Changes in soil phosphorus fractions across a toposequence in the estuary plains of Pakistan

Understanding the regional dynamics of soil phosphorus (P) chemistry is essential for developing the best fertilizer management practices aimed at enhancing P use efficiency in cropping systems. The soil content of apatite, an important P-containing lithogenic mineral, can be influenced by its position in the local relief of a landscape. The objective of this study was to determine quantitative distribution of various P-forms in estuary plains of southern Pakistan in relation to soil genesis. Soils at different positions within the estuary plain were sampled at various genetic horizons. Apatite-P was the most abundant inorganic P constituent (380-590 mg kg^?1) in all cases, followed in decreasing abundance by iron oxides surfaces adsorbed phosphorus (Fe-P), octacalcium phosphates (Ca₈-P), aluminum oxides with surface bound P (Al-P) and the least abundant was the phosphorus occluded in iron oxides mineral (Occl-P). The abundance of apatite-P and these other forms of secondary phosphate varied for the soils at different relief positions in these estuary plain landscapes.     

Enhancing phosphorus availability,soil organic carbon,maize productivity and farm profitability through biochar and organic–inorganic fertilizers in an irrigated maize agroecosystem under semi‐arid climate

Biochar amendments offer promising potential to improve soil fertility, soil organic carbon (SOC) and crop yields; however, a limited research has explored these benefits of biochar in the arid and semi‐arid regions. This two‐year field study investigated the effects of Acacia tree biomass‐derived biochar, applied at 0 and 10 t ha^?1 rates with farmyard manure (FYM) or poultry manure (PM) and mineral phosphorus (P) fertilizer combinations (100 kg P ha^‐1), on maize (Zea mays L.) productivity, P use efficiency (PUE) and farm profitability. The application of biochar with organic–inorganic P fertilizers significantly increased soil P and SOC contents than the sole organic or inorganic P fertilizers. Addition of biochar and PM as 100% P source resulted in the highest soil P (104% increase over control) and SOC contents (203% higher than control). However, maize productivity and PUE were significantly higher under balanced P fertilizer (50% organic + 50% mineral fertilizer) with biochar and the increase was 110%, 94% and 170% than 100%‐FYM, 100%‐PM and 100% mineral fertilizer, respectively. Maize productivity and yield correlated significantly positively with soil P and SOC contents These positive effects were possibly due to the ability of biochar to improve soil properties, P availability from organic–inorganic fertilizers and SOC which resulted in higher PUE and maize productivity. Despite the significant positive relationship of PUE with net economic returns, biochar incorporation with PM and mineral fertilizer combination was economically profitable, whereas FYM along biochar was not profitable due to short duration of the field experiments.     

Dietary supplementation with glutamine and γ‐aminobutyric acid improves growth performance and serum parameters in 22‐ to 35‐day‐old broilers exposed to hot environment

This study was designed using 360 21‐day‐old chicks to determine the influences of diet supplementation with glutamine (5 g/kg), γ‐aminobutyric acid (GABA, 100 mg/kg) or their combinations on performance and serum parameters exposed to cycling high temperatures. From 22 to 35 days, the experimental groups (2 × 2) were subjected to circular heat stress by exposing them to 30–34 °C cycling, while the positive control group was exposed to 23 °C constant. The blood of broilers was collected to detect serum parameters on days 28 and 35. Compared with the positive control group, the cycling high temperature decreased (p < 0.05) the feed consumption, weight gain and serum total protein (TP), glucose, thyroxine (T4), insulin, alkaline phosphatase (ALP), glutamine, GABA and glutamate levels, while increased (p < 0.05) the serum triglyceride (TG), corticosterone (CS), glucagon (GN), creatine kinase (CK), glutamic oxaloacetic transaminase (GOT), nitric oxide synthase (NOS), glutamate pyruvate transaminase (GPT) and lactate dehydrogenase (LDH) levels during 22–35 days. However, dietary glutamine (5 g/kg) increased (p < 0.05) the feed consumption, weight gain and serum levels of glutamine, TP, insulin and ALP, but decreased (p < 0.05) the serum TG, CK, GOT, NOS and GPT levels. Diet supplemented with GABA also increased (p < 0.05) weight gain and the serum levels of TP, T4, ALP, GABA and glutamine. In addition, the significant interactions (p < 0.05) between glutamine and GABA were found in the feed consumption, weight gain and the serum ALP, CK, LDH, GABA, T3 and T4 levels of heat‐stressed chickens. This research indicated that dietary glutamine and GABA improved the antistress ability in performance and serum parameters of broilers under hot environment.     

Assessment of Extent of Apoptosis and DNA Defragmentation in Chilled Semen of Stallions During the Breeding Season

The objective of the study was to assess apoptosis and DNA defragmentation in equine semen diluted and chilled to +4°C. Semen was collected from nine fertile stallions, including four Arabian thoroughbreds and five coldbloods. Examinations were carried out immediately after semen collection (0) and at five storage times (24, 48, 72, 96 and 120 h). The basic semen evaluation was performed in terms of volume, sperm concentration, viable sperm percentage, progressive motility and morphology. Using flow cytometry, DNA defragmentation and cell membrane integrity of spermatozoa were determined. The results of basic tests did not demonstrate significant differences amongst stallions, except for progressive sperm motility, which was significantly higher (p < 0.05) in the semen of Arabian stallions. In the semen of the same stallions, a significant decrease in the percentage of alive spermatozoa was observed at 72, 96 and 120 h of storage, whereas a significant increase in the number of spermatozoa with DNA defragmentation was found after 24 h storage. In the semen of coldblood stallions, significantly reduced live spermatozoa percentage was observed at 96 and 120 h, while increased DNA defragmentation was observed at 48 h. These findings demonstrated that the semen of Arabian stallions chilled to +4°C retained original characteristics until 24 h of storage, whereas in coldbloods, these were preserved up to 48 h of storage.     

Hierarchical models for white mould in snap bean

Limitations on the acceptable proportion (incidence) of pods with white mould may lead to the rejection of entire fields of processing snap bean. The low tolerances (no more than 2% to 6% of pods with white mould) are difficult to estimate with sufficient precision in the field when time is limited. These constraints motivated this study of white mould across three spatial hierarchical levels: pods, plants and quadrats consisting of two adjacent plants within rows. Hierarchical relationships are required when designing formal rules for estimating the incidence of pods with white mould from units higher in the spatial hierarchy. Disease assessments were made on all pods from 38 within‐row transects of 40 plants each of the snap bean cultivar Hystyle. Using probability‐based principles, equations were derived and fitted to data on the incidence of white mould on pods (i_pod), plants (i_pad) and quadrats (i_q(2)), which led to a function directly linking i_pod to i_q(2). The variance of i_pod increased with i_q(2), but that may be of little consequence at the lower values of i_q(2) likely to be associated with i_pod values at processor‐set tolerances. For example, at i_q(2) = 0.1 there was a 92% probability that i_pod was less than 0.02. Assessing i_q(2) may be more efficient than directly estimating i_pod because i_q(2) was about an order of magnitude higher than i_pod. Results suggest it may be feasible to design sampling plans for estimating the proportion of pods with white mould from an assessment of the proportion of diseased quadrats.     

Health and mineral nutrition status of yaks in southern Mustang,Nepal

Biochemical values and mineral concentrations in blood plasma were investigated to evaluate the statuses of health and mineral nutrition among yaks in Mustang District, Nepal. In total, 118 plasma samples of female yaks collected in April and September/October of 2013–2015 were offered. Seventy‐four percent of yaks showed lower plasma total‐cholesterol concentrations than the lowest limit of reference range (100 mg/dL) and the values in spring (83.41 mg/dL) were lower (P < 0.05) than those in autumn (95.05 mg/dL). All the yaks had lower plasma albumin concentrations than the lowest limit of reference range (3.0 g/dL) and 66% of yaks showed lower plasma inorganic phosphorus concentrations than the critical level of phosphorus deficiency (4.5 mg/dL). Thirty‐five percent of yaks showed lower plasma calcium concentrations than the lowest limit of normal range (8 mg/dL) and the concentrations were lower in spring than in autumn (P < 0.01). Seventy‐five percent of yaks presented lower copper concentrations than the critical level (0.65 mg/L) and the concentrations were lower in spring than in autumn (P < 0.01). Since the low plasma total‐cholesterol might have indicated shortage of dry matter and energy intake, attention should be paid to the nutritional statuses of energy, phosphorus, calcium and copper in winter and early spring.     

Identification and characterization of important sterile and maintainer lines from various genotypes for advanced breeding programmes of onion (Allium cepa)

Onion is one of the major vegetable crops in terms of production as well as consumption. In the current research, available onion genetic stock was evaluated to identify male-sterile lines and produce high-yielding F₁ hybrids for future breeding programmes. A mitochondrial DNA-based marker was mapped and correlated with phenotypic traits to isolate male-sterile plants. Based on the floral and pollen structure, nine putative male-sterile lines were identified. On the other hand, for nuclear marker identification at Ms locus, two sets of primers were used, one for Ms dominant allele and another for sterile and maintainer plants. Results revealed that 70% of open pollinated varieties (OPVs) possess plants with sterile cytoplasm coupled with genetic sterility at Ms locus, called sterile “A” line. Approximately 20% of plants in some genotypes were identified with normal (N) cytoplasm having recessive fertility gene at Ms locus, called maintainer “B” line. Based on the present findings, “A”, “B” and “R” (restorer line), future F₁ hybrid seed production systems in onion is discussed.     

Assessment of reference dietary amino acid pattern for juvenile red sea bream, <Emphasis Type="Italic">Pagrus major</Emphasis>

Four semi-purified diets, containing crystalline amino acids (CAAs), were fed to juvenile red sea bream, Pagrus major in order to ascertain the ideal dietary amino acid pattern for this species. A control diet containing 50% casein–gelatin as protein sources, but no CAAs were fed to the fish. The other diets contained 30% casein–gelatin and 20% CAAs. CAAs were added to diets to simulate with amino acid pattern of the red sea bream eggs protein (REP), red sea bream larvae whole body protein (RLP), red sea bream juvenile whole body protein (RJP), and brown fishmeal protein (BFP). The juveniles (average initial body weight, 1.58 ± 0.01 g) were maintained in triplicate tanks and fed twice daily for 30 days. The highest weight gain was observed in juveniles fed the RJP diet. No significant difference was observed in juveniles fed the RLP and BFP diet. Feed efficiency ratio, protein efficiency ratio and amino acid retention in the whole body were significantly (p < 0.05) affected by the simulated dietary amino acid patterns. The essential amino acid profile and A/E ratios of the whole body after the growth trial showed little difference among the dietary treatments. The results suggest that red sea bream juveniles are able to utilize high amounts of CAA in coated form. The amino acid pattern of RJP could be used as an appropriate of reference dietary amino acid for this species.     

Temperature Dependent Seed Transmission of Stagonospora nodorum in Wheat

The transmission of Stagonospora nodorum from four naturally infected winter wheat seedlots was quantified in controlled environment germination chambers at 9, 13, 17, 21, and 25 °C. Seedlings were harvested when the second leaf began to emerge. Coleoptiles and first seedling leaves were examined for the presence of lesions caused by S. nodorum. First leaves were incubated on Bannon's medium for 2 weeks, after which they were examined for pycnidia of S. nodorum. Transmission to the coleoptile occurred at all temperatures, but decreased from 100% to 72% as temperature increased from 9 to 25 °C. Transmission to the first leaf was less, dropping from 37% to 2% as temperature increased from 9 to 25 °C. At least 44% of infected first leaves were symptomless at all temperatures, with 96% of infected leaves showing no symptoms at 25 °C. Transmission to seedling leaves occurred over a broad temperature range. Under the high densities at which wheat is sown, a significant number of infected seedlings per unit area may originate from relatively low initial seed infection levels and transmission efficiencies.