YIELD EFFICIENCY IN PROGENY TRIALS WITH COCOA

2006 ◽  
Vol 42 (3) ◽  
pp. 289-299 ◽  
Author(s):  
JOE THAU-YIN PANG

Yield efficiency of cocoa, defined as yield over a period of time divided by the increment in trunk cross-sectional area over that period, was estimated in four factorial matings in Sabah, Malaysia, evaluated at a single planting density. The parents were 18 seedlings of Upper Amazon Forastero type, broadly representative of Peruvian Amazon material, and 15 clones of Trinitario type, selected from cultivated cocoa in Ecuador, Trinidad and Papua New Guinea. Both the Upper Amazon and Trinitario parents varied in general combining ability (gca) for yield efficiency, with strong evidence of additive inheritance of the trait. Some of the Upper Amazon parents showed higher yield efficiency than many of the Trinitarios. Correlations between gcas for yield efficiency and yield were inconsistent. This is thought to be because the parents differed markedly in optimal planting density, which is higher for many of the Upper Amazons with high gca for yield efficiency than it is for some of the Trinitarios. At the current stage of cocoa breeding, selection for adaptation to planting density is a higher priority than selection for yield efficiency.

2019 ◽  
Vol 64 (2) ◽  
pp. 165-174
Author(s):  
Dragan Milatovic ◽  
Mirjana Radovic ◽  
Gordan Zec ◽  
Djordje Boskov

The paper examines the influence of three clonal rootstocks ('Pixy', 'Fereley' and 'St. Julien A') along with seedlings of Myrobalan (control) on the growth, yield and fruit quality of the plum cultivar 'Cacanska Rana'. Research was conducted in the area of the Belgrade Danube basin for the six-year period (2013-2018). In comparison to control, all three clonal rootstocks have shown a significant effect on the decrease of vigor expressed as a trunk cross-sectional area. The lowest vigor was found in trees on the 'Pixy' rootstock, then on 'Fereley' and 'St. Julien A' rootstocks. Regarding the rootstocks 'Fereley' and 'St. Julien A', significantly higher fruit set and yields were achieved in comparison to control. Clonal rootstocks induced an increase in the yield per hectare ranging from 72% to 93% compared to Myrobalan. The highest yield efficiency was found in the trees on the 'Fereley' rootstock, followed by the yields observed in the trees on the 'Pixy' and 'St. Julien A' rootstocks. Significantly higher fruit weight compared to control was obtained in the trees on the 'Fereley' rootstock. Rootstocks did not show any significant effect on the soluble solids and total acid contents of the fruit. Based on the results obtained, it can be concluded that all three clonal rootstocks showed better results than Myrobalan, and can be recommended for establishing intensive plum plantations with higher planting density. The best results in terms of yield and fruit quality were obtained with the 'Fereley' rootstock.


1995 ◽  
Vol 120 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Richard H. Zimmerman ◽  
George L. Steffens

Tissue-culture (TC)-propagated `Gala' and Triple Red `Delicious' apple trees grown at three planting densities were not treated (CON) or treated with plant growth regulators (PGRs) starting the third or fourth season to control tree size and maximize fruiting. `Gala' and `Delicious' trees budded on M.7a rootstock (BUD) were also included as controls. `Gala' trees were larger than `Delicious' after the first three growing seasons but `Delicious' were larger than `Gala' at the end of 9 years. BUD trees were larger than CON trees the first few seasons hut final trunk cross-sectional area (TCSA) of CON trees averaged 43% greater than BUD trees. Paclobutrazol and uniconazole treatments more readily controlled the growth of `Gala' than `Delicious' and uniconazole was more effective than paclobutrazol in controlling tree size. Daminozide + ethephon sprays (D+E-S) did not influence tree size. Tree size of both cultivars was inversely related to planting density and both triazole PGRs were more effective in controlling tree size as planting density increased. The trees had fewer flowers as planting density increased and BUD trees generally had more Bowers than CON. Triazole PGRs had little effect on the flowering pattern of `Gala' trees but tended to stimulate flowering of young `Delicious' TC trees, although the increases were not sustained. The D+E-S treatment increased flowering of `Gala' trees the last 3 years of the experiment and consistently increased flowering of `Delicious' TC trees. Fruit yields were higher for young `Gala' compared to `Delicious' trees and the final cumulative yield per tree for `Gala' was also greater. Yield per tree decreased as tree density increased and was the same for BUD and CON trees. D+E-S increased cumulative per tree yield of `Delicious' but not of `Gala'. Cumulative yields per tree for triazole-treated TC trees were the same as, or significantly lower than, CON trees. Increasing tree density did not increase yield/ha. Yield efficiency of `Gala' trees was increased by three, and of `Delicious' trees by one, of the triazole treatments, because they reduced TCSA proportionally more than they reduced per tree yield. There was less bienniality with `Gala' than `Delicious' and no difference between BUD and CON trees. Bienniality indices were higher for paclobutrazol-treated `Gala' trees compared with CON `Gala' but only uniconazole applied as a trunk paint increased the bienniality index of `Delicious' trees. Chemical names used: succinic acid-2,2-dimethyl hydrazide (daminozide), (2-chloroethyl) phosphonic acid (ethephon), (2RS,3RS)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)pentan-3-01 (paclobutrazol), (E)-(l-chlorophenyl)-4,4-dimethyl-2-(I,2,4-triazol-l-yl)-1-penten-3-ol (uniconazole).


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 282
Author(s):  
Elizabeth Villasis ◽  
Katherine Garro ◽  
Angel Rosas-Aguirre ◽  
Pamela Rodriguez ◽  
Jason Rosado ◽  
...  

The measurement of recent malaria exposure can support malaria control efforts. This study evaluated serological responses to an in-house Plasmodium vivax Merozoite Surface Protein 8 (PvMSP8) expressed in a Baculovirus system as sero-marker of recent exposure to P. vivax (Pv) in the Peruvian Amazon. In a first evaluation, IgGs against PvMSP8 and PvMSP10 proteins were measured by Luminex in a cohort of 422 Amazonian individuals with known history of Pv exposure (monthly data of infection status by qPCR and/or microscopy over five months). Both serological responses were able to discriminate between exposed and non-exposed individuals in a good manner, with slightly higher performance of anti-PvMSP10 IgGs (area under the curve AUC = 0.78 [95% CI = 0.72–0.83]) than anti-PvMSP8 IgGs (AUC = 0.72 [95% CI = 0.67–0.78]) (p = 0.01). In a second evaluation, the analysis by ELISA of 1251 plasma samples, collected during a population-based cross-sectional survey, confirmed the good performance of anti-PvMSP8 IgGs for discriminating between individuals with Pv infection at the time of survey and/or with antecedent of Pv in the past month (AUC = 0.79 [95% CI = 0.74–0.83]). Anti-PvMSP8 IgG antibodies can be considered as a good biomarker of recent Pv exposure in low-moderate transmission settings of the Peruvian Amazon.


2009 ◽  
Vol 66 (2) ◽  
pp. 204-209 ◽  
Author(s):  
Leonardo Oliveira Medici ◽  
Salete Aparecida Gaziola ◽  
Vanderlei Aparecido Varisi ◽  
José Antonio Carmezini de Paula ◽  
Renato Rodrigues Ferreira ◽  
...  

Six S5 lines of maize, with differences for lysine and oil contents in grains, were used to carry out a complete series of diallelic crosses. The resulting 15 hybrids were grown in a field at two nitrogen levels (10 and 130 kg N ha-1). The general combining ability (GCA) and specific combining ability (SCA) were obtained by using the method 4, model I of Griffing for grain yield, and grain lysine and oil contents. Significant (p < 0.001) interaction was observed between GCA and N levels for grain yield, indicating the selection of different lines for each N level. This interaction was not significant for lysine content, but there were significant effects of GCA for this trait at both N levels (p < 0.1). Significant effects were not observed for GCA or SCA for oil content, however a positive correlation was observed between lysine and oil contents in the hybrids, in the lines and even in the control cultivars. The results indicate the effectiveness of selection for lysine content, irrespective of N level, in the studied non-opaque maize lines, and the possibility of achieving both high lysine and oil content in grains.


PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0249653
Author(s):  
Agricola Odoi ◽  
Ronita Samuels ◽  
Craig N. Carter ◽  
Jackie Smith

Background Inappropriate antimicrobial use (AMU) is a global concern. Opinions of veterinarians regarding AMU and its role in the development of antimicrobial resistance (AMR) may influence their prescription practices. It is important to understand these opinions, prescription practices and their potential impact on the development of AMR in order to guide efforts to curb the problem. Therefore, the objective of this study was to investigate the antimicrobial prescription practices and opinions of veterinarians in Kentucky regarding AMU and AMR. Methods This cross-sectional study used a 30-question survey questionnaire administered to veterinarians who were members of the Kentucky Veterinary Medical Association. Survey responses from 101 participants were included in the study. Descriptive statistics were computed and associations between categorical variables assessed using Chi-square or Fisher’s exact tests. Firth logistic models were used to investigate predictors of “Compliance with prescription policies” and “Cost of antimicrobial affects prescription decisions”. Results Almost all (93%) respondents indicated that improper AMU contributed to selection for AMR. A total of 52% of the respondents believed that antimicrobials were appropriately prescribed, while the remaining 48% believed that antimicrobials were inappropriately prescribed. Significant predictors of compliance with prescription policies were availability of prescription policy at the veterinary facility (Odds Ratio (OR) = 4.2; p<0.001) and over-prescription (OR = 0.35; p = 0.025). Similarly, significant predictors of cost of antimicrobials affecting prescription decisions were lack of post-graduate training (OR = 8.3; p = 0.008) and practice type, with large animal practices having significantly lower odds of the outcome (OR = 0.09; p = 0.004) than small animal practices. Conclusion Most veterinarians indicated that improper AMU contributed to selection for AMR. Since the odds of compliance with prescription policies were 4-times higher among veterinarians working at facilities that had prescription policies compared to those at facilities that didn’t, more veterinary facilities should be encouraged to adopt prescription policies to help improve compliance and reduce AMR. Veterinarians would also benefit from continued professional education to help improve prescription practices, antimicrobial stewardship and curb AMR.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Naoko Yoshida ◽  
Masato Yamauchi ◽  
Ryosuke Morikawa ◽  
Francis Hombhanje ◽  
Toshihiro Mita

Abstract Background The C580Y mutation in the Plasmodium falciparum kelch13 gene is the most commonly observed variant in artemisinin-resistant isolates in the Greater Mekong Subregion (GMS). Until 2017, it had not been identified outside the GMS, except for Guyana/Amazonia. In 2017, three parasites carrying the C580Y mutation were identified in Papua New Guinea (PNG). As the C580Y allele rapidly spread in the GMS, there is concern that this mutant is now spreading in PNG. Methods In 2020, a cross-sectional survey was conducted at two clinics in Wewak, PNG. Symptomatic patients infected with P. falciparum were treated with artemether plus lumefantrine following a national treatment policy. Blood samples were obtained before treatment, and polymorphisms in kelch13, pfcrt, and pfmdr1 were determined. Parasite positivity was examined on day 3. The results were compared with those of previous studies conducted in 2002, 2003, and 2016–2018. Results A total of 94 patients were included in this analysis. The proportion of C580Y was significantly increased (2.2% in 2017, 5.7% in 2018, and 6.4% in 2020; p = 4.2 × 10–3). A significant upward trend was observed in the wild-type proportion for pfcrt (1.9% in 2016 to 46.7% in 2020; p = 8.9 × 10–16) and pfmdr1 (59.5% in 2016 to 91.4% in 2020; p = 2.3 × 10–6). Among 27 patients successfully followed on day 3, including three with C580Y infections, none showed positive parasitaemia. Conclusions Under the conditions of significant increases in pfcrt K76 and pfmdr1 N86 alleles in PNG, the increase in kelch13 C580Y mutants may be a warning indicator of the emergence of parasites resistant to the currently used first-line treatment regimen of artemether plus lumefantrine. Therefore, nationwide surveillance of molecular markers for drug resistance and assessment of its therapeutic effects are important.


2018 ◽  
Vol 103 (3) ◽  
pp. 338-342 ◽  
Author(s):  
Ling Lee ◽  
Fabrizio D'Esposito ◽  
Jambi Garap ◽  
Geoffrey Wabulembo ◽  
Samuel Peter Koim ◽  
...  

ObjectiveTo estimate the prevalence and main causes of blindness and vision impairment in people aged 50 years and older in Papua New Guinea (PNG).DesignNational cross-sectional population-based survey in National Capital District (NCD), Highlands, Coastal and Islands regions.MethodsAdults aged 50 years and above were recruited from 100 randomly selected clusters. Each participant underwent monocular presenting and pinhole visual acuity (VA) assessment and lens examination. Those with pinhole VA<6/12 in either eye had a dilated fundus examination to determine the primary cause of reduced vision. Those with obvious lens opacity were interviewed on barriers to cataract surgery.ResultsA total of 4818 adults were examined. The age-adjusted and sex-adjusted prevalence of blindness (VA <3/60), severe vision impairment (SVI, VA <6/60 but ≥3/60), moderate vision impairment (MVI, VA <6/18 but ≥6/60) and early vision impairment (EVI, VA <6/12 but ≥6/18) was 5.6% (95% CI 4.9% to 6.3%), 2.9% (95% CI 2.5% to 3.4%), 10.9% (95% CI 9.9% to 11.9%) and 7.3% (95% CI 6.6% to 8.0%), respectively. The main cause of blindness, SVI and MVI was cataract, while uncorrected refractive error was the main cause of EVI. A significantly higher prevalence of blindness, SVI and MVI occurred in the Highlands compared with NCD. Across all regions, women had lower cataract surgical coverage and spectacle coverage than men.ConclusionsPNG has one of the highest reported prevalence of blindness globally. Cataract and uncorrected refractive error are the main causes, suggesting a need for increased accessible services with improved resources and advocacy for enhancing eye health literacy.


2019 ◽  
Vol 97 (8) ◽  
pp. 3199-3212
Author(s):  
Paul L Greenwood ◽  
Brendon A O’Rourke ◽  
Joe Brunner ◽  
William H Johns ◽  
Paul F Arthur ◽  
...  

Abstract This study assessed cellular characteristics of longissimus lumborum (LL) and semitendinosus (ST) muscles in steers genetically selected for low (Low) or high (High) muscling using live muscle scoring, and High steers with 1 copy of the loss-of-function 821 del11 MSTN allele (HighHet). We hypothesized High and HighHet have altered muscle cellular characteristics and mechanisms influencing muscling compared with Low steers. Angus steers 25 mo old comprising 14 High, 19 Low, and 11 HighHet were backgrounded to 20 mo of age, grain finished for 150 d, and then slaughtered. Body and carcass weights did not differ due to muscling line (P = 0.46). Weight of LL was 16% greater (P = 0.004) and total protein in LL was 18% greater (P = 0.012) in HighHet than Low steers. ST weight in HighHet was 10% and 13% greater than in High and Low steers (P = 0.007), respectively, and of total ST protein 12% and 17% greater in HighHet than High or Low (P = 0.002). Cross-sectional area (CSA) of LL was greater in HighHet than in High and greater in High than in Low (85.0 vs. 77.0 vs. 70.4 cm2, P < 0.001). Apparent number of myofibers and myofibers per unit CSA did not differ between the muscling lines in LL (P = 0.14) or ST (P = 0.47). Myofiber CSA was greater in the ST of Low than of High and HighHet for type 1 (36% and 31% respectively, P = 0.005) and 2A (22% and 25%, P < 0.001). HighHet steers had greater area of glycolytic (type 2X) relative to more oxidative myofiber types within LL (P = 0.02; 11% and 43% more than High and Low, respectively) and ST (P < 0.001; 27% and 75%). Concentration of RNA in LL was 13% and 10% greater (P = 0.005) in High than in Low and HighHet, respectively, and total amount of RNA in LL was 22% greater in High and 20% greater in HighHet than in Low (P < 0.001). The LL of High steers had less protein to RNA (P = 0.03; 57.4 vs. 65.6) and more RNA to DNA (P = 0.007; 9.03 vs. 7.83) than Low. HighHet steers had 11% more DNA in ST than High (P = 0.04) and 19% more RNA in ST than Low (P = 0.012). The shift towards glycolytic myofibers was consistent with loadings in a principal component that explained 39% of the variation in LL and 38% in ST. Overall, these findings show that selection for increased muscling using live cattle muscle scoring, and 1 copy of the 821 del11 MSTN allele, results in more glycolytic muscle. They also suggest that increased muscling of the High compared with Low steers may be associated with increased translational capacity in the LL.


Pathogens ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 348
Author(s):  
Sonia Ortiz-Martínez ◽  
José-Manuel Ramos-Rincón ◽  
María-Esteyner Vásquez-Chasnamote ◽  
Jhonatan Alarcón-Baldeón ◽  
Jorge Parraguez-de-la-Cruz ◽  
...  

Strongyloidiasis is a soil-transmitted helminthiasis with a high global prevalence. Objectives: We aimed to evaluate the prevalence of Strongyloides stercoralis infection and assess strongyloidiasis serology as a screening technique in the Peruvian Amazon. Material and Methods: We performed a cross-sectional study of strongyloidiasis in 300 pregnant women in Iquitos (Peru) from 1 May 2019 to 15 June 2019. Women were tested using serology (Strongyloides IgG IVD-ELISA kit) as an index test and the modified Baermann technique and/or charcoal fecal culture as the parasitological reference standard. Results: The reference tests showed S. stercoralis in the stool of 30 women (prevalence: 10%; 95% confidence interval [CI] 7.1% to 13.9%), while 101 women tested positive on the blood test (prevalence: 33.7%; 95% CI 28.6% to 39.4%). Fourteen of the 15 women (93.3%) with positive results according to the modified Baermann technique, and 14 of the 23 women (56.5%) with positive charcoal cultures also had positive serological results. Serology showed a sensitivity of 63.3% and a negative predictive value of 94.4%. Conclusion: In Iquitos, pregnant women have a high prevalence of S stercoralis. S. stercoralis ELISA could be an excellent tool for population-based screening, as it has a high negative predictive value that can help to rule out the presence of active infection.


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