Simulating rice stem borer, Scirpophaga incertulas Wlk., damage for developing decision support tools

InfoCrop, a generic crop–pest simulation model, was used to validate yellow stem borer, Scirpophaga incertulas Wlk., damage mechanism on two rice cultivars, Pusa Basmati 1 and Ratna. Data sets consisted of three experiments, one under natural infestation of the pest and two involving artificial detillering. The simulated yields showed less than 10% variation from the observed yields, except in one treatment, where the difference was 10.5%. The simulated yield losses were also proximal to respective observed yield losses (R²=0.922, RMSE=3.825), indicating proper validation of damage mechanism of the stem borer. As the model simulated the pest damage appropriately under natural injury, as well under artificial detillering; artificial detillering seemed comparable to natural injury of the stem borer in its effect on rice growth and yield. Validated InfoCrop was used to simulate economic injury levels (EILs) of the stem borer at different rice growth stages for varied control expenditure, incurred on two and three sprays of monocrotophos and one granular application of carbofuran, and for three market prices of produce. The EIL consistently decreased with advancing crop age and it exhibited a positive relationship with control expenditure and a negative relationship with market value of the produce. The simulated EILs were observed to be comparable to empirical injury levels that were previously established. The validated model was also used to devise iso-loss curves that depicted same yield loss for different combinations of the stem borer injury and crop age. Crop simulation model-based EILs and iso-loss curves are useful in monitoring the stem borer injury and in need assessment for pesticide application, thereby avoiding unnecessary expenditure and environmental contamination. Due to their mechanistic nature, crop models can be used to formulate location-specific decision support tools and therefore, help improve decision making in pest management.     

Nutritional potential ofVigna minima (Roxb.) Ohwi and Ohashi:

Quantitative variation in different fractions of seed proteins and their amino acid levels in populations ofVigna minima (Roxb.) Ohwi and Ohashi and inV. umbellata cv. IC 1568 — the rice bean — were investigated. Globulin I fraction, together with globulin II, constitutes 38 to 54 per cent of the total seed protein. The alkali soluble (glutelin) fraction is the second largest fraction. Both these fractions show broad range of variation, suggesting a broad genetic base. The profiles are population specific; the coastal population, which contains higher seed protein also possesses maximum levels of globulin I and glutelin fraction suggesting its potentiality for breeding lines with high protein content, high nutritive value, and salt tolerance. Protein content is positively correlated with globulin I and glutelin fractions, which are in turn positively correlated with each other. The amino acid profiles are specific not only to the fractions but also to the populations. The range of variation in the levels of all amino acids in different fractions is broad suggesting substantial genetic diversity. The average levels of lysine and sulphur amino acids are high in globulin I and glutelin fractions.     

Identification of genomic regions linked to blast (Pyricularia grisea) resistance in pearl millet

Blast disease causes serious economic yield losses in pearl millet. Identification and introgression of genomic regions associated with blast resistance can help to develop resistant cultivars to minimize yield losses incurred from blast outbreaks. In this study, 384 advanced pearl millet genotypes were screened against six blast pathotype-isolates (major pearl millet growing agro-ecologies of India), namely, Pg 45, Pg 118, Pg 138, Pg 186, Pg 204 and Pg 232. Analysis of variance showed significant (P < .001) variation among genotypes for blast reaction (susceptible to resistance). ICMR 08111 and ICMR 10888 genotypes showed resistance to all six blast pathotypes. A genome-wide association study performed with 264,241 single nucleotide polymorphic markers could successfully identify 15 SNPs (P = 1.26 × 10⁻⁷ to 9.22 × 10⁻¹²) underlying the genomic regions governing blast-resistance across five different chromosomes. The SNPs reported had a significant association in at least two of the three models tested (GLM, MLM and Farm CPU). These SNPs can be used in pearl millet-resistant breeding programmes after their function has been validated across different genetic backgrounds.     

The annual reproductive cycle and sex inversion of the Picnic seabream,Acanthopagrus berda (Forsskål 1775) from Indian waters: Histological and morphometric description

The annual reproductive cycle of picnic seabream, Acanthopagrus berda (Forsskål, 1775), one of the potential aquaculture candidate from estuarine waters of Calicut, Kerala (India) was studied. Based on the morphological and histological studies, the ovotestes of A. berda were classified as active male, active female, inactive male, inactive female, transitional and undifferentiated. Histological observation of transitional gonads showed signs of degeneration in the testicular lobe, proliferation of connective tissue and empty sperm ducts indicating protandrous hermaphroditism in A. berda. Ovary was classified into seven maturity stages (virgin, developing virgin, developing, maturing, mature, running, spent) and testis into five maturity stages (resting, maturing, mature, running, spent). Gonadal development in A. berda indicated resting phase (February–July), pre‐spawning phase (March–August) and spawning phase (August–December). Inactive (24.6%) and active males (21.6%) were observed as dominant in smaller length classes (140–250 mm TL), whereas inactive (18%) and active females (51%) were observed as dominant in larger length classes (251–450 mm TL). Few primary females (28.1%) were observed in smaller (below 250 mm TL) and few primary males (28.5%) were observed in larger length classes (above 250 mm TL). From the present study, it can be concluded that in A. berda, most of the individuals function first as males and then change sex to female, but few continue to function as either male or female throughout their lifespan indicating digynous protandrous hermaphroditism.     

Effect of dietary rosemary extract on cell-mediated immunity of young rats

The impact of rosemary extract on splenic mononuclear cell proliferation was determined. Weanling male Sprague-Dawley rats were fed diets containing 0, 100, 200 or 400 ppm rosemary extract or 400 ppm butylated hydroxytoluene (BHT) in combinatiion with 10 or 20% casein enriched diets for 8 weeks. Splenic mononuclear cells were isolated from these animals and mitogenic response to Concanavalin A (Con A), Phytohemagglutinin (PHA) and lipopolysaccharide was determined. Con A and PHA-stimulated proliferation of spleen cells from rats fed 10% casein and 200 ppm rosemary extract was significantly higher than that of cells from the corresponding control animals. However, other levels of rosemary at 10% dietary casein or rosemary at any concentration fed along with 20% dietary casein had no impact on the mitogenic stimulation of splenic mononuclear cells. Thus, these results suggest that the use of rosemary might not have a generalized immunoenhancing effect, and will probably be effective in some stressed conditions, such as protein or antioxidant deficiency.     

Effect of crop load,fruit position and shoot vigour on yield and quality of Annona atemoya × Annona squamosa in India

The effect of crop load, position of the fruit on the shoots and vigour of the shoots on yield and quality of Annona atemoya × A. squamosa hybrid ‘Arka Sahan’ was investigated in India over two years. The trees were hand-pollinated and thinned to 20, 40, 60, 80 or 100 fruit after fruit set. Information was collected on total and marketable yield, yield efficiency, average fruit fresh weight, peel weight, the number of seeds per 100 g of pulp, pulp content in the fruit, total soluble solids (TSS) and total titratable acidity. In other experiments, fruit were harvested from weak, medium or vigrous shoots, or from basal, middle or apical nodes. Total yield increased up to 60 or 80 fruit per tree and marketable yield increased up to 60 fruit per tree. Average fruit weight and peel weight increased as cropping increased. These results suggest that optimum productivity and quality is associated with 60 fruit per tree or 0.17 to 0.19 kg cm² trunk-cross sectional area. The quality of the fruit in different positions on the shoots or on the different types of shoots was highly variable and generally not affected by the various treatments.     

Long‐term effects of organic manure and manufactured fertilizer additions on soil quality and sustainable productivity of finger millet under a finger millet–groundnut cropping system in southern India

In a 20‐yr‐old long‐term experiment, the impact of continuous application of organic manures and inorganic fertilizers on soil quality and the sustainability of finger millet production was conducted on two cropping systems: finger millet and finger millet–groundnut on an Alfisol of semi‐arid southern India. The study was conducted from 1992 to 2011 at the All India Coordinated Research Project for Dryland Agriculture, UAS, Bangalore, using a randomized block design. The treatments comprised of T₁: control [no fertilizer and no farmyard manure (FYM) applied], T₂: FYM 10 t/ha, T₃: FYM 10 t/ha + 50% of recommended NPK (50:50:25 kg/ha), T₄: FYM 10 t/ha + 100% of recommended NPK and T₅: 100% recommended NPK. Comparison of long‐term yield data between treatments was used to calculate a ‘sustainability yield index’ (SYI), which was greatest for T₄ (FYM 10 t/ha + 100% of recommended NPK), in both rotational (0.68) and monocropping (0.63) situations. Soil quality indices were determined using principal component analysis linear scoring functions. The key indicators which contributed to the soil quality index (SQI) under rotation were organic C; potentially available N; extractable P, K and S; exchangeable Ca and Mg; dehydrogenase activity and microbial biomass C and N. The largest SQI (7.29) was observed in T₄ (FYM 10 t/ha + 100% NPK), and the smallest (3.70) SQI was for the control. Application of 10 t/ha FYM together with NPK (50:50:25 kg/ha) sustained a mean yield of 3884 kg/ha.     

Application of encapsulated nano materials as feed additive in livestock and poultry: a review

Veterinary Research Communications - Livestock plays a significant role in the socio-economic development of developing countries by providing livelihood and nutritional security, transport,...