Weed Flora of Andhra Pradesh

Abstract

A large scale white grub control campaign was launched by the Marathwada Agricultural University, Parbhani. Pit trapping indicated that there was an initial beetle population of about 50 million in an area of 876 ha. About 9,000,000 beetles were collected mechanically and destroyed. One spraying of 12,000 babul and neem trees with 0.4% DDT killed 88% of the beetles. The percentage reduction in the plant population of rice, chillies, jowar and sugarcane, due to white grub attack was 1.83, 6.34, 3.59 and 3.02 in the treated area as against 65.54, 56.06, 49.68 and 8.94 in the untreated area. In cotton there was no reduction in plant population in the treated area. There was an increase in yield in paddy, chilli, cotton and jowar to the extent of 164.5, 102.2, 27.8 and 12.7% respectively in the treated area of Ratoli. There was an 80% reduction in the white grub larval population.     

Imaging elemental distribution and ion transport in cultured cells with ion microscopy

Both elemental distribution and ion transport in cultured cells have been imaged by ion microscopy. Morphological and chemical information was obtained with a spatial resolution of approximately 0.5 micron for sodium, potassium, calcium, and magnesium in freeze-fixed, cryofractured, and freeze-dried normal rat kidney cells and Chinese hamster ovary cells. Ion transport was successfully demonstrated by imaging Na+-K+ fluxes after the inhibition of Na+- and K+ -dependent adenosine triphosphatase with ouabain. This method allows measurements of elemental (isotopic) distribution to be related to cell morphology, thereby providing the means for studying ion distribution and ion transport under different physiological, pathological, and toxicological conditions in cell culture systems.     

Feasibility of cultivation of Kappaphycus alvarezii (Doty) Doty at different localities on the Northwest coast of India

Kappaphycus alvarezii was cultivated at three places, viz. Mithapur, Okha and Beyt Dwarka on the Northwest coast of India. The biomass and growth rates were measured at 15-day intervals up to 45 days and varied differently for different growth periods at these places. Thus, at 15, 30 and 45 days, the biomass (fresh wt) varied from 182.0±19.96 to 435.0±23.66 g, from 366.0±118.09 to 1096.0±61.43 g and from 530.5±50.95 to 1537.0±43.54 g, respectively, with respective daily growth rates (%) from 3.95±0.78 to 9.80±0.63, from 3.64±0.01 to 13.98±3.07 and from 3.69±0.23 to 6.07±0.06. The seawater temperature, salinity, nitrate and phosphate ranged from 19.3 to 26.9 °C, from 30.81 to 36.83‰, from 11.60 to 19.75 μmol L⁻¹ and from 2.37 to 5.0 μmol L⁻¹ respectively. The growth rate between the culture months was significantly different at Okha at P <0.01. Further, it was significantly correlated to salinity at Mithapur while at Okha and Beyt Dwarka, the same was significantly correlated to nitrate and seawater temperature. Based on this study, commercial cultivation at these localities is quite feasible.     

The glycerinated body wall of the sea cucumber as a suitable preparation for electron microscopic and physiological studies of ‘catch mechanism’

ABSTRACT:   The body wall of the sea cucumber changes its stiffness by ionic environments. The stiff state can be held for a long time, and the mechanism concerned is known as 'catch mechanism'. In the present study, the direct effects of ions on the mechanism using the glycerinated body wall treated with 50% glycerin to clarify how the ions effect changes of stiffness were examined. The glycerinated body walls contained collagen fibers and some broken cells in the connective tissue ultrastructurally. Cell membranes were not clearly present in the broken cells, and cell organelles were dispersed around the cells. The glycerinated body walls went into a limp state during addition of 10 mM ethylenediaminetetraacetic acid (EDTA), and showed height elongation rate in this study's experimental system. In contrast, the elongation rate decreased by the addition of 10 mM CaCl₂, that is, the body wall came to a stiff state. This stiff state could be considered as equivalent to 'catch state' of glycerinated body wall. Collagen fibers in those samples showed more compact arrangements at 10 mM CaCl₂ treatment than the one of 10 mM EDTA ultrastructurally. These features and physiological results suggested that EDTA and/or CaCl₂ from outside affect directly to the main part of the 'catch' mechanism in the glycerinated body wall.     

Amelioration of altered oxidant/antioxidant balance of Indian water buffaloes with subclinical mastitis by vitamins A, D3, E, and H supplementation

The effect of vitamins A, D₃, E, and H supplementation on oxidative stress indices in Indian water buffaloes suffering from subclinical mastitis was investigated. Changes in the total oxidant capacity (TOC), total antioxidant capacity (TAC), nitric oxide (NO), and activities of glutathione peroxidase (GSH-Px), catalase (CAT), and superoxide dismutase (SOD) in milk were evaluated before and after the supplementation of vitamins A, D₃, E, and H. The buffaloes suffering from subclinical mastitis revealed remarkable alterations in the milk oxidants/antioxidants balance shifted towards oxidative status. The buffaloes with subclinical mastitis revealed significantly (P?≤?0.01) higher TOC, NO contents, and CAT activity, while TAC content and GSH-Px activity were significantly (P?≤?0.01) lower in comparison with the healthy controls. However, SOD activity did not show any significant change. Supplementation of vitamins A, D₃, E, and H to these animals revealed significant (P?≤?0.01) reduction in TOC, NO, and CAT, while a significant (P?≤?0.01) increase in TAC and GSH-Px activity was also evident. From the present study, it may be concluded that supplementation of these vitamins can help ameliorate the altered milk oxidants/antioxidants balance towards normalcy and, thus, ensue recovery from subclinical mastitis in the Indian water buffaloes.     

Dissipation behaviour of spinosad insecticide in soil, cabbage and cauliflower under subtropical conditions

BACKGROUND: Pesticides used on cauliflower and cabbage, which are important vegetable crops for India, must be investigated for the persistence and magnitude of their residues in the crops and soil to ensure human and environmental safety. The behaviour of spinosad, an effective insecticide with a favourable environmental profile, was investigated in field trials under subhumid and subtropical conditions. RESULTS: The persistence of spinosad in soil, cabbage and cauliflower was evaluated at two application rates (17.5 and 35.0 g ha(-1)) by high-performance liquid chromatography (HPLC). At 17.5 g ha(-1), spinosad persisted up to 7 days in soil, cabbage and cauliflower. However, at 35.0 g ha(-1), spinosad residues persisted up to 7 days in soil and 10 days in cabbage and cauliflower. CONCLUSION: The dissipation of the insecticide from soil, cabbage and cauliflower appeared to occur in a single phase and conformed to first-order kinetics. The half-lives of spinosad residues in cabbage, cauliflower and soil were calculated as 1.5, 2.8 and 2.8 days respectively for the 17.5 g ha(-1) treatment, and as 2.6, 2.0 and 2.0 days for the 35 g ha(-1) treatment.     

Development of DRAIN-WARMF model to simulate flow and nitrogen transport in a tile-drained agricultural watershed in Eastern Canada

A new watershed model, DRAIN-WARMF, was developed to simulate the hydrologic processes and the nitrogen fate and transport that occur in small, predominantly subsurface-drained, agricultural watersheds that experience periodic freezing and thawing conditions. In this modeling approach, surface flow is simulated using a watershed scale model, WARMF, and subsurface flow is estimated using a field-scale model for subsurface-drained shallow water table fields, DRAINMOD 5.1. For subsurface flow calculations, the watershed is subdivided into uniform cells, and DRAINMOD is run on each cell with inputs based on the individual hydrologic characteristics of the cell. The coupling results in a distributed parameter model that calculates the total flow at the outlet of a watershed as well as the nitrogen losses. The model was evaluated for the St. Esprit watershed, located approximately 50 km northeast of Montreal. Simulations were carried out from 1994 to 1996; data from 1994 and 1995 was used for model calibration and data from 1996 was used for model validation. The new model was able to adequately simulate the hydrologic response and nitrate losses at the outlet of the watershed. Comparing the observed daily flow/monthly nitrogen with the model's outputs over the validation period returned an R² value of 0.74/0.86 and modeling efficiency of 0.72/0.83. This clearly demonstrates the model's ability to simulate hydrology and nitrogen losses occurring in small agricultural watersheds in cold climates.     

干旱热带地区土地利用变化对土壤微生物群落组成及有机碳含量的影响

Restoration of forests poses a major challenge globally,particularly in the tropics,as the forests in these regions are more vulnerable to land-use change.We studied land-use change from natural forest (NF) to degraded forest (DF),and subsequently to either Jatropha curcas plantation (JP) or agroecosystem (AG),in the dry tropics of Uttar Pradesh,India,with respect to its impacts on soil microbial community composition as indicated by phospholipid fatty acid (PLFA) biomarkers and soil organic carbon (SOC) content.The trend of bacterial PLFAs across all land-use types was in the order:NF ＞ JP ＞ DF＞ AG.In NF,there was dominance of gram-negative bacterial (G-) PLFAs over the corresponding gram-positive bacterial (G+) PLFAs.The levels of G-PLFAs in AG and JP differed significantly from those in DF,whereas those of G+ PLFAs were relatively similar in these three land-use types.Fungal PLFAs,however,followed a different trend:NF ＞ JP ＞ DF =AG.Total PLFAs,fungal/bacterial (F/B) PLFA ratio,and SOC content followed trends similar to that of bacterial PLFAs.Across all land-use types,there were strong positive relationships between SOC content and G-,bacterial,fungal,and total microbial PLFAs and F/B PLFA ratio.Compared with bacterial PLFAs,fungal PLFAs appeared to be more responsive to land-use change.The F/B PLFA ratio,fungal PLFAs,and bacterial PLFAs explained 91％,94％,and 73％ of the variability in SOC content,respectively.The higher F/B PLFA ratio in JP favored more soil C storage,leading to faster ecosystem recovery compared to either AG or DF.The F/B PLFA ratio could be used as an early indicator of ecosystem recovery in response to disturbance,particularly in relation to land-use change.     

Real-time PCR carried out on DNA extracted from serum or blood sample is not a good method for surveillance of bovine brucellosis

Bovine brucellosis is endemic in many parts of the world including India. The disease diagnosis and surveillance are usually carried out by serological tests, which however have drawbacks. This study was undertaken to evaluate the potential of real-time PCR (RT-PCR) targeting bcsp31 gene for surveillance of bovine brucellosis. A total of 461 samples, which included 408 stored serum and 53 prospective blood samples, were used. It was found that 33 (7.15 %) samples were positive by RT-PCR, whereas 149 (32.32 %) and 132 (28.63 %) were positive by Rose Bengal plate test (RBPT) or standard agglutination test (STAT), respectively. The results of this study suggest that RT-PCR targeting bcsp31 gene carried out on DNA extracted from serum or blood may not be a suitable method for surveillance of brucellosis in bovines.     

Chemical transformation of copper in some sludge-amended soils

In a laboratory incubation study, the periodic changes in different chemical fractions of copper (Cu) in three sludge-amended soil types (acidic sandy clay loam, neutral clay loam and alkaline clay loam) of varying soil reaction were monitored under field capacity and flooding moisture regime over 16 months. The water soluble and exchangeable fraction of Cu was very low (≤1% of total Cu) in all three soil types. At the end of incubation (16 months), the sodium acetate extractable (carbonate sorbed)- and residual-Cu fractions transformed into Fe-Mn oxide fraction, irrespective of moisture regime in all three soil types. However, the extent of transformation varied among soils.