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21.
Field experiments were conducted to evaluate the effects of eco-friendly organic matrix entrapped urea (OMEU) on growth, productivity, and yield of rice (Oryza sativa L. cv. Basmati) and soil enrichment in the paddy field at Rohtak (Haryana) located near Delhi. The OMEU prepared in granular form contained cow dung, rice bran (grain cover of Oryza sativa), powder of neem leaves (Azadirachta indica), and clay soil (diameter of particles < 0.02 mm) in 1:1:1:1 ratios and saresh (plant gum of Acacia sp.) as binder along with half of the recommended dose of commercially available soluble urea (free urea; FU). Single basal application of OMEU showed an increase in plant growth in terms of fresh and dry weights, root length, root, leaf and tiller numbers, soluble protein, total N and ammonium in leaves, productivity in terms of grain and straw yield, and nutritional and microbial activities of field soil over free form of urea and no fertilizer application. Nutritional status of rice grains was also improved over the free urea and no fertilizer controls. Our data indicate that OMEU, which is low cost and based on bio-degradable, non-toxic, and locally available agro-waste, can be attempted to replace the conventional use of soluble urea in rice.  相似文献   
22.
In Nepal, in traditional rice farming systems many diverse landraces are grown in all of the rice agro-ecosystems from low to high altitude. Three case study sites were selected to represent the major rice agro-ecozones: Bara (100–150 m) for the low-altitude terai (plain); Kaski (700–1,206 m) for the mid-hill zone; and Jumla (2,200–3,000 m) for the high-hill zone. The diversity in rice varieties was compared in these three sites and nine survey villages in a series of surveys conducted in 1998, 1999 and 2006. The level and distribution of diversity on farm varied with the physical and socio-economic settings of the farming communities. The mid-hill site (Kaski) had the highest rice landrace diversity. This was adapted to the diverse agro-ecosystems found there and there was equal diversity in Kule khet (irrigated lands by seasonal canals) and Sim khet (marshy wet land). The next most diverse system was Nicha khet (irrigated lowlands) in Bara, the low-altitude site. The high-hill site (Jumla) had the lowest rice diversity. Across all sites many of the landraces were rarely grown and then only in small areas, reflecting the specialized uses to which they were put. At all sites the most common single landrace occupied less than half of the rice area. Resource-rich farmers were the more important custodians of on-farm rice varietal diversity across the sites. There was more rice diversity in favourable environments than in less favourable ones. This was true whether diversity was measured across sites or across rice domains within sites.  相似文献   
23.
The population status and regeneration of a data-deficient tree species were examined in both protected and unprotected areas. The target species was found in six habitat types, seven aspects between 2,100- to 3,300-m altitude, and sites dominated by different species. The species was best represented in a shady moist habitat, north and northwest aspects, altitudinal range >2,700 m, and sites dominated by Acer caesium in both protected and unprotected sites; but the generalized linear model indicated nonsignificant effect of sites, habitat, altitude, and dominance except for aspects. Difference in sapling and seedling density among aspects and sites only was significant. Probability of use and resource use index indicated poor preference and less pressure as fuel. It can be concluded that the species is not under any significant threat in the study area. But, further studies on population status, regeneration, and relationship with environmental factors in a wider geographic region are suggested to evaluate species and place under suitable priority category.  相似文献   
24.
A field experiment was conducted on summer mungbean residue recycling (SMBRR) and basmati rice–wheat cropping system (BRWCS) at New Delhi, India. The SMBRR enhanced the system productivity and net returns by ~19.1% and 22.1% compared to summer fallow (SF) with highest magnitude under genotypic sequence of P 2511/HD 2967. Two genotypes each in basmati rice (PB 1 and P 2511) and wheat (HD 2967 and HD 2733) responded well to SMBRR with respect to grain yield efficiency index (GYEI) ≥ 1.0. SMBRR also registered ~13.5% higher microbial biomass carbon (MBC) than SF. Soil organic carbon (SOC) storage also increased by ~6.8% in 0–30 cm soil layer. The rice–wheat–summer mungbean system produced significantly highest energy efficiency compared to the rice–wheat–summer fallow system with highest values under genotypic sequence of P 2511/HD 2967 as a result of better yield expression. Overall, SMBRR with suitable genotypic sequence improved the system productivity, profitability, and nutrient dynamics in BRWCS, which are vital for long-term sustainability of this system.  相似文献   
25.
26.
The population of the freshwater animal was declined day by day due to the degradation of habitat and use of illegal fishing methods, which cause a great threat to these aquatic animals. The main purpose of this study was to scrutinize the wild population and fecundity of freshwater prawn Macrobrachium assamense peninsulare in Rawasan stream to assess the health status of prawn. Fecundity was estimated by a random sampling of prawn from five selected sites of Rawasan stream. A wild collection of a total of 35 ovigerous females was collected for an interval of 2 years (August 2013–July 2015) from May to September month, that is breeding session. The maximum number of eggs was 102 eggs in an individual having 52 mm total length and 2.66 g body weight. It was concluded that fecundity of Macrobrachium assamense peninsulare was low, and egg dimension was larger than other closely related species of freshwater prawn. Fecundity of Macrobrachium assamense peninsulare showed a positive relationship with a total weight (R2 = .71) and moderate with the total length (R2 = .38). A strong correlation exists between egg mass and total weight, and between egg mass and total length of female (R2 = .849 and R2 = .77 at p < .05) respectively. The numbers of eggs, that is fecundity, in a female were increased with the body growth of an individual, which results in a linear graph.  相似文献   
27.
Shoe-string disease caused by Cucumber mosaic virus (CMV) is one of the major threats to tomato production worldwide. The alteration in some biochemical parameters in leaves of the susceptible tomato genotype (Nagina) associated with CMV infection and the effect of exogenous application of salicylic acid (SA) and benzothiadiazole (BTH) were studied in this paper. Results showed that exogenous treatment with SA and BTH not only led to plants which gave significantly more yield than diseased controls (DC), but also delayed symptom expression and reduced disease severity. Analysis of biochemical parameters indicated that exogenous application of elicitors and viral infection, significantly affected the activity of peroxidase (POD), superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX). Compared to the DC plants, minimum disease severity and maximum number of fruit were recorded after a single dose of SA + BTH. Maximum plant height was recorded after weekly application of SA and maximum fruit yield per plant was gained with single dose of SA. Moreover, the activity of POD was significantly elicited many-fold after weekly application of SA + BTH, while higher amount of SOD was recorded with single dose of SA. The activity of CAT was also significantly accelerated after weekly application of SA + BTH while increased level of APX was noticed with single dose of BTH. In conclusion, the combined application of SA and BTH played an important role in induction of defense mechanism against CMV infection and can be useful in tomato disease management programs.  相似文献   
28.
In this experiment, weed management was studied in zero tillage (ZT) and conventional tillage (CT) wheat with and without crop residue and nitrogen (N). The treatment ZT with crop residue retention (R) and 75% of required N plus GreenSeeker? (GS)-aided N management (ZTRNGS) resulted in a reduction of density and dry weight of weeds compared to CT and ZT without residue. Sequential application of pendimethalin and sulfosulfuron (PMT-SSF) reduced the weed density and dry weight compared to the weedy check (WC). Importantly, the richness and diversity indices were high in ZTRNGS and in WC treatments. Greater wheat grain (5.11 t/ha) and biomass yield (13.31 t/ha) were observed in ZTRNGS than CT without residue and blanket split application of N (CTN). The treatment ZTRNGS recorded 14.1% and 16.9% higher gross and net returns, respectively, over CTN. This study demonstrates that surface retention of crop residue in ZT is more useful than residue incorporation under CT for effective weed control, improving crop yield and profitability.  相似文献   
29.
The Western Himalayan region of India possesses rich genetic diversity of rice (Oryza sativa L.). Rice landraces having withstood the rigors of biotic and abiotic stresses, suit to the local conditions of farms and reflect socio-cultural preferences can still be found in crop fields located distantly in rural and tribal areas. This region is known for growing World fame basmati in the foot hills and many varieties of red rices grown at higher elevations, known for cold tolerance and medicinal properties. Genetic resources of rice were collected for about 8 years (1999–2006) and 1069 germplasm accessions including 154 named landraces were collected. Prominent landraces such as Begumi, Ramjwain, Thapachini, Naurang, Hansraj, Tilakchandan, Lalsati, Jhini, Mushakbudji, Jattoo, Barpasso, Qadirbeigh, Safedbrez, Shahie known for their special quality attributes were collected. The change in land use, cropping patterns and aggressive introduction of modern varieties in the region has resulted in the loss of a large number of landraces especially from irrigated lands. The present paper looks at the status of rice genetic resources, genetic variability, genetic erosion and future strategies to conserve rice germplasm on farm and to maximize its use in rice breeding.  相似文献   
30.
This research was conducted to explore genetic material that can yield better under salt stress conditions. The experiment was laid out using 27 upland cotton genotypes in a RCBD 2 factorial arrangement with two replications. Saline water (NaCl at 20 dS/m) was applied after satisfactory emergence was achieved. The crop was raised to maturity and data relating to yield, fiber quality and ionic traits were recorded. Analysis of variance showed significant variations in the germplasm. Plant height, bolls per plant, boll weight, GOT%, staple length, staple strength, K+ and K+/Na+ ratio under salinity stress showed a highly significant correlation with seed-cotton yield. The highest direct effect on seedcotton yield per plant was exhibited by bolls per plant and boll weight. The results from the correlation and path coefficient analyses revealed that although the K+/Na+ ratio had a strong positively significant association with seedcotton yield, its direct effect on the seed-cotton yield was negative and thus selection on the basis of K+/Na+ may not be fruitful. Hence, only indirect selection through bolls per plant and boll weight may be effective in increasing the seedcotton yield per plant under salinity stress.  相似文献   
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