With the aim of inducing early cropping, the effects of irrigation, fertilization, and polyethyle... more With the aim of inducing early cropping, the effects of irrigation, fertilization, and polyethylene covering on bud emergence were studied in a 1-year-old plantation of prickly pear (Opuntia fucus-indica Mill.) established on sandy soil in the western Negev desert of Israel. Interruption of either irrigation and fertilization (N, P, K) or of irrigation in winter reduced the number of floral buds per plant and slightly delayed their emergence when compared to plants receiving continuous irrigation and fertilization. Polyethylene covering placed over the plants from mid-February to the end of March induced early floral bud emergence associated with early flowering, but was accompanied by a significant decrease in the number of floral buds per plant.
Journal of the American Society for Horticultural Science
Tomato (Lycopersicon esculentum Mill ‘FC111’) plants were dripirrigated with two different concen... more Tomato (Lycopersicon esculentum Mill ‘FC111’) plants were dripirrigated with two different concentrations of diluted seawater (3 or 6 dS·m−1) applied at appearance of the first true leaf (early) or at first breaker fruit (late) stages of plant development. In general, salinity improved flavor and increased percent total soluble solids and sugar concentration. It also reduced color flaws, thus improving the overall quality of fruit. Shelf life was not affected by saline treatments, whereas the yield and fruit size were generally lower than those of fruit from the control treatment. The most important findings were that the overall yield of plants irrigated with the low concentration of saline water at the late stage of development was not significantly different from that of control plants; export quality yield was the same, while fruit quality was still significantly better than that of the control. The use of saline water for quality improvement of tomato fruit grown on sand dunes ...
Journal of the American Society for Horticultural Science
The abstract for the paper, “Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor ... more The abstract for the paper, “Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor of Tomato Fruit” by E. Kopeliovitch, Y. Mizrahi, H. D. Rabinowitch, and N. Kedar [J. Amer. Soc. Hort. Sci. 107(3):361–364. 1982.], contains several errors. The correct version of the abstract is as follows: Organoleptic tests of the nonripening tomato mutants rin and nor and their F1 hybrids with the normal-fruit-bearing cultivar ‘Rutgers’ indicated that fruits of the rin heterozygous plants (rin/+) were slightly inferior and that those of heterozygote nor (nor/+) were distinctly inferior in flavor to fruits of the normal genotype (+/+), all sampled 3–5 days after ethylene and CO2 evolution rates attained maximum levels. The flavor of fruits of the double heterozygotes rin/+, nor/+ was poorer than either of the 2 single-gene heterozygotes, while fruits of both homozygous plants, nor/nor and rin/rin, were unpalatable. Analyses of pH, titratable acidity, total soluble solids, and reducing ...
Current studies on betalains are focused on searching of new plant sources of these pigments. In ... more Current studies on betalains are focused on searching of new plant sources of these pigments. In this light, purple pitaya (Hylocereus polyrhizus) is a valuable batalain-containing fruit. Betalains are known to be sensitive at elevated temperatures conditions. Nevertheless, addition of specific food stabilizers (EDTA, ascorbic acid, citric acid) as well as natural matrix compounds may exert stabilizing effect on maintenance of pigments. Therefore, in presented study, the stability of betalains in Hylocereus polyrhizus juices with protective addition of ascorbic acid at 85 ̊C was examined. Spectrophotometric analyses enable monitoring of reaction during heating of solutions. The hypsochromic shift of λmax to 460 nm is observed in more acidic media without ascorbic acid, suggesting the generation of new reaction products. These absorption bands in solutions with ascorbic acid are not detected, indicating on retaining of the basic structure of betalain chromophore. Generally, pigment r...
Climatic changes have created the imminent need for the development of new crops for arid regions... more Climatic changes have created the imminent need for the development of new crops for arid regions. We started to domesticate and introduce wild and exotic fruit trees to our deserts in 1984. We tested different species in five eco zones in Israel, differing from each other in terms of maximum and minimum temperatures, type and degrees of salinities, water evaporation rates, rainfall, etc. We succeeded in cultivating pitaya species using hybrids from the Hylocereus and Selenicereus genera, and with a different species from the Cactaeae Cereus peruvianus, which we named Koubo. These two species are from the Cactaceae family, known for high water use efficiencies (WUE). We already have investors who started the semi-commercial production of Marula, Sclerocarya birrea sbsp. Caffra, and Argan—Argania spinosa. In spite of the fact that we developed good clones and knowledge of how to grow and ship White Sapote, Casimiroa edulis, and Indian jujube, Ziziphus mauritiana, we failed due to a l...
Field experiments were conducted to examine the effect of fertilization and short periods of drou... more Field experiments were conducted to examine the effect of fertilization and short periods of drought on the out-of-season winter crop in prickly pear [Opuntia ficus-indica (L.) Mill.]. In addition, the winter and summer crops were compared regarding floral bud production and fruit characteristics. Under both continuous fertigation (N, P, K applied with the irrigation water) and continuous irrigation, the number of floral buds per plant was much lower in the winter than in the summer crop. Fertilization increased production of floral buds in both crops, but to a greater extent in the winter crop. The increase in floral bud production in fertilized plants was associated with an increase in NO3-N content in the cladodes. Suspension of fertigation for 4 or 8 weeks immediately after the summer harvest decreased cladode water content and delayed and reduced floral bud emergence as compared with continuous fertigation (control) or late drought (4 or 8 weeks) applied 4 weeks after the summe...
Fruit growth and ripening and the effect of various storage temperatureson fruit quality were stu... more Fruit growth and ripening and the effect of various storage temperatureson fruit quality were studied in Hylocereus undatus and H. polyrhizus growing in Beer-Sheva (Israeli Negev desert) under greenhouse conditions. Dimensional growth of the fruit had a sigmoid pattern with a negligible growth after the onset of peel color change. The first change in peel color was recorded 24-25 d after anthesis in H. undatus and 26-27 d after anthesis in H. polyrhizus. In both species, peel color turned fully red 4-5 days after first color change (mean temperature for the study period was 26.6 ± 2.1 °C). Parallel to color changes the content of pulp, SSC and soluble sugars increased while firmness and the content of starch and mucilage decreased. The surge in acidity before color change indicated the beginning of ripening processes. In H. polyrhizus fruit, which have a red-violet pulp, the pigment increased in parallel to the development of peel color. The fruit were proved nonclimacteric, and whe...
Journal of the American Society for Horticultural Science, 1991
A spontaneous tomato (Lycopersicon esculentum Mill.) triploid hybrid was analyzed by isozyme and ... more A spontaneous tomato (Lycopersicon esculentum Mill.) triploid hybrid was analyzed by isozyme and restriction fragment length polymorphism profiles. The double chromosome complement donor was shown to be the male parent, contrary to the prevailing hypothesis.
Journal of the American Society for Horticultural Science, 2009
This study examined the response of the crassulacean acid metabolism (CAM) vine-cactus fruit crop... more This study examined the response of the crassulacean acid metabolism (CAM) vine-cactus fruit crop species Hylocereus undatus to two CO2 regimes [enrichment (1000 μmol·mol−1) vs. ambient control (380 μmol·mol−1)] and to two fertilization regimes [0.5- vs. 0.1-strength Hoagland's solution (designated high and low, respectively)]. CO2 enrichment increased total daily net CO2 uptake, nocturnal acid accumulation, shoot elongation, and total dry mass by 39%, 24%, 14%, and 6% (averaging the two fertilization regimes) versus ambient CO2 treatment, respectively. Plants exposed to high fertilization demonstrated 36%, 21%, 198%, and 79% (averaging the two CO2 regimes) increases versus those receiving the low fertilization regime in total daily net CO2 uptake, nocturnal acid accumulation, stem elongation, and total dry mass, respectively. Plants exposed to high fertilization and elevated CO2 demonstrated 108%, 77%, 264%, and 111% increases versus those receiving the low fertilization regime...
Several different species of the columnar cacti of the genera Stenocereus and Pachycereus, were i... more Several different species of the columnar cacti of the genera Stenocereus and Pachycereus, were introduced into different semi-arid ecozones in Israel and most of these efforts were of disappointing outcomes, the only exception being the Cereus peruvianus (L.) Miller,which bore plenty of fruits, some of them of good taste. The original seeds of this plant were obtained from the late Mr. Amram (Ron) Kodish, who collected seeds from various private gardens in Southern California which bore fruits of reasonable qualities. The initial success of this species led us to initiate an intensive research study, and today it is already fruit-crop, marketed mainly in Israel under the name " Koubo" . This paper will describe our work of domestication of this new cactus fruit crop in Israel.
Hylocereus and Selenicereus are native to tropical and sub-tropical America. Based on its taxonom... more Hylocereus and Selenicereus are native to tropical and sub-tropical America. Based on its taxonomic status and crossability relations it was postulated that H. megalanthus (syn. S. megalanthus) is an allotetraploid (2n = 4x = 44) derived from natural hybridization between two closely related diploid taxa. The present work aimed at elucidating the genetic relationships between species of the two genera. Crosses were performed and the putative hybrids were analysed by chromosome counts and morphological traits. The ploidy level of hybrids was confirmed by fluorescent in situ hybridization (FISH) of rDNA sites. Genomic in situ hybridization (GISH) was used in an attempt to identify the putative diploid genome donors of H. megalanthus and an artificial interploid hybrid. Reciprocal crosses among four diploid Hylocereus species (H. costaricensis, H. monacanthus (syn. H. polyrhizus), H. undatus and Hylocereus sp.) yielded viable diploid hybrids, with regular chromosome pairing. Reciprocal...
With the aim of inducing early cropping, the effects of irrigation, fertilization, and polyethyle... more With the aim of inducing early cropping, the effects of irrigation, fertilization, and polyethylene covering on bud emergence were studied in a 1-year-old plantation of prickly pear (Opuntia fucus-indica Mill.) established on sandy soil in the western Negev desert of Israel. Interruption of either irrigation and fertilization (N, P, K) or of irrigation in winter reduced the number of floral buds per plant and slightly delayed their emergence when compared to plants receiving continuous irrigation and fertilization. Polyethylene covering placed over the plants from mid-February to the end of March induced early floral bud emergence associated with early flowering, but was accompanied by a significant decrease in the number of floral buds per plant.
Journal of the American Society for Horticultural Science
Tomato (Lycopersicon esculentum Mill ‘FC111’) plants were dripirrigated with two different concen... more Tomato (Lycopersicon esculentum Mill ‘FC111’) plants were dripirrigated with two different concentrations of diluted seawater (3 or 6 dS·m−1) applied at appearance of the first true leaf (early) or at first breaker fruit (late) stages of plant development. In general, salinity improved flavor and increased percent total soluble solids and sugar concentration. It also reduced color flaws, thus improving the overall quality of fruit. Shelf life was not affected by saline treatments, whereas the yield and fruit size were generally lower than those of fruit from the control treatment. The most important findings were that the overall yield of plants irrigated with the low concentration of saline water at the late stage of development was not significantly different from that of control plants; export quality yield was the same, while fruit quality was still significantly better than that of the control. The use of saline water for quality improvement of tomato fruit grown on sand dunes ...
Journal of the American Society for Horticultural Science
The abstract for the paper, “Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor ... more The abstract for the paper, “Effect of the Fruit-ripening Mutant Genes rin and nor on the Flavor of Tomato Fruit” by E. Kopeliovitch, Y. Mizrahi, H. D. Rabinowitch, and N. Kedar [J. Amer. Soc. Hort. Sci. 107(3):361–364. 1982.], contains several errors. The correct version of the abstract is as follows: Organoleptic tests of the nonripening tomato mutants rin and nor and their F1 hybrids with the normal-fruit-bearing cultivar ‘Rutgers’ indicated that fruits of the rin heterozygous plants (rin/+) were slightly inferior and that those of heterozygote nor (nor/+) were distinctly inferior in flavor to fruits of the normal genotype (+/+), all sampled 3–5 days after ethylene and CO2 evolution rates attained maximum levels. The flavor of fruits of the double heterozygotes rin/+, nor/+ was poorer than either of the 2 single-gene heterozygotes, while fruits of both homozygous plants, nor/nor and rin/rin, were unpalatable. Analyses of pH, titratable acidity, total soluble solids, and reducing ...
Current studies on betalains are focused on searching of new plant sources of these pigments. In ... more Current studies on betalains are focused on searching of new plant sources of these pigments. In this light, purple pitaya (Hylocereus polyrhizus) is a valuable batalain-containing fruit. Betalains are known to be sensitive at elevated temperatures conditions. Nevertheless, addition of specific food stabilizers (EDTA, ascorbic acid, citric acid) as well as natural matrix compounds may exert stabilizing effect on maintenance of pigments. Therefore, in presented study, the stability of betalains in Hylocereus polyrhizus juices with protective addition of ascorbic acid at 85 ̊C was examined. Spectrophotometric analyses enable monitoring of reaction during heating of solutions. The hypsochromic shift of λmax to 460 nm is observed in more acidic media without ascorbic acid, suggesting the generation of new reaction products. These absorption bands in solutions with ascorbic acid are not detected, indicating on retaining of the basic structure of betalain chromophore. Generally, pigment r...
Climatic changes have created the imminent need for the development of new crops for arid regions... more Climatic changes have created the imminent need for the development of new crops for arid regions. We started to domesticate and introduce wild and exotic fruit trees to our deserts in 1984. We tested different species in five eco zones in Israel, differing from each other in terms of maximum and minimum temperatures, type and degrees of salinities, water evaporation rates, rainfall, etc. We succeeded in cultivating pitaya species using hybrids from the Hylocereus and Selenicereus genera, and with a different species from the Cactaeae Cereus peruvianus, which we named Koubo. These two species are from the Cactaceae family, known for high water use efficiencies (WUE). We already have investors who started the semi-commercial production of Marula, Sclerocarya birrea sbsp. Caffra, and Argan—Argania spinosa. In spite of the fact that we developed good clones and knowledge of how to grow and ship White Sapote, Casimiroa edulis, and Indian jujube, Ziziphus mauritiana, we failed due to a l...
Field experiments were conducted to examine the effect of fertilization and short periods of drou... more Field experiments were conducted to examine the effect of fertilization and short periods of drought on the out-of-season winter crop in prickly pear [Opuntia ficus-indica (L.) Mill.]. In addition, the winter and summer crops were compared regarding floral bud production and fruit characteristics. Under both continuous fertigation (N, P, K applied with the irrigation water) and continuous irrigation, the number of floral buds per plant was much lower in the winter than in the summer crop. Fertilization increased production of floral buds in both crops, but to a greater extent in the winter crop. The increase in floral bud production in fertilized plants was associated with an increase in NO3-N content in the cladodes. Suspension of fertigation for 4 or 8 weeks immediately after the summer harvest decreased cladode water content and delayed and reduced floral bud emergence as compared with continuous fertigation (control) or late drought (4 or 8 weeks) applied 4 weeks after the summe...
Fruit growth and ripening and the effect of various storage temperatureson fruit quality were stu... more Fruit growth and ripening and the effect of various storage temperatureson fruit quality were studied in Hylocereus undatus and H. polyrhizus growing in Beer-Sheva (Israeli Negev desert) under greenhouse conditions. Dimensional growth of the fruit had a sigmoid pattern with a negligible growth after the onset of peel color change. The first change in peel color was recorded 24-25 d after anthesis in H. undatus and 26-27 d after anthesis in H. polyrhizus. In both species, peel color turned fully red 4-5 days after first color change (mean temperature for the study period was 26.6 ± 2.1 °C). Parallel to color changes the content of pulp, SSC and soluble sugars increased while firmness and the content of starch and mucilage decreased. The surge in acidity before color change indicated the beginning of ripening processes. In H. polyrhizus fruit, which have a red-violet pulp, the pigment increased in parallel to the development of peel color. The fruit were proved nonclimacteric, and whe...
Journal of the American Society for Horticultural Science, 1991
A spontaneous tomato (Lycopersicon esculentum Mill.) triploid hybrid was analyzed by isozyme and ... more A spontaneous tomato (Lycopersicon esculentum Mill.) triploid hybrid was analyzed by isozyme and restriction fragment length polymorphism profiles. The double chromosome complement donor was shown to be the male parent, contrary to the prevailing hypothesis.
Journal of the American Society for Horticultural Science, 2009
This study examined the response of the crassulacean acid metabolism (CAM) vine-cactus fruit crop... more This study examined the response of the crassulacean acid metabolism (CAM) vine-cactus fruit crop species Hylocereus undatus to two CO2 regimes [enrichment (1000 μmol·mol−1) vs. ambient control (380 μmol·mol−1)] and to two fertilization regimes [0.5- vs. 0.1-strength Hoagland's solution (designated high and low, respectively)]. CO2 enrichment increased total daily net CO2 uptake, nocturnal acid accumulation, shoot elongation, and total dry mass by 39%, 24%, 14%, and 6% (averaging the two fertilization regimes) versus ambient CO2 treatment, respectively. Plants exposed to high fertilization demonstrated 36%, 21%, 198%, and 79% (averaging the two CO2 regimes) increases versus those receiving the low fertilization regime in total daily net CO2 uptake, nocturnal acid accumulation, stem elongation, and total dry mass, respectively. Plants exposed to high fertilization and elevated CO2 demonstrated 108%, 77%, 264%, and 111% increases versus those receiving the low fertilization regime...
Several different species of the columnar cacti of the genera Stenocereus and Pachycereus, were i... more Several different species of the columnar cacti of the genera Stenocereus and Pachycereus, were introduced into different semi-arid ecozones in Israel and most of these efforts were of disappointing outcomes, the only exception being the Cereus peruvianus (L.) Miller,which bore plenty of fruits, some of them of good taste. The original seeds of this plant were obtained from the late Mr. Amram (Ron) Kodish, who collected seeds from various private gardens in Southern California which bore fruits of reasonable qualities. The initial success of this species led us to initiate an intensive research study, and today it is already fruit-crop, marketed mainly in Israel under the name " Koubo" . This paper will describe our work of domestication of this new cactus fruit crop in Israel.
Hylocereus and Selenicereus are native to tropical and sub-tropical America. Based on its taxonom... more Hylocereus and Selenicereus are native to tropical and sub-tropical America. Based on its taxonomic status and crossability relations it was postulated that H. megalanthus (syn. S. megalanthus) is an allotetraploid (2n = 4x = 44) derived from natural hybridization between two closely related diploid taxa. The present work aimed at elucidating the genetic relationships between species of the two genera. Crosses were performed and the putative hybrids were analysed by chromosome counts and morphological traits. The ploidy level of hybrids was confirmed by fluorescent in situ hybridization (FISH) of rDNA sites. Genomic in situ hybridization (GISH) was used in an attempt to identify the putative diploid genome donors of H. megalanthus and an artificial interploid hybrid. Reciprocal crosses among four diploid Hylocereus species (H. costaricensis, H. monacanthus (syn. H. polyrhizus), H. undatus and Hylocereus sp.) yielded viable diploid hybrids, with regular chromosome pairing. Reciprocal...
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