摘要:

Soils of the peach growing region of the Southeastern Coastal Plain are highly leached and excessively acid, with inherently low concentrations of subsoil magnesium (Mg). A greenhouse experiment was conducted to determine the effects of varying Mg concentrations at low pH on growth and Mg uptake of three peach seedling cultivars commonly used as rootstock in the region. Seedlings of ‘Lovell’, ‘Elberta’, [Prunus persica(L.) Batsch] and ‘Nemaguard’ [Prunus persica(L.) Batsch XPrunus davidianaCarriere] were grown for 36 days in nutrient solution containing 9, 21, 42, 84, 167, 333, and 667 μM Mg. Magnesium concentration in solution did not increase lateral length, number of laterals, trunk cross‐sectional area, or root volume. All terminal growth responses were cultivar related. Magnesium concentration in the leaves, stems, and roots were increased either by quadratic or cubic relationship with solution Mg concentration while Mg uptake rate was increased linearly with solution Mg concentration with all three seedling cultivar. Uptake rates of calcium, manganese, and zinc, and tissue concentrations of phosphorus, manganese, and zinc decreased with increasing Mg concentrations in nutrient solution. Predicted Mg uptake rates by‐regression analysis revealed a cubic uptake isotherm for Nemaguard and a quadratic isotherm for Elberta. Predicted tissue Mg concentration followed similar patterns of accumulation for leaves and stems, but root Mg concentration followed a cubic uptake isotherm for all three seedlings. The linear Mg uptake at low pH may be an important physiological characteristic that enables Lovell seedlings to outperform either Elberta or Nemaguard when used as a rootstock in the southeastern soils.

ISSN:0190-4167    

DOI:10.1080/01904168609363427

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Solution depletion experiments were conducted to study NH4+and NO3–absorption characteristics in pumpkin (Cucurbita moschataPoir.), as well as NH4+and NO3–interactions and K+effects on NH4+uptake. Ion absorption parameters Vmax, Km, and Cmin were calculated over a 5‐ to 7‐hour period in each of the studies.

ISSN:0190-4167    

DOI:10.1080/01904168609363428

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Two lettuce cultivars (Lactuca sativaL., cv. Calmar and cv. Climax) were selected to compare their tolerance to salt stress. The plants were grown in a hydroponic system using a 0.5 modified Hoagland solution. Treatments of 0, 40, 80, and 120 mol m–3NaCl or 0 and 20 mol m–3Na2SO4were started when the second leaf above the cotyledons appeared. The plants were harvested 20 days later. Climax showed a greater tolerance to salinity at the 40 mol m–3NaCl concentration; the % decrease in both shoot and root fresh weight was significantly less than Calmar. No differences between the cultivars were found in the Na2SO4experiments. Differences in root Cl–content at the 40 mol m–3concentration corresponded to an enhanced water content of the roots. A mechanism for the observed differences in salt tolerance between the two cultivars is discussed.

ISSN:0190-4167    

DOI:10.1080/01904168609363429

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

The effect of Ca2+on the salt tolerance of two lettuce cultivars (Lactuca sativaL. cv. Calmar and cv. Climax), differing in their salt tolerance, was investigated. The plants were grown in a 0.5 modified Hoagland solution. Treatments of NaCl or NaCl plus CaSO4(final Na+:Ca2+ratio approximately 7:1 on a mol m–3basis) were added to the nutrient solution when the second leaf above the cotyledons appeared. The plants were harvested 20 days after the treatments began. Plant growth was reduced by salinity (0 to 120 mol m–3NaCl), but addition of supplemental Ca2+did not affect salt tolerance. The mineral status of the plant, however, was affected by the Ca2+treatments. The Ca concentrations in both root and shoot, and the Mg concentrations in the shoot were higher than those in the low Ca2+treatment. High external Ca2+decreased the absorption of Na. The high Ca2+treatments did not affect Cl–1tissue concentrations, nor shoot or root growth. The effect of high Ca2+concentration on K tissue concentrations remained equivocal. The differential responses of these elements to high Ca2+suggested that selective ion transport was affected by salinity and Ca2+treatments.

ISSN:0190-4167    

DOI:10.1080/01904168609363430

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

摘要:

Using excised trifoliate leaves of 3 week‐oldGlycine max‘Bragg’ seedlings, a total of 31 organic and inorganic potassium compounds were tested for their efficacy of foliar potassium absorption at 10 mM K (using86Rb as a tracer for K) and pH 6.3. Of the 14 inorganic K compounds screened, potassium bicarbonate, nitrite and several phosphate compounds yielded the highest % K absorption. Five of the inorganic K compounds caused slight leaf burn. Most of the 17 organic K compounds yielded higher % K absorption than the inorganic K compounds. Potassium acetate had the highest % K absorption without causing leaf burn. Monocarboxylic K compounds had greater % K absorption than the di‐ and tricarboxylic compounds. Chemical groups which increased polarity tended to decrease absorption. The absorption data for all K compounds tested could be partially explained by considering molecular weights and drying characteristics on the leaf surface. There was a positive correlation between total % K absorption and the degree of translocation away from the treated area for the inorganic K compounds, but not for the organic K compounds.

ISSN:0190-4167    

DOI:10.1080/01904168609363431

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168609363426

出版商:Taylor & Francis Group    

年代:1986

数据来源: Taylor