Impact of sulfur fertilization on distribution of sulfur fractions and use efficiency in blackgram in subtropical acidic soil of Assam,India

A field experiment was conducted to assess the effect of sulfur (S) fertilization on distribution of S in soil and use efficiency on blackgram in subtropical Inceptisol of acidic soil of Assam, India. Five levels of S were applied (0, 10, 20, 30 and 40 kg S ha^?1) along with recommended dose of nitrogen, phosphorus and potassium. Available S content gradually decreased with the advancement of crop growth stages and lowest value was observed at 60 DAS. Different S fractions were found to increase with increasing levels of S application and 40 kg S ha^?1 resulted the highest content for all S fractions. The grain and stover yield of blackgram increased significantly up to 20 kg S ha^?1 which was 95.69% higher over control. Agronomic efficiency, apparent S recovery and recovery efficiency of S were higher at 10 kg S ha^?1and found decreased with increase in level of S.     

An assessment of benzimidazole resistance against caprine nematodes in Central India

Current status of resistance to benzimidazole (BZ) group of anthelmintic drugs against caprine nematodes in Central India at Amanala goat farm, Jabalpur, Madhya Pradesh (M. P.), was systematically investigated using faecal egg count reduction (FECR) test and egg hatch test (EHT). Besides, allele-specific PCR (AS-PCR) was deployed to ascertain the susceptible genotype (alleles) especially of the Haemonchus contortus. Randomly selected 30 goats, irrespective of age and sex, were divided into three groups of 10 each, to serve as treated and untreated controls. It was ensured that the animals were not administered with an anthelmintic drug for the past 3 months prior to undertaking the study, and faecal egg counts were estimated. FECR test evidenced fenbendazole resistance by partial elimination (24.90%) copro-egg counts in the treated group of animals vis-à-vis controls with a lower confidence interval of ?26%. Further, EHT revealed ED-50 value of 0.335 μg of thiabendazole/ml, confirming benzimidazole resistance in the animals of that farm. AS-PCR showed that 62% of H. contortus larvae were homozygous resistant (rr), 24% heterozygous (rS) and 14% homozygous susceptible (SS). The genotypic frequencies of three genotypes (rr, rS and SS) were significantly (P < 0.01) different. The prevalence of benzimidazole resistance allele (r) was also significantly (P < 0.01) higher (74%) as compared to susceptible allele (S) (26%). The resistance to benzimidazole has been discussed while emphasizing improved managemental practices designed to reduce exposure of the goat population to parasites, minimize frequency of anthelmintic use at optimum dose and rotational use of different chemical groups of medicines with different mode of action, so as to overcome and combat the upcoming problem in the field.     

Physio-biochemical parameters: a potential tool for target-selective treatment of haemonchosis in the small ruminants

This study aims to evaluate the conjunctiva colour-based FAMACHA score (FS) coupled with a body condition score (BCS), haemogram and stressor hormone level estimation, in identifying post-mortem (PM)/coproscopically proven individuals wanting therapy for economically important gastrointestinal (GI) helminths, Haemonchus contortus, in the small ruminants. The incidence of haemonchosis was significantly (p < 0.05) higher (60.81%) in the ruminants with FS = 3. The H. contortus count in the animals with FS 2, 3 and 4 was 23.2 ± 0.37, 62 ± 2.5 and 74 ± 3.2 (p < 0.05) [positive correlation (r = 0.841 in goats; r = 0.828 in sheep, p < 0.05)], respectively, with corresponding 2.8 ± 0.15, 2 ± 0.3 and 2 ± 0.16 BCS (negative correlation, p > 0.05). The infected animals of FS 2, 3 and 4 measured 8.2 ± 0.0, 7.5 ± 0.23 and 6.7 ± 0.34 g/dl Hb (r = ?0.452, p = 0.01) in goats/9.3 ± 0.8, 8.6 ± 0.5 and 7.6 ± 0.3 g/dl Hb (r = ?0.511, p = 0.05) in sheep with 21.2, 19.8 ± 1.8 and 17.8 ± 0.2% PCV (r = ?0.369, p = 0.05) in goats/26.7 ± 1.2, 22.2 ± 0.2 and 20.9 ± 0.6% PCV (r = ?0.251, p = 0.03) in sheep, respectively. The FS 2, 3 and 4 infected goats/sheep measured 6.1 ± 0, 7.9 ± 1.0 and 9.5 ± 0.9 (p < 0.05)/5.8 ± 2.3, 6.9 ± 1.2 and 7.8 ± 0.2% (p < 0.05) mid-granulocyte [(r = 0.928 (goats)/0.834 (sheep), p < 0.05], while the cortisol level was 15.6, 23 ± 4.5 and 42 ± 2.3 (p = 0.23)/12.1 ± 0, 15.9 ± 1.2 and 24 ± 3.4 (p = 0.29) μg/dl, respectively. The infected ruminants recorded low (p < 0.05) level of Hb/PCV while high level of mid-granulocytes/cortisol. Specificity of FAMACHA test was maximized (100%) when FS = 4 was considered anaemic, but sensitivity was low (35.29% in goats; 25% in sheep). The false negatives was 5.9 (goat)/12.5 (sheep)% when FS ≥ 3 was considered anaemic. The small ruminants with FS ≥ 3, BCS ≤ 2.5, Hb ≤ 7.5 g/dl (goats)/8.6 g/dl (sheep), PCV ≤ 19.8% (goats)/22.2% (sheep) and mid-granulocyte ≥7.9% (goats)/6.9 ± 1.2% (sheep) can be subjected to target-selective treatment for haemonchosis in the field simultaneously maximizing the economic benefit to the farmers.     

Suppression of Botryosphaeria canker of apple by arbuscular mycorrhizal fungi

Stem brown canker or Botryosphaeria canker disease impairs the growth and kills the shoots, limbs and even trunks of infected apple trees. Apple roots are usually colonized by arbuscular mycorrhizal fungi, which may have a positive influence on plant growth and suppression of diseases. In order to assess the efficacy of AM to suppress the disease severity and plant growth enhancement, nine AMF inoculation treatments (Sclerocystis dussi, Glomus intraradices, G. fasciculatum, G. bagyaraji, G. leptotichum, G. monosporum, Gigaspora margarita, a mixed AM culture and a non-mycorrhizal control treatment) were used in this present study. Two-year-old potted apple plants, maintained under glasshouse conditions, were either pre-inoculated with AMF followed by stem inoculation with Botryosphaeria ribis or simultaneously inoculated with Botryosphaeria ribis and AM. The results indicated that the incidence of canker was less severe in plants inoculated with AMF in comparison to non-mycorrhizal control. Timing of inoculation also had a significant effect on disease development and plant survival. Plants pre-inoculated with mycorrhiza performed better over those inoculated simultaneously with Botryosphaeria ribis and AM fungi. Furthermore, AM inoculation resulted in improved survival and growth of AMF-colonized plants; though, it varied by species of AM fungi utilized.     

Factors affecting sporulation of Pestalotiopsis disseminata causing grey blight disease of Persea bombycina Kost., the primary food plant of muga silkworm

The effect of inoculum concentrations, temperature, relative humidity (RH), incubation period and leaf age on sporulation of Pestalotiopsis disseminata and the development of grey blight disease on som (Persea bombycina Kost.) were studied in controlled environmental conditions. These factors had a significant role on spore germination and germ tube development of P. disseminata, the causal organism of the disease. The optimum inoculum concentration of the pathogen were found to be 1 × 10⁷ spores ml⁻¹ for maximum infection percentage. A nonlinear relationship was found between temperature and germination percentage of spores at a given relative humidity (RH). However, 25 °C (±2) temperature and 70% RH were the optimum parameters for better spore germination of the pathogen. Young leaves (leaf no. 1–4 from the top) were more susceptible for development of the diseases in a controlled environment than the older leaves. The germination of spores started at 8 h of incubation and gradually increased up to 20 h (maximum). The disease severity was favoured in the optimum range of temperature (25 ± 2 °C) and RH (70%) which had a combined effect. These epidemiological parameters could help in the management practices of the disease.     

Effect of soybean meal substitution by different concentrations of sunflower meal on egg quality traits of white and coloured dwarf dam lines

1. The effect of soybean meal substitution by different concentrations of sunflower meal on egg quality traits of white and coloured dwarf dam lines was investigated.

2. A total of 144 dwarf hens (38 weeks of age) from the same hatch were randomly divided into 12 groups of 12 birds (4 dietary treatments × 3 replicates).

3. A 2 × 4 factorial design was used to study the effect of 2 lines (Factor A) and substitution of soybean meal (SBM) with 4 concentrations (0, 10, 15 and 20%) of sunflower meal (SFM) [Factor B] on egg quality traits of dwarf dam line hens.

4. All the diets were designed to be isocaloric (11?3 MJ ME/kg) and isonitrogenous (180 g/kg crude protein) The duration of the experiment was 12 weeks.

5. Analysis of variance indicated a highly significant line effect. There were non-significant effects of substitution of soybean meal with different concentrations of sunflower meal on egg quality traits except for Haugh unit.

6. White plumaged dwarf broiler breeder dam line produced significantly fewer, but larger, eggs than coloured dwarf dam line hens.     

Systematics and taxonomic delimitation of vegetable,grain and weed amaranths: a morphological and biochemical approach

Amaranthus is a cosmopolitan genus comprising large number of species with many morphotypes cultivars/accessions having diversified morphological features. The species, morphotypes within Amaranthus are very closely related requiring microclassification even revision in present taxonomic status. Most of the works have been done employing grain Amaranthus and their putative ancestors applying morphological and molecular data. In present study along with morphological features, phenolic compounds (secondary metabolites), isozyme profile of acid phosphatase were applied to get comprehensive reflection of interrelationship and relative closeness among the species, morphotypes/accessions of few vegetable, grain and weed Amaranthus. Both the vegetable and grain Amaranthus are supposed to have originated from respective weed progenitor through occasional outcrossing and gradual domestication. The study strongly vouched the previous interpretations regarding interrelationship of grain Amaranthus and their derivation from their putative progenitor also showed clear separate clustering of vegetable and grain Amaranthus with their close relatives. A sharp congruence in cluster pattern was achieved between morphological dendrogram and cumulative dendrogram computed on morphological and biochemical parameters, which is a rare event in systematics.     

Physicochemical assessment and phosphorus storage of canal sediments within the Everglades Agricultural Area, Florida

Purpose

Excess nutrients such as phosphorus (P) transported from the Everglades Agricultural Area (EAA) in South Florida, USA, to downstream water bodies have been identified as contributing to trophic imbalances within the Florida Everglades. Decades of farming drainage from the EAA has led to accumulation of sediments in regional canals which may be transported to downstream ecosystems and act as potential internal source of P.

Materials and methods

Intact sediment cores were collected from three main conveyance and three farm canals within the EAA. Physicochemical assessment, mineralogy, P speciation, and storage were determined for surface and subsurface layers.

Results and discussion

The main conveyance canal sediments had higher total P (TP) concentrations (1,280?±?360?mg?kg^-1) than the farm canals (960?±?540?mg?kg^-1), while farm canal sediments showed higher organic matter content (28?C53?%) compared to the main canal (24?C27?%) sediments. The minerals found in main conveyance canal sediments were similar to those found in Lake Okeechobee. The labile KCl?CP fraction comprised <2?% of TP from all canal sediments, while NaOH?CPi (i?=?inorganic) fraction consisted of 1?C14?% of TP. The majority of P in the canal sediments was contained in the HCl?CP fraction (Ca?CP and Mg?CP), comprising >50?% of TP in the main and farm canal sediments. An estimated 73 metric tons (mt) of P was stored in the 0?C10-cm layer of the three main conveyance canals within the EAA boundary of which 57-mt P is reactive and potentially available for release at different time scales.

Conclusions

The EAA canal sediments are highly organic with low bulk density and susceptible of being transported to downstream ecosystems. Many factors can impact the potential release of the reactive stored P, including redox potential of sediments as well as the overlying water column P concentration. Further investigation of potential P release from these sediments is warranted.     

Photodegradation of hexythiazox in different solvent systems under the influence of ultraviolet light and sunlight in the presence of TiO2, H2O2, and KNO3 and identification of the photometabolites

The photodegradation of the carboxamide acaricide hexythiazox in three different solvent systems (aqueous methanolic, aqueous isopropanolic, and aqueous acetonitrilic solutions) in the presence of H(2)O(2), KNO(3), and TiO(2) under ultraviolet (UV) light (λ(max) ≥ 250 nm) and sunlight (λ(max) ≥290 nm) has been assessed in this work. The kinetics of photodecomposition of hexythiazox and the identification of photoproducts were carried out using liquid chromatography-mass spectrometry. The rate of photodecomposition of hexythiazox in different solvents followed first-order kinetics in both UV radiation and natural sunlight, and the degradation rates were faster under UV light than under sunlight. Hexythiazox was found to be more efficiently photodegraded in the presence of TiO(2) than in the presence of H(2)O(2) and KNO(3). Two major photoproducts were separated in pure form using column chromatography and identified according to IR, (1)H NMR, and mass spectral information as cyclohexylamine and 5-(4-chlorophenyl)-4-methylthiazolidin-2-one. Another nine photoproducts were identified according to LC-MS/MS spectral information. The plausible photodegradation pathways of hexythiazox were proposed according to the structures of the photoproducts.