Productivity impacts of the system of rice intensification (SRI): A case study in West Bengal,India

The system of rice intensification (SRI) has generated considerable debate globally, particularly with regard to its potential to raise rice yields. Proponents of SRI have reported that the average rice yield with SRI is double the current average yield and can be increased to the level of three to four times. Opponents say the reported high yields are due to measurement error and that usual information expected in support of these fantastic yields is missing. The number of SRI adopters has increased in India in recent years. We evaluate the impact of adoption of SRI practices on rice yields, the economics of paddy cultivation and labour inputs based on field research conducted in Purulia, West Bengal, India. Paddy yields with SRI were higher than those under conventional paddy cultivation by 32% and net returns were higher by 67%. Labour input was reduced by 8%. SRI adoption enabled farmers consistently to enhance paddy yields, increase returns and save labour; and enhance productivity with respect to the key inputs in terms of paddy output per unit of seed, fertilizer and labour-day. SRI promises to be a significant alternative for not only raising paddy yields, but also for managing paddy based farming in resource-starved regions.     

Contributing traits for nitrogen use efficiency in selected wheat genotypes and corollary between screening methodologies

ABSTRACT

Nitrogen uptake being part of nitrogen use efficiency (NUE) is largely decided by root traits. Root traits variability has hardly been explored by breeders mainly because of difficulties in scoring. The hydroponic system requiring lesser space for precise phenotyping of large numbers of genotypes independently of the growing season can be a suitable alternative. However, the effectiveness of hydroponic screening methods needs to be verified under the soil condition of the field or pot. In the present study, root traits and NUE were investigated in 19 genotypes under two conditions (hydroponic and pipe filled with soil). Both environments revealed large variability for root traits and NUE under high and low N conditions establishing the absence of any direct selection for these traits in the past. Under both sets of experimentation, NUpE was largely responsible for improved nitrogen efficiency mainly because of higher root biomass. The significant association between the two screening methods i.e. hydroponic and pot filled with soil under both low and high N condition support large scale screening for root traits under hydroponic condition.     

Impact of Aeration on the Growth Performance of Silver Barb,Puntius gonionotus,during Fingerling Rearing

Impact of aeration on growth of silver barb, Puntius gonionotus during fingerling rearing was studied through a 100‐d rearing experiment conducted in 18 concrete tanks of 50 m² (10 × 5 × 1.2 m) size. Fry (0.74 ± 0.27 g, 35 ± 6 mm) were stocked in the experimental tanks at three stocking densities (25, 50, and 75 fry/m²) and were evaluated with and without provision of 6 h (2400–0600 h) of night time aeration. Aeration resulted in higher pH and dissolved oxygen regime and increased fingerling length and weight. The results suggest a rearing density of 75/m² to be ideal for rearing fry to fingerling of this species when aeration is provided, whereas, under non‐aerated condition, rearing the fry to fingerling stage at 50/m² was found advantageous over those at 25 and 75/m².     

Multivariate analysis and genetic diversity for morphometric and root textural quality traits in ashwagandha (Withania somnifera Dunal)

Ashwagandha (Withania somnifera) is an important medicinal plant and its dried roots are used in traditional systems of medicine. The market price of roots is determined by physical (textural) quality. Brittle roots with high starch and low fiber are considered to be superior because of ease in grinding. Genetic diversity studies based on root textural parameters have not been done so far. So the present study was designed to assess genetic diversity for morphometric traits and root textural quality parameters among two morphologically distinct groups: Poshita and Nagore. The PCA separated the morphometric and root texture variables distinctly into two different principal components: PC-1 and PC-2 respectively, indicating that both are negatively associated. All the morphotypes in Poshita group showed high positive loadings in PC-1 indicating that component genotypes are high root yielding. Nagore morphotypes were low yielding but the root texture was good. Clustering of morphotypes grouped Poshita and Nagore separately with high inter-cluster distances indicating that both groups are highly divergent from each other, suggesting that there is sufficient scope for varietal improvement through hybridization.     

Blood groups and filariasis

Only a little is known about the studies done with filariasis in relation to blood groups. The present communication reports the results of a preliminary study carried out to investigate any relationship of ABO and Rho(D) blood groups in persons with circulating microfilariae (mf) in blood and with disease manifestations compared with healthy normal controls within a population in similar epidemiological and ecological conditions. Blood groups ABO and Rho(D) were investigated among 271 persons with filarial disease and 172 normal subjects from an endemic area of bancroftian filariasis. No relationship was observed between infection and blood groups. It appeared that blood groups and filarial infection were independent of each other. Also the sex of the individual and stage of the infection, i.e. persons with circulating mf only without manifestations and persons with established manifestation without mf, has no bearing on blood group inheritance. There were 95.05% of Rh-positive and 4.95% of Rh-negative persons in the whole studied population. The observations are similar to other studies.     

The photochemical decomposition of the herbicide isoproturon

The photochemical degradation of the herbicide isoproturon in aqueous and non-aqueous solutions and in soils has been investigated. Four new photometabolites were formed in non-aqueous solution and three in soil. These were characterised by spectroscopic methods and identified by comparison with authentic synthetic samples such as 3-(4-isopropylphenyl)-1-methylurea; 3-(4-isopropylphenyl)urea; 4,4′-diisopropylazobenzene and 4,4′-diisopropylazoxybenzene. The pathway of formation of these photo products is depicted.     

Immune reactions in guinea pigs due to somatic antigens from fourth-stage larvae of Bunostomum trigonocephalum

Lyophilized somatic antigens obtained from fourth-stage larvae of Bunostomum trigonocephalum induced significant resistance against the development of L4 from L3 and adults from L4. The higher antigen dose (1,000 LE) significantly reduced the number of adults developed from L4 as compared to the lower dose (600 LE) which did so only insignificantly. Inflammation of the intestinal tissue and loosening of the intestinal luminal contents were characteristics of the immunized animals.     

Poor serologic response to upper respiratory infection with Mycoplasma synoviae in turkeys

Mycoplasma synoviae (MS) was isolated from a flock of commercial tom turkeys in which a small percentage of the birds exhibited clinical signs and lesions typical of MS synovitis. However, serologic testing of such flocks revealed poor to inconsistent reactivity by agglutination, enzyme-linked immunosorbent assay (ELISA) or hemagglutination inhibition; isolation of MS from such flocks proved to be very difficult. Turkeys were challenged with one of the isolates (K4463B) either by aerosol or systemically by a combination of intravenous, foot pad, and eyedrop routes. Turkeys challenged by the systemic route responded normally to all serologic tests, whereas those challenged by aerosol either responded very poorly on all serologic tests or were seronegative up to 6 wk postchallenge even though they were positive for MS by tracheal culture. These results suggest that turkeys may harbor an upper respiratory infection with MS while remaining serologically negative.