Journal of Agriculture- University of Puerto Rico (J AGR U PUERTO RICO)

Publisher: University of Puerto Rico (Río Piedras Campus). Agricultural Experiment Station

Current impact factor: 0.00

Impact Factor Rankings

2016 Impact Factor Available summer 2017
2011 Impact Factor 0
2010 Impact Factor 0.023
2009 Impact Factor 0.077
2008 Impact Factor 0.204
2007 Impact Factor 0.037
2006 Impact Factor 0.047
2005 Impact Factor 0.028
2004 Impact Factor 0.116
2003 Impact Factor 0.156
2002 Impact Factor 0.044
2001 Impact Factor 0.083
2000 Impact Factor 0.041
1999 Impact Factor 0.089
1998 Impact Factor 0.085
1997 Impact Factor 0.04
1996 Impact Factor 0.098
1995 Impact Factor 0.04
1994 Impact Factor 0.022
1993 Impact Factor 0.011
1992 Impact Factor 0.047

Impact factor over time

Impact factor

Additional details

5-year impact 0.07
Cited half-life >10.0
Immediacy index 0.00
Eigenfactor 0.00
Article influence 0.03
Other titles The Journal of agriculture of the University of Puerto Rico, Journal of agriculture of University of Puerto Rico
ISSN 0041-994X
OCLC 2449950
Material type Government publication, Periodical, State or province government publication
Document type Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Municipal sewage sludge compost (MSC) is used as an alternate peat media in ornamental plants. Ornamental producers have demonstrated skepticism toward the use of MSC as a substratum because they understand it may contain pathogenic microorganisms. The objective of this study was the identification of fungi in MSC obtained from the compost plant of the Acueducts and Sewage Authority in Mayagüez, Puerto Rico. The samples were obtained from different piles. The treatments were four samples of MCS and one control, 100% peat, replicated three times. Serial dilutions from 10-1 to 10-4 were developed by means of 10 g of each treatment. The medium Ohio was used to grow fungi at 28 and 45° C. For each treatment of MSC and peat, fungi growth was observed at 28° C; at 45° C growth was observed only in the control. Three colonies were selected at random from petri dishes; 21 species of fungi were identified from genus: Aspergillus sp., Conidiobolus sp., Curvularia sp., Mucor sp., Penicillium sp., Rhizopus sp., Trichoderma sp., and Scopulariopsis sp. The fungi identified in MSC were classified as saprophytic and antagonistic. Aspergillus fumigatus Fresen, a species reported as a human pathogen, was identified in peat.
    No preview · Article · Oct 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: To evaluate the effects on litter size and expression of vascular endothelial growth factor (VEGF) and of uteroferrin, crossbreed gilts (n = 24) were supplemented with 0 or 60 mg daily of riboflavin during gestation. Litter size and average weight of piglets were determined at birth and at weaning. Samples of placenta were collected at farrowing to determine the relative expression of VEGF and uteroferrin. Supplemented and not supplemented gilts had 11.2 ± 0.6 and 8.2 ± 0.6 of total piglets born, respectively (P < 0.004). There were also corresponding increases in piglets born alive with 10.5 ± 0.6 versus 8.1 ± 0.6 (P < 0.01) and in total piglets weaned by the gilts supplemented with riboflavin (9.41 ± 0.6 and 7.5 ± 0.6, P < 0.05). A difference between treatments was found for total litter weight at birth, but not at weaning. Relative expression of VEGF was greater (P < 0.07) in the placenta of gilts supplemented with riboflavin than in those not supplemented, but no differences between treatments were observed in the relative expression of uteroferrin. The present results demonstrate that daily supplementation with 60 mg of riboflavin to gilts during gestation may increase litter size, perhaps by improving vascularization of the placenta, thus enhancing embryo/fetus survival.
    No preview · Article · Oct 2014 · Journal of Agriculture- University of Puerto Rico

  • No preview · Article · Oct 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: An experiment consisting of two periods (P1 and P2) was conducted to determine the effect of adding a probiotic of bacterial strains of Bacillus subtilis and B. licheniformis to a basal diet of low quality grass hays on voluntary consumption (VC) and digestibility. Ten Creole lambs were randomly assigned to one of two treatments: control (without additive) or probiotic (with additive in diet). The basal diet consisted of a daily forage offering equal to 4% of live weight (LW) on a dry matter (DM) basis. The forage offered was 50% native grass hay [71.7% neutral detergent fiber (NDF), 4.9% crude protein (CP) in P1; and 71.2% NDF, 5.4% CP in P2], and 50% of Hyparrhenia rufa hay (78.8% NDF, 3.5% CP in P1; and 75.6% NDF, 5.5% CP in P2). The lambs were supplemented with 225 g of commercial concentrate (CC) daily. The additive was mixed with the CC to supply 1.33 × 108 cfu/head daily during the 49 days of P1. From day 50 to 84 (P2), the probiotic addition was suspended to determine possible residual effects. The lambs were weighed weekly. The VC and digestibility of DM, NDF and CP were determined from day 42 to 49 in P1 and from day 77 to 84 in P2. The variables related to parasitism and anemia: fecal egg count (FEC), FAMACHA® index score and packed cell volume (PCV) were determined every 21 days. Data from each experimental period were analyzed according to a completely randomized design with five replicas per treatment. During P1, the daily LW gain of the lambs was 23 vs. 20 g for control and probiotic treatments, respectively. The dietary addition of probiotic increased (p < 0.05) total DM intake (445 vs. 484 g/d), DM intake as a percentage of LW (2.04 vs. 2.37) and forage DM as a percentage of total DM intake (54.77 vs. 59.42). The digestibility coefficients of DM (59.98 vs. 62.62%) and CP (59.35 vs. 61.76%) did not differ between treatments, but there was a tendency (p = 0.09) to improve NDF digestibility (58.71 vs. 62.48%) with probiotic addition. The FEC observed in the control and probiotic groups were 820 vs. 1, 380 eggs/g initially and increased more in the control (p < 0.05) to 2, 390 vs. 2, 780 eggs/g at day 21, then decreased less in this group to 1, 830 vs. 1, 480 eggs/g at day 42. The PCV values changed between days 0 and 42 from 24.4 to 17.9% in the control and from 20.6 to 22.6% in the probiotic group, but without significant effects (p > 0.05). The anemia level according to FAMACHA® score differed little between treatments and did not exceed a maximum of 2.6. During P2, the LW gain of the lambs of both control and previously probiotic treated groups was 48 g/d. Total DM intake was 587 vs. 562 g/d and digestibilities were: DM (58.46 vs. 57.59%), NDF (57.50 vs. 56.85%) and CP (60.78 vs. 62.11%) without significant differences (p > 0.05). The FEC decreased progressively to respective final values at 84 days of 1, 230 vs. 440 eggs/g, whereas the PCV increased to 23.4 vs. 25.1% at day 84 without significant differences. The maximum FAMACHA® score was 2.8 vs. 2.2 in the two respective treatments. In summary, the addition of the probiotic in the diet improved VC and tended to increase NDF digestibility, but did not affect growth, even though there were signs of animal health benefiting. After suspending the use of the additive, no residual effect on the variables evaluated was observed.
    No preview · Article · Oct 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: This study was divided into two parts. In the first part, data were collected from 57 sheep and 28 goats from different origins and slaughtered in abattoirs in the western region of Puerto Rico to develop a database of the carcass characteristics of small ruminant (SR) raised under traditional feeding management. The second part consisted of a feeding trial in which weaned lambs (n = 6) and kids (n = 6) were randomly assigned within species to one of two feeding regimes: with or without daily commercial concentrate (CC) supplementation, at the rate of 0.9% of body weight (BW) on a dry basis, to grazing native tropical grasses. Treatment effects on body weight gain, carcass characteristics, and meat quality were evaluated. The database on carcass characteristics of SR slaughtered commercially showed highly variable dressing percentages ranging from 37 to 46%, and 32 to 38% for sheep and goat, respectively, both species having similar (P > 0.05) average values. No differences were observed in dressing percentages between the sexes. Supplementation with CC increased (P < 0.05) total and daily BW gain in lambs by 2, 580 and 40 g, respectively, when compared to the non-supplemented controls. In kid-goats, BW gains with supplementation were appreciably, but not significantly greater (P > 0.05) than without supplementation. Dressing percentage, and fore and hind trunk percentages did not vary (P > 0.05) between treatments for either species. There were no differences (P > 0.05) in pH, moisture, crude protein, and fat percentages of longissimus muscle between treatments in either species. This research revealed the need to develop a local grading system to standardize the meat and improve its quality. Similarly, genetic selection of animals as well as research on alternative less-expensive feed resources for finishing meat-type animals are necessary to improve quantity and quality of local small ruminant meat (SRM).
    No preview · Article · Oct 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: This study evaluated two treatments based on addition of two commercial microbial Inoculants of lactic acid-producing bacteria (LAPB), one of the homolactic type (HOT) and the other a combination of homolatic with heterolactic bacteria (HHT), plus a control treatment without inoculation (CNT), on the fermentative characteristics of tropical maize In micro-silos and aerobic stability (AS) of the resulting silage. The fermentative characteristics were determined in triplicate samples taken at various lengths of fermentation (15, 30, 58 and 90 d), which were analyzed for pH, concentration of organic acids and NH3. To evaluate AS, changes in pH and temperature of the silage were monitored during five days of exposure to air. No significant differences were found among treatments In any of the fermentation characteristics studied. HOT resulted In the numerically lowest average pH (4.23) and the highest average percentage content of lactic acid (2.18), followed by HHT (4.28 and 2.11) and CNT (4.32 and 1.94), respectively. Also, regarding indicators of AS there were no significant differences among treatments, but numerically the average pH of exposed HOT silage was lower (5.30 vs 5.43 the average value of both HHT and CNT) and there was a trend (P <0.15) toward lower average temperature (°C) In favor of HHT (29.61 vs. 30.26 and 30.28 for HOT and CNT silages). In general, the use of LAPB inoculants in tropical maize silage did not result in large differences relative to non-inoculated silage in the variables under study regarding fermentation characteristics and AS.
    No preview · Article · Jan 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: The objective of this study was to evaluate the effect of two additives: one of enzymatic nature [Dyadic® Cellulase PLUS (ENZ)] and liquid urea nitrogen (LU) on crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), voluntary intake (VI) and digestibility of treated bluestem grass (BGH; Dichanthlum annulatum) hay fed to rams. Nine young rams were used in a 3×3 latin square design with the three treatments: BGH without additive (CON), and with added ENZ or LU. The additives were sprinkled over the hay 24 hours prior to being offered daily at the rate of 4% of the animal body weight (BW). Application of ENZ resulted In no important change In VI or digestibility of dry matter (DM), CP, NDF or ADF; but ENZ tended to slightly reduce (p <0.11) NDF content (73.91 vs. 74.27%), and increase (p < 0.09) ADF content (44.37 vs. 42.87%). Treatment of BGH with LU Increased (p < 0.01) the content of CP (8.11 vs. 6.41%), tended to depress (p <0.11) that of NDF (73.00 vs. 74.27%) and Increase (p < 0.09) those of ADF (43.17 vs. 42.87%) and lignin (6.30 vs. 5.89%). It also Increased VI of CP (87.46 vs. 67.25%) and tended (p < 0.06) to increase VI of DM (1027 vs. 986 g) and CP digestibility (61.11 vs. 53.98%). Daily VI of DM as a percentage of BW was not significantly affected by the treatments (3.13, 2.94 and 3.23% for CON, ENZ and LU, respectively).
    No preview · Article · Jan 2014 · Journal of Agriculture- University of Puerto Rico

  • No preview · Article · Jan 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: Limited research has been completed on the root rot complex of common bean (Phaseolus vulgaris L.) In the Caribbean, while yield losses of over 50% due to root rot disease have been reported worldwide. In this study, the predominant root rot pathogens in a 43-year old common bean root rot nursery in Isabela, Puerto Rico, were identified using standard and molecular diagnostic techniques over four planting periods. Evaluations were conducted from Dec. 2009 to Sept. 2012. The most prevalent fungi Identified were Fusarium solanl, causal agent of, Fusarium root rot; Macrophomlna phaseollna, causal agent of charcoal rot; and Sclerotlum rolfsll, which causes southern blight. Pythlum aphanldermathum and Pythlum gramlnlcola were also identified during the 2012 evaluation, which cause damping-off and root rot. Other fungi, such as Rhizoctonla solanl, were isolated from root and hypocotyl tissue with less frequency. The incidence of the predominant soil-borne pathogens was largely correlated across seasons. Low nitrogen levels In the soil, and low nitrogen, phosphorus, potassium, and magnesium in leaf tissue were identified in the nursery and have been achieved through no application of fertilizer. Knowledge of the prevalence of soil borne pathogens and fertility conditions will be used for targeting the selection of breeding materials at the Isabeia root rot nursery and In other testing locations.
    No preview · Article · Jan 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: Eight snap bean (Phaseolus vulgaris L.) cultivars and lines were grown under an organic management system in 2011 and 2012 in Lajas, Puerto Rico. Bean genotypes used in the trial were the commercial cultivars 'Contender', 'Festina', 'Fresh Pick', 'Jade', 'Nash' and 'Provider', and two experimental breeding lines PR1018-1 and PR1018-5. In 2011, 'Provider'and PR1018-5 had the highest yields, with 11.2 and 11.1 t/ha, respectively, but these were not significantly different from the yields of 'Contender', 'Festina', PR1018-1 or 'Nash'. 'Jade' had the lowest yield, with 6.5 t/ha. In 2012, the highest yielding cultivar was 'Festina', with 14.6 t/ha, which was not significantly different from 'Nash' (13.8 t/ha), PR1018-5 (12.6 t/ha) or 'Jade' (12.5 t/ha). 'Contender' (9 t/ha), 'Provider' (8.4 t/ha) and 'Fresh Pick' (8.4 t/ha) had the lowest yields. This study has shown that snap beans can be successfully grown in Puerto Rico under an organic management system, with yields similar or superior to conventionally produced snap beans.
    No preview · Article · Jan 2014 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: Citrus Greening (CG) caused by a phloem restricted bacteria, Candidates Liberibacter asiaticus (Ca. L. asiaticus), is one of the most devastating diseases of citrus worldwide. The disease dramatically affects the production of citrus trees. Following the detection of CG In Puerto Rico, a survey was conducted from February 2011 to March 2012 to determine the dissemination of the pathogen. Twenty orchards and seven nurseries located in the central mountain region, southern coast, northern and northwestern region of the island were sampled. Symptomatic and asymptomatic plants were collected and processed at the plant disease clinic of the University of Puerto Rico (UPR) Agricultural Experiment Station In Juana Diaz, Puerto Rico. A total of 345 samples were analyzed by Polymerase Chain Reaction using primers OH and OI2. Citrus Greening was detected in only 7.0% of the symptomatic samples collected in eight orchards covering an area of 235 hectares in the municipalities of Adjuntas, Anasco, Cabo Rojo, Coamo, Dorado, Juana Diaz, Las Marias and Santa Isabel. In 42 samples negative for Ca. L. asiaticus, two additional diseases were tested by serological methods: Citrus Tristeza Virus (CTV) and Citrus Variegated Chlorosis (CVC). Both diseases were detected: CVC in a sample from dales, CTV in 41 samples from various municipalities. Regular screening of Ca. L. asiaticus in orchards and nurseries, vector control strategies and removal of CG infected trees should be implemented to protect the citrus industry on the island.
    No preview · Article · Dec 2013 · Journal of Agriculture- University of Puerto Rico
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    ABSTRACT: Soils are being degraded around the world as a consequence of climate change, intensive cropping and inappropriate land management. These actions cause soil erosion and topsoil depletion. Eroded and bare soil is exposed to environmental pressures, which can increase its organic matter loss via CO2 release. The use of compost provides organic matter that can associate with clays acting as a cementing agent forming soil aggregates and preserving good chemical and physical soil qualities that can avoid soil degradation. The quality of soils is reduced as soil organic carbon decreases leading to decreasing crop yields. Depletion of soil organic matter impairs soil physical, chemical and biological properties. Organic matter buffers soil pH in some tropical soils. Organic matter has a buffering capacity. Acid soils tend to increase its pH, while alkaline soils tend to decrease it. The buffering effect is greater when the organic matter has a high concentration of humic acids. Soil exposure to environmental pressures can render nutrient deprived soils. When soils are weatherized hydrogen ions replace the exchangeable cations, Ca, Mg, K, Na, in its CEC hence decreasing the pH of the soil. Lower pH may increase the soils capacity to fix P into an unavailable form and cause aluminum toxicity, along changing physical qualities such as increasing low porosity and bulk density. A 2% SOC has been suggested as minimum level for proper soil-environmental and -agronomic conditions. At 0 to 30-cm depth, some Puerto Rican soils have less than 7.2 kg C/m2, equivalent to 2% SOC when soil bulk density is 1.2 Mg/ha. The reduction of soil organic matter could impede agricultural activity.
    No preview · Article · Dec 2013 · Journal of Agriculture- University of Puerto Rico