Department of Horticulture, Oregon State University, Corvallis, OR, 97331- 7304, USA; USDA-ARS, 45 Wiltshire Road, Kearneysville, WV, 25430-9606, USA, Forestry & Natural Resource Department, Purdue University, West Lafayette, IN, 47907-2072, USA, Departme
DOI: https://doi.org/10.37855/jah.2007.v09i01.01
Key words: Superoxide dismutase, oxidative stress, salt stress, transgenic tomato.
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Abstract: Production of reactive oxygen species (ROS) is associated with a number of physiological disorders in plants. Superoxide dismutase (SOD) catalyzes the breakdown of superoxide (O2-) into O2 and H2O2 and provides the first line of defense against the toxic effects of elevated levels of ROS. The effect of increased expression of Mn superoxide dismutase (Mn-SOD) on salt stress tolerance was studied using transformed tomato (Lycopersicon esculentum cv. Zhongshu No. 5) plants. Northern blots confirmed expression of the heterologous Mn-SOD in transgenic plants. Strong Mn-SOD enzyme activity was detected by native PAGE in transformed plants. Transgenic plants showed resistance to the superoxide-generating herbicide methyl viologen (MV, 10-4 M). The total SOD activity was one and one half- to two-fold higher, and APX (ascorbate peroxidase) activity was six to seven fold higher in transgenic, than in wild-type (WT) plant under MV stress. Germination of transgenic tomato seeds at a NaCl concentration of 150 mM was greater than wild-type seeds. When exposed to salt stress, roots of transgenic plants were less stunted and leaf injury was lower than that observed in WT plants. Also, the total APX activity of transgenic plants was 4 to 5 fold higher than that of WT under NaCl (200 mM) stress.
Department of Horticulture and Landscape Architecture, Oklahoma State University, Stillwater, OK 74078-6027, USA
DOI: https://doi.org/10.37855/jah.2007.v09i01.07
Key words: Briza media, Chasmanthium latifolium, Imperata cylindrica, Liriope muscari, Pennisetum alopecuroides, phytotoxicity, weed control.
Abstract: Tolerance of field- and container-grown lilyturf (Liriope muscari (Decne.)), (Liliaceae) and four species of ornamental grasses (Poaceae), perennial quaking grass (Briza media L.), Japanese bloodgrass (Imperata cylindrica (L.) Beauv. 'Red Baron'), river oats (Chasmanthium latifolium (Michx.) Yates) and dwarf fountain grass (Pennisetum alopecuroides (L.) Spreng. 'Hameln'), to five preemergent herbicides (isoxaben, oryzalin, oxadiazon, oxyfluorfen, and prodiamine) was evaluated. Grasses were planted in the fall of 1997 and in the spring of 1998. Herbicides were applied to the fall planting in the spring of 1998. The April, 1998 plantings received herbicide applications within two or 45 days after planting. Herbicides were applied within two days of planting in May and June of 1998. All species in the field and containers were damaged most by oxyfluorfen, followed by oxadiazon; however, injury was not as severe with oxadiazon as with oxyfluorfen. The oxadiazon-treated plants recovered more quickly than oxyfluorfen-treated plants. Plants were least damaged by prodiamine, oryzalin, and isoxaben. Field-grown Japanese bloodgrass, dwarf fountain grass and lilyturf were generally less damaged when herbicide was applied in June, regardless of planting date or herbicide applied than by the April herbicide application. Prodiamine, oryzalin, or isoxaben caused few phototoxicity symptoms in the species tested, but oxyfluorfen and oxadiazon caused unacceptable injury.
Faculty of Agriculture, Shahid Chamran, University, Ahwaz, Iran.
DOI: https://doi.org/10.37855/jah.2007.v09i01.08
Key words: Allium cepa, Aspergillus niger, cultivars, life storage, onion
Abstract: In Khuzestan (South Iran), onion bulbs are usually formed and harvested in spring and consumed either in the same season or during summer while some of these are kept for seed production. In order to study the losses in onion bulbs under hot store conditions, an experiment was conducted in autumn 2002 and spring 2003. The data were collected on five cultivars being produced at Shahid Chamran University, two local cultivars and three of those under commercial cultivation. The collected bulbs were kept in 30 x 50cm boxes, 15 cm in height. The experiment was replicated three times in completely randomized design. Data on change in number, weight of the healthy bulbs and decayed bulbs were recorded every 15 days. No bulb root was produced during the storage when maximum, average and minimum temperature were 48, 33 and 25oC, respectively with the average relative humidity (RH) of 30%. As far as storage life was concerned, there was a significant difference among the varieties. Compared to both the local and market bulbs, those produced at Shahid Chamran University showed more storage life. Another important finding of this research was that 50% of the local and university bulbs remained unspoiled after 120 days, whereas the Taxes Yellow Grano, Taxes Early Grano and G1 had the short storage life; 50% of the stock were destroyed after 60 days. In the present study, Aspergillus niger was found to be the most important factor responsible for onion decay in hot stores of Khuzestan.
Centro Universitario de Investigacion y Desarrollo Agropecuario Universidad de Colima. Km 40Autopista Colima-Manza-nilloTecomdn, Col. 28100Mexico. InstitutoNacionaldeInvestigacionesForestales, Agricolas y Pecuarias. Campo Experimental Tecomdn.
DOI: https://doi.org/10.37855/jah.2007.v09i01.09
Key words: Cucumis melo L., nitrogen fertilization, petiole sap, export product, soil moisture
Abstract: In cantaloupe farming (Cucumis melo L.), the production of export quality fruit require nutritional indicators that allow an adequate management of nitrogen fertilization and irrigation water supply. This study with cantaloupe muskmelon was carried out to test four nitrogen fertilization treatments and three levels of soil moisture tension under field conditions. Nitrate content (N-NO3) in the cellular extract was evaluated as an indicator of nutritional status. Significant correlation was found between the lowest nitrate concentrations in the petiole sap and the N fertilization doses in three different sample periods. The effect of soil moisture tension on nitrate concentration varied in both years; this was attributed to soil temperature differences. Results showed that it is feasible to establish outcome predictions of yield and quality of the fruit based on the nitrate concentration in petiole sap, concluding that this is an adequate indicator of the nutritional status of the cantaloupe plant. However, its use as a guide for managing fertilization and irrigation must include a permanent follow up of the crop that evaluates the effects of environmental factors in plant growth and uptake of the nutrients.
Faculty of Agriculture, Comahue National University, c.c. 85, 8303 Cinco Saltos, R.N., Argentina.
DOI: https://doi.org/10.37855/jah.2007.v09i01.10
Key words: Flower thinning, fruit size, growth curves, lime sulphur, maturity, Pyrus communis.
Abstract: Thinning is a central management activity in the production of high quality fruit required for the domestic and export market. Early thinning of fruit trees is important since it influences fruit size and the time of application affects flower bud formation for the following season. Furthermore, finding organic blossom thinners is a major challenge as hand thinning is a costly practice. At the High Valley region of Argentina (lat. 38?56' 67?59'W), lime sulphur was evaluated as flower thinner on 'Abbe Fetel' (Pyrus communis L.) pear trees trained to palmette leader. Treatments were 1) control, and 2) 7 % lime sulphur applied at 30 % bloom, using an orchard sprayer. Fruit diameter (FD) was recorded two weekly (n=20 per date and treatment). At 144 days after full bloom (DAFB), or initial commercial harvest, fruit weight and the maturity indices were determined. Fruits were then graded into size categories. Growth equations were developed using non linear regression and mean separations were computed with Student's t-test. The lime sulphur sprays significantly increased mean FD, starting from 115 DAFB. Logistic model best fitted the fruit growth vs. time curves. Percentage of fruits with <65mm diameter was 25 % for the control and 5.26 % for lime sulphur treatment. Treatment 2 increased final fruit weight by 16.5 %, as compared to the untreated pears. At 144 DAFB, thinned trees showed firmer fruits than the controls (64.4 vs. 61.7 N) and there were no statistical differences among treatments in soluble solids concentration and starch index. Consequently, data indicated that lime sulphur at 7 % was an effective flower thinning agent to enhance 'Abbe Fetel' pear seasonal fruit growth and quality.
Dipartimento S.En.Fi.Mi.Zo., Sezione di Frutticoltura Mediterranea, Tropicale e Subtropicale, Universitd degli Studi di Palermo, Viale delle Scienze 11, 90128Palermo, Italy.
DOI: https://doi.org/10.37855/jah.2007.v09i01.11
Key words: Canopy size, crop load, deficit irrigation, fruit growth, fruit quality, leaf area, shoot length, stomatal conductance, yield.
Abstract: We investigated the vegetative and productive responses of 'Golden Delicious' apple (Malus domestica Borkh.) trees to fixed partial rootzone drying under the dry climate of central Sicily. Soil water content (SWC), stomatal conductance, yield, fruit quality, fruit growth, and vegetative growth of conventionally irrigated trees (CI), where drip emitters on both sides of each tree were left open, were compared to that of fixed partial rootzone drying (FPRD) trees where only one side of the rootzone was irrigated for the entire season thus receiving 50% of the CI irrigation water. The irrigation season started on 31 July and ended on 13 September, 2004. Wet and dry rootzone sides showed significantly different SWC from 16 August until 14 September, whereas stomatal conductance of CI and FPRD trees differed significantly starting on 24 August. Relative growth rate of CI fruit was higher than that of FPRD fruit on 27 and 31 August, but fruit size was similar during the entire sampling period and at harvest. Trees of the two treatments had similar yields, number of fruits, crop load, fruit:leaf ratio, fruit quality, tree height, wood fresh and dry weight, canopy spread area, volume and density, shoot length and number, internode length, and leaf area. FPRD trees had higher yield efficiency, thinner shoots, lower leaf water content, higher canopy density and leaf dry weight and specific leaf weight than CI trees. Our observations suggest the extent of possible water savings without loss of yield and fruit quality using this partial rootzone drying strategy in 'Golden Delicious' apple orchards of central Sicily.
Department of Crop, Soil & Pest Management, Federal University of Technology, PMB 704, Akure, Nigeria
DOI: https://doi.org/10.37855/jah.2007.v09i01.12
Key words: Bell pepper, fertigation, hydraulics, stomata, canopy, leaf potential, water uptake
Abstract: The effect of fertigation regimes on water transport properties (soil, plant and canopy resistances) through the plant to the canopy in the Soil-Plant-Atmosphere-Continuum (SPAC) was studied in bell pepper in a Mediterranean climate. The treatments consisted of fertigated drip irrigation in factorial combinations of three levels (amounts) of water application (daily, twice and once weekly) and application frequencies (2, 6 and 10 times per fertigation event). Leaf water potential and stomatal conductance were monitored while whole plant hydraulic conductance was estimated by the evaporative flux method, using the Ohm's law analogy (the slope of the water potential difference (Ay) versus sap fluxes). Canopy conductance (inverse of resistance) was estimated from vapour pressure deficit (vpd) and transpiration flux. Differences in the intervals between fertigation events altered the environment for root development and affected soil moisture status, stomatal conductance (gs), leaf water potential (lwp), transpiration (sap) flux, and xylem and canopy water transport capacities in bell pepper. The components of the resistance elements in the SPAC differed under the fertigation treatments. Total plant resistance (Rp) increased with transpiration flux in a linear manner in addition to a proportional decrease in stomatal (gs) and canopy conductance (gc). Canopy component constitutes the least resistance (greatest conductance) to the flow of water, estimated soil resistance was much lower than total resistance to the flow of water, and the highest within plant resistance is contained in the root system which constituted a predominant part of total plant resistance. Bell pepper has an efficient xylem sap transport system, maintains gs and plant water status under variable soil moisture regimes. Bell pepper water use is affected by soil environment, plant architectural and xylem traits. The mechanisms underlying differences in water use and plasticity of physiological functions in bell pepper under variable fertigation regimes appeared to be offered through changes in the magnitudes of component resistances of the water transport pathways in the SPAC. The implications of knowledge of the magnitudes of the resistances to water flow pathway in the SPAC to irrigation management is discussed.
Catedra de Quimica Analitica, Catedra de Fitopatologia, lnvestigador alumno. Facultadde Agronomia de la Universidad de Buenos Aires (FAUBA) Av. San Martin 4453. Capital Federal (1416), lnstituto de Floricultura -INTA-CASTELAR. De los Reserosy
DOI: https://doi.org/10.37855/jah.2007.v09i01.13
Key words: Lactuca sativa, hydroponic, chloride, nitrate, vitamin C, nitrogen, phytotoxicity, pH, electrical conductivity
Abstract: Disinfection by chlorination was applied to the solution of a soilless closed system of Lactuca sativa varieties, Gallega and Mantecosa. The aim was to study the effect of the addition of different doses of chlorine on the production (fresh weight and dry matter), quality (nitrates, vitamin C and nitrogen contents), and phototoxicity to lettuce (chlorosis) with regard to the chemical properties of the solution (pH, electrical conductivity EC and chlorides). Four treatments were applied: 0.55, 5.5 and 11 mg L-1 (ppm) of chlorine and a control without addition of chlorine. The 11 mg L-1 treatment produced a decrease in production of Gallega, presenting a 40 % lower fresh weight than the control. Both varieties presented high contents of nitrates. Gallega presented the maximum values (2920- 8158 mg kg-1) and showed values under the permissible limit with the 0.55 and 5.5 mg L-1 treatments. Mantecosa showed lower maximum values (3787- 5291 mg kg-1), although with all the values above the limits of permission. The contents of nitrogen for both varieties exceeded the levels of sufficiency in all the treatments. This fact was related to the high nitrogen supply provided by the fertirrigation that contributed to the high nitrate contents. Gallega presented larger contents of vitamin C (19.3-28 mg.100g-1) than Mantecosa (15.3?19.98 mg 100g-1). Chlorination did not affect the chemical properties of the solution (pH and EC remained between the appropriate range for the species). Chloride contents in the nutrient solution were larger at the 11ppm doses; however the values remained under the toxicity levels for the species. For both the varieties, 0.55 mg L-1 treatment produced the higest fresh weight and vitamin C contents and the lowest nitrate contents and toxicity symptoms (chlorosis), while 11 mg L-1 treatment resulted more chlorosis and necrosis of leaves, diminishing the commercial quality of the plants.
Department of Horticulture Science, Box 7609, North Carolina State University, Raleigh, NC 27695-7609
DOI: https://doi.org/10.37855/jah.2007.v09i01.14
Key words: Paclobutrazol, piccolo, plant growth regulators, uniconazole
Abstract: Flurprimidol preplant bulb soaks (10 to 40 mg L-1) were applied to tulip (Tulipa sp. L.) bulbs for growth control. Three tulip cultivars ('Page Polka', 'Prominence' and 'Red Present') were used to determine if the efficacy of flurprimidol varied by cultivar. Flurprimidol was compared to paclobutrazol (50 and 100 mg L-1) and uniconazole (10 and 20 mg L-1). Flurprimidol preplant bulb soaks significantly (P < 0.05) controlled tulip plant height during the greenhouse forcing when applied to 'Page Polka' and 'Prominence' at concentrations > 15 mg L-1 and > 10 mg L-1, respectively. A concentration of 40 mg L-1 was needed to control plant height during the postharvest evaluation for 'Page Polka' while concentrations > 15 mg L-1 controlled postharvest plant height for 'Prominence'. No control during forcing or postharvest was provided by any concentration tested on 'Red Present'. The differences observed indicate that the efficacy of flurprimidol as a preplant bulb soak varied with cultivars. In order to determine optimal cultivar doses, growers will need to conduct their own tulip cultivar trials, with flurprimidol concentrations ranging between 10 and 40 mg L-1.
Faculty of Agriculture, The University of Tabriz, PO Box 51664, Tabriz, Iran
DOI: https://doi.org/10.37855/jah.2007.v09i01.15
Key words: Ni, cucumber, N, yield, quality, urea, nitrate
Abstract: The effects of Ni concentrations in the nutrient solution on the yield, quality and N assimilation of cucumber plants were evaluated in plants grown either with urea or nitrate as the sole N source. The cucumber plants (Cucumis sativus cv RS189 and Vikima) were treated with two N sources, urea and nitrate as NaNO3 at 200 mg L-1, and three concentration of Ni as NiSO4.6H2O (0, 0.5, and 1 mg L-1). Treatments were arranged in a randomized block design with six replicates. The highest concentration of Ni in the leaves (1.2 mg kg-1 DW) was observed in the urea-fed plants at 1 mg L-1 Ni concentration. Addition of Ni up to 0.5 mg L-1 had no effect on the fruit Ni concentration in the both urea and nitrate-fed plants. Ni supplement (0.5 mg L-1) increased the yield significantly (10 and 15% in RS189 and Vikima, respectively), in urea-fed plants but decreased when 1 mg L-1 Ni applied to the solutions. Nitrate-fed plants had higher percentage of total soluble solids compared to urea-fed plants. Nitrate concentration of the fruits in urea-fed plants in both cultivars was approximately 50% less than those nitrate-fed plants. The reduction of nitrate concentration in the fruits became more pronounced as the Ni concentration increased in the solution. The rate of photosynthesis (Pn) in urea-fed plants continuously increased with the increase of the Ni concentration in the solution. Both N concentration and NR (Nitrate Reductase) activity of young leaves were higher in urea-fed plants at 0.5 mg L-1 Ni concentration. Ni supplements enhanced the growth and yield of urea-fed plants by the increase of Pn, N concentration and NR activity. It can be concluded that Ni supplements (0.5 mg L-1) improves yield, quality and NR activity in urea-fed cucumber plants.
N. Poushkarov Institute of Soil Science, National Center of Agricultural Sciences, 7-Shosse Bankya str. 1080 Sofia, Bul?garia; Acad. M. Popov Institute ofPlant Physiology, Bulgarian Academy of Sciences, Acad. G. Bonchev str., Bl. 21, 1113 Sofia, Bulgaria
DOI: https://doi.org/10.37855/jah.2007.v09i01.16
Key words: Head cabbage, quality parameters, foliar fertilization, fertilizer application
Abstract: The influence of different fertilizer sources on head cabbage (Brassica oleracea var. capitata, cv. Pructor) yield and quality was studied. The field experiment was carried out on alluvial - meadow soil (fluvisol -FAO) pH 6.5. The trial included mineral fertilizer, farmyard manure and foliar fertilizer. The highest yield values were obtained with mineral fertilization. The best quality parameters in the cabbage leaves - dry weight, total soluble sugars, cellulose, vitamin C and nitrates content were obtained in the treatments with foliar fertilization followed by the treatments with organic fertilization. The observed decrease of N and K residuals after the harvest of head cabbage crop in comparison with the initial soil reserves indicated complete absorption of fertilizers supplied and this is a very important result from ecological point of view.
Department of Biotechnology, Faculty of Agriculture, Bu-Ali Sina University, Hamadan, Iran.
DOI: https://doi.org/10.37855/jah.2007.v09i01.17
Key words: Carnation, embryogenic callus, somatic embryos, sucrose.
Abstract: The effect of sucrose concentration was investigated on callus induction and differentiation of embryogenic callus derived from petal explants of carnation cultivar Nelson'. Embryogenic calli were produced on MS culture medium containing 9 uM 2,4-dichlorophenoxy acetic acid (2,4-D), 0.8 uM 6-benzyladenine (BA) and different concentrations of sucrose alone or in combination with sorbitol. In constant osmotic potential medium, number of explants containing embryogenic calli was significantly enhanced by increasing the sucrose concentration. Somatic embryos were induced on a hormone-free media containing various concentrations of sucrose alone or in combination with sorbitol. Different sucrose concentrations from 50 to 150 mM significantly increased somatic embryos. No callus and embryo formed when sorbitol was the sole carbon source. In the presence of a constant sucrose concentration, increasing the osmotic potential with sorbitol led to increase in the frequency of somatic embryos. In medium containing low concentration of sucrose (50 and 100 mM), reduced development of embryos was recorded. 90% of somatic embryos were regenerated to form the entire plantlets when they were transferred onto the half-strength MS culture medium containing 3% sucrose. Plantlets also continued to grow under greenhouse condition.
Division of Agriculture Faculty, University of Arkansas atMonticello, P.O. Box 3508, Monticello, Arkansas 71656, USA
DOI: https://doi.org/10.37855/jah.2007.v09i01.18
Key words: Tomato, foliar nutrient amendments, B, K, Ca, yield enhancement, fruit-set, biostimulants, Lycopersicon esculentum
Abstract: Field studies were established in 2004 and 2005 to determine the effects of transplant drench and foliar applications of organic-complex Ca, B, K amendments and a yield enhancement product, 'Perc PlusTM', on the flowering, fruiting, fruit yield and market value of Italian-cv. 'Classica' and large-fruited cv. 'Amelia' tomato (Lycopersicon esculentum Mill.). Treatments were an organic yield enhancement applied as a transplant drench and then foliar 7 days later (TD); once a week foliar amendments of organic-complex Ca, B, and K nutrients beginning at first bloom for 4 weeks (FA); a combination of the drench and foliar treatments (TD+FA); and a control (CON). Fruit-set of 'Classica' was significantly higher for the FA and TD+FA than the other treatments in 2004, however there was no effect on yield and quality of harvested fruit. Flowering and fruit-set of 'Amelia' were not affected by drench and/or foliar amendments in either year. Total fruit yield and quality of the treated plots were not significantly different than the CON for either cultivar or year.
Department of Crop Science, University of Nigeria, Nsukka, Nigeria; Department of Crop Science, Akperan Orishi College of Agriculture, Yandev, Benue State, Nigeria.
DOI: https://doi.org/10.37855/jah.2007.v09i01.19
Key words: Bananas and plantains, genotypic differences, nutrient uptake.
Abstract: Six genotypes comprising a landrace and a hybrid from each of the three Musa major genomic groups were evaluated in a soilless potting mix. Effect of genotype on most of the growth parameters was non-significant. But the uptake (total quantity accumulated, distribution pattern and tissue concentration) of N and K was significantly (P < 0.05) influenced by genotype (G), age of plant at sampling (AP) and G x AP interaction. Dessert bananas had higher N uptake while 'PITA 22' (a plantain hybrid) demonstrated an exceptional propensity for K uptake. Nitrogen and potassium concentration varied with tissue, genotype and age of plant at sampling. Nitrogen concentration in roots and leaves decreased with plant age while it increased in the corm. Potassium concentration in roots, corm and leaves increased progressively with plant age in all the genotypes. Significant differences in the quantity of N and K accumulated per plant, even though all the genotypes were planted in the same potting mix, suggested differential nutrient mining capacity of the genotypes. Implying that nutrient uptake and consequently nutrient demand varies with genotype, supplemental application would vary accordingly. The study suggested that genotype that had higher nutrient uptake will impoverish the soil faster, and thus require more external nutrient inputs to maintain/restore soil productivity.
Department of Applied Biological Sciences, Faculty of Agriculture, Kagawa University, Miki, Kagawa 761-0795, Japan
DOI: https://doi.org/10.37855/jah.2007.v09i01.02
Key words: Ammonia, ethylene, postharvest life, respiration, broccoli
Abstract: Sugars play indispensable roles in many metabolic processes in plants. In broccoli, the level of sugars, particularly sucrose, rapidly decline few days after harvest. This study investigated the influence of exogenous application of 10% (w/v) sucrose to broccoli heads during storage at 20oC. Hydration of the head was slowed down by sucrose treatment compared with the non-treated heads which gained weight by about 5% of the initial value at the end of the experimental period. Furthermore, sucrose application enhanced ethylene production as well as respiration rate. Glutamine synthetase (GS; EC 6.3.1.2) activity was higher in the florets of sucrose-treated heads but, like the non-treated heads, the activity continuously declined until the end of the storage period. The relatively higher GS activity during the early period of storage caused the delay of the onset of ammonia accumulation by about a day. In the branchlet portion, GS activity was higher in the sucrose-treated heads until day 2 but declined thereafter. The decline in GS activity in this portion, however, did not result to ammonia accumulation.