Modeling Main and Interactional Effects of Some Physiochemical Properties of Egyptian Soils on Cation Exchange Capacity Via Artificial Neural Networks

Eurasian Soil Science - The application of artificial neural networks (ANNs) in agricultural sciences has proved its importance as a mathematical modeling technique for prediction and providing...     

摩尔多瓦葡萄日光温室延迟栽培关键技术

为探索葡萄延迟栽培技术,以半地下式日光温室内2年生摩尔多瓦葡萄为试材,系统地研究推迟萌芽+延迟采收+挂树贮藏综合措施的延迟栽培效果。结果表明:在河北省阳原地区,摩尔多瓦葡萄可推迟至5月上旬萌芽,8月20日果粒开始着色,10月21日成熟,成熟后可挂树贮藏至元旦。浆果采收期比露地延迟50~120d,上市期为10月下旬至元旦。延迟采收前40d内,果粒体积和果粒重逐渐增大,可溶性固形物含量继续升高,酸含量、硬度降低,果皮变薄,颜色由蓝黑色变为黑色,口感多汁、浓甜和酸味消失;40d后,可溶性固形物含量继续升高,粒重开始下降,可滴定酸含量变化不大。利用春季夜间低温推迟葡萄萌芽期、秋冬季保温延迟采收和落叶后挂树贮藏3项关键技术措施,可使北方日光温室摩尔多瓦葡萄比露地栽培推迟50~120d上市,为11月至元旦市场和冬季观光采摘市场提供优质新鲜葡萄。     

Protein quality of four types of edible mushrooms found in Jordan

This study was conducted to determine the protein quality of four types ofedible mushrooms, Terfezia claveryi, Pleurotus ostreatus, Tricholoma terreum and Agaricus macrosporus that are common inJordan. Protein efficiency ratio (PER) and net protein utilization methods(NPU) were used. The four mushroom types failed to support growth asreflected by negative values for PER; –1.76 for T. claveryi; –0.23 for P. ostreatus; –0.98 for T. terreum and–0.41 for A. macrosporus. The NPU_(op), NPU_(st)and NdpE% for T. claveryi were 32.6, 33.9 and 3.89%,respectively. The respective values for P. ostreatus were 38.5, 40.7and 4.35%; T. terreum 29.1, 29.8 and 3.63%; and A.macrosporus 31.5, 32.9 and 3.91%. The results showed that the fourmushrooms were significantly (p 0.05) lower in protein qualitycompared with casein results (NPU_(op), NPU_(st) andNDpE% of 78.5, 86.4 and 7.16%, respectively.     

An evaluation of the effect of Bacillus cells and Bacillus spores in association with cowpea granules as starter cultures for the fermentation of African oil bean (Pentaclethra macrophylla Bentham) to `ugba'

Studies on the improvement of the traditional production of `ugba',a protein-rich fermented African oil bean seed product, were undertaken,by developing starter cultures of Bacillus subtilis cells andspores in association with cowpea granules. The viability of the cellsin association remained stable at 94.5% for 6 months at 30 <sup>°</sup>C and for up to 10 months at 4 <sup>°</sup>C while the viability of the sporesin association remained stable at ca. 96% for up to 10 months at both4 and 30 <sup>°</sup>C. The starter cultures resulted in high increases inprotease activity from ca 2.8 mg N/min to about 51.6 ± 0.4 mg N/minin 48 h and a corresponding increase in amino-nitrogen content of ca2.0 ± 0.2 mg N 100 g dry matter (DM) to ca 18.5 ± 0.3 mg N/100g (DM) during the same period. Changes in the protease activity of thenatural process were gradual and increased from 3.0 mg N/min to 38.0 ±0.8 mg N/min after 5 days of fermentation. The maximum amino nitrogencontent of `ugba' produced by the starter cultures (18.5 ± 0.3 mgN/100 g DM) after 2 days was significantly (p < 0.05) higher than themaximum amino nitrogen content (12.5 ± 0.8 mg N/100 g DM), of `ugba'obtained by the natural process. `Ugba' produced by the starter cultureswere well accepted and compared favorably with the natural product.     

Effect of nitrogenous amendments on the incidence of sclerotium wilt of potato

Summary The effects of nitrogen on the incidence of potato wilt caused bySclerotium rolfsii was tested on the highly susceptible cultivar Patronis grown in a greenhouse in earthen pots containing autoclaved sterilized soil artificially inoculated withS. rolfsii. Three levels, each of urea and mustard oil cak were applied at rates equivalent to 112, 140 and 168 kg N/ha 7 days after inoculating the soil and 5 days before planting the tubers. Both amendments reduced the incidence of sclerotium wilt but urea at the highest rate showed the highest reducing effect.     

Determinants of grassland primary production in seasonally-dry silvopastoral systems in Central America

Grassland primary productivity is the function that underpins the majority of the fodder production in cattle-rearing silvopastoral farms. Hence, understanding the factors that determine grassland productivity is critical for the design and management of silvpastoral systems. We studied the effect of two factors with documented impact on grassland productivity in seasonally dry silvopastures of Nicaragua, rainfall and trees. We assessed the effects of three species that differed in crown size and phenology, one evergreen, Cassia grandis, and two deciduous species, Guazuma ulmifolia and Tabebuia rosea. Overall, grassland ANPP had a quadratic response to rainfall, with a decline at high rainfall that coincided with peak standing biomass and grassland cover. Trees had a predominately negative effect on grassland productivity, and the effect was concentrated in the rainy season at peak productivity. The effect of the trees corresponded with the tree crown area, but not with crown density. Trees reduced the standing biomass of graminoids and increased forb biomass; thus, the effect of trees on grassland ANPP appears in part to respond to changes in grassland composition. We also found higher levels of soil moisture content below the tree canopy, particularly at the peak of the rainy season when soils tend to become waterlogged. The evergreen species, C. grandis, affected grassland ANPP more strongly than the deciduous species.     

Over-wintering growth of Macrobrachium rosenbergii (de Man) with carp polyculture in Bangladesh fed formulated diets

An experiment was conducted from December 2003 to April 2004 to observe the over‐wintering growth of freshwater prawn, Macrobrachium rosenbergii, with catla, Catla catla and rohu, Labeo rohita in polyculture using formulated diets. The study was conducted in eight experimental ponds, each 80 m². Three experimental diets containing 30% protein were prepared using fish meal, meat and bone meal, mustard oilcake, rice bran, wheat bran and molasses (binder), and assigned to treatments T₁, T₂ and T₃ respectively. A commercial diet from Saudi‐Bangla Fish Feed was assigned to T₄ (reference diet). Each treatment had two replicate ponds. Juvenile prawns and catla and rohu fingerlings (initial weight 1.60±0.10, 30.0±1.2 and 25.0±1.1 g respectively) were stocked at a ratio of 2:1:1 (prawn:catla:rohu). A total of 160 prawn and fish (20 000 ha^?1) were stocked in each pond. Fish were fed twice daily at 3% body weight (b.w.) for the first 3 months and 5% b.w. for the last 2 months. Prawns in T₁ fed diet 1 had significantly higher (P<0.05) weight gain compared with that of T₃. The reference group and T₂ had intermediate values not significantly different from either. Weight gains of catla and rohu were significantly higher in T₁. The feed conversion ratio values of different diets ranged between 1.89 and 2.13. Survival (%) ranged from 90.0% to 95.0% for catla, 87.5% to 92.5% for rohu and 70.0% to 76.3% for M. rosenbergii, and there were no significant differences (P>0.05) among different treatments. Total production ranged between 2196 and 2679 kg ha^?1, with T₁ showing significantly higher production and net profit (taka 56 531.9 ha^?1). The results of the study demonstrated that it is possible to culture M. rosenbergii with carp in polyculture during the winter utilizing the late‐produced PLs. Further study is needed to determine the optimum stocking density of M. rosenbergii in carp polyculture.     

Association of a novel SNP in exon 10 of the IGF2 gene with growth traits in Egyptian water buffalo (Bubalus bubalis)

Insulin-like growth factor 2 (IGF2) plays an important role in muscle growth and it might be used as a marker for the growth traits selection strategies in farm animals. The objectives of this study were to detect polymorphisms in exon 10 of IGF2 and to determine associations between these polymorphisms and growth traits in Egyptian water buffalo. PCR-single-strand conformation polymorphism (SSCP) and DNA sequencing methods were used to detect any prospective polymorphism. A novel single nucleotide polymorphism (SNP), C287A, was detected. It was a non-synonymous mutation and led to replacement of glutamine (Q) amino acid (aa) by histidine (H) aa. Three different SSCP patterns were observed: AA, AC, and CC, with frequencies of 0.540, 0.325, and 0.135, respectively. Association analyses revealed that the AA individuals had a higher average daily gain (ADG) than other individuals (CC and AC) from birth to 9 months of age. We conclude that the AA genotype in C287A SNP in the exon 10 of the IGF2 gene is associated with the ADG during the age from birth to 9 months and could be used as a potential genetic marker for selection of growth traits in Egyptian buffalo.     

The toxicologic pathology aspects of selected natural herbal products and related compounds

Herbal products have been in use for many years, but they are becoming more and more popular in recent years, and they are currently in widespread use throughout the world. In this review article we describe the histopathologic findings found after exposure to 12 dietary herbals in studies conducted in rodent model systems. Clear or some evidence for carcinogenic activity was seen with 6 herbals, with the liver being the most common organ affected. The intestine was affected by two herbals (aloe vera nondecolorized extract and senna), three had no clear evidence for carcinogenic activity and one was cardiotoxic (Ephedrine and Ephedra in combination with caffeine). Information from these studies can help to better understand potential target organs for further evaluation from exposure to various herbal products.