Pub Date : 2023-08-08DOI: 10.46429/jaupr.v106i2.21155
Luz M. Serrato-Diaz, L. L. Simbaña-Carrera, Yesenia Vélez-Negrón, L. Rivera-Vargas
Pineapple heart rot disease (PHRD) caused by Phytophthora spp. is one of the most important diseases of pineapple. This disease is characterized by soft rot and water-soaked lesions. In severe cases plant mortality is 100%. During a one-year survey, conducted from March 2018 to March 2019, a total of 29 pineapple hectares were evaluated from five commercial pineapple fields located in the Puerto Rican municipalities of Guánica, Lajas, Manatí and Santa Isabel, and at the Agricultural Experiment Substation of the University of Puerto Rico in Isabela. Symptoms of PHRD were observed in all fields evaluated, except at the Agricultural Experiment Substation in Isabela. Diseased plant tissue was surface disinfected and plated on PARPH-V8 selective media for Phytophthora spp. Aerial photography using a DJI Phantom 3 drone was used to corroborate PHRD incidence in the field. Approximately eight hectares were infected by P. nicotianae with an average of PHRD disease incidence of 28.82%. The highest percentage of PHRD incidence was observed in fields located at Guánica, Lajas and Manatí with 40%, 40% and 30%, respectively. Eleven isolates of Phytophthora nicotianae were collected from pineapple fields in Guánica, Lajas, Manatí and Santa Isabel and identified using morphology and phylogeny of sequences of the mitochondrial cytochrome oxidase subunit I region (COI). The estimation of the incidence of P. nicotianae as the causal agent of PHRD is important as a first step in developing specific control measures in the pineapple fields of Puerto Rico.
{"title":"Detection and incidence of pineapple heart rot disease caused by Phytophthora nicotianae in commercial farms of Puerto Rico","authors":"Luz M. Serrato-Diaz, L. L. Simbaña-Carrera, Yesenia Vélez-Negrón, L. Rivera-Vargas","doi":"10.46429/jaupr.v106i2.21155","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21155","url":null,"abstract":"Pineapple heart rot disease (PHRD) caused by Phytophthora spp. is one of the most important diseases of pineapple. This disease is characterized by soft rot and water-soaked lesions. In severe cases plant mortality is 100%. During a one-year survey, conducted from March 2018 to March 2019, a total of 29 pineapple hectares were evaluated from five commercial pineapple fields located in the Puerto Rican municipalities of Guánica, Lajas, Manatí and Santa Isabel, and at the Agricultural Experiment Substation of the University of Puerto Rico in Isabela. Symptoms of PHRD were observed in all fields evaluated, except at the Agricultural Experiment Substation in Isabela. Diseased plant tissue was surface disinfected and plated on PARPH-V8 selective media for Phytophthora spp. Aerial photography using a DJI Phantom 3 drone was used to corroborate PHRD incidence in the field. Approximately eight hectares were infected by P. nicotianae with an average of PHRD disease incidence of 28.82%. The highest percentage of PHRD incidence was observed in fields located at Guánica, Lajas and Manatí with 40%, 40% and 30%, respectively. Eleven isolates of Phytophthora nicotianae were collected from pineapple fields in Guánica, Lajas, Manatí and Santa Isabel and identified using morphology and phylogeny of sequences of the mitochondrial cytochrome oxidase subunit I region (COI). The estimation of the incidence of P. nicotianae as the causal agent of PHRD is important as a first step in developing specific control measures in the pineapple fields of Puerto Rico.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41461159","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}
{"title":"DINUROTHRIPS HOOKERI HOOD (THYSANOPTERA: THRIPIDAE: PANCHAETOTHRIPINAE): UN NUEVO RÉCORD PARA CUCUMIS SATIVUS EN PUERTO RICO","authors":"I. Cabrera-Asencio, Ermita Hernández, Marcos Obando","doi":"10.46429/jaupr.v106i2.21161","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21161","url":null,"abstract":"DINUROTHRIPS HOOKERI HOOD (THYSANOPTERA: THRIPIDAE: PANCHAETOTHRIPINAE): UN NUEVO RÉCORD PARA CUCUMIS SATIVUS EN PUERTO RICO","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45266830","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21158
L. Wessel-Beaver, L. Flores-López, B. Brunner
HIGHER PLANTING DENSITY INCREASES YIELD OF SEMI-BUSH TROPICAL PUMPKIN
较高的种植密度可提高半灌木热带南瓜的产量
{"title":"HIGHER PLANTING DENSITY INCREASES YIELD OF SEMI-BUSH TROPICAL PUMPKIN","authors":"L. Wessel-Beaver, L. Flores-López, B. Brunner","doi":"10.46429/jaupr.v106i2.21158","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21158","url":null,"abstract":"HIGHER PLANTING DENSITY INCREASES YIELD OF SEMI-BUSH TROPICAL PUMPKIN","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44717663","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21156
Isis J. López-Quintero, L. Wessel-Beaver, J. Ackerman, Jose Carlos V. Rodrigues
Transmission dynamics of viruses within and among cultivated plant species are often well known. Much less studied, especially in the tropics, is the dynamic of virus exchange between cultivated and nearby wild or weedy species, even though such exchanges are known to occur. To develop the best strategies for crop protection and general disease control, spatial distribution of viruses in non-cultivated plants needs to be understood. This research focuses on the potyviruses that infect Momordica charantia (Cucurbitaceae), an alien naturalized invasive vine in Puerto Rico. A total of 390 symptomatic and asymptomatic plants were sampled throughout Puerto Rico, including adjacent islands of Culebra and Vieques. Samples were subjected to an enzyme linked immunosorbent assay (ELISA) for general potyvirus screening, and to ELISAs specific for Papaya ringspot virus (PRSV) and Zucchini yellow mosaic virus (ZYMV). The species distribution model algorithm MaxEnt was used to predict suitable environments for the potential presence of potyvirus symptoms, potyvirus, PRSV or ZYMV in M. charantia. Almost half of the samples of M. charantia tested positive for ZYMV, PRSV or both viruses. Twice as many samples were positive for PRSV (39%) than for ZYMV (21%). About 14% of samples were positive for both potyviruses. Plants that tested positive for PRSV were three times more likely to be positive for ZYMV than were plants that were negative for PRSV. Plants that tested positive using the general potyvirus ELISA were much more likely to exhibit symptoms than plants testing negative for potyvirus. In comparison, PRSV and ZYMV samples testing positive or negative were equally likely to exhibit virus-like symptoms. When we classified samples according to habitat (agricultural, rural-nonagricultural, or urban), the presence/absence of symptoms and test results for potyvirus, PRSV and ZYMV were not dependent on habitat classification. By contrast, a MaxEnt model using 20 environmental variables was able to predict areas of Puerto Rico where environmental conditions are favorable for the potential presence of virus symptoms, potyvirus, PRSV or ZYMV in M. charantia. Conditions predicted by our model to be moderately to strongly suitable for the presence of PRSV in M. charantia covered a much larger area of Puerto Rico than they did for ZYMV. The vegetable growing region in the central to eastern south coast was predicted to have highly suitable environmental conditions for the presence of both potyviruses in M. charantia.
{"title":"Geographical distribution and detection of two potyviruses occurring in Momordica charantia (Cucurbitaceae) in Puerto Rico","authors":"Isis J. López-Quintero, L. Wessel-Beaver, J. Ackerman, Jose Carlos V. Rodrigues","doi":"10.46429/jaupr.v106i2.21156","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21156","url":null,"abstract":"Transmission dynamics of viruses within and among cultivated plant species are often well known. Much less studied, especially in the tropics, is the dynamic of virus exchange between cultivated and nearby wild or weedy species, even though such exchanges are known to occur. To develop the best strategies for crop protection and general disease control, spatial distribution of viruses in non-cultivated plants needs to be understood. This research focuses on the potyviruses that infect Momordica charantia (Cucurbitaceae), an alien naturalized invasive vine in Puerto Rico. A total of 390 symptomatic and asymptomatic plants were sampled throughout Puerto Rico, including adjacent islands of Culebra and Vieques. Samples were subjected to an enzyme linked immunosorbent assay (ELISA) for general potyvirus screening, and to ELISAs specific for Papaya ringspot virus (PRSV) and Zucchini yellow mosaic virus (ZYMV). The species distribution model algorithm MaxEnt was used to predict suitable environments for the potential presence of potyvirus symptoms, potyvirus, PRSV or ZYMV in M. charantia. Almost half of the samples of M. charantia tested positive for ZYMV, PRSV or both viruses. Twice as many samples were positive for PRSV (39%) than for ZYMV (21%). About 14% of samples were positive for both potyviruses. Plants that tested positive for PRSV were three times more likely to be positive for ZYMV than were plants that were negative for PRSV. Plants that tested positive using the general potyvirus ELISA were much more likely to exhibit symptoms than plants testing negative for potyvirus. In comparison, PRSV and ZYMV samples testing positive or negative were equally likely to exhibit virus-like symptoms. When we classified samples according to habitat (agricultural, rural-nonagricultural, or urban), the presence/absence of symptoms and test results for potyvirus, PRSV and ZYMV were not dependent on habitat classification. By contrast, a MaxEnt model using 20 environmental variables was able to predict areas of Puerto Rico where environmental conditions are favorable for the potential presence of virus symptoms, potyvirus, PRSV or ZYMV in M. charantia. Conditions predicted by our model to be moderately to strongly suitable for the presence of PRSV in M. charantia covered a much larger area of Puerto Rico than they did for ZYMV. The vegetable growing region in the central to eastern south coast was predicted to have highly suitable environmental conditions for the presence of both potyviruses in M. charantia.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47041018","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21160
Irma Cabrera-Asencio, E. Meléndez-Ackerman
INSECT VISITORS ON THE FLOWERS OF FOUR CULTIVARS OF MANGIFERA INDICA AT THE AGRICULTURAL EXPERIMENT SUBSTATION OF JUANA DIAZ, PUERTO RICO
在波多黎各胡安娜迪亚兹的农业试验站，昆虫在四个品种的芒果花上停留
{"title":"INSECT VISITORS ON THE FLOWERS OF FOUR CULTIVARS OF MANGIFERA INDICA AT THE AGRICULTURAL EXPERIMENT SUBSTATION OF JUANA DIAZ, PUERTO RICO","authors":"Irma Cabrera-Asencio, E. Meléndez-Ackerman","doi":"10.46429/jaupr.v106i2.21160","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21160","url":null,"abstract":"INSECT VISITORS ON THE FLOWERS OF FOUR CULTIVARS OF MANGIFERA INDICA AT THE AGRICULTURAL EXPERIMENT SUBSTATION OF JUANA DIAZ, PUERTO RICO","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47003999","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21157
J. Santiago-Vera, Irma Cabrera-Asencio
Hurricanes are known to affect plants and animals and their interactions. Usually, hurricanes defoliate trees and reduce the abundance and density of arthropods. The parasitic arthropod Holopothrips tabebuia was first reported in Puerto Rico in 2006. By 2007, it had established populations on two hosts: Tabebuia aurea and Tabebuia heterophylla. In September 2017, Hurricane María defoliated both hosts. This study aimed to determine the effects of a powerful hurricane on the abundance of this parasite and its relationship with its hosts. Although Hurricane María caused greater defoliation in T. aurea than in T. heterophylla, the post-hurricane abundances and densities of the parasite were much lower in both hosts. A negative correlation between the damage to the host caused by the hurricane and the infestation by the parasite was found. Evidence supports that hurricanes indeed have a negative effect on the dynamics of H. tabebuia and its relationship with its hosts.
{"title":"Hurricanes and phytophagous insects: Disturbance effects on the abundance of an invasive insect","authors":"J. Santiago-Vera, Irma Cabrera-Asencio","doi":"10.46429/jaupr.v106i2.21157","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21157","url":null,"abstract":"Hurricanes are known to affect plants and animals and their interactions. Usually, hurricanes defoliate trees and reduce the abundance and density of arthropods. The parasitic arthropod Holopothrips tabebuia was first reported in Puerto Rico in 2006. By 2007, it had established populations on two hosts: Tabebuia aurea and Tabebuia heterophylla. In September 2017, Hurricane María defoliated both hosts. This study aimed to determine the effects of a powerful hurricane on the abundance of this parasite and its relationship with its hosts. Although Hurricane María caused greater defoliation in T. aurea than in T. heterophylla, the post-hurricane abundances and densities of the parasite were much lower in both hosts. A negative correlation between the damage to the host caused by the hurricane and the infestation by the parasite was found. Evidence supports that hurricanes indeed have a negative effect on the dynamics of H. tabebuia and its relationship with its hosts.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42782509","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21159
María Y. Berrios-Rivera, Wilfredo Robles, Julia M. O'Hallorans-Castillo, Guillermo Ortiz-Colón
FLUCTUACIONES TEMPORALES DE LA BIOMASA Y CONTENIDO DE ALMIDÓN DE PASPALUM FASCICULATUM
束雀稗生物量和淀粉含量的时间波动
{"title":"FLUCTUACIONES TEMPORALES DE LA BIOMASA Y CONTENIDO DE ALMIDÓN DE PASPALUM FASCICULATUM","authors":"María Y. Berrios-Rivera, Wilfredo Robles, Julia M. O'Hallorans-Castillo, Guillermo Ortiz-Colón","doi":"10.46429/jaupr.v106i2.21159","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21159","url":null,"abstract":"FLUCTUACIONES TEMPORALES DE LA BIOMASA Y CONTENIDO DE ALMIDÓN DE PASPALUM FASCICULATUM","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48658977","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21150
V. Negrón-Pérez, A. Aponte
Heat stress causes detrimental effects on animals, such as dairy cows and heifers, resulting in decreased production and changes in physiological aspects. Some Holsteins carry a mutation in the prolactin receptor (Slick; SL) that causes them to have shorter hair and greater heat tolerance compared with the wild-type (WT) cattle. Slick animals have lower temperatures, greater milk production and shorter calving intervals. The objectives of the current study were to describe monthly weight, reproductive performance, and mortality rates of the SL Holstein compared with the WT. Experiments were conducted at the Agricultural Experiment Substation in Gurabo, Puerto Rico, to determine average monthly weights of 88 heifers (40 SL and 48 WT) born between 2017 and 2020. Heifers’ estrus (n=22 SL; n=27 WT) was synchronized followed by timed artificial insemination to determine differences in pregnancy rates. A subset of lactating cows was used to compare number of services required for pregnancy. Mortality frequency between genotypes was analyzed and compared. Data were analyzed using SAS University Edition, 2018 Proc-GLIMMIX and Tukey test. Compared to WT heifers, SL heifers were heavier after 14 months, required one to two fewer insemination services and died at a lower frequency rate (22% vs. 78%). Genetically selecting heat tolerant SL cows over WT may improve reproductive performance.
热应激会对奶牛和小母牛等动物造成有害影响，导致产量下降和生理方面的变化。与野生型（WT）牛相比，一些荷斯坦牛的催乳素受体（Slick；SL）发生突变，导致其毛发更短，耐热性更强。苗条的动物温度更低，产奶量更大，产仔间隔更短。本研究的目的是描述SL荷斯坦与WT相比的月体重、繁殖性能和死亡率。实验在波多黎各古拉博的农业实验变电站进行，以确定2017年至2020年间出生的88头小母牛（40头SL和48头WT）的月平均体重。小母牛的发情期（n=22 SL；n=27 WT）同步，然后进行定时人工授精，以确定妊娠率的差异。使用泌乳奶牛的子集来比较妊娠所需的服务数量。对不同基因型的死亡率进行了分析和比较。使用SAS University Edition，2018 Proc GLIMMIX和Tukey检验对数据进行分析。与WT小母牛相比，SL小母牛在14个月后体重更重，需要减少一到两次受精服务，死亡频率更低（22%对78%）。转基因选择耐热SL奶牛而不是WT可以提高繁殖性能。
{"title":"Developmental and reproductive performance differences of the slick-hair Holstein","authors":"V. Negrón-Pérez, A. Aponte","doi":"10.46429/jaupr.v106i2.21150","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21150","url":null,"abstract":"Heat stress causes detrimental effects on animals, such as dairy cows and heifers, resulting in decreased production and changes in physiological aspects. Some Holsteins carry a mutation in the prolactin receptor (Slick; SL) that causes them to have shorter hair and greater heat tolerance compared with the wild-type (WT) cattle. Slick animals have lower temperatures, greater milk production and shorter calving intervals. The objectives of the current study were to describe monthly weight, reproductive performance, and mortality rates of the SL Holstein compared with the WT. Experiments were conducted at the Agricultural Experiment Substation in Gurabo, Puerto Rico, to determine average monthly weights of 88 heifers (40 SL and 48 WT) born between 2017 and 2020. Heifers’ estrus (n=22 SL; n=27 WT) was synchronized followed by timed artificial insemination to determine differences in pregnancy rates. A subset of lactating cows was used to compare number of services required for pregnancy. Mortality frequency between genotypes was analyzed and compared. Data were analyzed using SAS University Edition, 2018 Proc-GLIMMIX and Tukey test. Compared to WT heifers, SL heifers were heavier after 14 months, required one to two fewer insemination services and died at a lower frequency rate (22% vs. 78%). Genetically selecting heat tolerant SL cows over WT may improve reproductive performance.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43631945","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21154
L. Wessel-Beaver, Sonia Martínez-Garrastazú, J. C. Rodrigues, Evelyn Rosa-Márquez, Guillermo Fornaris-Rullán, A. González-Vélez
Capsicum chinense is a small aromatic pepper native to the Amazon and widely used in the Caribbean Basin. Most types of C. chinense are highly pungent, but landraces in Puerto Rico generally have little or no pungency. This “sweet chili pepper” (or ají dulce, as it is known on the Island) is an integral part of the local cuisine. Ten sweet chili pepper lines derived from non-pungent landraces were evaluated in Lajas, Juana Díaz and Corozal, Puerto Rico, in 2009. The lines represented a diversity of fruit types common on the Island. Plants in Juana Díaz grew to about twice the height of those in Lajas and Corozal. Fruit yield varied from 809 g/plant in Lajas to 1,420 g/plant in Juana Díaz. Planting density (number of plants per hectare) was greater at Corozal compared to the other two locations, resulting in a yield per hectare similar to that of Juana Díaz (10,210 kg/ha in Juana Díaz; 10,112 kg/ha in Corozal). Yield was much lower in Lajas (6,400 kg/ha). Average fruit weight was greatest at Juana Díaz (12.1 g) and lowest at Corozal (10.0 g). Plant height at 11 weeks was weakly correlated (r = 0.33) with fruit yield. Plants infected by at least one of three genera of viruses, Cucumovirus, Tobamovirus and Potyvirus, were found at each location. Seed weight per 500 seeds averaged 2.34 g. The average fruit produced about 23 seeds. Genotype x environment (GxE) interaction (= line x location) was highly significant for height, number of fruit and fruit yield, but not for average fruit weight. Because of GxE interaction, the best performing lines varied, depending on location. The presence of GxE interaction presents challenges to a sweet chili pepper breeding program. Although it may be difficult to develop cultivars that perform equally well over diverse environments, improved cultivars with virus resistance should result in increased production. More research is needed to better understand the impact that variation in planting density has on sweet chili pepper yields.
{"title":"Performance of sweet chili pepper (Capsicum chinense Jacq.) landraces in three agricultural zones of Puerto Rico","authors":"L. Wessel-Beaver, Sonia Martínez-Garrastazú, J. C. Rodrigues, Evelyn Rosa-Márquez, Guillermo Fornaris-Rullán, A. González-Vélez","doi":"10.46429/jaupr.v106i2.21154","DOIUrl":"https://doi.org/10.46429/jaupr.v106i2.21154","url":null,"abstract":"Capsicum chinense is a small aromatic pepper native to the Amazon and widely used in the Caribbean Basin. Most types of C. chinense are highly pungent, but landraces in Puerto Rico generally have little or no pungency. This “sweet chili pepper” (or ají dulce, as it is known on the Island) is an integral part of the local cuisine. Ten sweet chili pepper lines derived from non-pungent landraces were evaluated in Lajas, Juana Díaz and Corozal, Puerto Rico, in 2009. The lines represented a diversity of fruit types common on the Island. Plants in Juana Díaz grew to about twice the height of those in Lajas and Corozal. Fruit yield varied from 809 g/plant in Lajas to 1,420 g/plant in Juana Díaz. Planting density (number of plants per hectare) was greater at Corozal compared to the other two locations, resulting in a yield per hectare similar to that of Juana Díaz (10,210 kg/ha in Juana Díaz; 10,112 kg/ha in Corozal). Yield was much lower in Lajas (6,400 kg/ha). Average fruit weight was greatest at Juana Díaz (12.1 g) and lowest at Corozal (10.0 g). Plant height at 11 weeks was weakly correlated (r = 0.33) with fruit yield. Plants infected by at least one of three genera of viruses, Cucumovirus, Tobamovirus and Potyvirus, were found at each location. Seed weight per 500 seeds averaged 2.34 g. The average fruit produced about 23 seeds. Genotype x environment (GxE) interaction (= line x location) was highly significant for height, number of fruit and fruit yield, but not for average fruit weight. Because of GxE interaction, the best performing lines varied, depending on location. The presence of GxE interaction presents challenges to a sweet chili pepper breeding program. Although it may be difficult to develop cultivars that perform equally well over diverse environments, improved cultivars with virus resistance should result in increased production. More research is needed to better understand the impact that variation in planting density has on sweet chili pepper yields.","PeriodicalId":14937,"journal":{"name":"Journal of Agriculture of The University of Puerto Rico","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43231977","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 : 2023-08-08DOI: 10.46429/jaupr.v106i2.21151
R. Tirado-Corbalá, M. L. Flores‐Mangual, Sadikshya Dangi
Field fires can modify soil nutrient cycling and alter soil microbial communities (SMC), although the latter is not well understood. In the southern region of Puerto Rico, field fires have become a significant problem during the dry season. To mimic the effects of a field fire, we performed prescribed fires on a hillside at the Juana Díaz Agricultural Experiment substation in October 2015 and March 2017. A complete randomized block design was established in Yauco soil (Typic calciustolls) that included the following treatments: negative control (unburned), positive control (burned plots, no remediation), mulching treatment (burned plots remediated with Leucaena spp. mulch), and surfactant treatment (burned plots remediated with a surfactant). In the first burning (2015), soil samples were collected before burning and at 30, 180, and 420 days after burning (DAB). In the second burning (2017), soil samples were collected at 30, 90, and 270 DAb. soil physicochemical properties and microbial community structure were assessed using phospholipid fatty acid (PLFA) analysis. Overall, burning increased soil exchangeable Ca2+ (except after 30 DAB in the second burning) and decreased exchangeable K+ when compared to unburned soils. compared to unburned plots, total fungal PLFA was significantly lower in burned plots with or without mulch and surfactant treatments, and total bacterial PLFA did not differ between burned and unburned plots after 30 days. Total microbial biomass was significantly (P<0.05) higher in mulch and surfactant treated burned soil compared to unburned and burned plots without treatment after 90 DAB (2017) and 420 (2015) DAB. The use of mulch and surfactant treatments in prescribed burning fields increased microbial communities 90 DAB. This study emphasizes short-term changes in microbial communities and suggests they are highly resilient to disturbances after prescribed fires.
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