scholarly journals Yield Performance of Six Lychee Cultivars Grown at Two Locations in Puerto Rico

2016 ◽  
Vol 26 (6) ◽  
pp. 748-753
Author(s):  
Ricardo Goenaga ◽  
David Jenkins ◽  
Angel Marrero

The globalization of the economy, increased ethnic diversity, and a greater demand for healthy and more diverse food production has increased the demand for tropical fruits. There is a lack of formal experimentation to determine yield performance and fruit quality traits of lychee (Litchi chinensis) cultivars. Six lychee cultivars (Bosworth-3, Brewster, Groff, Mauritius, Kaimana, Salathiel) grown on Mollisol and Inceptisol soils were evaluated for 8 years at the Adjuntas Agricultural Experiment Station of the University of Puerto Rico (UPR-Adjuntas) and La Balear farm, Adjuntas, Puerto Rico, respectively. At UPR-Adjuntas and La Balear, cultivar Groff had a significantly higher production (257,296 fruit/ha) of total fruit than other cultivars, whereas Salathiel had the lowest. However, total fruit production of ‘Groff’ was not significantly different from ‘Kaimana’ and ‘Bosworth-3’at La Balear. At UPR-Adjuntas, cultivars Groff and Bosworth-3 had significantly higher number of marketable fruit than the rest of the cultivars averaging 171,760 fruit/ha. At La Balear, ‘Kaimana’ had a higher number of marketable fruit, but it was not significantly different from ‘Groff’, ‘Bosworth-3’, and ‘Mauritius’, averaging 291,360 fruit/ha. At both sites, individual fruit weight of marketable fruit was higher in ‘Kaimana’ than the rest of the cultivars. However, at La Balear, there were no significant differences between ‘Kaimana’ and ‘Mauritius’. At both locations, cultivars exhibited erratic production patterns, which were characterized by lower production during 1 or 2 successive years following heavy cropping. At current farm gate prices and fruit yield reported in this study, cultivars Groff, Bosworth-3, and Kaimana can generate a good income for growers, and allow them to diversify crops as part of their farm operations.

Author(s):  
Ismael Carlo ◽  
C. L. Arcelay

The performance of the pigs of the 3/4 Duroc X 1/4 English Large Black Landrace line developed by the Station was compared with the performance of some imported animals. These imported pigs were from the Duroc, the Yorkshire, and the Hampshire breeds. The comparison and the evaluation of the animals was based on preweaning and postweaning characters. The preweaning characters considered were the number of pigs at farrowing, the number at 21 days, and at weaning age. The rate of gain, the feed efficiency, the back-fat thickness corrected to 200 pounds, and carcass evaluation were considered as postweaning characters. All the data obtained were submitted to analysis of variance and where the F values were significant, they were subjected to a Duncan Multiple Test to determine significance among the means. The overall evaluation of both preweaning and postweaning characters showed that the animals of the 3/4 Duroc X 1/4 English Large Black Landrace line of pigs were as good as any of the animals of the imported breeds with which they were compared, with the possible exception of the carcass evaluation, where the imported breeds gave somewhat better results. They were especially good in the number of pigs weaned, as well as in the weight at weaning time and in rate of gain.


1969 ◽  
Vol 97 (3-4) ◽  
pp. 119-134
Author(s):  
Margarita R. Marroquin-Guzman ◽  
Consuelo Estévez de Jensen

Citrus Greening (CG) caused by a phloem restricted bacteria, Candidatos 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 011 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, Añasco, Cabo Rojo, Coamo, Dorado, Juana Díaz, Las Marías 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 Ciales, 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.


Author(s):  
F. Méndez-Roig ◽  
G. Samuels ◽  
A. Colón

The sugarcane variety trials performed by the Agricultural Experiment Station of the University of Puerto Rico, Río Piedras, P.R., during the period 1952-57, involved 24 separate experiments and 51 crops. The following results are significant: 1. In the production of available 96° sugar per acre P.R. 980 was the outstanding variety of the Southern, Western, Northwestern, and Interior Areas of the Island. B. 37161 was first in the Eastern Area and in Caguas Valley, and it tied P.R. 980 in the North Central and B. 41227 in the Northeastern Areas of Puerto Rico. 2. P.R. 980 was first in 10 and B. 37161 in 6 of the 24 experimental sites in terms of tons of cane produced per acre. 3. The check varieties, M. 336, P.O.J. 2878, and P.R. 902 and 905, produced low yields in both tons of cane and of sugar per acre as compared with the leading varieties. 4. M. 336, P.R. 1016, M. 975, and P.P.Q.K. were the leading varieties in sucrose-percent-cane. 5. P.R. 980 and P.R. 1013 ranked first in tons of sugar produced per acre per month. 6. For agronomic evaluation, the leading varieties were ranked in a table in which consideration was given to such factors as germination, stooling, ratooning habit, girth, erectness, flowering, trashiness, and disease resistance.


1969 ◽  
Vol 85 (1-2) ◽  
pp. 63-68
Author(s):  
María de L. Lugo ◽  
Alvaro Acosta

Field experiments were conducted at the Adjuntas Agricultural Experiment Station of the University of Puerto Rico during 1996 and 1998 to evaluate the efficacy of the herbicides paraquat and sethoxydim on arracacha. In 1996, no differences were found among the treatments for weed control four weeks after the first and second herbicide applications. Weed control ranged from 72% (two applications of sethoxydim) to 87% (hand weeding) at four weeks after herbicide application, and from 43% (one application of paraquat) to 97% (two applications of paraquat) at four weeks after the second herbicide application. There were no significant differences in yield between treatments with two applications of paraquat and that of hand weeding.The lowest yield (7,632 kg/ha) was obtained when sethoxydim was applied once. In the 1998 experiment, no differences in weed control were found among treatments at four weeks after the first herbicide application; weed control ranged from 81% (two applications of sethoxydim) to 98% (hand weeding). When rated at four weeks after the second herbicide application, the lowest weed control (84%) was obtained with one late application of paraquat. There were no significant differences in yield and number of corms per hectare among treatments.


1969 ◽  
Vol 43 (2) ◽  
pp. 132-138
Author(s):  
Tara Singh Dhaliwal

The Mysore raspberry, Rubus albescens Roxb. (synonym, Rubus lasiocarpus Smith) has recently been introduced into Puerto Rico. The experimental plantings of this raspberry have been established at the University of Puerto Rico, Agricultural Experiment Substation, at Castañer, situated in the middle of the central-western mountainous region of the Island. Based on the study of the experimental plantings for the past 4 years the general characteristics, propagation, culture, use of fruits, etc., of the Mysore raspberry have been briefly presented in this paper. The Mysore raspberry has grown fairly well at Castañer. If the cultural practices are employed carefully it produces well-flavored, sweet, and juicy berries over a period of several months during the year. The fruits are good for eating fresh and also for making jellies, jams, etc. It is a promising new fruit for small-scale production in the central-western mountainous region of Puerto Rico.


2018 ◽  
Vol 2 ◽  
pp. e26014
Author(s):  
Nikolaos Schizas

With a total of more than 150,000 specimens, the 85-year old collections of insects and terrestrial, freshwater, and marine invertebrates of the University of Puerto Rico at Mayagüez (UPRM), western Puerto Rico, are among the most significant repositories for these groups in the Caribbean region. Located in Mayagüez and on Magueyes Island, these collections were created by outstanding insect and invertebrate specialists working in Puerto Rico and surrounding islands. Holdings are particularly strong in the Hemiptera, Lepidoptera, Coleoptera, Collembola, Crustacea, Mollusca, Echinodermata, and Cnidaria. Collecting and curatorial activities, initiated in the 1920s, were maintained throughout the 1980s, resulting in many taxonomically and historically valuable records for the region. From 1990 to 2005, the invertebrate collections were increasingly neglected, with certain parts scattered throughout multiple buildings and rooms, inaccessible, or inadequately stored and at risk of becoming damaged or lost. The support for these collections was not sustained at high levels due to a variety of factors, including changes in the research profile of new academic appointments and the shortsightedness of administrators to fully understand the cultural, educational and scientific value of the museum holdings. With the exception of a federal grant through NSF - DBI (National Science Foundation - Biological Research Collections - PI Frantz - 2007-2010), which initiated a flurry of Museum related activities to improve the deteriorating museum facilities throughout the UPRM campus, the Museum collections are now facing even more challenges, some anthropogenic and very recently, some natural. Major Hurricane Maria (Category 4), delivered a devastating blow to the island of Puerto Rico on 20 September 2017. Both terrestrial and marine ecosystems were heavily impacted. Extensive structural damage to roads, telecommunications, water systems, the energy grid and approximately 60,000 houses/buildings made Hurricane Maria the most damaging Hurricane (estimated cost ~ 90 billion dollars) in the USA after Katrina and Harvey. Flooding caused by the direct impact of Hurricane Maria (5 to 40 inches of rain fell during the first 48 hours in Puerto Rico) and subsequent extensive loss of electricity caused unfavorable conditions for the collections. The University of Puerto Rico in Mayaguez closed for approximately 45 days and limited electricity, if any, was available through diesel generators. High levels of humidity and heat can cause further structural damage as well as favor the growth of fungus in enclosed areas of UPRM, including the Museums. Efforts to safeguard the collections will be outlined here to ensure the collections remain a valuable natural asset of the people of Puerto Rico as part of their natural patrimony and as an irreplaceable education tool.


1969 ◽  
Vol 41 (3) ◽  
pp. 147-160
Author(s):  
Ferdinand Méndez-Roig ◽  
George Samuels

Sugarcane variety trials performed by the Agricultural Experiment Station, University of Puerto Rico, Río Piedras, P. R., During the period 1951-55, involved 19 separate experiments and 33 crops. The following results are significant: 1. In the production of available 96° sugar per acre B. 37161 was the outstanding variety of East and North Central cane areas of the Island. P.R. 980 was the leading variety in the Northwest, West, South, and Interior of Puerto Rico. 2. B. 40105, B. 37172, B. 41227, H. 328560, and P.R. 975 all were among the leading producers in tons of sugar per acre. 3. The check varieties M. 336, P.O.J. 2878, and P.R. 902, ranked poorly in the trials as compared with the leading varieties in tons of sugar produced per acre. 4. In terms of tons of cane per acre B. 37161 and P.R. 980 were the two leading varieties for the entire Island, with H. 328560, B. 41227, and B. 37172 also showing favorable cane-tonnage figures. All check varieties did poorly in tons of cane per acre as compared to the leading variety. 5. The varieties were also ranked according to their production of sucrose-percent- cane. P.R. 975 and B. 4362 were first and second, respectively. These two varieties also produced higher cane tonnage than the favored commercial variety M. 336, which ranked third. 6. Finally, the varieties were ranked according to the tons of sugar per acre produced per month, and P.R. 980 ranked first. The first eight experimental varieties produced over 0.60 ton of sugar per acre per month as compared with all commercial varieties, except B. 37161, which produced below 0.50 ton of sugar per acre per month. 7. The reluctance of Puerto Rican farmers to adopt the new cane varieties tested and proven superior to the old commercial varieties is very unprofitable to them. Yields are cited which show that if the land now used to grow the older cane varieties were planted to the new leading experimentally tested varieties discussed in this article, the present sugar crop in Puerto Rico could be produced on about two-thirds of the present acreage. This would release over 100,000 acres for other agricultural uses.


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