摘要:

The quantity of nutrients which can be sprayed onto the foliage of plants is limited by the onset of burn damage, but the mechanism(s) of burn induction are not defined. Droplets of KH2PO4applied to intact leaf cuticles induced burn damage at concentrations ≥ 0.50 M whereas K2HPO4was damaging at 0.05 M. Different cuticular penetration rates did not account for these differences. We report here on the comparative effects of these two salts on membrane integrity, as expressed by leakage of U.V. absorbing constituents from leaf cells. Infiltration of a hypotonic solution (0.05 to 0.10 M) of either salt into corn leaf segments did not induce selective acceleration of leakage of U.V. absorbing constituents from leaf cells during a 90 min. incubation. However, incubation in 0.10 M K2HPO4lead to a 87% increase in the efflux of cell constituents when followed by a 10 min. osmotic stress treatment in 1M sucrose and subsequent transfer to water.

ISSN:0190-4167    

DOI:10.1080/01904168309363088

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Plants of 3 progenies ofVacciniumsp. were utilized in exised root respiration studies over a range of O2levels from 2.5 to 21%. Root respiration of plants from an intraspecificV.asheiReade progeny, Powderblue x T‐142, were approximately half that of two other progenies, one with germplasm ofV. asheiand V. constablaei Gray and the other with germplasm ofV.corymbosumL.,V. asheiandV. constablaei. TheV. asheiprogeny was unaffected by reduced O levels under laboratory conditions, whereas the other two progenies showed significantly reduced root respiration rates, particularly at the 2.5% O2level. However, soil O2levels were near 21% at a depth of 15 cm under established blueberry bushes indicating that root respirationper semay be a more important criteria in blueberry adaptation to soil and environmental stresses than actual soil oxygen status.

ISSN:0190-4167    

DOI:10.1080/01904168309363089

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

A greenhouse experiment was conducted to study the effect of phosphorus application on the growth of rice and the concentration of P, N, K, Ca, Mg, Fe, Mn, Cu, B and Al in leaves, stems and roots. The results showed that application of phosphorus substantially increased the dry matter of leaves, stems and roots upto 30 ppm of P level. Application of phosphorus caused a decrease in the concentration of Fe, Cu and Al in leaves and stems and increased concentration in roots. Phosphorus concentration increased in all plant fractions, while N and Mn increased in leaves but decreased in stems and roots. Similarly Ca, Mg and B concentration decreased in leaves, stems and roots.

ISSN:0190-4167    

DOI:10.1080/01904168309363090

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Lettuce plants (Lactuca sativaL. cv. Grand Rapids) were grown in nutrient solution in controlled environment plant growth chambers to characterize certain qualitative responses to above ambient levels of CO2. Increased plant material produced under high CO2levels did not differ nutritionally from plants grown under ambient levels. No differences were found in chloroplast pigment content, protein content, or in carbohydrate content on a weight basis. Sequential harvests did reveal, however, that there is a greater accumulation of carbohydrate, under high CO2conditions, prior to an increased growth rate as the plants reach maturity.

ISSN:0190-4167    

DOI:10.1080/01904168309363091

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The effects of aluminum on the accumulation of sugars, amino acids and organic acids in two hybrid cultivars of sorghum were studied.

ISSN:0190-4167    

DOI:10.1080/01904168309363092

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

The Fe and Zn deficiency tolerances for two high yielding maize (Zea maysL.) hybrids (G‐2 and G‐5) and their parent cultivars were examined by growing them in nutrient solutions. The results indicated the occurrence of heterosis for Zn deficiency tolerance in G‐5, and to a lesser extent in G‐2. Each cultivar was susceptible to Fe deficiency and did not show signs of recovery from chlorosis. The symptoms of Fe deficiency were distinct from those for Zn deficiency. Plant growth was affected more by Fe deficiency than by Zn deficiency. The roots of cultivars were reduced in growth under Fe deficiency conditions.

ISSN:0190-4167    

DOI:10.1080/01904168309363093

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

摘要:

Five‐week‐old tomato plants were transplanted into pots containing 10 kg of potting compost which was amended with 0, 0.1, or 0.3 g of nitrapyrin and 4 g of N from KNO3, (NH4)2SO4or sewage sludge and were grown in a greenhouse. After 2 to 3 weeks, leaves of the plants grown on any nitrapyrin x N source combination were curled with reduced laminae. Symptoms were most severe with the nitrapyrin x sludge regimes and least severe with the nitrapyrin x KNO3treatments. With (NH4)2SO4and sludge, growth was depressed linearly by nitrapyrin additions but was unaffected with KNO3fertilization. The concentrations of Ca and Mg in the shoots were lowered linearly or curvilinearly by nitrapyrin combination with any fertilizer whereas that of K was unaffected. Levels of Mn in leaves rose with nitrapyrin additions to the (NH4)2SO4or sludge treatment but were stable with any of the nitrapyrin x KNO3combinations. Cation antagonism among NH4+, Ca++, and Mg++is suggested as affecting the concentrations of these ions in tissues, whereas acidification of the medium and a restriction in dry matter production may account for the elevated levels of Mn in the tomato shoots grown in the presence of nitrapyrin.

ISSN:0190-4167    

DOI:10.1080/01904168309363094

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor

ISSN:0190-4167    

DOI:10.1080/01904168309363087

出版商:Taylor & Francis Group    

年代:1983

数据来源: Taylor