Pub Date : 2021-04-05DOI: 10.46429/JAUPR.V101I1.14292
K. Domenech, Aixa Rivera, Américo Casas, M. Pagán, D. Cianzio, F. Pérez
Effects of chronological age (0, 2, 4, 6, and 8 permanent Incisors [PI]) and sex were evaluated on meat quality of the Longissimus lumborum muscle using 130 beef-type animals. Hot carcass weight (HCW), intramuscular fat (IF), pH, tenderness (WBS), color (L*, a*, and b*), water holding capacity and sensory properties (tenderness, juiciness, and general acceptance) were evaluated. Females had lower HCW (178 vs. 252 kg; P 0.05). To better understand how age and sex affect meat quality, pH variations must be addressed.
{"title":"Effect of chronological age and sex on tenderness and juiciness of beef from cattle raised in Puerto Rico","authors":"K. Domenech, Aixa Rivera, Américo Casas, M. Pagán, D. Cianzio, F. Pérez","doi":"10.46429/JAUPR.V101I1.14292","DOIUrl":"https://doi.org/10.46429/JAUPR.V101I1.14292","url":null,"abstract":"Effects of chronological age (0, 2, 4, 6, and 8 permanent Incisors [PI]) and sex were evaluated on meat quality of the Longissimus lumborum muscle using 130 beef-type animals. Hot carcass weight (HCW), intramuscular fat (IF), pH, tenderness (WBS), color (L*, a*, and b*), water holding capacity and sensory properties (tenderness, juiciness, and general acceptance) were evaluated. Females had lower HCW (178 vs. 252 kg; P 0.05). To better understand how age and sex affect meat quality, pH variations must be addressed.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":"6 1","pages":"35-49"},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75050633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-05DOI: 10.46429/JAUPR.V101I1.14290
Miguel Oliveras-Berrocales, L. Pérez-Alegría, D. Sotomayor-Ramírez
Studies were conducted in the 1950s to evaluate the degree and spatial extent of soil salinity and sodicity in the Lajas Valley in southwestern Puerto Rico. Problem areas were identified and most of these were remediated with the establishment of irrigation and drainage infrastructure, resulting in a four-fold increase in agricultural production over a 10-year period. The area is now an important agricultural region (known as the Lajas Valley Agricultural Reserve). But soil salinity and sodicity are important concerns among farmers. In this paper we used published data and re-created the spatial distribution of soil salinity and sodicity using geostatistical analysis with Geographic Information Systems (GIS). An Ordinary Kriging method was applied to map the spatial distribution of soil salinity and to classify soils in four classes: (i) Normal, (ii) Saline, (iii) Saline-Sodic, and (iv) Sodic. The original hand-drawn maps were digitized using the Georeferencing Tool in ArcGIS, guided by a recent aerial photo of the Lajas Valley. Salinity and sodicity isopleths were created using Surface Generation to map the spatial distribution and to compare the newly created data to the original maps. The relative error in aerial estimate between the old and new maps for Normal, Saline, Saline-Sodic, and Sodic surface soils was between 1 and 5 percent. The new maps developed with geostatistical analysis can predict soil problem areas with a 94% coincidence compared with the hand-drawn maps. The highest proportion of soils classified as Normal was found in the upper soil layers and the proportion of soils affected by salt and sodium increased with depth. The combination of geostatistical analysis and GIS is a cost-effective and trustworthy method for analyzing similar datasets that would otherwise be costly and involve lengthy time commitments.
{"title":"Geostatistical analysis for mapping soil salinity in the Lajas Valley Agricultural Reserve, southwestern Puerto Rico","authors":"Miguel Oliveras-Berrocales, L. Pérez-Alegría, D. Sotomayor-Ramírez","doi":"10.46429/JAUPR.V101I1.14290","DOIUrl":"https://doi.org/10.46429/JAUPR.V101I1.14290","url":null,"abstract":"Studies were conducted in the 1950s to evaluate the degree and spatial extent of soil salinity and sodicity in the Lajas Valley in southwestern Puerto Rico. Problem areas were identified and most of these were remediated with the establishment of irrigation and drainage infrastructure, resulting in a four-fold increase in agricultural production over a 10-year period. The area is now an important agricultural region (known as the Lajas Valley Agricultural Reserve). But soil salinity and sodicity are important concerns among farmers. In this paper we used published data and re-created the spatial distribution of soil salinity and sodicity using geostatistical analysis with Geographic Information Systems (GIS). An Ordinary Kriging method was applied to map the spatial distribution of soil salinity and to classify soils in four classes: (i) Normal, (ii) Saline, (iii) Saline-Sodic, and (iv) Sodic. The original hand-drawn maps were digitized using the Georeferencing Tool in ArcGIS, guided by a recent aerial photo of the Lajas Valley. Salinity and sodicity isopleths were created using Surface Generation to map the spatial distribution and to compare the newly created data to the original maps. The relative error in aerial estimate between the old and new maps for Normal, Saline, Saline-Sodic, and Sodic surface soils was between 1 and 5 percent. The new maps developed with geostatistical analysis can predict soil problem areas with a 94% coincidence compared with the hand-drawn maps. The highest proportion of soils classified as Normal was found in the upper soil layers and the proportion of soils affected by salt and sodium increased with depth. The combination of geostatistical analysis and GIS is a cost-effective and trustworthy method for analyzing similar datasets that would otherwise be costly and involve lengthy time commitments.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":"44 1","pages":"1-15"},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82283210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-05DOI: 10.46429/JAUPR.V101I1.14295
Ricardo Prieto-Prieto, E. Valencia, R. Tirado-Corbalá
The experiment consisted of two dates of planting [in September (D1) and February (D2)] of maize (Zea mays L.) DKC 67-60, to evaluate the effect of four N fertilization levels (0, 56, 112 and 185 kg/ha) and three ages at harvest [70, 77 and 84 days after planting (DAP)] on dry matter yield (DMY) of the leaves, stem, ear and of the entire plant; and as indicators of nutritive value [crude protein (CP) and neutral detergent fiber (NDF)] of harvested material prior to ensiling. In both plantings, the levels of N affected (P<0.05) DMY of leaves, stems, ears and entire plant, exhibiting both a linear and a quadratic response, and suggesting that the optimum N application rate is between 112 and 185 kg/ha. Age at harvest date affected (P<0.05) DMY of stems, ears and entire plant, but not that of the leaves. Greater DMY was observed at 84 DAP for all components. The CP concentration was greater in the forage of the first planting (D1). Increasing N application rates increased CP, but had no effect on NDF concentration. Age at harvest had no effect on CP, but progressively increased NDF. Both pH and organic acid concentrations in the silages were similar with the four N levels; all of the silages showed good fermentation characteristics.
{"title":"Nitrogen levels and age at harvest and their effects on the nutritive value and fermentative characteristics of corn (Zea mays L.)","authors":"Ricardo Prieto-Prieto, E. Valencia, R. Tirado-Corbalá","doi":"10.46429/JAUPR.V101I1.14295","DOIUrl":"https://doi.org/10.46429/JAUPR.V101I1.14295","url":null,"abstract":"The experiment consisted of two dates of planting [in September (D1) and February (D2)] of maize (Zea mays L.) DKC 67-60, to evaluate the effect of four N fertilization levels (0, 56, 112 and 185 kg/ha) and three ages at harvest [70, 77 and 84 days after planting (DAP)] on dry matter yield (DMY) of the leaves, stem, ear and of the entire plant; and as indicators of nutritive value [crude protein (CP) and neutral detergent fiber (NDF)] of harvested material prior to ensiling. In both plantings, the levels of N affected (P<0.05) DMY of leaves, stems, ears and entire plant, exhibiting both a linear and a quadratic response, and suggesting that the optimum N application rate is between 112 and 185 kg/ha. Age at harvest date affected (P<0.05) DMY of stems, ears and entire plant, but not that of the leaves. Greater DMY was observed at 84 DAP for all components. The CP concentration was greater in the forage of the first planting (D1). Increasing N application rates increased CP, but had no effect on NDF concentration. Age at harvest had no effect on CP, but progressively increased NDF. Both pH and organic acid concentrations in the silages were similar with the four N levels; all of the silages showed good fermentation characteristics.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":"7 1","pages":"79-90"},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88904037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-04-05DOI: 10.46429/JAUPR.V101I1.14296
Miguel A. García-Carrucini, Víctor Cartín Leyva, C. E. D. Jensen
Entomopathogenic fungi were isolated parasitizing coffee borer beetle (Hypothenemus hampei Ferrari) and banana weevils (Cosmopolites sordidus Germar) in different parts of the island of Puerto Rico to be identified and examined for their pathogenicity on pepper weevil (Anthonomus eugenii Cano). Fungi were isolated and purified in acidulated potato dextroseagar (PDA) in the laboratory of the Plant Disease Clinic at the Agricultural Experiment Station, Juana Diaz. Seven fungal isolates were obtained from the municipality of Comerio, and one from the municipality of Adjuntas. Morphology, DNA sequences of different genetic regions of interest, and microsatellites were used for identification of fungal isolates. Two of the eight isolates were identified as Beauveria bassiana, three as Beauveria caledonica, two as Paecilomyces fumosorosea and one as Paecilomyces lilacinum. Pathogenicity tests were conducted in vitro using conidia suspension (1 x 106 conidia/mL). Insects were inoculated by immersion (10 sec) in the conidia suspension. Daily mortality data was taken (TL50, TL90) and the mean of the treatments were determined. All the fungal species were pathogenic to A. eugenii. The most effective treatments were: P. fumosorosea (Pae1) and B. bassiana (Bb1 & Bb3) with TL50 of 2.39, 2.53 and 2.56 days, respectively, while TL50 for the control was 6.56. A 100% mortality for treatments occurred between the fourth and sixth day compared to control, which reached it in 12 days. These isolates have the potential to be used on an integrated management program for the control of the pepper weevil.
{"title":"Isolation of native entomopathogenic fungi with potential for control of the pepper weevil, Anthonomus eugenii Cano, in Puerto Rico","authors":"Miguel A. García-Carrucini, Víctor Cartín Leyva, C. E. D. Jensen","doi":"10.46429/JAUPR.V101I1.14296","DOIUrl":"https://doi.org/10.46429/JAUPR.V101I1.14296","url":null,"abstract":"Entomopathogenic fungi were isolated parasitizing coffee borer beetle (Hypothenemus hampei Ferrari) and banana weevils (Cosmopolites sordidus Germar) in different parts of the island of Puerto Rico to be identified and examined for their pathogenicity on pepper weevil (Anthonomus eugenii Cano). Fungi were isolated and purified in acidulated potato dextroseagar (PDA) in the laboratory of the Plant Disease Clinic at the Agricultural Experiment Station, Juana Diaz. Seven fungal isolates were obtained from the municipality of Comerio, and one from the municipality of Adjuntas. Morphology, DNA sequences of different genetic regions of interest, and microsatellites were used for identification of fungal isolates. Two of the eight isolates were identified as Beauveria bassiana, three as Beauveria caledonica, two as Paecilomyces fumosorosea and one as Paecilomyces lilacinum. Pathogenicity tests were conducted in vitro using conidia suspension (1 x 106 conidia/mL). Insects were inoculated by immersion (10 sec) in the conidia suspension. Daily mortality data was taken (TL50, TL90) and the mean of the treatments were determined. All the fungal species were pathogenic to A. eugenii. The most effective treatments were: P. fumosorosea (Pae1) and B. bassiana (Bb1 & Bb3) with TL50 of 2.39, 2.53 and 2.56 days, respectively, while TL50 for the control was 6.56. A 100% mortality for treatments occurred between the fourth and sixth day compared to control, which reached it in 12 days. These isolates have the potential to be used on an integrated management program for the control of the pepper weevil.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":"33 1","pages":"91-106"},"PeriodicalIF":0.0,"publicationDate":"2021-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87981347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-26DOI: 10.46429/jaupr.v96i3-4.3168
J. A. Dumas, C. Ortiz, S. Soler
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. The first objective of this research was to provide a robust set of data for carbohydrate type and levels, alcohol insoluble solids (AIS) and volatile organic compounds (VOC) from six cultivars of sweet potato, data which will allow us to have a quantitative selection tool besides crop yield, tuber size and appearance. The second objective was to relate VOC differences among sweet potato cultivars that can be attributed to chemical and physical differences of the pulp before and after cooking. A three harvest study was conducted to identify and determine major carbohydrate content, AIS, starch granule diameter and form, and tastes and odors of six cultivars of sweet potato, which were very sweet ('Gem'), sweet ('Miguela' and Travis'), moderately sweet ('Viola' and 'Martina') and non-sweet ('Ninetynine'). The average AIS contents were 81, 77, 79, 85, 66, and 76% for 'Martina', 'Miguela', 'Ninety-nine', 'Viola', 'Gem' and 'Travis', respectively. Scanning electron micrograph (SEM) indicated that the average starch granule diameters were 12.9, 15.3, 16.9 and 25.2 |jm for 'Martina', 'Miguela', 'Ninety-nine' and 'Viola', respectively. In addition, all of the sweet potato starch granules had both spherical and polygonal granules. The cultivars with greatest 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; for AIS and sweetness, correlation was -0.823. A similar correlation between the AIS and maltose was obtained for the data from the three harvests (-0.8493). Fifty volatile organic compounds of baked sweet potatoes were trapped in cold methylene chloride. The predominant volátiles were hexanal, 3-pente-2-ol, and isoledene. Other sweet aromas detected were 2,4-decadienal, 2-pentyl furan, benzaldehyde, 4-methyl-4-hydroxy-2-pentanone, and benzene acetaldehyde. The great differences in relative concentrations of volátiles among cultivars seem to be related to the synthesis of maltose and the content of AIS.
{"title":"Tastes and volatiles of tropical-type sweet potatoes","authors":"J. A. Dumas, C. Ortiz, S. Soler","doi":"10.46429/jaupr.v96i3-4.3168","DOIUrl":"https://doi.org/10.46429/jaupr.v96i3-4.3168","url":null,"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. The first objective of this research was to provide a robust set of data for carbohydrate type and levels, alcohol insoluble solids (AIS) and volatile organic compounds (VOC) from six cultivars of sweet potato, data which will allow us to have a quantitative selection tool besides crop yield, tuber size and appearance. The second objective was to relate VOC differences among sweet potato cultivars that can be attributed to chemical and physical differences of the pulp before and after cooking. A three harvest study was conducted to identify and determine major carbohydrate content, AIS, starch granule diameter and form, and tastes and odors of six cultivars of sweet potato, which were very sweet ('Gem'), sweet ('Miguela' and Travis'), moderately sweet ('Viola' and 'Martina') and non-sweet ('Ninetynine'). The average AIS contents were 81, 77, 79, 85, 66, and 76% for 'Martina', 'Miguela', 'Ninety-nine', 'Viola', 'Gem' and 'Travis', respectively. Scanning electron micrograph (SEM) indicated that the average starch granule diameters were 12.9, 15.3, 16.9 and 25.2 |jm for 'Martina', 'Miguela', 'Ninety-nine' and 'Viola', respectively. In addition, all of the sweet potato starch granules had both spherical and polygonal granules. The cultivars with greatest 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; for AIS and sweetness, correlation was -0.823. A similar correlation between the AIS and maltose was obtained for the data from the three harvests (-0.8493). Fifty volatile organic compounds of baked sweet potatoes were trapped in cold methylene chloride. The predominant volátiles were hexanal, 3-pente-2-ol, and isoledene. Other sweet aromas detected were 2,4-decadienal, 2-pentyl furan, benzaldehyde, 4-methyl-4-hydroxy-2-pentanone, and benzene acetaldehyde. The great differences in relative concentrations of volátiles among cultivars seem to be related to the synthesis of maltose and the content of AIS. \u0000 ","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41641350","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-26DOI: 10.46429/jaupr.v96i3-4.3172
Danilo Cianzio-Mujica, Cesar Rodríguez-Ramírez, Américo Casas-Guernica, Melvin Pagán-Morales, Luis Añeses-Loperena
EFECTO DE LA SINCRONIZACIÓN CON PROSTAGLANDINAS Y LA INSEMINACIÓN ARTIFICIAL SENCILLA O DOBLE SOBRE CARACTERÍSTICAS DEL ESTRO E ÍNDICES DE PREÑEZ Y PARICIÓN EN BOVINOS DE LA RAZA SENEPOL
与前列腺素同步以及单次或双次人工授精对老年波尔牛发情特征、孕期和产犊指数的影响
{"title":"EFECTO DE LA SINCRONIZACIÓN CON PROSTAGLANDINAS Y LA INSEMINACIÓN ARTIFICIAL SENCILLA O DOBLE SOBRE CARACTERÍSTICAS DEL ESTRO E ÍNDICES DE PREÑEZ Y PARICIÓN EN BOVINOS DE LA RAZA SENEPOL","authors":"Danilo Cianzio-Mujica, Cesar Rodríguez-Ramírez, Américo Casas-Guernica, Melvin Pagán-Morales, Luis Añeses-Loperena","doi":"10.46429/jaupr.v96i3-4.3172","DOIUrl":"https://doi.org/10.46429/jaupr.v96i3-4.3172","url":null,"abstract":"EFECTO DE LA SINCRONIZACIÓN CON PROSTAGLANDINAS Y LA INSEMINACIÓN ARTIFICIAL SENCILLA O DOBLE SOBRE CARACTERÍSTICAS DEL ESTRO E ÍNDICES DE PREÑEZ Y PARICIÓN EN BOVINOS DE LA RAZA SENEPOL","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47065406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-26DOI: 10.46429/jaupr.v96i3-4.2854
A. González-Vélez
The effects of chicken manure as a soil amendment and the application of nematicides on plant characteristics, yield and foliar nutrient content of the African Rhino plantain clone were evaluated. Chemical properties of the soil were monitored after chicken manure application. Chicken manure, at a rate of 25 t/ha, was incorporated during soil preparation. The nematicide treatment Included the use of etoprop at planting, followed by oxamyl at six and 12 months after planting. The application of chicken manure significantly increased the height and diameter of the pseudostem, reduced the number of days from planting to shooting, and increased bunch weight, and yield per hectare. With the use of chicken manure a yield of 34,242 kg/ha was obtained. This yield represents a 33% increase over that of the treatment without chicken manure. The use of nematicides significantly diminished the number of collapsed plants and Increased plantain yield. The use of chicken manure Increased the foliar content of N and Ca whereas the use of nematicide had no effect on any of the nutrient foliar content. The chemical properties of the soil (pH; organic matter; electric conductivity; N, P, K, Ca and Mg content) were not affected by the use of chicken manure.
{"title":"African Rhino plantain clone (Musa AAB) behavior when using chicken manure as soil amendment and nematicides.","authors":"A. González-Vélez","doi":"10.46429/jaupr.v96i3-4.2854","DOIUrl":"https://doi.org/10.46429/jaupr.v96i3-4.2854","url":null,"abstract":"The effects of chicken manure as a soil amendment and the application of nematicides on plant characteristics, yield and foliar nutrient content of the African Rhino plantain clone were evaluated. Chemical properties of the soil were monitored after chicken manure application. Chicken manure, at a rate of 25 t/ha, was incorporated during soil preparation. The nematicide treatment Included the use of etoprop at planting, followed by oxamyl at six and 12 months after planting. The application of chicken manure significantly increased the height and diameter of the pseudostem, reduced the number of days from planting to shooting, and increased bunch weight, and yield per hectare. With the use of chicken manure a yield of 34,242 kg/ha was obtained. This yield represents a 33% increase over that of the treatment without chicken manure. The use of nematicides significantly diminished the number of collapsed plants and Increased plantain yield. The use of chicken manure Increased the foliar content of N and Ca whereas the use of nematicide had no effect on any of the nutrient foliar content. The chemical properties of the soil (pH; organic matter; electric conductivity; N, P, K, Ca and Mg content) were not affected by the use of chicken manure.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48812805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-02-26DOI: 10.46429/jaupr.v96i3-4.3170
M. Daza, F. Gallardo
The braconid Mirax insularis Muesebeck Is a koinoboint parasitoid of the coffee leafminer, Leucoptera coffeella Guérin-Méneville & Perrottet, in Puerto Rico. However, their reproductive capacity under artificial rearing conditions of the leafminer is not known. The objective of this study was to determine its reproductive potential in larvae of 1st and 2nd instar of L. coffeella. Reproductive capacity tests showed significant differences (test t-Student, P < 0.05) in the preference of M. insularis for 2nd instar larvae with 7% of parasitization, whereas in 1st instar it gained only 5%. The average oviposition of M. insularis increases three folds (14 eggs per female) in a period of 48 hours on 2nd instar when compared to 1st instar. In the analysis of variance, the treatments that showed a significant difference (Tukey test, P < 0.05) were those with densities of 60 to 80 parasitoids per experimental unit on 2nd instar. Correlation tests find that there is a correlation (R = 0.453, P = 0.547) among the progeny of M. insularis produced when using larvae of the 1st instar. However, there is a positive correlation (R = 0.981, P = 0.019) when using 2nd instar larvae. The parasitization of M. insularis is higher when performing inoculations with 60 to 80 parasitoids on 2nd instar, producing a progeny of 365 and 480 parasitoids, respectively.
{"title":"Reproductive capacity of Mirax insularis - Muesebeck (Hym: Braconidae) in larvae of the coffee leaf miner, Leucoptera coffeella- Guérin-Méneville and Perrottet 1842 (Lep: Lyonetiidae).","authors":"M. Daza, F. Gallardo","doi":"10.46429/jaupr.v96i3-4.3170","DOIUrl":"https://doi.org/10.46429/jaupr.v96i3-4.3170","url":null,"abstract":"The braconid Mirax insularis Muesebeck Is a koinoboint parasitoid of the coffee leafminer, Leucoptera coffeella Guérin-Méneville & Perrottet, in Puerto Rico. However, their reproductive capacity under artificial rearing conditions of the leafminer is not known. The objective of this study was to determine its reproductive potential in larvae of 1st and 2nd instar of L. coffeella. Reproductive capacity tests showed significant differences (test t-Student, P < 0.05) in the preference of M. insularis for 2nd instar larvae with 7% of parasitization, whereas in 1st instar it gained only 5%. The average oviposition of M. insularis increases three folds (14 eggs per female) in a period of 48 hours on 2nd instar when compared to 1st instar. In the analysis of variance, the treatments that showed a significant difference (Tukey test, P < 0.05) were those with densities of 60 to 80 parasitoids per experimental unit on 2nd instar. Correlation tests find that there is a correlation (R = 0.453, P = 0.547) among the progeny of M. insularis produced when using larvae of the 1st instar. However, there is a positive correlation (R = 0.981, P = 0.019) when using 2nd instar larvae. The parasitization of M. insularis is higher when performing inoculations with 60 to 80 parasitoids on 2nd instar, producing a progeny of 365 and 480 parasitoids, respectively.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42020650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-27DOI: 10.46429/jaupr.v74i3.6659
Agenol Gonzâlez, M. Santiago, L. A. Figueroa
The following plantain clones were evaluated for yield and morphological characteristics at the Agricultural Experiment Substation of Corozal: plátano enano, Congo enano, Dominican Dwarf, Hartón, Maricongo, Congo 300 and Lacknau. Plátano enano, Dominican Dwarf, Hartón and Maricongo belong to the horn type of plantain; the other clones to the French type. The experiment was planted August 1987 in a Corozal clay soil (Aquic Tropudults) at a spacing of 1.8 square meters per plant. The Congo 300 clone produced the most fruits per hectare, 211,593 fruits, and the Hartón clone the lowest, 47,242 fruits. The Lacknau clone yielded highest: 39.4 mt/ha and the Hartón lowest, 19.5 mt/ha. Congo 300 produced an average of 82.3 fruits per bunch and was significantly different from the other clones except for Congo Enano. Although Congo 300 had the highest number of fruits per bunch, it had the lowest average fruit weight, 131 g. All fruits from clones of the horn type averaged more than 280 grams, a weight well accepted for the Puerto Rican market. All clones flowered in an average of 452 days; the Maricongo clone was the earliest in flowering, 429 days, and the Congo 300 the latest, 495 days. All clones were harvested in an average of 107 days after flowering: the Hartón was harvested in 96 days, and Congo Enano in 118 days.
{"title":"Plaintain clones","authors":"Agenol Gonzâlez, M. Santiago, L. A. Figueroa","doi":"10.46429/jaupr.v74i3.6659","DOIUrl":"https://doi.org/10.46429/jaupr.v74i3.6659","url":null,"abstract":"The following plantain clones were evaluated for yield and morphological characteristics at the Agricultural Experiment Substation of Corozal: plátano enano, Congo enano, Dominican Dwarf, Hartón, Maricongo, Congo 300 and Lacknau. Plátano enano, Dominican Dwarf, Hartón and Maricongo belong to the horn type of plantain; the other clones to the French type. The experiment was planted August 1987 in a Corozal clay soil (Aquic Tropudults) at a spacing of 1.8 square meters per plant. The Congo 300 clone produced the most fruits per hectare, 211,593 fruits, and the Hartón clone the lowest, 47,242 fruits. The Lacknau clone yielded highest: 39.4 mt/ha and the Hartón lowest, 19.5 mt/ha. Congo 300 produced an average of 82.3 fruits per bunch and was significantly different from the other clones except for Congo Enano. Although Congo 300 had the highest number of fruits per bunch, it had the lowest average fruit weight, 131 g. All fruits from clones of the horn type averaged more than 280 grams, a weight well accepted for the Puerto Rican market. All clones flowered in an average of 452 days; the Maricongo clone was the earliest in flowering, 429 days, and the Congo 300 the latest, 495 days. All clones were harvested in an average of 107 days after flowering: the Hartón was harvested in 96 days, and Congo Enano in 118 days.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41705470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-01-01DOI: 10.46429/jaupr.v105i1.19632
Héctor Tavárez, C. Alamo, Edgardo Nieves, Christian Flores
Product differentiation is a strategy used to develop products with particular attributes valued by consumers who are willing to buy them at higher prices. We use a single-bounded dichotomous choice contingent valuation method through in-person interviews (N=575) to estimate consumers’ willingness to pay (WTP) for high-quality and regular coffees produced locally. The results show that consumers are willing to pay $13.60 for a 227-g (8-ounce) bag of highquality coffee produced locally and $10.90 for regular coffee produced locally. It may be inferred that consumers are willing to pay $2.70 more for high-quality coffee, holding all else constant, which suggest that consumers value more the attribute of being locally produced than that of quality. The results also suggest that household size, income and education level of consumers can affect WTP values. We provide evidence that additional revenue can be generated by producing differentiated coffees. However, a cost analysis is required to complement this study and to better understand the economic viability of producing coffee with the characteristics evaluated in this investigation.
{"title":"Using contingent valuation to estimate consumers’ willingness to pay for differentiated coffees in Puerto Rico","authors":"Héctor Tavárez, C. Alamo, Edgardo Nieves, Christian Flores","doi":"10.46429/jaupr.v105i1.19632","DOIUrl":"https://doi.org/10.46429/jaupr.v105i1.19632","url":null,"abstract":"Product differentiation is a strategy used to develop products with particular attributes valued by consumers who are willing to buy them at higher prices. We use a single-bounded dichotomous choice contingent valuation method through in-person interviews (N=575) to estimate consumers’ willingness to pay (WTP) for high-quality and regular coffees produced locally. The results show that consumers are willing to pay $13.60 for a 227-g (8-ounce) bag of highquality coffee produced locally and $10.90 for regular coffee produced locally. It may be inferred that consumers are willing to pay $2.70 more for high-quality coffee, holding all else constant, which suggest that consumers value more the attribute of being locally produced than that of quality. The results also suggest that household size, income and education level of consumers can affect WTP values. We provide evidence that additional revenue can be generated by producing differentiated coffees. However, a cost analysis is required to complement this study and to better understand the economic viability of producing coffee with the characteristics evaluated in this investigation.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43855223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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