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91.
Abdullahi Iliyasu Zainal Abidin Mohamed Mohd Mansor Ismail Amin Mahir Abdullah Salleh Mohamed Kamarudin Hashim Mazuki 《Aquaculture Economics & Management (Blackwell Science)》2013,17(3):221-247
Most research works on the production frontier in aquaculture focus on efficiency measurement using either Stochastic Production Frontier (SPF) or Data Envelopment Analysis (DEA). The studies on productivity growth in aquaculture were limited, perhaps due to lack of time-series data. Nevertheless, total factor productivity analysis (TFP) in fish farms has started gaining popularity in recent years. In addition, the majority of the efficiency studies have centered on technical efficiency analysis but substantial increases in the output levels can be fully realized through improving overall economic efficiency. Therefore, this review suggests that future research should estimate all three efficiency indices (i.e., technical, allocative and economic efficiencies). 相似文献
92.
【目的】比较鉴别3个不同类型甜菜品种的产量和品质,以期为在农业产业中的应用提供参考。【方法】分别于2008~2009、2009~2010年度,在埃及Kafer El-Sheikh省(北三角洲)Sakha试验站对分属于3种不同形态分化类型E(Ertrag)、Z(Zucker)和N(Normal)的每4个甜菜栽培品种进行两个田间试验。【结果】E类型甜菜的平均块根重和块根产量显著高于Z和N类型的,但Z类型的转光度(蔗糖分)、出糖率(可榨出糖百分比)、回收率最高,而杂质和糖蜜糖最低。此外,糖产量是产量和品质两方面结合的结果,在3个甜菜类型中,糖产量以Farida最高、Lp11最低。此外,在2个年度的试验中,3个类型的每费丹(4200m。)糖产量均以Farida(E类型)、Glereos(Z类型)和Kawemira(N类型)3个品种最高。【结论】在所有甜菜类型中,N类型甜菜品种的块根产量和糖含量在所有类型表现居中,种植此类型甜菜品种,可使农民和糖厂都获得较大的利益。 相似文献
93.
Roohparvar R Mehrabi R Van Nistelrooy JG Zwiers LH De Waard MA 《Pest management science》2008,64(7):685-693
BACKGROUND: The major facilitator superfamily (MFS) drug transporter MgMfs1 of the wheat pathogen Mycosphaerella graminicola (Fuckel) J Schroeter is a potent multidrug transporter with high capacity to transport strobilurin fungicides in vitro. The data presented in this paper indicate that, in addition to the predominant cause of strobilurin resistance, cytochrome b G143A subsititution, MgMfs1 can play a role in sensitivity of field strains of this pathogen to trifloxystrobin. RESULTS: In a major part of field strains of M. graminicola (collected in the Netherlands in 2004) containing the cytochrome b G143A substitution, the basal level of expression of MgMfs1 was elevated as compared with sensitive strains lacking the G143A substitution. Induction of MgMfs1 expression in wild-type isolates upon treatment with trifloxystrobin at sublethal concentrations proceeded rapidly. Furthermore, in disease control experiments on wheat seedlings, disruption mutants of MgMfs1 displayed an increased sensitivity to trifloxystrobin. CONCLUSION: It is concluded that the drug transporter MgMfs1 is a determinant of strobilurin sensitivity of field strains of M. graminicola. 相似文献
94.
Serhat Türkmen Orhan Tufan Eroldoğan Hatice Asuman Yılmaz Abdüllatif Ölçülü Gül Ayten Kiriş Inan Zeynep Erçen Nazmi Tekelioğlu 《Aquaculture Research》2012,43(11):1643-1650
The compensatory growth response of the European sea bass (Dicentrarchus labrax) that faced cycling starvation and restricted ration was assessed. Juveniles (10.5 g) were stocked into 15 tanks at a density of 25 fish per tank. Five different feeding regimes were tested on triplicate groups of fish: CSatiation: control fed for 60 days without deprivation, CRestricted: 25% restricted feeding, S‐R: 1 day starvation then 4 days CRestricted feeding, R‐F: 1 day CRestricted feeding then 4 days CSatiation feeding, and, finally, S‐F: 1 day starvation then 4 days CSatiation feeding. The specific growth rate of fish in the CSatiation (2.5 ± 0.06% day?1), S‐F (2.5 ± 0.11% day?1) and R‐F (2.4 ± 0.18% day?1) were significantly higher than that of CRestricted (2.2 ± 0.05% day?1) or S‐R (2.0 ± 0.01% day?1). Fish in S‐F group were able to achieve catching up with the CSatiation. There was no significant difference in feed conversion rates but R‐F and S‐F consumed approximately 34% more feed than CSatiation following the first re‐feeding day. Although, the highest lipid content was observed in CSatiation (14.4%), S‐R (33.3% dry matter) had the highest water content compared with the CSatiation and CRestricted (37.8% and 36.9% dry matter respectively). In conclusion, it may be concluded that sea bass has rapid response to cycling starvation/re‐feeding and that a 25% restricted feeding ratio is insufficient to invoke a compensatory growth response in sea bass. 相似文献
95.
Tahjib-Ul-Arif Md. Roy Popy Rani Al Mamun Sohag Abdullah Afrin Sonya Rady Mostafa M. Hossain M. Afzal 《Journal of Crop Science and Biotechnology》2018,21(4):383-394
Journal of Crop Science and Biotechnology - Salinity is one of the most brutal abiotic stressors, commencing a great stumbling block in the way of attaining food security in Bangladesh. Cultivation... 相似文献
96.
M. Haggag Wafaa M. M. Tawfik H. F. Abouziena M. S. A. Abd El Wahed R. R. Ali 《Gesunde Pflanzen》2017,69(3):149-158
Arid climate has contributed to crops yield production decrement in many regions due to water shortage and soil salinization. The main target of this research is to enhance wheat production under arid climate stresses by utilizing bio-elicitors. Two common wheat assortments i.?e. cv. Gemmiza 10 and Sakha 93 accomplished tolerant to these stresses utilizing bio elicitors include Acremonium coenophiulum, Streptomyces griseus, Trichoderma harzanium, T. viride, Rhodotorula glutinis, Paenibacillus polymyxa, Bacillus subtilis, B. megaterium, Pseudomonas putida, P. fluorescens compared with natural elicitors as methyl jasmonate (MJ), chitosan (CHI), ascorbic acid and putrescein (PUT). Varieties were planted in two progressive seasons in recently reclaimed lands, where two fields were selected the first is located in North Sinai while the second is situated to the south of Behira Governorate. Bio elicitors reduced abiotic stress and enhance physiological characteristic expressed as Proline, soluble carbohydrates %, Chl.a, Chl.b, Chl.a + b; Chl.a/Chl.b; Carotenoids and increased the concentration of Crude protein, N, P and total soluble carbohydrates in wheat grains. Using P. fluorescens exhibted increment in grain yield of wheat plants, cv sakha 93 amounted by 68.3% in Sinai region, while in Behira region the increement reached (45.5%) with P. polymyxa treatment. The response of Gemmiza 10 variety to the Bio-elicitors was less compared to Sakha 93 variety in both regions, where the highest increments due to P. putida treatment were18.9 and 19.7% in Sinai and beheirwa regions, respectively, compared to the control in each region. A remarkable increments of wheat growth, development and extended survival under salt and water limiting and restricting conditions. These findings demonstrate that wheat plants can display improved stress tolerance through bio-elicitors, and recommend that innovation may be useful in reducing effects of climate change and environmental stress on other crops and expanding agricultural production onto marginal lands. 相似文献
97.
Journal of Plant Diseases and Protection - Black spot disease is the most common diseases of landscape roses and is caused by Diplocarpon rosae Wolf. In Rosa multiflora, the screening of black... 相似文献
98.
Heart development requires coordinated activity of various factors, the disturbance of which can lead to congenital heart defects. Heart lectin‐associated matrix protein‐1 (hLAMP‐1) is a matrix protein expressed within Hensen's node at Hamburger–Hamilton (HH) stage 4, in the lateral mesoderm by HH stages 5–6 and enhanced within the left pre‐cardiac field at HH stage 7. At HH stages 15–16, hLAMP‐1 expression is observed in the atrioventricular canal and the outflow tract. Also, the role of hLAMP‐1 in induction of mesenchyme formation in chick heart has been well documented. To further elucidate the role of this molecule in heart development, we examined its expression patterns during HH stages 8–14 in the chick. In this regard, we immunostained sections of the heart during HH stages 8–14 with antibodies specific to hLAMP‐1. Our results showed prominent expression of hLAMP‐1‐positive particles in the extracellular matrix associated with the pre‐cardiac mesoderm, the endoderm, ectoderm as well as neuroectoderm at HH stages 8–9. After formation of the linear heart tube at HH stage 10, the expression of hLAMP‐1‐stained particles disappears in those regions of original contact between the endoderm and heart forming fields due to rupture of the dorsal mesocardium while their expression becomes confined to the arterial and venous poles of the heart tube. This expression pattern is maintained until HH stage 14. This expression pattern suggests that hLAMP‐1 may be involved in the formation of the endocardial tube. 相似文献
99.
Iman Tahmasbian Zhihong Xu Kadum Abdullah Jun Zhou Roya Esmaeilani Thi Thu Nhan Nguyen Shahla Hosseini Bai 《Journal of Soils and Sediments》2017,17(8):2091-2103
Purpose
The main objective of this study was to examine the potential of using hyperspectral image analysis for prediction of total carbon (TC), total nitrogen (TN) and their isotope composition (δ13C and δ15N) in forest leaf litterfall samples.Materials and methods
Hyperspectral images were captured from ground litterfall samples of a natural forest in the spectral range of 400–1700 nm. A partial least-square regression model (PLSR) was used to correlate the relative reflectance spectra with TC, TN, δ13C and δ15N in the litterfall samples. The most important wavelengths were selected using β coefficient, and the final models were developed using the most important wavelengths. The models were, then, tested using an external validation set.Results and discussion
The results showed that the data of TC and δ13C could not be fitted to the PLSR model, possibly due to small variations observed in the TC and δ13C data. The model, however, was fitted well to TN and δ15N. The cross-validation R2 cv of the models for TN and δ15N were 0.74 and 0.67 with the RMSEcv of 0.53% and 1.07‰, respectively. The external validation R2 ex of the prediction was 0.64 and 0.67, and the RMSEex was 0.53% and 1.19 ‰, for TN and δ15N, respectively. The ratio of performance to deviation (RPD) of the predictions was 1.48 and 1.53, respectively, for TN and δ15N, showing that the models were reliable for the prediction of TN and δ15N in new forest leaf litterfall samples.Conclusions
The PLSR model was not successful in predicting TC and δ13C in forest leaf litterfall samples using hyperspectral data. The predictions of TN and δ15N values in the external litterfall samples were reliable, and PLSR can be used for future prediction.100.
Taia A. Abd El–Mageed Ahmed M.A. El-Sherif Mahmoud M. Ali Mohamed H. Abd El-Wahed 《Archives of Agronomy and Soil Science》2017,63(6):827-840
A 2-year field experiment (2013 and 2014) was conducted in calcareous soil (CaCO3 19.2%), on soybean grown under three irrigation regimes 100%, 85% and 70% of crop evapotranspiration combined with three potassium (K2O) levels (90, 120 and 150 kg ha?1). The objective was to investigate the complementary properties of potassium fertilizer in improving soybean physiological response under water deficit. Plant water status (relative water content RWC, chlorophyll fluorescence Fv/F0 and Fv/Fm), had been significantly affected by irrigation or/and potassium application. Potassium improved growth characteristics (i.e. shoot length, number, leaf area and dry weight of leaves) as well as physiochemical attributes (total soluble sugars, free proline and contents of N, P, K, Ca and Na). Yield and yield water use efficiency (Y-WUE) were significantly affected by irrigation and potassium treatments. Results indicated that potassium application of 150 and 120 kg ha?1 significantly increased seed yield by 29.6% and 13.89%, respectively, compared with 90 kg ha?1 as average for two seasons. It was concluded that application of higher levels of potassium fertilizer in arid environment improves plant water status as well as growth and yield of soybean under water stress. 相似文献