Efficacy of carbofuran and phorate at different intervals of application for control of rice tungro

Abstract

The relationship between the catch of male Spodoptera litura (F.) moths in sex pheromone‐baited traps and the number of egg‐masses in groundnut crop at the International Crops Research Institute for Semi‐Arid Tropics Centre Patancheru, India was examined during the post‐rainy season of 1983. Significant positive correlations were found between the number of egg‐masses and the total number of male moths caught during the 7 days preceding the egg‐mass count. 75% of the variance in the egg‐mass counts and pheromone trap catches could be accounted for by the regression.     

Spatial variability of total soil carbon and nitrogen stocks for some reclaimed minesoils of southeastern Ohio

Reclamation of drastically disturbed minesoils and subsequent planting of trees and/or grasses can result in a rapid build‐up of carbon (C) in the soil. However, the amount of C sequestered in reclaimed minesoils may vary with the amount of time since reclamation. In this study, we assessed total carbon (TC) and total nitrogen (TN) concentrations for reclaimed minesoils located in northeastern Ohio and characterized by distinct reclamation age chronosequences. Reclaimed minesoils studied were R78G, reclaimed in 1978 and immediately seeded to grass; R82GT, reclaimed in 1982 and immediately seeded to grass and trees were planted 5 years later; and R87G, reclaimed in 1987 and immediately seeded to grass. An unmined site, UMG, was also included as a reference. Our objectives were to evaluate the variability with respect to mean and the spatial variability of pH, bulk density (ρ_b), TC and TN concentrations, and stocks in each reclaimed minesoil. Thirty soil samples were collected at each of the 0–15, 15–30, and 30–50 cm depth. The coefficient of variation (CV) for ρ_b was least, <15 per cent at each site and depth. For TN concentration and stock, CV was moderate, 15–35 per cent, in each field except the UMG where it was high, >35 per cent at 0–15, and 15–30 cm depths. For TC concentration and stocks, CV was high, >35 per cent, across all minesoils and generally increased with depth. The C/N ratio followed the same tend as TC and TN stocks and ranged from 40 per cent to 123 per cent across minesoils. Geostatistical analysis also showed an increase in sample variance with increasing amount of time since reclamation for most soil properties under investigation. Sample variance for TC concentration and stocks also increased with depth in reclaimed minesoils. However, no definite relationship emerged between amount of time since reclamation and the spatial dependence of TC and TN concentrations and stocks. Overall this study showed that reclamation of drastically disturbed minesoils increased the soil C concentration and stocks and reclamation by initially seeding to grasses followed by planting trees was the best management option for speedy accretion of soil C and soil quality enhancement. Copyright © 2007 John Wiley & Sons, Ltd.     

Symptoms in slash pine seedlings following inoculation with the cone rust fungus Cronartium strobilinum

Six‐week‐old seedlings of slash pine (Pinus elliottii) were inoculated with sporidia of Cronartium strobilinum, which is the cause of southern cone rust disease, by wounding the apical tips of the seedlings. Pycnial sori developed abundantly within 1 month of inoculation on the epicotyl and primary needles. The progress of the pathogen was confirmed histologically within the cells of the stem and haustoria were observed near the nucleus of the cells. In the needles, pycnial pustules developed and the fungus was abundant in the mesophyll.     

Effect of fly ash extract on growth and development of corn and soybean seedlings

Different concentrations of aqueous extract of fly ash were prepared by soaking air dried fly ash and mixing thoroughly with an electric blender. Extracts were then applied to the seeds of corn (Zea mays L.) and soybean (Glycine max L.) after being filtered through a Whatman No. 42 filter paper. Fly ash extract in the lower concentration range of 0.5 to 1.0% (W/V) had no significant effect on germination and seedling growth of each of the two crops. Higher concentrations of fly ash extracts, however, had deleterious effects on the percentage of germination, viability, number of roots, shoot and root length, fresh weight and dry weight of seedlings of both the crops. The elemental concentrations in shoot and root systems of control seedlings of corn and soybean were found to be the same, whereas in the extract treated corn and soybean seedlings, a relatively high elemental concentration was found in roots as compared to shoots.     

Spatial Distribution of Surface Soil Acidity,Electrical Conductivity,Soil Organic Carbon Content and Exchangeable Potassium,Calcium and Magnesium in Some Cropped Acid Soils of India

Land degradation is a global problem. Best management of degraded land can be done by evaluating the spatial variability of soil properties including chemical properties of degraded land and mapping such variations. Since, a significant portion of arable land in India is chemically degraded due to soil acidity; the present study was conducted to study the spatial variability of soil acidity (pH), electrical conductivity (EC), soil organic carbon (OC) content, exchangeable potassium (K⁺), calcium (Ca²⁺) and magnesium (Mg²⁺) contents in some cropped acid soils of India. A total of four hundred (one hundred from each series) representative surface (0–0.15 m depth) soil samples were collected from arable soils representing four soil series namely Hariharapur, Debatoli, Rajpora and Neeleswaram situated in Orissa, Jharkhand, Himachal Pradesh and Kerala states of India, respectively, and were analyzed. Soil acidity (pH between 3.90 and 6.45) showed a low variability, in contrast to other soil properties, which showed moderate variability. The coefficients of variation varied from 32.4 to 74.3, 31.2 to 50.9, 45.6 to 100, 71.9 to 93.0 and 59.0 to 79.8% for EC (mean between 0.05 and 0.09 dS m⁻¹), OC (mean between 0.29 to 1.86%), exchangeable K⁺ (mean between 39.1 and 77.7 mg kg⁻¹), Ca²⁺ (mean between 148 and 293 mg kg⁻¹) and Mg²⁺ (mean between 111 and 191 mg kg⁻¹), respectively. Soil pH and OC content were positively and significantly correlated with exchangeable K⁺, Ca²⁺ and Mg²⁺ content. Geostatistical analysis revealed that the best fit models were gaussian, exponential and spherical for different soil properties with moderate to strong spatial dependency. Copyright © 2014 John Wiley & Sons, Ltd.     

Quantification of organic carbon and primary nutrients in litter and soil in a foothill forest plantation of eastern Himalaya

The present study was an effort to understand the amount of litter fall and its subsequent decomposition and quantify the release of available nutrients and soil physicochemical characteristics in plantations of four forest tree species(Lagerstroemia parviflora, Tectona grandis, Shorea robusta and Michelia champaca) in the Chilapatta Reserve Forest of the Cooch Behar Wildlife Division in the Terai zone of West Bengal, India. The most litter(5.61 Mg ha~(-1))was produced by T. grandis plantation and the least(4.72 Mg ha~(-1)) by L. parviflora. The material turnover rate to the soil through decomposition from total litter was fastest during the first quarter of the year and subsequently decreased during the next two quarters. The material turnover rate was only 1 year, which indicates that more than90% of the total litter produced decomposed within a year.The available primary nutrient content in litter varied across the four plantations over the year. The plantations generally did not significantly influence the soil physical characteristics but did significantly influence the availability of primary nutrients and organic carbon at two depths(1–15 and16–30 cm) over the year. The availability of soil primary nutrients in the four plantations also increased gradually from the first quarter of the year to the third quarter and then decreased during the last quarter to the same level as in the first quarter of the year at both depths. The availability for soil organic carbon in the plantations followed a similar trend. The amount of litter produced and the material turnover in the soil in the different plantations differed, influencing the nutrient availability and organic carbon at the plantations. The amount of soil organic carbon was highest for T. grandis(2.52 Mg ha~(-1)) and lowest for L. parviflora(2.12 Mg ha~(-1)). Litter is the source of soil organic matter,and more the litter that is produced by the plantations, the higher will be the content and amount of soil organic carbon in the plantation.     

Protection of mice against <Emphasis Type="Italic">Brucella abortus 544</Emphasis> challenge by vaccination with recombinant OMP28 adjuvanted with CpG oligonucleotides

Brucella abortus, a gram negative, facultative intracellular pathogen causes brucellosis in many animal species and humans. Although live, attenuated vaccines are available against this infection, they suffer from certain limitations. Therefore, the development of an effective subunit vaccine against brucellosis is an area of intense research. The outer membrane proteins (OMPs) of Brucella species have been extensively studied for its immunogenicity and protective ability. We have investigated the potential of CpG ODN to enhance the immunogenicity and protective efficacy of recombinant 28 kDa outer membrane protein (rOMP28) of Brucella melitensis. The study demonstrated vigorous immunoglobulin G (IgG) response of OMP28. The administration of rOMP28 with CpG caused increased cell mediated immune response in terms of induced IgG2a, T-cell proliferation and up-regulation of type I cytokine expression. In contrast, the free antigen suppressed the interferon gamma (type I cytokine) production on in-vitro stimulation of spleenocytes. The result indicates the role of OMP28 in the down regulation of IFN-γ production. Moreover, the B. abortus S-19 vaccinated mice showed highest production of IL-4 and IFN-γ. The protective ability of the antigen was evaluated by systemic bacterial clearance after challenging the mouse with B. abortus 544 pathogen. The level of protection was significant in rOMP28+CpG treated mice but was lower than the required level. The results of the present study indicate that rOMP28 could be an immunogen capable of inducing both humoral and cellular immune response. The humoral response was biased towards Th1 type when it was co-administered with CpG.     

Properties of red maple laminated veneer lumber impregnated with waterborne micronized and two soluble copper formulations

ABSTRACT

Certain important quality parameters of red maple (Acer rubrum) laminated veneer lumber (LVL) impregnated with three waterborne formulations: copper azole (CA-B), micronized copper azole (MicroCA or MCA) and alkaline copper quaternary (ACQ-D) bonded with phenol formaldehyde or cross-linked polyvinyl acetate (XPVAc) adhesives were evaluated. Pre-dipping of veneers before LVL production and two post-manufacturing procedures, viz., vacuum-pressure and post-dipping of LVL, were applied. Maximum copper retention in pre-dip-treated, vacuum-pressure and post-dip-treated LVL was 1.4, 9.7 and 1.7?kg/m³, respectively. Copper retention in MCA-treated LVL was relatively lower than soluble formulations. Various physical, mechanical and bonding properties of treated LVL such as density, water absorption, swelling, flexural properties, hardness, tensile shear strength, delamination and wood failure (%) were studied and compared with untreated LVL. Little to negligible deleterious effect was observed on properties of LVL due to these chemical treatments. Analysis of variance results showed that most of properties of red maple LVL were not significantly different compared with those of untreated LVL. Therefore, vacuum-pressure impregnation process can be used to treat the red maple LVL with novel micronized copper formulations for increasing the service life of such products against biodegradation without affecting techno-mechanical quality parameters.     

Comparative study on growth,wood quality and financial returns of teak (Tectona grandis L.f.) managed under three different agroforestry practices

Growth, wood quality parameters and productivity estimations of 12-year-old teak (Tectona grandis L.f.) grown under three agroforestry systems, namely unmanaged block (B_um), unmanaged line on the farm boundary (L_um) and intensively managed block (B_im) plantations are studied. Mean annual increment (MAI) of 0.020, 0.006 and 0.016 m³ tree^?1 year^?1 was recorded in L_um, B_um and B_im, respectively. Overall growth performance of teak raised in L_um, plantation appears to be better than two block plantations (B_um and B_im). For evaluating various wood quality parameters, tree logs from each plantation were tested for different physical and mechanical properties according to the standard procedures. The wood quality of B_um was found to be comparatively superior to B_im and much better than those of L_um. The 12-year-old farm teak trees from three systems exhibited lower average values of different wood quality parameters compared to mature forest teak. Since physical and strength properties of B_um were inferior compared to L_um and B_im, its exploitation is not advisable at this stage. Line plantation, however, releases land for cultivation of arable crops and does not demand any special silvicultural management as required by B_im. Although, total extractable volume of teak wood available after 12-years of age from B_um was much smaller compared to B_im or L_um, its commercial exploitation at an early age may be preferred over other two practices due to better wood quality and lower management cost. For optimum economic utilization and mechanical maturity of wood, harvesting of block plantation may be delayed for about 10-15 years because growth volume and strength properties are expected to improve with age of tree.