摘要:

Several hybrid corns and grain sorghums were grown in adjacent plots and given identical treatments in so far as possible for three consecutive years. Mineral composition of plant tissues taken at several growth stages were compared. Values were found to be quite similar in seedling whole‐plant samples, but major differences were demonstrated in vegetative, bloom, and fruiting stage leaf samples. There is a need for specific grain sorghum nutrient sufficiency values.

ISSN:0010-3624    

DOI:10.1080/00103627209366377

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Grain sorghums were grown during a three year period under widely varying soil conditions. Soil analysis, plant analysis, and grain yield were used to define plant response to cultural practices. Yield and mineral composition of the plant at different growth stages could be greatly affected by treatments. Seasons and variety variables often had lesser effects. Nutrient deficient solution studies in the greenhouse demonstrated changes in mineral composition and nutrient balances of young grain sorghums under known nutrient stress conditions.

ISSN:0010-3624    

DOI:10.1080/00103627209366378

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Grain sorghums were grown in field plots for three years. Soils were varied greatly in P, K, and pH and resulted in wide yield variation. Information from plant sample analyses at four growth stages was plotted individually against grain yield measurements. The diagrams were employed to estimate normal nutrient levels for each stage of growth. Low deficient, and high values are outlined as far as possible. Effects of climatic conditions are discussed.

ISSN:0010-3624    

DOI:10.1080/00103627209366379

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Fifty samples of tomato fruit have been analysed for sugars using a reliable but laborious volumetric method and the results compared with those obtained both by a rapid automated colorimetric procedure employing the Technicon AutoAnalyzer and by a gas Chromatographic (GLC) technique. Using cleared fruit extracts, the overall mean results for the volumetric and automated methods were not significantly different. Automated analysis of uncleared extracts gave only slightly lower results and in view of its speed this method is recommended for the rapid routine analysis of tomato fruit. The GLC procedure gave results some 4% lower than those for cleared extracts by the other methods, but this technique has the advantage that the concentrations of the individual sugars (glucose and fructose) are readily obtained if required.

ISSN:0010-3624    

DOI:10.1080/00103627209366380

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The influence of phosphate nutrition on the kinetics of phosphate absorption by sterile excised barley roots was examined. The roots of seedlings grown in dilute CaSO4showed uptake kinetics similar to roots grown in phosphate deficient nutrient culture. The absence of microorganisms did not abolish the dual form of the absorption isotherm at pH 4.0

ISSN:0010-3624    

DOI:10.1080/00103627209366381

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Coffea arabicaL. seedlings (cv. S.L.34) were sprayed with varying concentrations of cuprous oxide at 0.0, 0.25, 0.50 and 0.75% for 30 days. Significant increases in the total mean fresh and dry weight; rate of transpiration; stomatal apertures; the total leaf area and plant vigor were observed on the seedlings with increasing concentrations of Cu treatments. The content of N, K, Ca and Cu were significantly increased in the seedlings at Cu spray treatments of 0.50 and 0.75% It is possible that the growth promoting effects produced in coffee by spraying high concentrations of copper is partly nutritional. This is brought about by the catalysing effects of the absorbed Cu ions, by accelerating enzymatic activities within the plant and hence increasing nutrient uptake.

ISSN:0010-3624    

DOI:10.1080/00103627209366382

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Eight grasses were grown under high water table conditions for 14 weeks in a greenhouse experiment. Water tables were maintained at 2 or 5 inches below the soil surface. Differences in water table depth influenced clipping yields only slightly. Although total root weights were not reduced with the 2‐inch water table, there was a trend for fewer roots at lower depths and more roots near the surface with this treatment. The shallowest root systems occurred with annual bluegrass, Kentucky bluegrass and creeping red fescue. Elemental composition of the clippings was influenced by species and time of sampling. The greatest effect of water table depth on elemental content of the clippings occurred with Mn.

ISSN:0010-3624    

DOI:10.1080/00103627209366383

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

The quantitative reduction of nitrate in an acid medium with reduced Fe was applied to the alkaline permanganate solution used to absorb NO and NO2evolved from soils during denitrification reactions. The method involves addition of H2SO4to acidify the solution and ensure oxidation of nitrite to nitrate, and treatment with reduced Fe at 100°C to reduce nitrate to ammonium. The solution is made alkaline with NaOH and ammonium determined by standard distillation procedures. It is simple and precise, and applicable to nitrogen isotope ratio analysis of NO and NO2evolved from soils.

ISSN:0010-3624    

DOI:10.1080/00103627209366384

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

摘要:

Cotton petioles from irrigated plants grown under varying nitrogen regimes were analyzed for nitrate‐N (NO3‐N). The most recent, fully matured petioles were selected. The concentration of NO3‐N in the petioles was related to applied N rates and the yields of lint obtained. The concentration of NO3‐N for any given N application declined as the season progressed. The concentration of petiole nitrate increased at all sampling dates as the rate of applied N increased. The relationship between applied N and NO3‐N concentrations was most predictable when samples were collected two weeks after the initiation of squaring. The influence of applied N on the concentration of petiole nitrate was also greatest at this stage. The diagnosis of either N deficiency or excess N would be feasible by petiole analysis when the effects of stage of growth could be separated from the effects of soil N.

ISSN:0010-3624    

DOI:10.1080/00103627209366385

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor

ISSN:0010-3624    

DOI:10.1080/00103627209366386

出版商:Taylor & Francis Group    

年代:1972

数据来源: Taylor