Chiwon W. Lee

Micro nutrient toxicity in French marigold

Abstract The influence of elevated levels of micronutrients on the growth and flowering of French marigold (Tagetes patula L.) was investigated. Plants were grown with nutrient solution containing 0.25, 0.5, 1, 2, 3, 4, 5, or 6 mM boron (B), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), or zinc (Zn) and toxicity development was monitored. The threshold micronutrient concentrations that induced visible foliar toxicity symptoms were 0.5 mM B, 4 mM Cu, 4 mM Fe, 2 mM Mn, 1 mM Mo, and 5 mM Zn. The dry matter yields during the 5 week experimental period were reduced when micronutrient concentrations exceeded 0.5 mM B, 3 mM Cu, 3 mM Fe, 6 mM Mn, 0.5 mM Mo, and 5 mM Zn in the fertilizer solution. Leaf chlorophyll contents decreased when the nutrient solution concentrations of Cu, Fe, and Mn were greater than 0.5 mM, 3 mM, and 2 mM, respectively. Visual toxicity symptoms of the six micronutrients were characterized.

Plant regeneration in Kentucky bluegrass (Poa pratensis L.) via coleoptile tissue cultures

SummaryPlant regeneration in Kentucky bluegrass (Poa pratensis L. cv. Touchdown) via culture of seedling tissues was investigated. When coleoptile, leaf, and stem sections of dark-germinated seedlings were cultured on Murashige and Skoog (MS) medium, different types of callus were produced, depending on the expiant source and growth regulator combinations. Only compact-friable callus (type 3) and moderately compact, friable callus (type 2) produced shoots upon subculture. The nonstructured watery callus (type 4) produced roots without shoots. Shoot differentiation from callus tissues was highest when the culture medium contained 0.2 mgL−1 picloram + 0.01 mgL−1 α-naphthaleneacetic acid (NAA). Calli grown from coleoptiles had higher shoot regeneration frequency (32%) than that obtained from either stem sections (12%) or young leaf tissues (2%) of the same seedlings. Some organogenic callus lines produced exclusively green plants, while others produced albino shoots or a mixture of green and albino shoots. The green plants were multiplied in a medium containing 0.1 mgL−1 BAP plus either 0.2 mgL−1 picloram or 0.1 mgL−1 indole-3-acetic acid (IAA). Over 90% of the cultures in the shoot proliferation medium produced roots in 4 weeks. The rooted plants were successfully established in soil medium and grown in the greenhouse.

Influence of ammonium, nitrate, and chloride on solution pH and ion uptake by ageratum and salvia in hydroponic culture

Abstract The influence of nitrogen (N) forms and chloride (Cl) on solution pH and ion uptake in the hydroponic culture of Ageratum houstonianum [ammonium (NH4 +)‐tolerant] and Salvia splendens (NH4 +‐sensitive) for a period of 216 hours was investigated. The pH of the hydroponic solution (initially 6.50) containing either NH4 + or NH4 ++nitrate (NO3 ‐) was drastically lowered (3.08), whereas that of the same solution containing NO3 ‐ was raised (7.74). Solution pH changed more by ageratum than by salvia. The solution Cl‐ concentration did not influence pH significantly. However, addition of Cl‐ in the solution lowered transpiration rate in both NH4 + and NO3 ‐ treatments. Total N uptake was the greatest in the NH4 + + NO3 ‐ treatment and the lowest in the NO3 ‐treatment. In the NH4 + + NO3 ‐ treatment, NO3 ‐ uptake was suppressed by NH4 + (to about 50%), while NH4 + uptake was not affected by NO3 ‐. The rate of Cl‐ uptake was the lowest in the NH4 + treatment, but was similar in the NH4 + + NO3 ‐ and NO3 ...

INFLUENCE OF ELEVATED PHOSPHORUS LEVELS IN NUTRIENT SOLUTION ON MICRONUTRIENT UPTAKE AND DEFICIENCY SYMPTOM DEVELOPMENT IN STRAWBERRY CULTURED WITH FERTIGATION SYSTEM

The relationship between the total amount of micronutrients absorbed by the above-ground plant tissue and the occurrence of visible micronutrient deficiency symptoms in two strawberry cultivars as influenced by elevated phosphorus (P) levels in fertigation solution was investigated. The plants were cultured with a fertilizer solution containing 0, 0.5, 1, 2, 4, or 6 mM P and tissue nutrient content were determined at 120 days after transplanting. Young leaves of the plants grown with nutrient solution P levels higher than 4 mM and 2 mM, respectively, in ‘Keumhyang’ and ‘Seonhong’, developed interveinal chlorosis. Tissue concentrations (mg·kg−1 dry weight) of metallic micronutrients [iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn)] in both cultivars did not decrease, but the total amount absorbed by the aboveground plant tissue decreased in the treatments in which nutrient deficiencies were observed. These results indicate that total amount of micronutrients is a better indicator of P-induced micronutrient deficiency.

Growth and nutrient uptake responses of ‘Seolhyang’ strawberry to various ratios of ammonium to nitrate nitrogen in nutrient solution culture using inert media

� concentration in the petiole sap, EC and pH of the root substrate were quadratic, with a coefficients of R 2 = 0.99***, 0.98***, and 0.73*.

Micronutrient toxicity in buffalograss

Abstract The growth responses of buffalograss [Buchloe dactyloides (Nutt.) Engelm.] to elevated micronutrient levels in the fertilizer solution were investigated. Seedling plants established in peat‐lite mix in 11‐cm (0.6 L) pots in the greenhouse were irrigated with solutions containing 0.5, 1, 2, 4, 6, 8, or 12 mM of boron (B), chlorine (Cl), copper (Cu), iron (Fe), manganese (Mn), molybdenum (Mo), or zinc (Zn). The control solution contained (in μM): 20 B, 0.5 Cu, 40 Fe, 10 Mn, 0.5 Mo, and 4 Zn. A standard macronutrient concentration was used for all treatment solutions. Boron and Mo induced visual toxicity symptoms more readily than other micronutrients. Boron toxicity was characterized by chlorosis often accompanied by bleached leaf tips, while Mo toxicity resulted in leaf necrosis. The lowest levels that induced visual foliar toxicity were 0.5 mM B, 2 mM Cu, 4 mM Fe, 6 mM Mn, 1 mM Mo, and 4 mM Zn. Chloride did not induce foliar abnormalities in the concentration range tested. Biomass yield was reduc...

Germinated Wheat: Phytochemical Composition and Mixing Characteristics

Germinated grain has been gaining popularity owing to its beneficial effect on human health. In this research, whole wheat samples obtained after three days and five days of germination were analyzed for biochemical components and mixing characteristics. Three days of germination caused severe initial degradation of SDS-insoluble glutenin macropolymers, which was accompanied by deterioration of mixing characteristics. Proteolysis during germination resulted in a significant increase of free amino acid concentration. For example, free asparagine concentration increased significantly after five days of germination. γ-Aminobutyric acid concentration, which was undetectable in nongerminated grain, also increased substantially during germination. Phenolic concentration and antioxidant activity level were elevated exponentially during germination, showing a high linear correlation between them (r = 0.999, P < 0.05). These findings indicate that germinated wheat flour may be a valuable ingredient for functional ...

Visual Symptom and Tissue Nutrient Contents in Dry Matter and Petiole Sap for Diagnostic Criteria of Phosphorus Nutrition for 'Seolhyang' Strawberry Cultivation

Abstract‘Seolhyang’ strawberries (Fragaria ananassa Duch.) were grown in a soilless substrate with fertigation solutions to evaluate the effects of six different P concentrations (0, 0.5, 1, 2, 4, and 6 meq·L−1) on the growth and nutrient contents in dry matter of above-ground tissue and petiole sap. The changes in electrical conductivity (EC) and pH of the root substrate were also investigated. Deficient and excess concentrations of phosphorus, such as 0 and 6 meq·L−1, seriously restricted the plant growth. These two treatments showed the least values in leaf number, plant height, leaf length and width, petiole length, and fresh and dry weights. The solution containing 1 meq·L−1 of phosphorus showed the greatest plant growth compared to the other treatments. The macro-element contents such as P, K, Ca, and Mg showed increased tendencies as P concentrations were elevated but, micro-elements such as Fe and Mn showed decreased tendencies in dry matter of above-ground tissue. When P concentrations were elevated, the pH and EC in the soil solution of root substrate decreased. Considering the crop growth and tissue nutrient contents, the P concentrations should be between 0.5 to 2.0 meq·L−1 and the P contents in the dry matter and petiole sap were 0.23 to 0.62% and 205 to 305 mg·kg−1.

Influence of fertilizer concentrations on the performance of seedling grafts of tomato grown in coir based root media

The influence of various concentrations of the standard fertilizer on the performance of seedling grafts tomato was investigated using coconut coir containing root media. Two different formulations of coir dust (CO) with perlite (PL) and vermiculite (VM) (5:5 and 7:3 mixtures of CO + VM and CO + PL, v/v) were used as growing media. Five variations (0, 0.1, 1, 2, 4x conc.) of a standard fertilizer (SF) containing (mg · L−1) 190 N, 54.5 P2O5, 149 K2O, 542 CaO, 24.3 MgO, 19.5 S, and micronutrients in pre-plant fertilizers were used for seedling growth before grafting. The root stock (cultivar J3B Strong) and scion (cultivar Sunmyung) were grown in 50 cell (volume 33 cc) and 105 cell (volume 18 cc) trays, respectively. Both were fertilized once a week with the N concentrations of 50, 120, and 200 mg · L−1 (using 14-00-14 and 20-10-20 commercial analysis fertilizers alternately) in stages 2, 3, and 4, respectively. At 31 days after sowing, seedling plants of both the root stock and scion were excised above the soil line, trimmed, and used for seedling grafting. The cut grafted plants were planted into the 50-cell pack trays (cell volume 33 cc) and incubated for 7 days inside a plastic tunnel under a shade cloth for callusing and adventitious root formation. After an additional 7 days of gradual acclimatization with lower humidity, the rooted grafted plants began to receive fertilizer treatments once a week. When examined 31 days after sowing, the highest weights of the root stock seedlings were obtained with the 2x SF solution in CO + PL mix (4.1 g/seedling) and 1x SF solution in CO + VM mix (5.0 g/seedling). The electrical conductance (EC) of the soil extracts for the two treatments were 3.85 and 1.94 dS · m−1, respectively. Fresh weights of the grafted plants (Sunmyung/J3B Strong) grown in CO + VM and CO + PL mixes were not significantly different from each other when measured 13 days after grafting. Elevated plug-phase fertilizer levels in CO + PL mix resulted in an increase of fresh weights from the grafted plants in 13 days. However, substrate EC (5.19 dS · m−1) at 4x SF solution in CO+PL mix was much higher than that recommended for plug seedling production. Grafted plants were tolerant to high salinity. Fresh weights of grafted plants were higher when grown with 200 mg · L−1N in CO + PL mix or 100 mg · L−1 N CO + VM mix than other treatments. The substrate ECs of the two treatments were 3.85 and 1.94 dS · m−1, respectively. Grafted plants grew well when exposed to elevated substrate salt concentrations. Results of this experiment suggest that the production of high quality tomato seedling grafts is possible with salt concentrations much higher than that recommended for plug seedling production. The optimum fertilizer concentration, however, must be determined separately for a given root medium mixture containing coconut coir.

Optimization of substrate formulation and mineral nutrition during the production of vegetable seedling grafts

The use of seedling grafts has been increasingly popular in the production of fruit vegetables in Korea. Superior scion cultivars grafted on seedling rootstocks tolerant to soil-borne diseases often results in higher crop yield and quality. For the production of healthy grafted transplants, seedlings have to be grown under the most favorable cultural conditions. Substrate composition and property as well as mineral nutrition play an important role. Various substrates containing peatmoss, perlite, vermiculite, and coir-dust have been tested for their influence on seedling growth. In the chemical properties of substrates investigated just before grafting and after formation of grafted union, the ECs in 4 substrates rose as the pre-plant fertilizer level was elevated. The ECs in peatmoss containing substrates were lower than those in coir dust containing substrates when all substrates contained equal amount of pre-plant fertilizers. The ECs in substrates containing vermiculite were higher than those in perlite. In all substrates, the elevation of pre-plant fertilizer levels resulted in the increase in NO3−-N and K+ concentrations and decrease in Na+ concentration. The recommended EC levels of substrates for the raising of plug seedlings of bedding plants are applicable to fruit vegetables when the seedlings are grown in peatmoss + perlite (PP) substrate. But those in peatmoss + vermiculite (PV), coir-dust + perlite (CP) and coir-dust + vermiculite (CV) substrates should be altered based on the kinds and rates of substrate components. In case of crops, the water melon rootstock ‘Cham Bak’ (Lagenaria siceraria Standl), showed the stronger salt tolerance than cucumber rootstock ‘Heukjong Hobak’ (Cucurbita ficifolia) indicating that pre-or post-plant fertilizer levels should be varied based on the kinds of crops grown. The peppers grew well in PP and PV substrates rather than CP or CV substrates in before or after grafting. This also implies that the components of substrates should be changed based on the specific crops.