Legume-based intercropping for the management of fall armyworm,Spodoptera frugiperda L. in maize

Journal of Plant Diseases and Protection - Fall armyworm, Spodoptera frugiperda (Noctuidae: Lepidoptera), is an economically important invasive pest infesting maize. Habitat manipulation as a...     

Eddy-driven stratification initiates North Atlantic spring phytoplankton blooms

Springtime phytoplankton blooms photosynthetically fix carbon and export it from the surface ocean at globally important rates. These blooms are triggered by increased light exposure of the phytoplankton due to both seasonal light increase and the development of a near-surface vertical density gradient (stratification) that inhibits vertical mixing of the phytoplankton. Classically and in current climate models, that stratification is ascribed to a springtime warming of the sea surface. Here, using observations from the subpolar North Atlantic and a three-dimensional biophysical model, we show that the initial stratification and resulting bloom are instead caused by eddy-driven slumping of the basin-scale north-south density gradient, resulting in a patchy bloom beginning 20 to 30 days earlier than would occur by warming.     

Tobacco streak virus: an emerging threat to cotton cultivation in India

Tobacco streak virus (TSV), inciting cotton necrosis, exhibits multifarious symptoms. Common types of symptoms include, purplish brown, necrotic lesions in the leaves, squares, and petioles. Telangana (India) had the highest incidence of TSV (51.11 PDI - hybrid RCH659), among the surveyed locations including, Tamil Nadu, Andhra Pradesh, Telangana and Maharashtra states of India. Environmental factors greatly influenced the establishment of TSV in cotton. Minimum temperature (22.81 °C), relative humidity (81.42%), and leaf wetness (23.94 h) favoured maximum TSV incidence with a mean PDI of 30.68 at Annur, (Tamil Nadu, India). Serological assay through DAC-ELISA confirmed the presence of TSV in cotton samples expressing necrosis symptoms. Bioassay revealed that Chenopodium amaranticolor and Chenopodium quinoa are excellent indicator host plants with high virus titres. Further, molecular characterization revealed the conserved nature of the coat protein gene, among the TSV isolates infecting cotton in four different states (Tamil Nadu, Andhra Pradesh, Telangana, and Maharashtra).     

Comment on "Eddy/wind interactions stimulate extraordinary mid-ocean plankton blooms"

McGillicuddy et al. (Reports, 18 May 2007, p. 1021) proposed that eddy/wind interactions enhance the vertical nutrient flux in mode-water eddies, thus feeding large mid-ocean plankton blooms. We argue that the supply of nutrients to ocean eddies is most likely affected by submesoscale processes that act along the periphery of eddies and can induce vertical velocities several times larger than those due to eddy/wind interactions.     

Fungus,Aspergillus niger,fermented groundnut oil cake as a fishmeal alternative in the diet of Penaeus vannamei

Commercial de‐fatted groundnut oil cake (GNC) fermented with the fungus Aspergillus niger was evaluated as a fishmeal alternative in the diet of Penaeus vannamei. A 45‐day growth trail was performed using nine iso‐nitrogenous and iso‐lipidic diets. Untreated/fermented GNC was included at the rate of 0 (control), 25, 50, 75 and 100 g/kg by replacing fishmeal (w/w). Each diet was randomly assigned to triplicate group of 20 shrimps (initial weight of 3.09 ± 0.03 g). Results revealed that shrimp fed with diets having untreated GNC up to 50 g/kg has no significant difference in growth, whereas the inclusion level was enhanced to 100 g/kg with fermented GNC with no deleterious effect. The negative linear trend was found for SGR with increasing the inclusion of both untreated and fermented GNC. The feed and protein efficiency measures, viz. feed conversion ratio, protein efficiency ratio and apparent protein utilization, were better in shrimps fed with diets having fermented GNC than those fed the respective level of untreated GNC. The broken‐line analysis indicated that the inclusion of 72.5 g/kg fermented GNC showed the best FCR. No significant difference was observed in survival (86.67%–96.67%) between the dietary treatments. There was a significant difference in ether extract of shrimp between the treatments, whereas other parameters were not affected. Haemolymph indices showed a significant difference in total protein, glucose, cholesterol and triglycerides between control and test diets. The results conclude fermented GNC, which can be better than untreated one in the diet of shrimp.     

Effect of dietary protein level on fattening and mineral profiles of mud crab,Scylla serrata,in individual cages under mangrove ecosystem

A fattening demonstration was carried out in Sorlagondi (15.8640⁰N, 80.9671⁰E) mangrove ecosystem in Diviseema region, Krishna district, Andhra Pradesh, India, by adapting a holistic approach of “Integrated Mangrove Fishery Farming System.” The local Yanadi tribal communities engaged in mangrove afforestation programmes were provided with 144 individual crab fattening cages (60 × 40 × 30 cm). Two formulated feeds were prepared with two levels of protein (32% and 36%) and were tested on fattening of the marketable size (200–1,000 g) of mud crabs, Scylla serrata. Significantly (p < 0.05) higher weight gain, feed and protein efficiency measures were observed in crabs fed with CP‐36% diet across all size groups. This diet also reduced the time (days) taken for fattening crabs irrespective of the size. Moisture content was very high in soft crabs (>800 g/kg) compared with hard crabs (679.70–688.65 g/kg), whereas the reverse trend was observed for protein, ether extract and ash content. Both diet and size of the crab have not shown much influence on proximate composition. However, cultured hard crabs had higher ether extract (20.10 g/kg) than wild hard crabs (17.06 g/kg). The changes in concentration of mineral values on wet basis indicated the increase in concentration in hard crabs compared with soft crabs, whereas when the percentage change, values on dry matter basis indicated the reduction in concentration of mineral contents of K, Na, P, Cu, Fe and Zn. This higher concentration of minerals in soft crabs could possibly be attributed to the reabsorption of minerals into soft muscle or to the body fluids.