Lantana invasion: An overview

We review the key features of Lantana ( Lantana camara L.), an invasive plant species considered to be among the world's 10 worst weeds. Lantana occurs in diverse habitats and on a variety of soil types, and its spread is encouraged by animal activities and by human disturbances, such as cultivation, road construction, and changes in fire regimes. Lantana is morphologically distinct in the different regions of its invasive range compared to those regions in its native range. The biological attributes contributing to the success of Lantana as an invader species include: fitness homeostasis, phenotypic plasticity, dispersal benefits from destructive foraging activities, widespread geographic range, vegetative reproduction, fire tolerance, better competitive ability compared to native flora, and allelopathy. Mechanical, chemical and biological options for the eradication and control of Lantana are available. It is emphasized that ecosystem-level consequences of Lantana invasion, particularly on the biodiversity of native flora, are little understood and studies are needed to fulfill this knowledge gap.     

Variation in the immune status of two Australian pig breeds

Objective To investigate the variation in immune competence of two Australian pig breeds.
Design A panel of immune tests were used to assess breed and sire differences in weaner piglets of Large White and Duroc breeds.
Procedure All piglets were immunised against porcine leptospirosis. Blood samples were taken for studies on lymphocyte phenotypes, mitogenic responses of blood cells and serological analysis.
Results Significantly larger blood leucocyte numbers were found in Large White piglets compared with Duroc piglets after vaccinations. No significant difference in concanavalin A induced blood cell proliferation was found between these two breeds before or after vaccinations. Some significant breed variation in blood lymphocyte phenotypes was found. While the age-related changes of lymphocyte phenotypes were similar for the two breeds, the Large White breed had significantly larger numbers of CD2+ and CD4+ cells than the Duroc breed after the two vaccinations. There were also significant sire effects on CD8+ cells within the Large White breed after the first vaccination. No significant breed difference was detectable in serum IgG concentrations but sire differences within each breed before the primary vaccination were found. The serum antibody response to vaccination against leptospirosis was generally small, and showed no variations due to either breed or sire. No gender effects were found during the entire study.
Conclusion The study demonstrated significant differences in some important immune components of the pig breeds studied. This may in turn indicate the variation in their immune competence or disease resistance. However, further investigation into the heritability and correlation with specific immune responses is required.     

Natural infection of cucumber mosaic virus on Dianthus barbatus in India

Cucumber mosaic virus (serologically closely related to strains CMV-C and CMV-D) is reported for the first time as a natural infection of Dianthus barbatus causing leaf crinkle and stunting of plants. It was mechanically transmitted to healthy D. barbatus and Vaccaria pyramidata (Caryophyllaceae) and to other herbaceous test plants, and was also aphid-transmissible from D. barbatus to D. barbatus. A convenient host for multiplication and purification of the virus was Nicotiana rustica. The presence of CMV was confirmed in D. barbatus and also in V. pyramidata by Western immunoblotting, but the concentration was too low in both the hosts to detect the virus by agar double diffusion tests.     

Contribution of microbial phytases to the improvement of plant growth and nutrition: A review

Phytases belong to the class of phosphohydrolases that begin the step-wise hydrolysis of phosphates from phytates. Phytates are a derivative of myo-inositol, which is the primary storage form of organic phosphorus in plant cells. Phytase has been used globally to diminish phosphorus pollution and to enhance nutrition in monogastrics. In this review, the classification, sources, and diversity of microbial phytases, and their practical applications, as well as supplementation of the soil with transgenic and wild types of microbial strains, which can release phytase to enhance phosphorus availability for plant uptake and reduce the need for fertilizers, are discussed. The overexpressed microbial phytases in transgenic plants enhance the growth capacity of co-cultivated plants and can therefore be employed in agricultural and biotechnological practices, such as intercropping. The introduction of phytases into the soil for improved plant growth and enhanced crop yield can be accomplished without extra cost. A diverse group of photoautotrophic microalgae can synthesize phytase and will likely be useful in many human food and animal industries.     

Properties of soil kaolinites from south-western Australia

The clay fraction of soils from south-western Australia is dominated by kaolinite. These soil kaolinites give broad basal reflections (median value for WHH 001 =0.41° 2θ) and have poorly ordered structures. The median value of the Hughes & Brown crystallinity index for 35 soil kaolinites is 5.4 compared to 42.0 for mineral standard kaolinites. The median values for surface area and cation exchange capacity of soil kaolinites are 35 m² g⁻¹ and 56.7 mmol_c kg⁻¹, respectively, compared to 10 m² g⁻¹ and 4.8 mmol_c kg- ^l for standard kaolinites. The dehydroxylation temperature of soil kaolinites is about 50 K lower than for standard kaolinites and decreases with increasing Fe content. Soil kaolinite crystals are much smaller (c. 0.10 pm) and are irregular subrounded to rounded plates in comparison to the larger (c. 0.28 pm), perfectly hexagonal euhedral plates of Georgia kaolinite. Analytical electron microscopy of single soil kaolinite crystals indicates that the Fe content varies with an average value of c. 2.5% Fe,₂O₃. X-ray diffraction line broadening data indicate that crystal size decreases as the Fe content increases. Crystal order also decreases with increasing Fe content. The P sorption maximum of soil kaolinite ranges from 486–654 μg P g^−l and is thus about six times larger than for the clay fraction of Georgia kaolinite.     

Co-inoculation of indigenous Pseudomonas oryzihabitans and Bradyrhizobium sp. modulates the growth, symbiotic efficacy, nutrient acquisition, and grain yield of soybean

Soil microbes play a vital role in improving plant growth, crop productivity, and soil health through solubilization of essential nutrients. Present investigation was conducted to access the efficacy of Bradyrhizobium sp. LSBR-3 and the indigenous phosphate-solubilizing Pseudomonas oryzihabitans LSE-3 in improving the symbiosis, nutrient accumulation, and yield of soybean. The isolate LSE-3, selected on the basis of phosphate solubilization, was screened for beneficial traits, antagonistic activities, and pathogenicity. The levels of indole acetic acid production (50.34 ±2.35 μg mL^-1), phosphate solubilization (184.4 ±7.4 mg L^-1), biofilm formation (optical density at 560 mm, 1.389 6 ±0.04), siderophore production (121.46 ±1.61 μg mL^-1), and 1-aminocyclopropane-1-carboxylate deaminase activity (0.51 ±0.07 mmol α-ketobutyrate μg^-1 protein h^-1) were significantly higher with the dual inoculants (LSBR-3 and LSE-3) than with the single inoculant LSBR-3. The plant growth-promoting traits of single and dual inoculants were evaluated for the synergistic effects on soybean under field conditions. Soybean plots treated with LSBR-3 + LSE-3 exhibited improvement in seed germination, plant height, plant biomass, and chlorophyll content compared with the uninoculated control. Dual inoculant treatments resulted in significantly higher symbiotic efficacy evidenced by increased nodulation (40.0 ±0.75 plant^-1), nodule biomass (188.52 ±6.29 mg plant^-1), and leghemoglobin content (11.02 ±0.83 mg g^-1 fresh nodule), and significantly increased activities of phosphatase (75.16 ±3.17 and 58.77 ±6.08 μg p-nitrophenol g^-1 h^-1 for alkaline and acid phosphatase, respectively) and dehydrogenase (32.66 ±1.92 μg triphenylformazan g^-1 h^-1) compared with the control. Dual inoculation with LSBR-3 and LSE-3 enhanced the uptake of macro- and micronutrients, reduced Na content in shoots, and resulted in 10.85% higher grain yield and ca. US$96.80 ha^-1 higher profit compared with the control. This is the first report on the effectiveness of combined inoculation of LSE-3 and LSBR-3 in promoting the growth, symbiotic efficacy, and yield of soybean for sustainable agriculture.     

Effect of lameness (hoof disorders) on productivity of Karan Fries crossbred cows

In present study production performance of 96 lame cows was compared with 67 healthy cows. No significant effect of parity and year of calving on milk yield were observed but the effect of season of calving was significant (P < 0.01). Effect of lameness on milk yield at the second, third and fourth months and 305 days was highly significant (P < 0.01), and was also significant (P < 0.05) on lactation yield of the fifth and tenth months. The effect of lameness on monthly and 305‐day milk yield was significant (P < 0.01) only for those cows diagnosed lame before calving and during the first month of lactation. The differences in mean monthly yield were highly significant (P < 0.01) at the second, third and fourth months; and significant (P < 0.05) in the first and fifth months. The loss in the first lactation month of cows which were diagnosed as lame in the second month, was found to be significant (P < 0.05). Thus the yield of the month previous to the diagnosis (sub‐clinical stage) was also affected. A significant (P < 0.01) total loss of 498.95 kg of milk yield was observed during a period of 305 days.     

Improving Rice-Based Cropping Pattern Through Soil Moisture and Integrated Nutrient Management in Mid-Tropical Plain Zone of Tripura,India

An experiment was conducted in three fallow paddy fields situated on the mid-tropical plain zone of a northeastern Indian state(Tripura) to provide rice fallow management options using leftover soil moisture and nutrients. The three experimental fields were managed by growing rice under the system of rice intensification as the rainy season crop and then groundnut, lentil, rapeseed and potato as the post-rainy season crops. Fertilization under the integrated nutrient management system and lifesaving irrigation at critical stages of each post-rainy season crop were provided. Results showed that the field water use efficiency values were 5.93, 2.39, 2.37 and 59.76 kg/(hm2·mm) and that the yield of these crops increased by approximately 20%, 34%, 40% and 20% after applying two lifesaving irrigations in groundnut, lentil, rapeseed and potato, respectively. Therefore, fallow paddy field can provide possible profitable crops during the post-rainy season by utilizing the residual moisture and minimum supplemental irrigation under improved nutrient management practices.     

土壤碳氮对多年生能源草、覆盖作物和氮施肥的响应

Cover crop and nitrogen(N) fertilization may maintain soil organic matter under bioenergy perennial grass where removal of aboveground biomass for feedstock to produce cellulosic ethanol can reduce soil quality. We evaluated the effects of cover crops and N fertilization rates on soil organic carbon(C)(SOC), total N(STN), ammonium N(NH_4-N), and nitrate N(NO_3-N) contents at the0–5, 5–15, and 15–30 cm depths under perennial bioenergy grass from 2010 to 2014 in the southeastern USA. Treatments included unbalanced combinations of perennial bioenergy grass, energy cane(Saccharum spontaneum L.) or elephant grass(Pennisetum purpureum Schumach.), cover crop, crimson clover(Trifolium incarnatum L.), and N fertilization rates(0, 100, and 200 kg N ha~(-1)). Cover crop biomass and C and N contents were greater in the treatment of energy cane with cover crop and 100 kg N ha~(-1) than in the treatment of energy cane and elephant grass. The SOC and STN contents at 0–5 and 5–15 cm were 9%–20% greater in the treatments of elephant grass with cover crop and with or without 100 kg N ha~(-1)than in most of the other treatments. The soil NO_3-N content at 0–5 cm was 31%–45% greater in the treatment of energy cane with cover crop and 100 kg N ha~(-1)than in most of the other treatments.The SOC sequestration increased from 0.1 to 1.0 Mg C ha~(-1)year~(-1)and the STN sequestration from 0.03 to 0.11 Mg N ha~(-1)year~(-1)from 2010 to 2014 for various treatments and depths. In contrast, the soil NH_4-N and NO_3-N contents varied among treatments,depths, and years. Soil C and N storages can be enriched and residual NO_3-N content can be reduced by using elephant grass with cover crop and with or without N fertilization at a moderate rate.