Factors determining the adoption of laser land leveling in the irrigated rice–wheat system in Haryana,India

Laser land leveling has been increasingly adopted in the irrigated rice (Oryza sativa L.)–wheat (Triticum aestivum L.) cropping system in the state of Haryana (India), located in the north-western Indo-Gangetic Plains. Still, many farmers have applied it to only a fraction of their land. In this study, we used data collected from 621 farm households in Haryana and applied a double-hurdle model for assessing the factors that determine the adoption and intensity of laser-leveling technology. The results show that large land holders are more likely to laser level their farm land; however, we found a negative association between land holdings and the proportion of laser-leveled land. Information about technology through farmer-to-farmer communication and through private traders, participation in agricultural training and membership in local agricultural institutions increased both the likelihood and the intensity of adoption. Our findings call for a closer collaboration among the various stakeholders, specifically to promote farmer-to-farmer communication through increased participation in local institutions and increase the rate of adoption of laser leveling technology.     

Clonal adaptive radiation in a constant environment

The evolution of new combinations of bacterial properties contributes to biodiversity and the emergence of new diseases. We investigated the capacity for bacterial divergence with a chemostat culture of Escherichia coli. A clonal population radiated into more than five phenotypic clusters within 26 days, with multiple variations in global regulation, metabolic strategies, surface properties, and nutrient permeability pathways. Most isolates belonged to a single ecotype, and neither periodic selection events nor ecological competition for a single niche prevented an adaptive radiation with a single resource. The multidirectional exploration of fitness space is an underestimated ingredient to bacterial success even in unstructured environments.     

Serological evidence of Trichinellosis in local pigs of Nepal

In Nepal, animal husbandry is a major source of income. Pig husbandry is practiced in rural, peri-urban, and urban communities. Free ranging "back yard" pigs and the practice of feeding offal is a very common management practice which potentially allows for the transmission of trichinellosis; however, this zoonosis has never been reported from this region. A total of 425 serum samples were collected from local pigs. These were initially screened by ELISA after which positive samples were examined by Western blot. This procedure identified two samples which had clear specific bands for Trichinella; however, muscle samples tested by HCL-pepsin digestion were found to be negative. If these highly specific serological analyses are confirmed, this would be the first report of trichinellosis in Nepal and a prevention program should be initiated to limit the access of pigs to open garbage dumps which exist both in towns and on farms.     

Isolation and functional analysis of the zmARM4 locus in a novel maize (Zea mays) grain-filling mutant

Maize grain filling (GF) and grain weight (GW) are closely associated with grain yield. In our study, the ZmARM4 locus affecting GF and GW was identified using a reverse genetics screen of UniformMutator (Mu). First, MutatorDR-flanking sequence (MuDRFs) was isolated from the mutant by the MuDR-amplified fragment length polymorphism method, and it was verified by cosegregation (between MuDRFs and phenotype) and linkage analyses. Second, the target gene of the MuDRFs was found to encode the Armadillo domain of the repeat protein gene families and has high expression in the GF stage. Third, association mapping between SNPs in the ZmARM4 region and the GW of 489 maize lines indicated that ZmARM4 is a functional gene that is closely related to GW. Moreover, bioinformatics analysis suggested that ZmARM4 may be relevant for the activity of sucrose transport or the number of cell divisions in endosperm cells. Therefore, ZmARM4 may be used as an important locus for maize GW in molecular breeding.     

Management practice to optimize wheat yield and water use in changing climate

ABSTRACT

Field experiments for six seasons (2008–2013) for present time slice (PTS; 2008–2013) and simulation studies for mid-century (MC; 2021–2050) were carried out to assess different planting dates, varieties and irrigation schedules in addressing the impact of climate change on grain yield and water use efficiency (WUE) in bread wheat (Triticum aestivum L.). During field experimentation, WUE (averaged over other treatment) was unaffected by planting date; however, it was 6% higher in late variety (V₁) than early variety (V₂). Simulation study suggested that in MC, increase in maximum and minimum temperatures compared to PTS would reduce wheat yield by 17–27%. In MC, WUE would be reduced by 14.8% due to shortening of crop duration (1–11 days). The reduction in WUE could be ascribed to relatively more reduction in yield (22%) than evapotranspiration (ET) (4%). The WUE in MC3 (2041–2050) was relatively more than MC1 (2021–2030) and MC2 (2031–2040) due to more yield and less ET. Delaying planting date of wheat crop by 15–30 days in this region emerged as the best adaptation measure to tackle climate change impact for sustaining yield and having higher WUE in MC.     

Effects of dietary energy levels on Pectoralis major mixed muscle protein turnover and body composition in two broiler lines housed in different grow-out environments

This study determined the Pectoralis (P) major mixed muscle protein turnover (PT) in two meat broiler lines, Line A and Line B, during the finishing grow-out feeding period (21–42 days) as affected by the dietary metabolizable energy (ME) levels and ambient temperatures. Experimental finishing diets consisted of 80, 90, 100, 110 and 120% ME of recommended nutrient guidelines for energy level. Fractional synthesis rates (FSR) or fractional degradation rates (FDR) were measured in P. major at day 36 and 42. Protein and fat mass gain were measured, and respective energy retention efficiencies as protein and fat (EREp and EREf) were determined. Metabolic heat production (HP) was also reported. Experimental feeding studies were conducted in cool season (24 hr mean: 69.91˚F and 63.98% RH) and in hot season (24 hr mean: 77.55˚F and 86.04% RH). Results showed that FSR or FDR values were not affected by dietary ME levels at day 36, whereas reduced FSR (p < .05) were observed at day 42 fed diets with reduced ME levels (≤100% ME) which could have resulted from greater maintenance energy requirement of maturing broilers at that age. Broilers fed reduced ME diets (≤100% ME) maintained protein mass (equivalent to broilers fed ≥100%–120% ME) by reduced FDR and increased feed intake. Grow-out ambient temperature did not affect FSR or FDR values across ME levels. Line B retained higher protein mass, lower fat mass and greater HP compared to Line A. This was followed by higher feed intake in Line B. Further, Line B exhibited higher EREp and lower EREf across dietary ME levels. In summary, PT homeostasis and body composition changes in broiler lines studied seemed to be regulated by the birds’ intent to normalize energy intake as per physiological need by controlling feed intake.     

Elevated CO2 affects plant nitrogen and water‐soluble carbohydrates but not in vitro metabolisable energy

The effects of elevated concentrations of atmospheric CO₂ (e[CO₂]) on the nutritive value of wheat vegetative matter and grain as a feedstock for ruminants were investigated in a study undertaken at the Australian grains free‐air CO₂ enrichment (AGFACE) facility. The study included two commercial wheat cultivars (Janz and Yitpi) and two genetic selections from a Seri/Babex population (SB003 and SB062) which had previously been characterised for low and high water‐soluble carbohydrate accumulation efficiency. The trial was grown under ambient (~390 µmol/mol) and elevated (~550 µmol/mol) CO₂ conditions, and plants harvested at tillering, anthesis and physiological maturity. Composition analyses to determine the nutritive value for ruminant feed were undertaken on stems, leaves and grain. Plant and grain nitrogen were reduced in the e[CO₂] treatments, and as expected, the water‐soluble carbohydrates increased. All genotypes responded to e[CO₂] with the effects of altered composition evident within 60 days of sowing. Determinants of ruminant feed quality such as neutral and acid detergent fibre and estimated in vitro metabolisable energy were not significantly affected. The reduced plant and grain N will impact on the nutritive value and supplementation may be required. The impact of e[CO₂] on chemical composition of wheat plants may be greater if the predicted climate change is associated with concomitant abiotic stress such as high ambient temperature or low soil moisture.     

Classification Methods Based on Pattern Discrimination Models for Web-Based Diagnosis of Rice Diseases

Two classification and identification methods based on pattern discrimination models and the majority-vote technique were investigated for implementing a World Wide Web-based system for the identification of rice diseases. The experiment was carried out using color and shape patterns in 425 images of three rice diseases, which were classified into four classes： two classes of leaf blast, and one class each of sheath blight and brown spot. A method consisting of two discrimination steps involving application of multiple discrimination models of a support vector machine gave the best result because of its capacity to evaluate the similarity of disease types. This accuracy of the method was 88% for leaf blast （A-type）, 94% for sheath blight, and 80% for leaf blast （B-type） and brown spot; on average, the accuracy of this method was 5% greater than that of the other method when three classes were used in the model. Although the accuracy of both methods was inadequate, the results of this study show that it is possible to estimate the least number of possible or similar diseases from a large number of diseases. Therefore, we conclude that there is merit in grouping classes into subgroups rather than attempting to discriminate between all classes simultaneously and that these methods are effective in identifying diseases for web-based diagnosis.