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21.
A nano-emulsion system was developed for pesticide formulation. Pseudoternary phase diagrams were constructed consisting emulsion system of long-chain fatty acid methyl esters (LFAMEs)/mixed surfactant/water and a quarternary component, glyphosate isopropylamine (IPA) as a herbicide active. Isotropic (L) regions were formed in the phase diagrams using mixed surfactant long-chain alkylpolyglucosides (LAPG) and ethoxylated 3-(3-hydroxypropyl)-heptamethyltrisiloxane (organosilicone) at the ratios of 9:1, 8:2 and 7:3. Pre-formulation concentrates were chosen from the L regions with less than 20% (w/w) of inerts (LFAMEs + mixed surfactant) and were characterized with regard to particle size, particle aging rate and thermostability study. A pre-formulation concentrate with the lowest aging rate and stable at high temperature (54 °C) was selected for the mechanisms study of the pre-formulation concentrate in conjunction with the development of nano-emulsion formulation. The transmission electron microscopy (TEM) result showed that the pre-formulation concentrate appeared as a polymerized multi-connected network. Upon water dilution of the pre-formulation concentrate with gentle stirring (low-energy emulsification method), well-dispersed nanoparticles were formed with no needle structure being observed. The nano-emulsion particles were incorporated well with the glyphosate IPA thus inferring that this nano-emulsion system could ameliorate the bioactivity and bioavailability of the herbicide.  相似文献   
22.
From January 2010 to December 2011, samples of leaves from citrus varieties Kinnow, Musambi and Feutral were taken from the five tehsils (administrative subdivisions) of Sargodha District in Pakistan including Sargodha, Bahalwal, Silanwalli, Sahiwal and Kotmomin, to study the population trends in citrus leaf miner (CLM), Phyllocnistis citrella (Stainton) (Lepidoptera: Gracillariidae), and its correlation with various environmental factors: (temperature, humidity and rainfall); plant morphological factors: moisture contents of leaves, leaf thickness, surface area (cm 2 ), and biochemical percentage of calcium, potassium and magnesium in leaves. The maximum population of CLM was observed on Kinnow and Feutral, followed by Musambi. The effect of these factors on the larval population was 8.39- 2.30(Mg)+2.73(K)-0.398(Ca)-0.100(Temp)0.038(Humidity)+0.567(Rain)+0.07(Moist) 1.01 (Thickness)-0.022(Surface area). This equation revealed that magnesium, calcium, temperature, humidity, leaf thickness and leaf surface area are negatively correlated with larvae population, whereas potassium, rainfall and moisture are positively correlated with larvae population.  相似文献   
23.
The effect of selection for greater growth rate in the GIFT strain on traits related to female reproduction (weight at spawning, number of eggs, number of fry, total weight of fry and number of dead fry) was studied. Available records comprised 10 generations of data from a total of 935 breeding females with known pedigree. Female body weight at spawning was 255 g, whereas the averages for number of eggs, number of live fry at hatching, number of dead fry and total fry weight per spawning were 1444, 908, 64.90, and 7.24 g respectively. Heritabilities for reproductive traits were low to moderate (0.20 for number of eggs, 0.16 for number of hatched fry and 0.11 for fry weight per female at spawning). The genetic correlations between female body weight at spawning and reproductive traits were very low to low (0.01 to 0.31) and not significantly different from zero. The genetic correlations among reproductive traits (i.e. number of eggs, number of hatched fry and fry weight) were high (0.75 to 0.92). Phenotypic correlations were consistent with the genetic correlations, ranging from 0.56 to 0.85. Correlated responses in reproductive traits measured as differences in least squares means between Selection and Control lines were positive and significant (except for the number of dead fry) when age of females at spawning was fitted as a covariate. However, there were no significant differences in all studied traits when body weight of the female at spawning was fitted as a covariate within lines. This indicates that the greater reproductive rate was due to the greater size of females in the Selection line, but the efficiency of reproduction per unit weight of female did not change as a consequence of selection for growth.  相似文献   
24.
长枝木霉TlCC鉴定及其生物学特性研究   总被引：1，自引：1，他引：1  
从土壤中分离得到1株木霉TlCC,为明确其分类地位及其生物学特性,对该菌进行形态学鉴定和分子鉴定,并对其生长培养基、光照、温度、碳源、氮源、微量元素和pH等生物学特性进行研究。鉴定结果显示,该菌株为长枝木霉（Trichoderm longibrachiatum）。生物学特性结果表明：菌株TlCC在PDA上生长量最大,查氏培养基和基本培养基上生长量最小;不同光照条件下,菌丝生长无明显差异,但在连续光照条件下可明显促进孢子产生;在15~40℃范围能够生长产孢,在35℃时菌丝生长最快,但产孢量在25~35℃最大;果糖最能促进菌丝生长,果糖、可溶性淀粉最有利于产孢;谷氨酸对菌丝生长和孢子产生都有促进作用;Cu最能促进菌丝生长,而Zn、K和Mg则对菌丝生长有一定抑制作用,Cu最有利于产孢,Zn对产孢明显抑制;在pH值在2~10范围内均可生长,在pH为5时为生长最佳,在pH值3~7范围内最有利于产孢。  相似文献   
25.
Flesh characteristics comprising chemical composition (protein, fat and moisture percentages and pH) as well as a sensory attribute (colour) were measured in 1951 fillet samples from two generations of two populations (a selection line, selected for increased harvest weight, and a control line, selected for average breeding values for harvest weight) of the genetically improved farmed tilapia (GIFT) strain of Nile tilapia. These data were jointly analysed with 5331 harvest weight records from three generations to estimate genetic parameters and correlated selection responses. Multiple trait animal models were used in the analyses. The potential for correlated responses was evaluated by estimating heritabilities and genetic correlations between body traits (weight, length, depth and width) and fillet traits (weight and yield) with the above mentioned flesh characteristics. The heritabilities for protein%, fat% and colour were low (0.06–0.11), whereas for moisture% and pH they were moderate (0.15–0.20). Genetic correlations among some flesh characteristics (moisture% with protein%, fat% and pH and with fat%) as well as between body and fillet traits with flesh characteristics, were significantly different from zero but low (?0.34 to 0.31). Correlated responses were evaluated by comparing the least squares means between the Selection and Control lines. Our results indicate that selection for high growth increased harvest weight in the Selection line relative to the Control line but it did not change the flesh characteristics of the GIFT strain.  相似文献   
26.

Many attempts/efforts have been made to cope with the fluctuated production performance in rice production in Malaysia. There is a crucial need in technological advancement to tackle the issue of environmental variability, decreasing productivity and the rising cost in rice cultivation. The use of variable rate technology has increased rice yield through efficient resource allocation. Notwithstanding, an evaluation of the feasibility of this technology is required in terms of economic and intangible benefits. Therefore, this study attempted to determine the potential benefits that could come out of the use of precision agriculture technologies in rice cultivation. A precision farming technology package was developed by the Malaysian Agricultural Research and Development Institute. It consists of two components, namely a variable rate seed application system and a variable rate fertilizer application system. The study estimated the monetary benefits gained from the use of these two technology components at Federal Land Consolidation and Rehabilitation Authority Seberang Perak. The study also compared the performance of the technology package against the conventional practice. The Cost–Benefit Analysis exercise has been implemented to show the benefits and implications comprised in the study. It was found that there is an additional net income per hectare in between Malaysian Ringgit (MYR) 1109 to MYR 1333 due to the reduction in the production cost if the precision farming technology packages were adopted. The advancement in two cultivation stages showed a positive impact monetarily for both small-scale and large-scale farmers in the study. However, many challenges are to be faced for the technologies implementation since the existing rice cultivation recommended practices throughout all stages even yet to be practiced and taken seriously.

  相似文献   
27.
Converting oil palm empty fruit bunches into biochar is an alternative waste management method and has strong potential to improve N fertiliser use efficiency in agriculture. The aim of this study was to determine the effectiveness of oil palm empty fruit bunch biochar (EFBB) in improving recovery of 15N-labelled nitrogen fertiliser by maize (Zea mays L.) and leaching of mineral N and K. An experiment was conducted in a mini-lysimeter system with randomised complete block design layout and six replications under controlled environment in a rain shelter. Each mini-lysimeter was filled with 20 kg of sandy loam soil before adding EFBB (0, 5, 10 and 20 Mg ha?1). The N source used was (15NH4)2SO4 at 80 kg N ha?1 (2 at% 15N excess). Maize was irrigated to induce leaching every 4 days. Maize plant and soils were sampled 58 days after sowing (tasselling stage). Application of EFBB significantly reduced cumulative leachate volume and mineral N leaching. Soils applied with EFBB significantly improved 15N fertiliser recovery in maize and dry matter weight. This study shows that EFBB has the potential to be applied on highly weathered acidic soil as an amendment to improve fertiliser efficiency and crop growth.  相似文献   
28.
Latent polyphenol oxidase (LPPO), an enzyme responsible for the browning reaction of sago starches during processing and storage, was investigated. The enzyme was effectively extracted and partially purified from the pith using combinations of nonionic detergents. With Triton X-114 and a temperature-induced phase partitioning method, the enzyme showed a recovery of 70% and purification of 4. 1-fold. Native PAGE analysis of the partially purified LPPO revealed three activity bands when stained with catechol and two bands with pyrogallol. The molecular masses of the enzymes were estimated by SDS-PAGE to be 37, 45, and 53 kDa. The enzyme showed optimum pH values of 4.5 with 4-methylcatechol as a substrate and 7.5 with pyrogallol. The LPPO was highly reactive toward diphenols and triphenols. The activity of the enzyme was greatly enhanced in the presence of trypsin, SDS, ethanol, and linoleic acid.  相似文献   
29.
This study aimed to investigate the effects of key lime juice (KL) in combination with vacuum packaging (VP) or air storage (SB) on the quality changes of white shrimp stored at 2 ± 1ºC. The quality was assessed using microbiological analysis, color measurement, pH, and total volatile base nitrogen (TVBN). Treatment with KL exhibited inhibitory activity on the growth of spoilage microflora. KL in combination with VP revealed a lower bacterial count in the range of 4.37–4.91 log CFU gˉ1 on day 12 of storage as compared to other treatments. VP + KL and VP samples could inhibit melanosis. In addition, lower TVBN content was obtained in VP + KL (5.33 mg N/100 g), followed by VP (6.03 mg N/100 g) samples on day 12 of storage (p < 0.05). VP in combination with KL had the lowest loss of quality changes for the white shrimp. Therefore, VP + KL could be used as an alternative preservative method to extend the shelf life for white shrimp.  相似文献   
30.
Rice noodles, which are widely consumed noodles in Southeast Asia, were evaluated as a potential carrier for fortificants such as vitamin A, folic acid, and iron. Because flour particle size was found to affect the noodle properties, this study was conducted to investigate the effect of five different particle sizes (≤63, 80, 100, 125, and 140 µm) of dry‐milled rice flour on the cooking quality, microstructure, texture, and sensory characteristics of the rice noodles. The retention of fortificant in the noodles at every stage of processing as affected by the flour particle size was also determined. It was found that the rice noodles produced from flour with the smallest particle size studied (≤63 µm) had the best quality and were the most liked by the consumers. In addition, the noodles had the most compact and regular structure, which could be attributed to having the most severely gelatinized starch. This starch would have caused the least leaching of the fortificant into the surrounding water during the boiling stage of the rice noodle processing. Retention of iron in the cooked fortified rice noodles prepared from flour with the smallest particle size was high at around 87%, whereas that of vitamin A and folic acid were below 15%. Because the losses of the fortificant from the rice noodles were mostly owing to the boiling process, further improvements of the rice noodle processing conditions are required for reduction of the vitamin losses.  相似文献   
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