Effect of post‐methanation effluent on soil physical properties under a soybean‐wheat system in a Vertisol

Post‐methanation effluent (PME) generated through bio‐methanation of distillery effluent, a foul‐smelling, dark colored by‐product of distillery industries, is applied to arable land in some areas near the vicinity of the distillery industries as an amendment. The PME contains considerable amount of organic matter and salt besides its high plant‐nutrient content. The present investigation was conducted for three years during 1999–2002 on soybean‐wheat cropping sequence to evaluate the effect of graded levels of post‐methanation effluent (PME) on soil physical properties and crop productivity in a deep Vertisol of central India. Six application doses of PME viz. S_2.5+W₀: 2.5 cm PME applied to soybean and wheat on residual nutrition, S_2.5+W_1.25: 2.5 cm PME to soybean and 1.25 cm to wheat, S_5.0+W₀: 5 cm PME to soybean and wheat on residual nutrition, S_5.0+W_2.5: 5.0 cm PME to soybean and 2.5 cm to wheat, S_10.0+W₀: 10 cm PME to soybean and wheat on residual nutrition, and S_10.0+W_5.0: 10.0 cm PME to soybean and 5.0 cm to wheat, were compared with 100% recommended NPK+FYM ? 4 Mg ha^–1 and control (no fertilizer, manure or PME). The application of PME increased the organic carbon content and electrical conductivity of the soil compared to control and 100% NPK+FYM treatment. The organic C content was maximum in S_10.0+W_5.0 (11.2 g kg^–1) and minimum in control (5.2 g kg^–1). Electrical conductivity increased from 0.47 dS m^–1 in control to 1.58 dS m^–1 in highest dose of PME (S_10.0+W_5.0). The PME treatments have not affected the soil pH. The application of PME showed a significant improvement in the physical properties of the soil. The mean weight diameter (MWD), percent water‐stable aggregation (% WSA), saturated hydraulic conductivity (K_sat), and water retention (WR) at 0.033 MPa suction were significantly (P < 0.05) more while bulk density (BD) and penetration resistance was significantly less in PME‐treated plots than that of control. The MWD showed a linear and positive relationship (r = 0.89**) with the soil organic C. Soybean recorded significantly higher seed yield at all PME treatments than control. Highest average soybean yield (2.39 Mg ha^–1) was recorded in S_10.0+W₀ but yield decreased significantly in S_10.0+W_5.0 (2.08 Mg ha^–1). In wheat, all the PME‐treated plots except S_2.5+W₀ yielded significantly higher than control while the 100% NPK+FYM treatment yielded (3.46 Mg ha^–1) at par with the S_10.0+W_5.0 (4.0 Mg ha^–1) and S_5.0+W_2.5 (3.66 Mg ha^–1). Fresh application of PME to wheat resulted in significant improvement in grain yield over that grown on residual fertility. Thus, application of PME to arable land, as an amendment, could be considered as a viable option for the safe disposal of this industrial waste.     

Mixed feeding schedules in semi‐intensive pond culture of Nile tilapia,Oreochromis niloticus,L.: is it necessary to have two diets of differing protein contents?

Two semi‐intensive grow‐out trials of Nile tilapia, Oreochromis niloticus (L.), each consisting of seven mixed feeding schedules (rhythmic presentation of high and low protein) and two constant, a high‐protein and the other low‐protein feeding schedules, were carried out simultaneously for 60 days. Mixed feeding schedules were achieved, in Trial 1, by alternating the presentation of a high feed ration (H; 2.3% body weight (BW)) with a low feed ration (L; 1.5% BW) of a single diet A (crude protein content 33%), and in Trial 2, by alternating the presentation of diet A with diet B of a relatively low protein content (crude protein content 22%). In both trials, significant improvements in protein utilization parameters, such as apparent protein conversion efficiency and protein efficiency ratio against continuously high protein feeding were obtained because of the adoption of mixed feeding schedules without any significant decline in the growth parameters such as net fish yield or daily weight gain. In both trials, the mixed feeding schedule ensuring 2 days of high followed by 3 days of low protein presentation, viz. 2H/3L of Trial 1 and 2A/3B of Trial 2 performed the best. Improvement in nutrient utilization in both trials was comparable; however, at existing market prices cost saving because of adoption of mixed feeding schedules was greater in Trial 1.     

In vitro assay of plant protease inhibitors from four different sources on digestive proteases of rohu, Labeo rohita (Hamilton), fingerlings

The in vitro inhibitory effect of protease inhibitors from four seed extracts (soybean, grasspea, black gram and horse gram) on digestive proteases of rohu was assessed by enzyme inhibition assay and substrate sodium dodecyl sulphate‐polyacrylamide gel electrophoresis. High proteolytic activity was detected in the intestinal extract of rohu (Labeo rohita) fingerlings at two different pH ranges (8–8.5 and 10–11). That protein digestion occurs mainly in the alkaline condition in this fish without a stomach is evident from very high trypsin activity (0.95±0.04 benzoyl‐dl ‐arginine‐p‐nitroanilide U mg protein⁻¹) in the intestine. In case of grass pea seed, more than 50% inhibition of alkaline protease activity was recorded when the ratio of inhibitor to enzyme was 9.41 μg U⁻¹. More than 40% inhibition of protease activity was recorded in case of horse gram seed when the ratio of inhibitor to enzyme was 5.51 μg U⁻¹. Black gram at 11.0 μg U⁻¹ and soybean seed proteins at 62.75 μg U⁻¹ resulted in 50% and more than 30% inhibition of digestive protease activity in rohu fingerlings respectively. A plot of the inhibition values obtained by changing the relative concentrations of enzyme/inhibitor resulted in different dose–response curves for different protein sources. The use of substrate gel electrophoresis allowed the visualization of the aforementioned differences in inhibition. Each seed extract produced a characteristic profile of protease inhibition. It is concluded that protease inhibitors present in plant protein sources adversely affect the digestive proteases in fish and hence there is a need to eliminate/reduce the amount of such inhibitors through proper processing before incorporation into aquafeeds.     

Effect of diluting Marek's disease vaccines on the outcomes of Marek's disease virus infection when challenged with highly virulent Marek's disease viruses

Dilution of Marek's disease (MD) vaccines is a common practice in the field to reduce the cost associated with vaccination. In this study we have evaluated the effect of diluting MD vaccines on the protection against MD, vaccine and challenge MD virus (MDV) kinetics, and body weight when challenged with strains Md5 (very virulent MDV) and 648A (very virulent plus MDV) by contact at day of age. The following four vaccination protocols were evaluated in meat-type chickens: turkey herpesvirus (HVT) at manufacturer-recommended full dose; HVT diluted 1:10; HVT + SB-1 at the manufacturer-recommended full dose; and HVT + SB-1 diluted 1:10 for HVT and 1:5 for SB-1. Vaccine was administered at hatch subcutaneously. One-day-old chickens were placed in floor pens and housed together with ten 15-day-old chickens that had been previously inoculated with 500 PFU of either Md5 or 648A MDV strains. Chickens were individually identified with wing bands, and for each chicken samples of feather pulp and blood were collected at 1, 3, and 8 wk posthatch. Body weights were recorded at 8 wk for every chicken. Viral DNA load of wild-type MDV, SB-1, and HVT were evaluated by real time-PCR. Our results showed that dilution of MD vaccines can lead to reduced MD protection, reduced relative body weights, reduced vaccine DNA during the first 3 wk, and increased MDV DNA load. The detrimental effect of vaccine dilution was more evident in females than in males and was more evident when the challenge virus was 648A. However, lower relative body weights and higher MDV DNA load could be detected in chickens challenged with strain Md5, even in the absence of obvious differences in protection.     

Heavy metals and arbuscular mycorrhizal (AM) fungi can alter the yield and chemical composition of volatile oil of sweet basil (<Emphasis Type="Italic">Ocimum basilicum</Emphasis> L.)

The effects of increasing levels of metals (10 and 20 mg of Cr kg^-1 and 25 and 50 mg of Cd, Pb, and Ni kg^-1 soil) and arbuscular mycorrhizal (AM) fungi Glomus intraradices on the yield, chemical composition of volatile oil, and metal accumulation in sweet basil (Ocimum basilicum L.) were investigated in a pot experiment. The shoot yield, content of essential oil, and root yield of sweet basil were increased by the application of low dose of Cd, Pb, and Ni as compared to control. The application of high level of metals had deleterious effect on the yield. In soil with low dose of metal applied, AM fungi inoculation significantly enhanced the metal concentration in shoots and had adverse effect on the yield, whereas in soil with high dose of metal applied, AM fungal inoculation reduced the metal concentration in shoot and had beneficial effect on the yield. The content of linalool in basil oil was decreased and that of methyl chavicol was increased by the application of Cr, Cd, and Pb in soil as compared to control. Similarly, the level of linalool and methyl chavicol was decreased and that of methyl eugenol was increased by the application of Ni as compared to control. However, AM fungal inoculation led to maintain the content of linalool, methyl chavicol, and methyl eugenol in volatile oil, which were either increased or decreased by the application of metals. We conclude that the AM–sweet basil symbiosis could be used as a novel approach to enhance the yield and maintain the quality of volatile oil of sweet basil under metal-contaminated soils.     

Influence of strain, dose of virus, and age at inoculation on subgroup J avian leukosis virus persistence, antibody response, and oncogenicity in commercial meat-type chickens

The effects of viral strain, viral dose, and age of bird at inoculation on subgroup J avian leukosis virus (ALV J) persistence, neutralizing antibody (VNAb) response, and tumors were studied in commercial meat-type chickens. Chickens were inoculated on the fifth day of embryonation (5 ED) or on day of hatch (DOH) with either 100 or 10,000 50% tissue-culture infective dose (TCID50) of one of three ALV J strains, namely ADOL Hcl, ADOL 6803, or ADOL 4817. At 1, 3, 7, 11, 15, 19, 23, 27, and 32 wk posthatch, chickens were examined for ALV J viremia and VNAb against the inoculated strain of ALV J. A high incidence (83%-100%) of ALV J persistence was observed in all treatment groups. Development of VNAb did not always lead to viremia-free status; even though 18% of the chickens developed VNAb, only 4% were able to clear viremia. The viral strain, dose, and age of bird at inoculation seemed to have an effect on the incidence of VNAb; however, the differences were statistically significant in only some treatment groups. Chickens infected with ADOL 6803 had higher incidence of VNAb than chickens infected with ADOL Hc1 and ADOL 4817 (P < 0.05 in groups 5 ED at 100 TCID50 and DOH at 10,000 TCID50). There was a trend in all groups inoculated with 100 TCID50 to have higher incidence of VNAb than that of groups inoculated with 10,000 TCID50 (ADOL 6803 at 5 ED and ADOL 4817 at DOH [P < 0.05]; ADOL Hc1 at DOH [P < 0.08]). In most treatment groups (ADOL Hc1 at 100 and 10,000 TCID50, ADOL 6803 at 10,000 TCID50, and ADOL 4817 at 100 TCID50), chickens inoculated at DOH had higher incidence of VNAb than that of chickens inoculated at 5 ED (ADOL 6803 at 10,000 TCID50 [P < 0.05], ADOL Hc1 at 100 TCID50 [P < 0.08]). Incidence of ALV J-induced tumors and tumor spectrum were influenced by viral strain, age at inoculation, and VNAb response.     

The perfect ocean for drought

The 1998-2002 droughts spanning the United States, southern Europe, and Southwest Asia were linked through a common oceanic influence. Cold sea surface temperatures (SSTs) in the eastern tropical Pacific and warm SSTs in the western tropical Pacific and Indian oceans were remarkably persistent during this period. Climate models show that the climate signals forced separately by these regions acted synergistically, each contributing to widespread mid-latitude drying: an ideal scenario for spatially expansive, synchronized drought. The warmth of the Indian and west Pacific oceans was unprecedented and consistent with greenhouse gas forcing. Some implications are drawn for future drought.     

Assessment of genetic diversity,population structure and phytochemical variations in Polygonatum cirrhifolium (Wall.) Royle: an endangered medicinal herb

Genetic Resources and Crop Evolution - Polygonatum cirrhifolium (Wall.) Royle is an important medicinal herb of the family Asparagaceae used to cure several ailments. The rhizome of the species...     

Microclimate modifications,growth and yield of intercrops under Hardwickia binata Roxb. based agroforestry system

An experiment was conducted by planting Hardwickia binata Roxb. at 200, 400 and 800 trees ha^???1, intercrops viz., Brassica campestris (mustard) and Glycine max (soybean) were sown from the second year onwards in winter and summer respectively at the National Research Centre for Agroforestry, Jhansi, U.P., India with the objectives of evaluating agrosilvicultural potential of the system and to study the effect of tree densities on ecophysiology of understorey crops. Tree growth was affected by both density and intercrop in the initial years of growth. Photosynthetic photon flux density (PPFD) available to the intercrops reduced with increasing densities. Transpiration rate and stomatal conductance in intercrops decreased due to the presence of trees. No significant changes in leaf temperature were observed till the fifth year of the growing season. Yield was significantly higher in pure crop in comparison with all the densities in mustard. Soybean yield under 200 trees ha^???1 was comparable to that of the pure crop. Trees at the density of 200 trees ha^???1 provided a conducive microenvironment to the intercrops.     

HPTLC analysis of guggulsterone isomers in Commiphora wightii (Arn.) Bhandari: an endangered oleo-gum resin species heading towards extinction

The oleo-gum resin of Commiphora wightii (Arn.) Bhandari, a pharmacologically important balsamiferous woody shrub, has been used in treating various ailments and disorders since ancient times (2000 B.C.) due to the presence of steroidal compound guggulsterone. Two bioactive isomers of guggulsterone, E and Z, are responsible for lipid- and cholesterol-lowering and anti-cancerous activities. Further, guggul has been approved as food supplement by US-FDA as well as Council of Europe. Indiscriminate harvest of C. wightii from wild with negligible conservation efforts has lead to its inclusion in IUCN assemblage of endangered plant species. For identification of high guggulsterone yielding ecotypes of C. wightii, using high-performance thin-layer chromatographic (HPTLC) analysis, stem samples were collected from 50 plants from eleven locations in arid tracts of Haryana, Gujarat and Rajasthan. Dried, powdered material was subjected to extraction with petroleum ether using soxhlet apparatus. Samples were spotted on precoated activated silica plates (60F-254) and were developed using toluene–acetone (9:1 v/v) as mobile phase. The analysis was carried out in the absorbance mode at 250 nm using HPTLC scanner. The regression analysis data for the calibration plots for E and Z guggulsterone showed good linear relationship with R² = 1 and 0.9897, respectively. Highest concentration of guggulsterone E (284 μg/g dry wt) was found in the accession collected from Palana, Bikaner whereas highest guggulsterone Z concentration (89.5 μg/g dry wt) was found in the accession collected from CAZRI, Jodhpur.