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 fruit, including rambutan (Nephelium lappaceum). Replicated field trials to evaluate performance of rambutan cultivars have been very limited and as with many other tropical fruit crops, there is a scarcity of information on best management practices and optimal growing conditions for rambutan. The objective of this study was to determine the yield potential of three rambutan cultivars (Jitlee, R-134, R-162) when the age of grafted trees was ≈20 years. The data were compared with that obtained from an early production period when the age of the trees was ≈10 years. This information may help rambutan growers make expansion and/or investment plans. Number of fruit and yield in 2017 were significantly higher in 2017 than in 2016. In 2017, average fruit number and yield of cultivars were 582,774 fruit/ha and 19,528 kg·ha−1, respectively, whereas in 2016 were 394,269 fruit/ha and 13,164 kg·ha−1, respectively. There were no significant differences among cultivars for number of fruit produced, averaging 488,521 fruit/ha. This production is higher than the 5-year average obtained from the 2005–09 harvest period when grafted trees were about 9 years old. The results of this study demonstrate that grafted rambutan trees can remain prolific in mature orchards.
There is a scarcity of information on how carambola (Averrhoa carambola) cultivars perform in various agroenvironments. Nine carambola cultivars—Arkin, B-10, B-16, B-17, Kajang, Kari, Lara, Sri Kembangan, and Thai Knight—grown on an Oxisol, an Ultisol, and a Mollisol were evaluated for 4 years under intensive management at Isabela, Corozal, and Juana Díaz, PR, respectively. There were no significant differences in number and weight of marketable fruit per hectare area among locations averaging 258,761 fruit/ha and 30,978 kg·ha−1, respectively. There were no significant differences of marketable fruit weight per hectare among highest yielding cultivars B-17, Thai Knight, and Sri Kembangan between locations. The average marketable fruit weight for these highest-yielding cultivars was 36,060 kg·ha−1. ‘Arkin’ and ‘B-16’ were the lowest yielding cultivars, averaging 23,490 kg·ha−1 of marketable fruit. ‘Kari’ produced significantly longer fruit at all locations, whereas ‘B-16’ produced the shortest fruit. Significantly higher soluble solids concentration values were obtained from fruit of ‘B-17’ at all locations, whereas lower values were obtained from those of ‘Arkin’. Overall, cultivars were highly adaptable to the diverse agroenvironments in which they were planted. The fact that ‘B-17’ had high production of marketable fruit, high marketable yield, and high soluble solids concentration at all locations makes this cultivar suitable for planting in diverse agroenvironments.
Ricardo Goenaga* and Edmundo Rivera
Nine carambola (Averrhoa carambola) cultivars grown on an Oxisol, Ultisol, and Mollisol were evaluated for 2 years under intensive management at Isabela, Corozal and Juana Diaz, Puerto Rico, respectively. There were no significant differences in number and weight of marketable fruits per hectare between Corozal and Isabela; average values for both locations were 249,824 fruits/ha and 29,864 kg/ha. At Juana Diaz these values were 196,254 fruits/ha and 24,339 kg/ha, respectively. There were no significant differences in weight of marketable fruit per hectare among cultivars B-17, Thai Knight, B-10, Sri Kembangan, and Kajang between locations. The average marketable fruit weight for these higher yielding cultivars was 31,457 kg/ha. Cultivar Kari produced significantly longer fruits at all locations, whereas cultivar B-16 produced the shortest fruits. Significantly higher brix values were obtained from fruits of cultivar B-17 at all locations whereas lower values were obtained from those of Arkin.
Ricardo Goenaga and David Jenkins
The globalization of the economy, increased ethnic diversity, and a greater demand for healthy and more diverse food products have opened a window of opportunity for the commercial production and marketing of tropical fruit, including rambutan (Nephelium lappaceum). There is a lack of formal experimentation to determine yield performance and fruit quality traits of rambutan cultivars. Eight rambutan cultivars (Benjai, Gula Batu, Jitlee, R-134, R-156Y, R-162, R-167, and Rongren) grown on an Ultisol and an Oxisol soils were evaluated for 5 years at Corozal and Isabela, PR, respectively. There was a significant difference in the number and weight of fruit per hectare between locations, averaging 415,103 fruit/ha and 13,826 kg·ha−1, respectively, at Corozal and 167,504 fruit/ha and 5149 kg·ha−1, respectively, at Isabela. At Corozal, ‘R162’ had the highest 5-year mean for number and weight of fruit per hectare, but this cultivar was not significantly different from the rest except for ‘Benjai’ and ‘R-156Y’, which had significantly lower values. At Isabela, cultivars Gula Batu and R-162 had significantly higher number of fruit per hectare but the latter was not different from ‘Benjai’. Overall, there were no differences in soluble solids concentration except for cultivars Gula Batu and R-156Y, which had significantly lower values at both locations. Cultivar R-162 had higher number and weight of fruit per hectare and high soluble solids concentration at both locations, making it suitable for planting in various agroenvironments particularly on Ultisols typical of the humid tropics.
Ricardo Goenaga and David Jenkins
As consumers seek healthy and more diverse food products, the demand for tropical fruits has increased significantly during the last 15 years. There is a lack of formal experimentation to determine the yield performance and fruit quality traits of atemoya (Annona squamosa × A. cherimola) hybrids. Six atemoya hybrids (‘Bradley’, ‘Geffner’, ‘Priestly’, ‘Lisa’, ‘47-18’, and ‘75-9’) grown on an Oxisol soil were evaluated for 4 years at Isabela, PR. ‘Geffner’ and ‘Lisa’ had the highest number of marketable fruit averaging 8542 fruit/ha, and the highest yield of marketable fruit, averaging 1507 kg·ha−1; they did not differ from each other, but were greater than all other hybrids. Individual weight of marketable fruit was significantly higher in ‘75-9’ and ‘Priestly’ which averaged 264.8 g. Significantly higher soluble solids concentration values were obtained from fruit of ‘75-9’, ‘Bradley’, and ‘Geffner’ which averaged 23.8%; they did not differ from each other, but were greater than all other hybrids.
Ricardo Goenaga and David Jenkins
The demand for tropical fruits has increased significantly during the last decade as consumers seek healthy and more diverse food products. There is a lack of formal experimentation to determine yield performance and fruit quality traits of mamey sapote (Pouteria sapota) cultivars. Six mamey sapote cultivars (Copan, Magaña, Mayapan, Pace, Pantin, Tazumal) grown on Ultisol and Oxisol soils were evaluated for 5 years at Corozal and Isabela, PR, respectively. There was a significant difference in the number and weight of fruit per hectare between locations, averaging 25,929 fruit/ha and 16,527 kg·ha−1 at Corozal and 17,887 fruit/ha and 11,920 kg·ha−1 at Isabela. ‘Tazumal’ had the highest 5-year mean number and weight of fruit per hectare, but fruit of this cultivar was very small and contained several seeds, which could reduce its marketability. At Corozal, cultivars Tazumal and Magaña had significantly higher fruit yield per hectare than the rest of the cultivars, whereas ‘Magaña’, ‘Tazumal’, and ‘Pantín’ had the highest fruit yield at Isabela. At both locations, ‘Pantin’ had relatively high yield, above-average soluble solids concentration values, and adequate fruit size and weight for domestic and export markets (650–900 g), making this cultivar suitable for planting at various agroenvironments typical of the humid tropics.
Ricardo Goenaga, Heber Irizarry and Brian Irish
Ricardo Goenaga, Adolfo Quiles and A. Graves Gillaspie
Cowpea or Southernpea [Vigna unguiculata (L.) Walp.] is an important grain legume in many parts of the tropics. However, viral diseases, particularly Cucumber mosaic virus (CMV) and Blackeye cowpea mosaic virus (BlCMV), can be a limiting factor in cowpea production. We evaluated in replicated field plots and under virus pressure nine PIs (441919, 441925, 441917, 147071, 146618, 180014, 180355, 194208, 612607) and three commercial cultivars (Coronet, KnuckleHull-VNR, Pinkeye Purplehull), some of which had shown absence of symptoms for CMV and BlCMV in unreplicated, seed regeneration plots of the U.S. cowpea collection. Only 3% of all plots had plants infected with both CMV and BlCMV in 2003 and 2004. This percentage increased to 47% in 2005. The accession PI 441917 had the highest 3-year mean for grain yield. However, PI 147071, PI 180014, and ‘KnuckleHull-VNR’ had higher seed protein concentration than other genotypes, but their grain yield was significantly lower than that of PI 441917. The cultivar Coronet and PI 180355 attained midbloom and maturity earlier than the other genotypes. Overall, PI 441917 outperformed all other genotypes for grain yield, including virus-resistant PI 612607 and the cultivar KnuckleHull-VNR. This accession is in the process of being released as a virus-tolerant genotype and should be useful in cowpea breeding programs to help control yield losses by CMV and BlCMV.
Ricardo Goenaga, David Jenkins and 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.
Ricardo Goenaga, Tomas Ayala and Adolfo Quiles
Cowpea or southernpea (Vigna unguiculata) is an important legume crop used as a feed for livestock, as a green vegetable and for consumption of its dry beans, which provide 22% to 25% protein. The crop is very sensitive to alkaline soil conditions. When grown at a soil pH of 7.5 or higher, cowpea develops severe leaf chlorosis caused by deficiencies of iron, zinc, and manganese resulting in stunted plant growth and yield reduction. We evaluated in replicated field experiments at St. Croix, U.S. Virgin Islands, and Miami, FL, four PIs and one commercial cultivar, some of which have shown some tolerance to alkaline soils in unreplicated, seed regeneration plots of the U.S. cowpea collection. At both locations, PI 582702 had significantly higher seed protein concentration than the other PIs, averaging 28%. Alkaline soil conditions at St. Croix were severe resulting in average yield of PIs at this location being significantly lower and 69% less than that in Florida. Nevertheless, some PIs performed well at both locations. For example, PI 582605 had significantly higher yield in Florida, whereas in St. Croix, PIs 582605, 582674, and 582702 were the highest yielders. These PIs may serve as an alternative to growers or home gardeners wishing to establish a legume crop in areas where agricultural production is severely restricted by high soil alkalinity.