Journal of Agriculture- University of Puerto Rico Impact Factor & Information

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

Current impact factor: 0.00

Impact Factor Rankings

2015 Impact Factor Available summer 2016
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: 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.
    Journal of Agriculture- University of Puerto Rico 12/2013; 97(1).
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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.
    Journal of Agriculture- University of Puerto Rico 12/2013; 92(3-4):117-132.
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    ABSTRACT: We report results from a survey of palm-associated Fulgoroidea (planthoppers), following the recent discoveries of Haplaxlus crudus, a known palm phytoplasma vector, and of other potential planthopper vectors In Puerto Rico. The survey, which sampled from 40 sites, resulted in the identification of 30 morpho-species belonging to eight Fulgoroidea families. The 10 most common species accounted for 93.9% of individuals, whereas near one third (n = 9) of the species were represented by single individuals. Derbids and cixiids accounted for 90% of collected Individuals. The most common species were the derbids Cedusa Inflata (Ball) and Omollcna puertana Caldwell, while the most common cixiids were Bothrlocera undata (F.) and Ollarus complectus Ball; and the most common flatids were Petrusa epllepsls (Kirkaldy) and Melornemls antillarum (Kirkaldy). Three species are new records for Puerto Rico: the cixiids Haplaxlus crudus Van Duzee and Nymphomyndus carlbbaea (Fennah), and the derbid Neocenchrea nr. pallida Metcalf. Impact of polyphagy and of abundance-diversity patterns of this planthopper guild on phytoplasma epidemiology are briefly discussed.
    Journal of Agriculture- University of Puerto Rico 01/2013; 97(3-4):107-117.
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    ABSTRACT: The Jobos Bay National Estuary Research Reserve (JBNERR) in Salinas, Puerto Rico, serves as sink for many anthropogenic substances that may affect the quality of the soil and water and the integrity of the biota. Six transects were established in the southeast part of JBNERR for interstitial water collection. In addition, soil samples were collected along transect II, which was affected by runoff from a road closer to the Salinas landfill. The concentration of lead (Pb) in interstitial water from the above mentioned transects ranged between 0.07 and 0.68 mg/L; chromium (Cr) concentration ranged between 0.03 and 0.24 mg/L; and manganese (Mn) concentration ranged between 0.35 and 15.25 mg/L. The total Pb in soil samples ranged between 57 and 776 μg/g in an uneven distribution along transect II. The low Pb concentrations in water in comparison to that in soil indicate the high capacity of the JBNERR soils to serve as sink for heavy metals. The linear correlation between Pb concentrations in the interstitial water and the electrical conductivity indicates that marine water intrusion increases Pb dissolution from soils. Also detected in interstitial water were anthropogenic organic compounds such as benzothiazole, 1-methyl-2-pyrrolidinone and tert-butyl phenol; however no residues of agricultural pesticides used in nearby farms were found. Results have shown that human activities have affected soil and water quality in the JBNERR.
    Journal of Agriculture- University of Puerto Rico 01/2012; 96(1-2):23-25.
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    ABSTRACT: For fresh market, sweet potato (Ipomea batatas (L) Lam) quality is defined in terms of attractiveness, sweetness, texture, and flavor composed of taste and odor after cooking. There is a scarcity of information regarding taste and volatiles of tropical type sweet potatoes. A three-harvest study was conducted to identify and determine major carbohydrate content, alcohol insoluble solids (AIS), starch granule diameter and form, and tastes and odors of six sweet potato varieties among very sweet (Gem), sweet (Miguela and Travis), moderate sweet (Viola and Martina) and non sweet (Ninetynine). The average alcohol insoluble solids (AIS) content were 81, 77, 79, 85, 66 and 76 % for Martina, Miguela, Ninetynine, Viola, Gem and Travis varieties, respectively. Scanning electron micrograph (SEM) indicated that the average starch granule’s diameters were 12.9, 15.3, 16.9 and 25.2 μm for Martina, Miguela, Ninetynine and Viola types, respectively. In addition all of the sweet potato starch granules had both spherical and polygonal granules. The varieties with highest change in AIS and maltose content (raw vs. baked) were Gem, the sweetest, and Travis. Correlation between sucrose index (SI) and AIS for baked samples was 0.956, and for AIS and sweetness correlation was0.823. Similar correlation between the AIS and maltose was obtained for the data in the three harvests (-0.8493). Fifty volatile organic compounds of baked sweet potatoes were trapped in cold methylene chloride. The predominant volatiles were hexanal, 3-pente-2-ol, and isoledene. Other sweet aromas such as 2,4-decadienal, 2-pentyl furan, benzaldehyde, 4-methyl-4-hydroxy-2-pentanone and benzene acetaldehyde were detected. The great differences in relative concentrations of volatiles among varieties seem to be related to the synthesis of the maltose and the content of AIS.
    Journal of Agriculture- University of Puerto Rico 01/2012; 96(3-4):183-197.
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    ABSTRACT: Maize (Zea mays L.) inbred seed production fields on the southern semiarid coast of Puerto Rico are usually fallow each year from May to September. Inbreds have lower seed yields than single-cross hybrids, yet producers tend to apply high fertilizer nitrogen (N) levels In efforts to increase yields. Inbred maize response to fertilizer-N was evaluated on the southern semiarid coast of Puerto Rico In a cover crop-maize cropping sequence in 2009, and in a fallow-maize sequence in 2010 in a Fluventic Haplustoll. In general, maize produced after a legume cover crop of velvetbean (Mucuna prurience) or cowpea (Vigna unguiculata 'Iron Clay') had better yields and agronomic traits than maize after the fallow treatment. In 2009, maximum seed yields of 2,726 kg/ha were obtained with fertilizer-N application in the range of 112 to 224 kg N/ha. In 2010, maximum seed yields of 1,447 kg/ha were obtained with fertilizer-N application in the range of 84 to 211 kg N/ha. Harvest index was 0.26 and 0.27 in 2009 and 2010 for all fertilizer-N treatments; higher than that for unfertilized maize. In general, agronomic traits were superior as a result of fertilizer-N application without consistent differences among fertilizer-N levels applied. The SPAD chlorophyll meter, leaf color index and leaf area index were suitable indicators of N status in the maize plants. Highest N use efficiencies were observed for the 112 kg N/ha and 84 kg N/ha fertilizer levels for 2009 and 2010, respectively, and decreased with increasing fertilizer-N applied. Fertilizer-N rates in soils, climatic systems, and maize inbreds similar to the ones tested should be between 84 and 112 kg N/ha. Greater amounts of fertilizer-N will result in decreased economic benefit and potential environmental contamination.
    Journal of Agriculture- University of Puerto Rico 01/2012; 96(1):37-55.
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    ABSTRACT: Alternaria isolates were collected from onion foliage at different stages of the plant life cycle. Incidence of Alternaria species in cultivars 'Mercedes' and 'Excalibur' was determined during two consecutive growing seasons in fields located In southern Puerto Rico. Leaves showing purple to brown sunken elliptical lesions with chlorotic halos were taken at random. Five leaf sections (0.5 cm) from each sample were superficially disinfested, transferred to culture media and incubated, and Isolations were documented. Disease incidence ranged from 25 to 52% in 60- to 100-day-old plants. An increase in Alternaria incidence was observed in response to high relative humidity in the fields. A total of 280 isolates were obtained, and 35 were selected for morphological, pathogenic and molecular characterization. A complex of five different Alternarla species is associated with onion leaf blight on the island. Alternaria destruens, A. tenuissima, A. palandul, A. allii and a group of small-spore Alternaria sp., belonging to a taxonomlcally undescribed group, were identified. Sixty-two percent of selected isolates belong to this group having an A. arborescens intermediate sporulation pattern. Alternaria destruens and A. palandui have not been previously reported as associated with onions in the Caribbean or in the Western Hemisphere. Pathogenicity tests showed that A. allii, A. tenuissima and Alternaria sp. were pathogenic to onion foliage, with A. allii as the most virulent. Molecular characteristics of the isolates were determined by using the ITS of the rDNA gene. Phylogenetic relationships based on rDNA ITS sequences from Alternaria isolates and other Pleosporaceae distinguished three clades. The first clade of large filiform-beaked spores included A. allii from this study, as well as isolates from the GenBank (A. porri, A. solani, A. macrospora, A. zinniae and A. sesamicola). These formed a monophyletic group, discrete from other members of the genus. The second clade included a diverse group of smallspore Alternaria: A. tenuissima, A. alternata, A. palandui, A. destruens and Alternaria sp.; the third clade included Stemphylium spp.
    Journal of Agriculture- University of Puerto Rico 01/2011; 95(1):57-78.
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    ABSTRACT: A sooty mold disease on longan (Dimocarpus longan L.) was found on trees growing close to bodies of water in Puerto Rico. On the basis of the morphological characters the fungi associated with this disease were identified as Tripospermum porosporiferum Matsushima and T. variabile Matsushima. T. porosporiferum produced hyaline to pale brown tri or tetraradiate conidia. Conidia (40 x 6.6 µm) have four septate appendages, with a shorter two-celled axis 16 µm long. Conidia are constricted at septa. T. variabile produced pale brown, triradiate (T-shape) conidia (36 x 6.6 µm) with main axis not bent back. Conidia are constricted at septa and the shorter part of axis which is 6.39 µm long. Both organisms have been reported in Puerto Rico in decaying vegetation in bodies of water. Studies will be initiated to assess the impact of these fungi on production of trees cultivated near bodies of water where these fungi are most commonly found
    Journal of Agriculture- University of Puerto Rico 01/2010; 94(2-4):285-287.
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    ABSTRACT: FAMACHA© as a tool to detect anemia in meat goats in Puerto Rico. The FAMACHA© system (where the ocular mucous membranes of sheep and goats are classified by comparison with a laminated color chart bearing pictures of sheep conjunctivae classified into five categories ranging from the normal red, through pink to practically white in severe anemia) was developed in South Africa to detect anemia in sheep caused by gastrointestinal parasites (Haemonchus contortus) and has been validated for use in goats in South Africa and the southeastern United States, but in Puerto Rico there are few confirmatory data available. The objective of this study was to validate the FS for detecting anemia in goats under Puerto Rican conditions. The criteria used to diagnose anemia and apply antihelmintic treatment were: eye score values of 4 and 5 and packed cell volume (PCV) value ≤ 19. Sensitivity, specificity, and both negative and positive predictive values were determined. The relations between FAMACHA© score and PCV and between fecal egg counts (FEC) and PCV were determined using Pearson correlation coefficients. Sensitivity was found to be 100% and specificity 73.5%. There were 22.5% of false positive results and 15% of true positives, but there was no false negative. This indicates that all anemic animals received treatment. Predictive value of a negative result was 100% and of a positive was 62.5%. Significant correlations were found between PCV and FAMACHA© score (p= 0.0028) and between PCV and FEC (p= 0.0128), the respective correlation coefficients being -0.46 and -0.39. It is concluded that the FAMACHA is a useful tool to determine anemia in goats under local conditions.
    Journal of Agriculture- University of Puerto Rico 01/2009; 93(1-2):61-68.