摘要:

Sweet paprika response to water and nitrogen has not been reported in the literature, even though the crop is widely used in the food dyes industry. The objective of the present work was to determine the effects of water rate (IR), N concentration in water (CN), and transient starvation on total processable yield, yield quality and dry matter production and partitioning among fruits, leaves and stems. The experiment was carried out in 10‐liter pots filled with volcanic scoria and consisted of 4 × 3 IR × CNtreatments plus 3 starvation treatments. In all treatments, about 95% of the total dry matter found in the tops of the plants was located in the fruits. Plants that gave good yields (100–120 and 170–210 g/plant high quality and total processable pods yield, respectively) were characterized at harvest time by 4.2–4.8% N in leaves, 1.8–1.9% N in fruits, 2% N in stems and 1.0–1.3% N in roots, and their total N consumption was 4.5–5.2 g/plant. Diminishing N application rates had only a small effect on % N in plants but induced an appreciable reduction in dry matter production. In cases where equal rates of N were applied, the dry matter production and pod yields were greater when N was added through a combination of higher IR and lower CNthan the reverse N, even when water was not a limiting factor for plant growth. The high‐quality‐yield‐(QY)‐to‐total‐processable‐yield ratio decreased when IR was elevated from 600 to 1000 ml/plant/day. Transient starvation for 4 days reduced QY by about 50% and increased %N in the fruits, but did not affect fruiting uniformity. N and P absorption indicated no antagonism between the uptake of these elements in the present experiment.

ISSN:0190-4167    

DOI:10.1080/01904168409363261

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

A system was described for concurrent measurement of Centripetal Passage (CP)1of radiophosphorus and of water flow across intact bean roots. It was based on a comparison by double ratio of radiophosphorus which had completed Centripetal Passage with isotope in the xylem sap. Phosphorus and water data were collected for plants exposed to various agents commonly used to produce water stress. Readings were taken after the first hour and showed a variety of behavior patterns. Glucose and mannitol had no effect on phosphorus or water passage. Fructose, sucrose, polyethylene glycol and phenylmercuric acetate decreased both phosphorus and water passage. Mannose decreased phosphorus passage but had no effect on water flow. Glycerol decreased phosphorus passage but increased water flow.

ISSN:0190-4167    

DOI:10.1080/01904168409363262

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Nitrogen in winter wheat (Triticum aestivumL.) forage was fractionated into water‐soluble protein N (WSPN) and non‐protein N (NPN). Both WSPN and NPN can be rapidly converted to ammonia in the rumen which may increase pH of rumen fluid and decrease solubility of Mg compounds and lead to increased incidence of grass tetany. In plant samples taken after spring growth initiation, WSPN represented approximately 50% of total N and NPN represented approximately 25% of total N. Total N concentration and relative percentages of WSPN and NPN decreased with advancing plant maturity in 1974, but during 1975 the relative WSPN and NPN percentages remained relatively constant at 43 to 55% and 18 to 30% of total N, respectively. Total N, WSPN, and NPN concentrations decreased as plants matured.

ISSN:0190-4167    

DOI:10.1080/01904168409363263

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Seedlings of two maize genotypes, differing in grain yield, were deprived for five days of either nitrogen or sulfur, or both. At the end of each shortage period, prior to the development of any deficiency symptom, uptake rates and internal pools of sulfate and nitrate, extractable activities of ATPS, OASS, NR, GDH, GS were evaluated. The comparison with seedlings supplied with complete solution showed that after S + N deprivation the rate of sulfate uptake was enhanced 46 and 30% in the higher and lower yield genotype respectively, while that of nitrate was the same of control. In both genotypes GS activity did not change, sulfate and nitrate internal pools were reduced and significant changes in activity concerned NR, which was strongly depressed, GDH, which increased 35%. OASS increased 60 and 30% in the higher and lower yield genotype respectively. In the case of deprivation of only one of the two elements, each of the metabolic parameters tested, except GS activity, was differently affected by N and S deprivation. SO2‐4uptake rate, OASS activity and SO2‐4pools were affected mainly by S; NR and GDH activities by N deprivation, the responses being similar to those given to S + N deprivation. Interactions between S and N metabolism were demonstrated by NO−3pool in roots, which was enhanced mainly by S deficiency, and by ATPS activity, which was depressed mainly by N deficiency. Sulfur metabolism appears better adapted than N metabolism to withstand nutrient shortage. A key‐role in productivity could be assumed for the SO2‐4transport system and OASS activity which were the only parameters showing a better efficiency in the higher yield genotype.

ISSN:0190-4167    

DOI:10.1080/01904168409363264

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Distribution of vanadium and its influence on growth, chlorophyll formation and certain aspects of iron metabolism were studied in tomato plants (Lycopersicon esculentumMill. cv. ‘Walter). Vanadium in the nutrient solution increased plant height, weight, number of leaves, and number of flowers. Vanadium also enhanced chlorophyll formation and Fe metabolism in tomato plants, and increased the Hill reaction activity of isolated chloroplasts.

ISSN:0190-4167    

DOI:10.1080/01904168409363265

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Greenhouse experiments were conducted to study the P and Mo interactions during uptake by burley tobacco(Nicotiana tabacumL., cv. ‘Ky 14') and the effect of their interactions on plant dry matter and Mo concentration. In Experiment 1, plants were grown in an intermittently irrigated gravel culture system. The nutrient variables were Mo (0–0.63 μeq/L) and P (0 to 1.8 meq/L). Experiment 2 was conducted in soil‐sand mixtures. The soil types used were Shelbyville silt loam (Mollic Hapludalf) and Baxter silt loam (Typic Paleudalf) each containing, respectively, 36 and 368 kg P/ha by the Bray 1 soil test. Treatments consisted of four rates of P (0, 84, 168, and 336 kg/ha) and five rates of Na2MoO4‐2H2O (0, 0.56, 1.12, 2.24, and 4.48 kg Mo/ha).

ISSN:0190-4167    

DOI:10.1080/01904168409363266

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Nitrogen and phosphorus fertilizers were applied at different levels to three hard winter wheat cultivars ranging in grain protein potential to elucidate their interaction and relationship to yield components. Plant N content was higher in the high‐protein cultivar than in the normal‐protein cultivars at jointing two years and at anthesis one year. Plant P content was higher in the semidwarf cultivars than in the tall cultivar and was unrelated to protein potential. All cultivars contained similar plant N and P levels at maturity. Nitrogen fertilization increased plant N content and decreased plant P content at all stages, whereas P fertilization usually increased plant P content but did not affect plant N content. Grain protein was correlated positively with plant N content at all stages and with plant P content at maturity. Grain yield was correlated positively with plant N content at anthesis but correlated negatively with plant P content at maturity. We concluded that high plant N content at anthesis is necessary for high grain yield and protein content regardless of the cultivars1inherent protein potential and that plant P nutrition is more critical when N nutrition is altered by fertilization or by genetics.

ISSN:0190-4167    

DOI:10.1080/01904168409363267

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

The free amino acids proline and glutamic acid increased in the crown of winter wheat in all treatments when exposed to cold‐hardening. Glutamine also increased except when 90–80 N‐P fertilizer was applied. The increase of proline and glutamic acid was enhanced with the application of P but counteracted by N. This enhancement was smaller with glutamine. The decrease of threonine, tyrosine, phenylalanine, lysine and α‐aminobutyric acid with cold‐hardening was not counteracted by application of N and P. However, isoleucine in cold‐hardened winter wheat increased with the application of 180–0 fertilizer and aspartic acid increased when P was added. The increase in alanine with cold‐hardening was enhanced by P alone but counteracted by N‐P treatments. The marked increase in proline during cold‐hardening could be useful in the detection of cold‐hardiness in winter wheats.

ISSN:0190-4167    

DOI:10.1080/01904168409363268

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Relatively low amounts of the phosphorus (P) added to soils is recovered by plants. Many plants show differences in their ability to take up and use P, but the mechanisms for these differences are not fully understood. The purpose of this study was to determine differences among sorghum [Sorghum bicolor(L.) Moench] genotypes for P uptake rates and distribution in plant parts.

ISSN:0190-4167    

DOI:10.1080/01904168409363269

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor

摘要:

Kinetic experiments were conducted to examine Mg+2[28Mg] and K+[86Rb] absorption by 2‐week‐old tall fescue (Lolium multiflorumLam. XFestuca arundinaceaSchreb.) seedlings. Magnesium absorption was linear for 180 min and was approximately 3.5 ueq Mg+2g dry weight‐1.h‐1from a 0.0625 mM Mg+2solution. Shoot accumulation of Mg was reduced by increased solution K+. A curvilinear concentration absorption isotherm for roots was obtained for Mg+2. The resultant hyperbolic Hofstee plot could be separated into two linear components with Km values of 0.833 and 0.0117 mM, suggesting that two systems are operable in Mg+2absorption. Increased solution pH increased Mg+2absorption both in the presence and absence of NH+4. At pH 6.5 NH+4increased Mg+2absorption 75%; at pH 3.5 the increase was more than 6‐fold. Potassium absorption was linear through 60 min and was decreased by increased Mg2+levels. Shoot accumulation of [86Rb] was decreased by the first increment of Mg+2, whereas further increases in Mg+2did not result in significant decreases. In the presence of NH+4, K absorption was significantly decreased in the alkaline range. In the absence of NH+4, much higher rates of Absorption were observed and less of a reduction was noted at the higher pH values.

ISSN:0190-4167    

DOI:10.1080/01904168409363270

出版商:Taylor & Francis Group    

年代:1984

数据来源: Taylor