS cycles as previous crops. All experimental fields have history of the disease. One cultivar with low resistance was used in SM and two genotype-resistance levels (high and low; characterized by six and eight cultivars each, respectively) in the WS sequences. Leaf mottle severity in all environments, Verticillium dahliae colony forming units (CFU)/g of soil in 2005 or 2006 trials, density of microsclerotia in the stem pith at 0.5 m above the soil line in WS, and grain yield and oil content in WS with fescue as previous crop were recorded. Every year, disease severity was higher in CT than in NT in all trials. In SM, disease severity increased during the 3 years in CT from 58% to 88%, while in NT disease severity remained around the initial level (49%). The V. dahliae-CFU/g of soil after 3 years in SM or three cycles of WS was approximately three times higher in CT than in NT. In WS, density of microsclerotia in stem pith were higher in CT than in NT. In WS with fescue pasture as previous crop, grain yield and oil content tend to increase with NT in relation to CT. The combination of NT and high-resistant genotypes reduced the disease and the production of microsclerotia in stem pith to very low values. NT + high resistance should be viewed as a preventative, not a curative disease management option because the microsclerotia persist in soil for a long time. Therefore, NT + high resistance programs should be initiated early, before inoculum builds up to high levels in the soil. Thus, the combination of NT and high-resistant cultivars promises to be an interesting tool to manage V. dahliae and Verticillium wilt in sunflower and would have potential in other crops like alfalfa, cotton or strawberry. 相似文献
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Maxence Gemin Alberto Pea‐Rodríguez Eduardo Quiroz‐Guzmn Paola Magalln‐Servín Diana Barajas‐Sandoval Regina Elizondo‐Gonzlez 《Aquaculture Research》2019,50(12):3741-3748
Seaweed production represents one of the rising activities in the aquaculture industry. This study explores the impact of bacteria associated with the growth of Ulva clathrata, a promising alga in the field of food and bioremediation. Fifty‐six bacteria isolated from four seaweed (Caulerpa sp., Gracilaria sp., Ulva lactuca and U. clathrata) were tested to evaluate their effect on U. clathrata growth. Eight of them showed a significant growth‐promoting effect (p < .05). Isolates Ul‐11 and Ul‐12 from U. lactuca induced an increase of 73 and 81% of growth respectively. They were classified as Reugeria sp. and Alteromonas sp. based on 16S DNA sequencing (>95.0% sequence identity). Multiple combinations of the growth‐promoting bacteria were also tested on U. clathrata, and the best result was achieved by combining Ca‐3/Uc‐18/Ul‐12 isolates with a significant increase in seaweed growth of up to 76%; however, no synergistic effect was observed compared to Ul‐12 alone. Scanning electron microscopy revealed no alteration in the cell wall of U. clathrata when inoculated with selected bacteria, showing an average increase of bacterial density on U. clathrata. 相似文献
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Cristina Escobedo‐Fregoso Florikeren Escobedo‐Yam Alberto Pea‐Rodríguez Ana Maria Ibarra Eduardo Quiroz‐Guzmn 《Aquaculture Research》2019,50(7):1903-1911
The microalga Chaetoceros calcitrans was cultured with three concentrations of vitamin B12 (cyanocobalamin) to supplement the feed for the oyster Crassostrea gigas. In two additional assays, vitamins B12 and B9 (folic acid) were dissolved in the water to increase the methyl donors necessary for the one‐carbon cycle and DNA methylation. Microalgae did not present differences in their concentration of vitamins, and no correlation was found between the concentration of vitamin supplement and the vitamin concentration in oysters; however, changes in the expression of genes involved in the DNA methylation were found. The expression of proton‐coupled folate transporter (PCFT) was lower in oysters supplemented with Vit. B9. The expression of proton‐coupled folate transporter (PCFT) was lower in oysters supplemented with Vit. B9., however, the expression of genes implicated in the release of the methyl used to maintain methylation such as methionine synthase (MS) and DNMT1 expression was high, suggesting faster transportation of Vit. B9. The methylenetetrahydrofolate reductase (MTHFR), implicated in the reduction of folic acid, was lower in oysters supplemented with Vit. 9 and B12 dissolved in the water. DNA methyltransferase DNMT1A, involved in DNA maintenance, was higher in oyster supplemented with Vit. B9, but the expression of DNMT1B was not different. In conclusion, the supplementation with folic acid increases the expression of genes implicated in the maintenance of DNA methylation in C. gigas. 相似文献
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Effect of light limitation on the water quality,bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity 
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下载免费PDF全文 Héctor M Esparza‐Leal Ely S López‐Álvarez Jesús T Ponce‐Palafox Josué A Melendrez‐Soto Marco A Medina‐Astorga Antonio Luna‐González Wenceslao Valenzuela‐Quiñónez Píndaro Álvarez‐Ruiz Gerardo Rodríguez‐Quiroz 《Aquaculture Research》2017,48(8):4371-4379
The aim of this study was to evaluate the effect of light limitation on the water quality, bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity (≈9 g L?1). Two treatments were designed: T1 = culture with natural sunlight and T2 = culture in darkness. After 28 days, in both treatments, the final weight of shrimp was over 0.6 g with a specific growth rate over 7.4% d?1, and a survival rate over 70%. In both treatments, Vibrio sp. concentration presented low values (culture with natural sunlight = 0.1 to 9.9 × 102 CFU mL?1, culture in darkness = 0.4 to 11.7 × 102 CFU mL?1) and Bacillus sp. had high values (culture with natural sunlight = 0.7 to 66.0 × 104 CFU mL?1, culture in darkness = 0.7 to 65.8 × 104 CFU mL?1). All water quality parameters remained within the ranges suitable for shrimp culture, except for alkalinity during the first stage of the study. Although in some sampling periods some significant differences were found in bacterial counts and water quality parameters, shrimp productive performance under culture with biofloc at low salinity was not affected significantly by light limitation. 相似文献
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New Forests - Pinus ponderosa P. & C. Lawson was introduced in Chile as a promising species for the diversification of the forest productivity and to optimize the soil productivity in areas... 相似文献
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Crop growth analysis and modeling based on a slightly modified version of the LINTUL model was used for the assessment of the effect of genetic diversity, as expressed by differences in characteristics such as ploidy, parentage and other specific traits, on the growth and yield responses of Andean potatoes to agroecological conditions in Bolivia. The aim of the present study was to conduct a comparative growth analysis of nine genotypes to describe their performance under the prevalent conditions in the high Andes. We also simulated the performance of nine genotypes from the species Solanum tuberosum subspecies andigenum and tuberosum, Solanumajanhuiri, and their hybrids as affected by frost. The simulations were run using a user-friendly simulation model based on the LINTUL framework. 相似文献
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影响鸡早期骨骼发育的因素 总被引：1，自引：0，他引：1
家禽与其它动物相比生长速度快,所以任何异常情况都会很快地综合表现为腿软,腿病因此也就成了导致家禽死亡的主要因素。骨病常常是因发育、营养、环境或疾病感染等因素中的几个因素与生长不适应,干扰骨骼的正常生长发育造成的。本文对近年来鸡腿病的研究报道进行综述,表明鸡品种、生长阶段、营养(钙、磷、钙磷比、微量元素、维生素等)、饲养管理(运动、密度、光照)、中毒、其它传染性疾病等均与腿病的发病率有关。 相似文献