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Atlantic Cool Climate Crop Research Centre, Agriculture and Agri-Food Canada, P.O. Box 39088, 308 Brookfield Road, St. John's, NL A1E 5Y7, Canada. Institut Polytechnique LaSalle Beauvais, Rue Pierre Waguet, BP 30313, F-60026 Beauvais Cedex, France

DOI: https://doi.org/10.37855/jah.2009.v11i02.17

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Abstract: Data on molecular markers, anthocyanin contents and antioxidant activities are increasingly used in breeding programs of many horticultural crops. Inter simple sequence repeat (ISSR) analysis, anthocyanin contents and antioxidant activities were used to characterize 10 strawberry (Fragaria x ananassa Duch.) cultivars and nine breeding lines. Fifteen primers generated 240 polymorphic ISSR-PCR bands. Cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) revealed a substantial degree of genetic similarity among the genotypes ranging from 45% to 73% that were in agreement with the principal coordinate (PCO) analysis. Wide genetic diversity was observed among the strawberry genotypes for anthocyanin contents and antioxidant activities. The ISSR analysis together with data for antioxidant activities and anthocyanin contents in strawberries could be used for germplasm management and more efficient choices of parents in current strawberry breeding programs.

United States Department of Agriculture, Agricultural Research Service 2413 E. Hwy 83 Weslaco, Texas 78596.

DOI: https://doi.org/10.37855/jah.2009.v11i02.18

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Abstract: Regulation of flowering in 'Koroneiki' olives by various regimes of daytime and nighttime temperatures was investigated. The trees flowered profusely under chilling (2.5?C; 569 inflorescences tree^-1) and non-chilling nighttime temperatures (8.3?C; 729 inflorescences tree^-1) when daytime temperatures were kept optimal (18.3?C). Chilling nighttime temperatures (2.5?C) did not produce any greater number of inflorescence than non-chilling temperatures of 8.3?C. High daytime temperatures (26.6?C) strongly inhibited flowering at both chilling and non-chilling nighttime temperatures (i.e., 0.5 and 0.0 inflorescences tree¹ under chilling and non-chilling temperatures, respectively). Mildly high daytime temperatures (23.9?C) also inhibited flowering but there were significantly more inflorescences per tree at 23.9?C (220 and 127 inflorescences tree^-1 under chilling and non-chilling nighttime temperatures, respectively) than at 26.6?C. There was no significant difference in the number of inflorescences tree^-1 between chilling and non-chilling nighttime temperatures at both inhibitory daytime temperatures; i.e. 23.9?C and 26.6?C. The trees that were kept vegetative by high daytime temperatures (26.6?C), but given flower inducing nighttime temperature for three months, when returned to optimal flower inducing conditions did not flower before the normal induction period (70-80 days), indicating that inhibitory daytime temperatures canceled any effects of nighttime flower inducing temperatures. Surprisingly, trees kept vegetative in growth chamber at a high daytime temperature (26.6?C) produced fewer inflorescences compared to trees kept vegetative in the greenhouse where temperatures were less controlled but generally, with a few exceptions, remained between 15-20?C in the night and 25-30?C during day.

USDA-ARS, 2217 Wiltshire Rd., Appalachian Fruit Research Station, Kearneysville, WV, 25430, USA.

DOI: https://doi.org/10.37855/jah.2009.v11i02.19

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Abstract: Adequate mineral nutrition is critical for high fruit quality and sustained yield of fruit trees. In this experiment, peach [Prunus persica L. (Batch)] trees with different shoot and root growth habits were evaluated for leaf nitrogen (N) and phosphorus (P) concentrations after fertilizer applications in the greenhouse and field. In the field during 2008, Compact trees had higher root length density than Pillar and Standard trees (6.2, 3.8, and 3.7 mm cm^-3, respectively). Compact trees also had higher foliar P (0.21%) but the same N (1.3%) as Standard and Pillar trees (P concentrations of 0.14 and 0.11%, respectively) when fertilizer was applied once in the greenhouse. Following multiple applications of fertilizer, Compact tree leaves had the same P (approximately 0.21 and 0.29% in the greenhouse and field, respectively) as the other growth habits. After multiple fertilizer applications, Pillar trees had the greatest increase in foliar N and P, which was associated with high transpiration rates. Pillar, Compact, and Standard had transpiration rates of 3.0, 2.1, and 2.3 mmol H₂O m^-2 s^-1, respectively. The data indicate that peach trees with fibrous roots systems may have an advantage to absorb nutrients such as P that move primarily by diffusion, when the nutrient is present in low concentrations in the soil. However, under conditions of high soil fertility, fibrous root systems did not improve nutrient uptake and trees with greater transpiration rates absorbed greater levels of nutrients. Different growth habits of peach have diverse root systems and transpiration rates that affect nutrient uptake and, consequently, the selection of tree growth habit should be considered in orchard soil management plans. Growth habits with more fibrous root systems may require reduced inputs of nutrients with low diffusion coefficients.

Department of Plant, Soil, and Agricultural Systems, Southern Illinois University, Carbondale, IL 62901, USA.

DOI: https://doi.org/10.37855/jah.2009.v11i02.20

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Abstract: Phytophthora blight, caused by Phytophthora capsici Leonian, is a widespread and destructive disease of bell pepper (Capsicum annuum L.). Bell pepper yield, farm-gate revenues and Phytophthora blight incidence were determined during 2005 and 2006 in a P. capsici-infested field near Shawneetown, Illinois. The study evaluated 12 bell pepper cultivars (one resistant, three tolerant, and eight susceptible to P capsici) with or without a recommended fungicide treatment (mefenoxam at transplant and dimethomorph + copper alternated with manganese ethylenebisdithiocarbamate + copper at 10 day intervals). Bell pepper plants receiving fungicide applications showed less Phytophthora blight incidence throughout the growing season and produced greater yield and farm-gate revenues compared to untreated plants. Additionally, P capsici-resistant 'Paladin' and P capsici-tolerant 'Alliance', 'Aristotle X3R', and 'Revolution' produced greater yields (> 17,800 and 33,800 kg ha^-1 for 2005 and 2006, respectively) and farm-gate revenues [> $12,700 and $27,000 (USA) ha^-1 for 2005 and 2006, respectively] compared to the susceptible cultivars. Therefore, in fields with a high incidence history of Phytophthora blight, 'Paladin' could be a reliable choice for commercial bell pepper production. However, 'Alliance', 'Aristotle X3R', and 'Revolution' may be preferred by growers due to the added benefits of bacterial spot [Xanthomonas campestris pv. vesicatoria (Doidge) Dye] resistance and better fruit quality compared to 'Paladin'. Furthermore, this research indicates that plant resistance and/or tolerance should not be relied upon as the only method of P capsici control and growers should also incorporate fungicides into their management program to provide additional protection.

Department of Statistics, TU Dortmund University, 44221 Dortmund, Germany, Department of Mathematics and Statistics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA

DOI: https://doi.org/10.37855/jah.2009.v11i01.02

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Abstract: For combining results from independent experiments, it is essential that information about the precision of the estimates of treatment effects is available. In publications of horticultural experiments, the results of multiple comparisons tests are often reported without sufficient information about the precision of the experiments. Based on limited information of the precision of an experiment such as treatments with the same letter are not significantly different, we develop a method for extracting a possible range of the precision of the experiment which can then be used for meta-analysis. The procedure is demonstrated using a real data example where alternatives to methyl bromide are studied in pre-plant soil fumigation. We also provide an R program which computes the possible range of the precision.

Department of Agricultural and Environmental Sciences, University of Perugia, Borgo XX giugno, 74,1-06121, Perugia (Italy).

DOI: https://doi.org/10.37855/jah.2009.v11i01.03

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Abstract: The model CropSyst has proven useful for management-oriented simulations of growth and yield of cereals and other field crops, but no scientific information is available with reference to processing tomato. The aim of this paper was to parameterise and validate the crop module of CropSyst for the simulation of potential fruit production in processing transplanted tomato (Lycopersicon esculentum Mill.). Parameterisation and calibration were performed by using field data from an experiment carried out in 1997 in Central Italy. The same set of parameters was validated against five independent experiments, carried out on the same location in 1998, 1999, 2000, 2001 and 2002. The simulation of aerial biomass was always very good, with RRMSE values ranging from 7.5 to 13.4% and modelling efficiencies (EI) always above 0.976. The simulation of LAI was very good during the first part of growing season (up to 40-50 days after transplanting), while the decreasing trend in the final part of growing cycle was not always reliably simulated. Indeed, RRMSE for LAI ranged from 13.5 to 26.8% and EI ranged from 0.849 to 0.966. The differences between simulated and observed final fruit yield were below 10%, except in one year (18% in 2001), confirming the practical value of this model, for management and legislative purposes. For research purposes, it is confirmed that the simulation of dry matter partitioning is a crucial issue in vegetable crops such as tomato, wherein the growth of sources and sinks coexists for a main part of crop cycle.

Faculty of Agriculture and Life Science, Hirosaki University, Bunkyocho, Hirosaki 036-8561, Japan.

DOI: https://doi.org/10.37855/jah.2009.v11i01.04

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Abstract: Fruit maturity indices, i.e. respiration rate and ethylene production, amylose (AM) and amylopectin (AP) content, total hydrolytic activity, and sugar content were investigated during the growth and maturation of 'Tsugaru' (early-maturing) and 'Fuji' (late-maturing) apples (Malus domestica Borkh.). Different starch degradation characteristics during the growth and maturation processes were observed between 'Tsugaru' and 'Fuji'. By iodine staining, the loss of starch in 'Tsugaru' was observed earlier than in 'Fuji'. The different degradation patterns of starch were also demonstrated through the observations on AM and AP content. In 'Tsugaru', AM and AP degraded rapidly between 95 to 110 days after full bloom (DAFB) and almost all starch were lost rapidly at 125 DAFB with simultaneous increases in rate of respiration and production of ethylene. However, in 'Fuji', starch degraded gradually throughout growth and maturation process and was clearly degraded at 170 DAFB with a low level of ethylene production and decreased respiration. In both the cultivars, content of AM and AP were highest in the outer cortex and lowest in the inner cortex. Starch degradation was observed simultaneously in 3 different tissue zones and there was little difference in the total hydrolytic activity among tissue zones in both cultivars. These results suggest that starch hydrolysis in the apple flesh began simultaneously rather than preferentially in any one tissue zone. For sugar content, although differences among tissue zones were not clear, it increased distinctly with loss of starch content. Moreover, sugars from the degradation of accumulated starch and sugar translocation seem to influence mainly the sweetness quality as the fruit ripens.

United States Department of Agriculture, Agricultural Research Service, Kika de la Garza Subtropical Agricultural Research Center, 2413 E. Hwy. 83, Weslaco, Texas 78596

DOI: https://doi.org/10.37855/jah.2009.v11i01.01

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Abstract: The South Texas citrus industry needs an inventory of soil properties within existing citrus (Citrus spp.) orchards, wants data at the county level showing soils that are suitable for citrus production, and would value any information related to the establishment of citrus orchards. This study discusses integration of citrus, soil survey geographic data (SSURGO), and U.S. Census spatial and tabular data with geographical information system (GIS) technology for citriculture. For this study, Hidalgo County Texas was evaluated because it is the major citrus producing county in South Texas. The spatial and tabular data and commercial GIS software were used to inventory selected soil chemical and physical properties within citrus groves, to identify orchards that may be affected by urban expansion, and to select potential sites for establishing new citrus orchards. Results indicated that citrus, SSURGO, and U.S. census spatial and tabular data integrated with GIS technology can be a powerful tool for citriculture. The information provided in this study should appeal to producers, extension agents, scientists, and government agencies within the U.S. and abroad.