Effects of insecticide profenophos on germination,early growth,meiotic behavior and chlorophyll mutation of barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.)

The genotoxicity of different concentrations of insecticide, profenophos (O-4-bromo-2-chlorophenyl O-ethyl S-propyl phosphorothioate) was evaluated at various stages of cell cycle (G₁, S and G₂) by using the seeds of barley (Hordeum vulgare L.). The aim of this work was to investigate the effects of insecticide profenophos at various stages of cell cycle on germination, seedling height and meiotic behavior in M₁ and chlorophyll mutations in M₂ generation. From the present study, it can be concluded that the stages of cell cycle were sensitive for the treatments of chemicals and it also showed that the S-phase of cell cycle is more sensitive than other phases of cell cycle.     

On-farm monitoring of economic and environmental performances of cropping systems: Results of a 2-year study at the field scale in northern Italy

Cropping systems in northern Italy are intensively managed, but an integrated environmental accounting of these systems has not been published yet. We conducted this study to evaluate cropping systems management in a study area in northern Italy using indicators. The study area is a regional agricultural Park, with cereal and livestock farms, cultivating mostly maize, rice, meadows, and winter cereals.To select the indicators, we identified for the study area the most relevant issues concerning the potential impact of agriculture on the environment: nutrient and pesticide management, use of fossil energy and soil management. Subsequently, we selected indicators from the literature, which could address these issues. We also added indicators describing the economic performance. The data were collected at the field level by periodic face-to-face interviews with seven farm managers over 2 years. Indicators were calculated for all crops cultivated in each field (n = 266).According to the methodology proposed, the best economic performance (gross margin) was obtained by rice, followed by maize, winter cereals, and forage crops. Nitrogen and phosphorus surpluses were high for maize (due to a large use of animal manures), and moderate for rice and permanent meadows (where mineral fertilisers are not usually applied). Maize used high fossil energy inputs; however, the output/input ratio (an indicator of the dependence of food and feed production on non-renewable energy) was elevated, due to high aboveground biomass production. The potential impact due to pesticide use (evaluated with indicators that consider the toxicity and the exposure to active ingredients) was relevant only for rice, moderate for maize and other cereals, and null for forages. Finally, soil management was evaluated for the 2-year crop succession on each field (n = 131): permanent meadows are excellent (due to continuous soil cover and large returns of organic carbon to soil), rice-based successions are unsatisfactory (due to low residues and manure application and continuous cropping), and maize successions are intermediate. This work shows that good quality data can be collected on-farm for economic and environmental accounting at field level. The indicators chosen for the analysis describe a range of issues in the study area, and make it possible to clearly separate and characterise different cropping systems. The procedure for their calculation is transparent and sound, and can be applied for ex-ante, ex-post, and monitoring procedures.     

Runoff from tomato cultivation in the estuarine environment: biological effects of farm management practices

The use of plastic row covers (plastic mulch) on vegetable farms increases runoff of pesticides after rainfall events and has been linked to toxic events in adjacent tidal waters. In coastal Virginia, USA, runoff from tomato fields with plastic mulch was suspected of causing mortality of commercial hard clam larvae at a hatchery located downstream of farming operations. Concern about the putative impacts of this practice on local waters resulted in a collection of studies to: (1) determine the sensitivity of early life stages of bivalves to copper, a commonly used fungicide; (2) examine acute and chronic biological effects of runoff on tidal creeks; and (3) examine the efficacy of management practices designed to reduce the delivery of pesticides to adjacent creeks. Laboratory bioassays revealed that 48-h LC₅₀ values for embryonic clams Mulinia lateralis and Mercenaria mercenaria were 38 and 20 μg/l, respectively. In situ bioassays with Palaemonetes pugio showed that pulsed toxic conditions sometimes occur downstream of some tomato farms in plastic mulch following rainfall events. Growth, mortality rates and bioaccumulation of copper and organic pesticides in oysters were not correlated with the use of plastic mulch in watersheds. Sediment bioassays indicated potential toxicity in sediment collected downstream of some tomato fields in plastic mulch, but the effects were not consistent between years. Closer examination of management practices on the farms suggests that controlling runoff can prevent toxic impacts. Elevated levels of crop protectants measured at the outflow of farm ponds suggested that they may do little to reduce loadings of some pesticides. However, forested buffer zones and ephemeral sedimentation basins appeared to be effective in reducing pesticide concentrations in runoff and pulsed toxicity in tidal creeks.     

Effects of orally administered insecticides and polychlorinated biphenyls on the parasite fauna of two species of piscivorous birds

A study was initiated to determine the effects of various levels of ingested DDT and its metabolites and polychlorinated biphenyls on young double-crested cormorants, Phalacrocorax a. auritus, and white pelicans, Pelencanus erythrorhynchos. One phase of this research was concerned with the effects of ingested insecticides and polychlorinated biphenyls on the parasite fauna of these birds. Statistical analysis indicated a decrease in the numbers of ectoparasites on the feathers of cormorants as dosage of insecticides and as residue levels on the feathers increased. Similar results were noted with ectoparasites and gular lice of white pelicans receiving a daily dosage of either polychlorinated biphenyls or a mixture of DDT, DDD, and DDE. There were no significant differences in the numbers of endoparasites between the control and treated birds in either the cormorants or pelicans.