Effects of salinity on growth characteristics and osmoregulation of juvenile cobia,Rachycentron canadum (Linnaeus 1766), reared in potassium‐amended inland saline groundwater

The suitability of inland saline groundwater as a medium to culture juvenile cobia, Rachycentron canadum, was assessed. In the first experiment, juvenile cobia stocked in raw (unamended) saline groundwater at salinities of 5, 10, and 15 g/L exhibited complete mortality after 108, 176, and 195 hr, respectively. The second experiment evaluated the rearing of juvenile cobia (mean weight ~9.23 ± 0.12 g) in potassium (K⁺)‐amended saline groundwater (100% K⁺ fortified) and reconstituted seawater at salinities of 5, 10, and 15 g/L to assess growth and osmoregulation in distinct culture media. Following 60 days of culture, all fish survived the experimental period. Final mean bodyweight of cobia reared in K⁺‐amended saline groundwater (103.2–115.8 g) and seawater (111.2–113.8 g) of different salinities did not vary significantly (p > .05). No differences (p > .05) were observed in specific growth rate, weight gain (%), and feed conversion ratio between treatment groups. Serum osmolality increased with salinity and was significantly higher (p < .05) for fish in K⁺‐amended saline groundwater (353–361 mOsmol/Kg) than in reconstituted seawater (319–332 mOsmol/Kg), although differences were not observed between salinities by water type. Cobia stocked in saline groundwater of different salinities were osmoregulating normally, and the higher values observed may be because of variations in ionic composition and other interfering ions in saline groundwater. Trial results suggest that juvenile cobia can achieve optimal growth in K⁺‐amended saline groundwater of low and intermediate salinities.     

Biocontrol potential of Pseudomonas azotoformans,Serratia marcescens and Trichoderma virens against Fusarium wilt of Dalbergia sissoo

Wilt disease caused by Fusarium solani is a serious constraint to Dalbergia sissoo (shisham) plantations in northern India. In this study, the antagonistic potential of 40 bacterial isolates recovered from rhizophere soil of healthy shisham trees, and a well‐characterized Trichoderma species (Trichoderma virens) were tested for their possibility as biocontrol agents for F. solani. Two promising isolates (S1 and S15) were identified which inhibited pathogen growth, caused chitin degradation, produced siderophores and solubilized phosphate in vitro. Isolate S15 scored highest for hydrogen cyanide (HCN) production while isolate S1 was a non‐HCN producer. These two isolates were identified as Serratia marcescens (S1) and Pseudomonas azotoformans (S15) following sequence analysis of 16S rDNA. In dual culture assays, T. virens caused 80% inhibition of mycelial growth of the test fungus. The three selected antagonists when tested in planta in the glasshouse completely suppressed production of wilt symptoms on 12‐month‐old shisham plants. Further work is needed to ascertain the potential of these isolates to be used as biocontrol agents to manage shisham wilt under field conditions.     

Adoption and Impact of Modern Rice Varieties on Poverty in Eastern India

The factors affecting the adoption of modern varieties(MVs) of rice and impact on poverty in Odisha, India were discussed. A total of 363 households from Cuttack and Sambalpur districts of Odisha via multistage sampling technique participated in the survey. The Cragg's Double hurdle model was used to model the determinants of adoption and intensity of adoption of MVs of rice, and the propensity score matching was used to analyze the impact of adoption on poverty. The results showed that age, education, risk aversion, land size, yield, perception of MVs as high yielding, resistant to diseases and availability of MVs positively influenced the decision to adopt. However, variables such as household size, experience of a farmer, off-farm job participation, amount of credit received, cost of seeds, insecticides and fertilizers negatively influenced the adoption of MVs. Intensity of adoption of MVs was negatively influenced by experience of a farmer, cost of fertilizer and marketability of MVs, and positively affected by household size, risk aversion, land size, cost of insecticides, perception of MVs as high yielding and availability of MV seeds. Poverty incidence, gap and severity were high among non-adopters to adopters of MVs. After matching adopters and non-adopters of MV groups using four different algorithms of nearest neighbour matching, stratification matching, radius matching and kernel matching, the impact of MV adoption resulted in higher per capita monthly household expenditure by about US$ 52.82 to US$ 63.17.     

High night-time temperature during flowering and pod filling affects flower opening,yield and seed fatty acid composition in canola

Winter canola (Brassica napus L.) is highly sensitive to increasing temperatures during the reproductive and pod-filling stages. Although the impact of high day-time temperature stress on yield and quality has been documented in canola, similar information under high night-time temperature (HNT) stress is not available. Using six hybrids and four open-pollinated cultivars, we observed a marked shift in peak flowering towards earlier, cooler hours of the morning under HNT. Averaged across two independent experiments, the photochemical efficiency of photosystem II was significantly decreased (3%), with a significant increase in thylakoid membrane damage (13%) in the leaves of susceptible cultivars under HNT stress. Similarly, the susceptible cultivars also recorded significant reduction in biomass (34%), pod number (22%), pod weight (37%) and total seed weight (40%) per plant while the same set of agronomic traits were not affected among the tolerant cultivars. Quantitative impact of heat stress was confirmed with increased sensitivity to HNT exposure from gametogenesis until maturity resulting in a significantly higher yield loss compared to stress exposure from post-flowering till maturity. HNT significantly decreased oil concentration, but increased protein concentration and saturated fatty acid levels in seeds of the susceptible cultivars. However, HNT had no impact on the unsaturated fatty acids in both hybrids and the open-pollinated cultivars. Breeding targets based on fatty acid composition for enhancing canola seed quality may not be easily amenable due to the inconsistency documented with the compositional changes under heat stress. In summary, our findings conclude that canola hybrids are better suited to regions experiencing heat stress, compared to open-pollinated cultivars, indicating the possibility of a complete shift to hybrid canola cultivation under predicted hotter climates in the future.     

Utilization of Weather Data in Predicting Bread Loaf Volume by Neural Network Method

The unique ability of wheat (Triticum aestivum L.) flour to produce cohesive dough has helped to make it the most widely used cereal crop for bread and other baked food products. Measurement of end‐use qualities, such as loaf volume, is ideally carried out through assessing loaves of bread; however, this is resource intensive. Predictive testing methods are more often utilized to identify wheat genotypes with potentially acceptable loaf volume, although more accurate predictive methods would be beneficial. Our objectives were to study the influence of weather observations on bread loaf volume and flour and dough quality data, to use a neural network (NN) model to predict loaf volume with select input data, and to compare the best multiple regression models identified with their NN counterparts. Weather data collected at 20 days after heading (DAH) showed the highest correlations with bread loaf volume when compared with prior intervals. A NN model containing maximum, minimum, and nighttime temperatures produced the highest coefficient of determination for predicting loaf volume. Our results showed that the NN model explained up to 20% more loaf volume variation than a similar regression model. Weather parameters representing conditions at 20 DAH played a significant role in loaf volume prediction.     

The Embeddedness of Collective Action in Nepalese Community Forestry

Collective action by local communities has been recognised as crucial for effective management of natural resources, particularly the management of forests in rural settings in developing countries. However, the processes and outcomes of collective action in forest management are often analysed through a narrow rational choice model, ignoring the impacts of wider social, political and economic processes in conditioning peoples’ decisions to act (or not to act) collectively. Optimistic assumptions are made for collective action being instrumental to enhance both social and ecological outcomes, but there is a paucity of empirical evidence on how and why the condition of forests has improved (or deteriorated) under collective action, and what impacts the change in forest condition has on various groups within local communities. This study critically examines the emergence, evolution and outcomes of collective action in a case of community forestry in Nepal. A mix of qualitative and quantitative methods has been used to collect primary data from the forest, households, key informants and focus groups. The emergence and outcomes of collective action is found to be embedded in social, economic and political relationships, where powerful actors control the use of forests in order to ensure conservation, thereby resulting in the underutilisation of forest products. Poor users, who depend heavily on forests, are found to be worse off economically under community forestry, but still engage in collective action for a variety of socio-political reasons. This contradicts the conventional wisdom which assumes that people only cooperate when they benefit from cooperation. It is concluded that a deeper understanding of the embeddedness of community forestry is needed in order to achieve the potential of collective action.

Ecological and anthropogenic niches of sal (Shorea robusta Gaertn. f.) forest and prospects for multiple-product forest management - a review

Sal (Shorea robusta Gaertn. f.) forests cover over 11 millionha in India, Nepal and Bangladesh, and these forests are conventionallymanaged for timber. Recently, interest in producing multipleproducts from sal forests has increased; accordingly, a silviculturalregime for managing sal forest for multiple products is a centralconcern. Forest managers need a comprehensive scientific understandingof natural stand development processes and anthropogenic factorsaffecting sal forest when designing silvicultural regimes formultiple-product management. We review ecology and productivityplus anthropogenic niches of sal forests. Information on edaphicfactors, phenology and stand development processes (regeneration,growth characteristics, soil nutrient requirement, growth allocation,nutrient cycling, stand structure and successional stages) isimportant for designing scientific forest management of salforest; likewise, knowledge of anthropogenic factors associatedwith use of sal forest is also required for effective implementationof the recently paradigmed management efforts. Sal forest silviculturehas been evolving since the beginning of the twentieth centurymainly concentrating on timber production, though the sal forestshave always been used also for grazing and collection of fodder,fuelwood, litter and many other products. Instead of integratingthese products in sal forest management, governments have attemptedto control these additional uses through enforcing forest legislation.These attempts resulted in the persistent conflicts betweenthe interests of local people and the government, and the deterioratingcondition of sal forests. Community-based forestry in this regionemerged in response to the severe degradation of forest resources,and local people initiated protection practices and demonstratedthe success of sal forest from coppice. The coppice systemsallow managing forests with intermittent products (non-timberforest products, including fodder and litter) while producingtimber in the long term. Accordingly, a policy has been developedto manage coppice sal forest for multiple products. Managingthe sal forest for multiple products is, however, a relativelyrecent development and scientific investigations on variousaspects of multiple-product forest management need to be initiated.Ecological processes indicate good prospects of managing salforest for multiple products. The review indicates that theecological processes and anthropogenic factors form sound basisfor developing multiple-product management.     

Diofenolan: a novel insect growth regulator in common citrus butterfly, <Emphasis Type="Italic">Papilio demoleus</Emphasis>

Penultimate and last instar larvae of the common citrus swallowtail butterfly, Papilio demoleus L. (Papilionidae: Lepidoptera), were treated with different doses of a novel juvenoid, diofenolan. Several deformities were observed as a result of topical administration of diofenolan which include delay in larval–larval and larval–pupal ecdysis, ecdysial failure, mortality, severe reduction in pupation, deformed pupae and complete inhibition of adult emergence. The juvenoid diofenolan severely hampers the normal growth, development and metamorphosis of P. demoleus and can be incorporated into integrated pest management programs for successful control of this important pest of citrus all over the world.     

Zaluzanin D: a fungistatic sesquiterpene from Vernonia arborea

Zaluzanin D, a sesquiterpene lactone has been isolated from the aerial parts of Vernonia arborea as a major constituent (0.04%). Antifungal activity of zaluzanin D has been studied against six plant-pathogenic fungi.     

Resistance of pearlspot larvae,Etroplus suratensis,to redspotted grouper nervous necrosis virus by immersion challenge

Viral nervous necrosis (VNN) affects more than 120 species mostly belonging to the order Perciformes. However, none of the brackishwater species belonging to the family Cichlidae under the order Perciformes are reported to be susceptible. Hence, the present experiment was undertaken to study the susceptibility of the brackishwater cichlid, pearlspot, Etroplus suratensis to NNV. Thirty‐day‐old pearlspot larvae were infected with NNV by immersion. Mortality was recorded till 14 days post‐infection, and the infected larvae were subjected to nested RT‐PCR and histology. The virus was isolated from infected larvae using SSN‐1 cells. To study the replication of the virus in vitro, primary cultured brain cells of E. suratensis and IEK cells were infected with NNV. No mortality was observed in any of the control or experimentally infected larvae. However, the experimentally infected larvae were positive for NNV by nested RT‐PCR and the virus was isolated using SSN‐1 cells. Further, the infected pearlspot brain cells and IEK cells showed cytopathic effect at second and third passage of the virus and they were positive for NNV by nested RT‐PCR. Pearlspot is relatively resistant to VNN although the virus could replicate in the larvae and in cell culture.