ISSN:0190-4167    

DOI:10.1080/01904168809363919

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168809363920

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Iron (Fe) chlorosis induced by heavy phosphate (P) fertilizations is a serious problem for macadamia(Macadamia integrifolia)in Hawaii. To address this problem, a study was conducted to quantify the effects of P‐Fe interaction on macadamia leaf composition and chlorosis. The soil used was a limed Oxisol (Tropeptic Eutrustox, Wahiawa Series), pH 5.5. Phosphate was added as treble superphosphate at 0, 150 and 500 mg P/kg. The 150 mg P/kg rate was designed to yield approximately 0.04 mg P/L in the soil solution, a level considered adequate for macadamia growth. The 500 mg P/kg rate was intended to produce approximately 0.2 mg P/L, a level required by many horticultural crops but considered excessive for macadamia. Iron was added as Fe‐DTPA at 0, 5 and 10 mg Fe/kg soil, and factorially imposed on the P treatments. Color Index, a numerical rating based on hue, value and chroma from a Munsell Color Chart for Plant Tissues, was correlated with leaf chlorophyll concentration and used as an indicator of chlorosis.

ISSN:0190-4167    

DOI:10.1080/01904168809363921

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Nutrient concentrations in leaves of self‐rooted apple trees propagated by tissue culture (TC) were compared to the same cultivars budded on seedling, MM 106, and M.26 rootstock planted at two sites, Beltsville, MD and Kearneysville, WV. Leaf samples were monitored annually for 3 years after planting for N, P, K, Ca, Mg, Mn, Fe, Cu, B, Zn and Al from ‘Ozark Gold’ and ‘Stayman’ apples at both sites and ‘Northern Spy’ at Beltsville only. Leaf K and Mn concentrations tended to be higher in trees on M.26 and MM 106, while Ca was higher in TC or seedling trees. Foliar Mg was lower in trees budded on MM 106. Variation in P concentrations was greatest over years, while leaf N and Fe displayed only slight variation among rootstocks. Leaf B and Zn did not exhibit any consistent trends and Cu and Al were not affected by year, rootstock, cultivar or site.

ISSN:0190-4167    

DOI:10.1080/01904168809363922

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

An almond X peach seed line, ‘Titan’ X Nemaguard (T X NG), which is tolerant to lime‐induced chlorosis, was compared to a susceptible seedling rootstock, Nemared, under alkaline conditions. The tolerant rootstock's growth was not affected by Fe stress, whereas the susceptible rootstock showed chlorosis which corresponded to approximately a 20% chlorophyll loss in the new foliage during the 18‐week stress period, a 62% decrease in shoot dry weight and a 22% decrease in plant height.

ISSN:0190-4167    

DOI:10.1080/01904168809363923

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Mineral element concentrations of twelve Kentucky bluegrass (Poa pratensisL.) cultivars grown in alkaline soil (pH = 7.8) were determined. The range of average mineral nutrient concentrations among cultivars was 22.8 to 28.2 mg g‐1for N, 3.7 to 4.8 mg g‐1for P, 16.8 to 20.2 mg g"1for K and 157 to 259 ug g‐1for Fe. Leaf color was influenced by year and N concentration but not by Fe concentration using a stepwise regression analysis procedure.

ISSN:0190-4167    

DOI:10.1080/01904168809363924

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Nutrient effects on the growth of Crassulacean acid metabolism plants have received little attention.Agave desertiandA. lechuguillawere therefore selected for study because their rate of leaf unfolding from the central spike relates closely to growth, thus providing a convenient means for monitoring the effect of nutrient applications. The greater fractional influence of nitrogen fertilization on leaf unfolding for A.desertican be explained by its lower soil level of N than for A.lechuguilla;high application levels of N near 500 kg ha‐1proved slightly inhibitory compared with 100 kg N ha‐1during the first year after application but not during the second year for A.deserti. Agave desertioccurred in soils much higher in phosphorus, potassium, and boron than for A.lechuguilla;consistent with this, application of these three nutrients in the field had little influence on the rate of leaf unfolding forA. desertitut could significantly increase the leaf unfolding rate forA. lechuguilla.Applications of nutrient levels that greatly stimulated leaf unfolding forA, lechuguilla,such as 100 kg N ha‐1or 500 kg P ha‐1, led to large increases in net COg uptake over2kh; applications of 500 kg K ha‐1or 100 kg B ha"1led to lower enhancements in CO2uptake and in the leaf unfolding rate, but again prevented any major decrease in net COg rate during the night. In agreement with studies on other CAM plants, the macronutrients N, P, and K and the micronutrient B can enhance the growth of agaves, depending on the relative level of these nutrients in the soil.

ISSN:0190-4167    

DOI:10.1080/01904168809363925

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Cabbage (Brassica olearaceavar.capitataL.) yield differences from added P were highly significant up to the predicted response level of 0.4 mg 1 . The increases in yield were basically due to larger head sizes. No statistical differences were found after the soil P levels were adjusted above 0.4 ppm, as determined by P isotherms constructed from initial soil samples. Slight differences occurred between years, but likely were due to cultivar growth differences. Data show that the isotherm predicted level fits rather closely the P requirements for cabbage as related to crop yields. Since extraction methods measure only the intensity factor of P, these methods could lead to incorrect P fertilization recommendations. The absorption of P is progressively reduced as the temperature goes down.

ISSN:0190-4167    

DOI:10.1080/01904168809363926

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

A corn cultivar × P × K factorial experiment was conducted to evaluate differential responses of selected parameters to P and K soil fertility. Yield along with leaf nutrient concentration of some nutrients differed among cultivars and nutrient concentration of some elements was affected by soil fertility. Leaf K and Mg were more consistently affected by K fertility than other variables studied. Fertility effects upon micronutrient leaf concentration were not consistent among cultivars or between years.

ISSN:0190-4167    

DOI:10.1080/01904168809363927

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor

摘要:

Ammonium nutrition of radish plants (Raphanus sativusL.) suppresses their accumulation of Ca. The objective of this study was to determine the critical Ca concentration of radish in order to assess if NH4+nutrition induces Ca deficiency in this crop. Cultivar Cherry Belle was grown in sand culture in a greenhouse. Nitrogen was provided as nitrate or ammonium salts, and Ca was varied from 1 to 200 mg/liter in solution. With N03’ nutrition, plant growth increased curvilinearly with increased Ca in solution. Calcium accumulation in shoots was a good index of relative root (edible radish) growth. The critical Ca concentration in shoots for optimum root growth was 2% of the dry matter. With NH4+nutrition, plant growth declined linearly with increased Ca in solution and with Ca accumulation in the shoots. A critical Ca concentration could not be determined for plants grown with NH4+nutrition. The antagonism between Ca and NH4+nutrition could not be explained by deficiencies or toxicities of other elements.

ISSN:0190-4167    

DOI:10.1080/01904168809363928

出版商:Taylor & Francis Group    

年代:1988

数据来源: Taylor