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1.
The results of two spacing experiments, one with var. Offenham only and the other with vars. Offenham and Avonresister, are described and discussed.

The number of plants per sq. ft. affected mean root size; about 2 plants per sq. ft. gave the highest yield of roots >2 in. crown diameter, whereas about 4 to 6 plants per sq. ft. gave the highest yield of prepackingsized roots (1½ in. to 2½ in.). At a given plant density, however, varying the row spacing over a range likely to be used commercially had no significant effect on the total yield of roots or their size grading.

The greatest difference in the yielding ability of the two varieties occurred at low plant densities, where Offenham outyielded Avonresister by up to 88%, whereas at high plant densities the yield difference was only about 10%. A mathematical model relating yield to plant density was used to analyse the results and characterize the difference in the response of the two varieties to plant density.  相似文献   

2.
A study was made of the effects of plant density, plant arrangement and row orientation on the yield of bulbs and flowers from small offsets of narcissus var. King Alfred left in the ground for 2 years. Over the density range of 2–14 plants per sq. ft., flower number increased from 2 to 12 per sq. ft. and stem length increased from 29 to 35 cm. Total bulb yield per unit area increased with density from 171 to 696 gm. per sq. ft.; the weights in each of four commercial bulb grades also increased. When the ratio of the between-row distance to the within-row distance was increased, bulb yield declined in E-W rows, but not in the N-S rows.  相似文献   

3.
Iris bulbs of the varieties Wedgewood and Prof. Blaauvv were injected with 50 or 500 μg. gibberellic acid (GA) before or after cold storage (10° C.) of 18 or 35 days. GA injection accelerated flowering by up to 19 days ; it had little or no effect on length of leaves or flower stem. It was most effective when applied at an early stage after flower initiation.

GA injection reduced bulb yield of Wedgiwood plants, and had no effect on, nor increased bulb yield of, Prof. Blaauw plants.

GA spraying (seven times at 10-2M of GA) accelerated flowering and increased foliage growth in both varieties. It increased flower stem elongation and reduced bulb yield in Wedgfcwood plants.  相似文献   

4.
A three-year experiment on the high-temperature treatment of tulip bulbs established that yield could be increased by between 8 and 31 % for bulb weight or between 14 and 29 % for numbers of large bulbs, depending upon season, associated with a near-complete flower kill. The optimum pre-treatment storage temperature was 17°C, and the best date (of the five tested) for starting blindstoken at 33°C for one week was 20th-21st September.

Yield increases were greater when the blindstoken treatment was applied to bulbs whose shoots were short; later treatment, or treatment after pre-treatments which allowed faster shoot growth, were less effective. For optimum flower kill and yield increase the shoot should be about 1 cm high at treatment. Bulb weight and large bulb number were correlated, suggesting that the treatment increases total bulb weight by increasing bulb size rather than by differentially affecting the growth of daughter bulbs.

No adverse effects of the treatments were observed when the bulbs were forced in a glasshouse the following season.  相似文献   

5.
Five experiments carried out over three years are described in which the effects of irrigation at various growth stages on the yield of peas from plants grown at different plant densities were determined. Results showed that, irrespective of the density at which the plants were grown, plants irrigated at the start of flowering and again as the pods were swelling produced significantly higher yields than unirrigated plants. Yield of peas per plant was consistently reduced as density increased but yield per unit area did not show a consistent relationship with plant density from year to year. The results indicated that, even when irrigation is available, plant densities of five to six plants per sq. ft. should not be exceeded.  相似文献   

6.
Summary

The establishment of the optimum plant population has been shown to be one of the most crucial determinants of the marketable yield of bulbous crops. This study was conducted to determine the best plant arrangements for maximum yields and maximum bulb quality in rainfed garlic (Allium sativum L.) grown under Mediterranean conditions. The effects of row width and plant spacing on the yield and quality of the two cvs. Morado de Pedroneras and Germidour, were investigated on Córdoba, Spain, in Vertisol Chromoxerert soil. In 1987–1988, a wet growing season, higher yields and higher bulb quality were obtained than in 1988–1989; cv. Germidour yielded more per unit of land area of higher quality bulbs during both seasons. Narrow row width and/or narrow plant spacing resulted in higher values of dry matter, LAI, LAD, CGR and yield, whereas wide row spacing and/or wide plant spacing resulted in higher ware-sized bulb yield. LAD was closely related to yield (r2 = 0.96**) and total dry matter (r2 = 0.90**). Mean leaf surface was affected by plant density and climatic conditions and showed a high positive relationship (r2 = 0.90**) with the percentage of Extra grade of bulbs (>50 mm). As a result of this study, a row width of 45–60 cm with plant spacing of 12–16 cm is recommended for cv. Germidour and 45 × 16 cm for cv. Morado, to maximize the proportion of high-quality yield under Mediterranean rainfed cropping systems.  相似文献   

7.
The effects of planting densities on the development and yield of tulip bulbs were studied for the cultivar ‘Lustige Witwe’ (planting size 8–9 cm, type A) in two successive growing seasons. The total number of lifted bulbs decreased with increasing density due to shrivelling of certain buds. The shrivelling started at the time of anthesis, mainly in the buds in the axils of the outermost bulb scales.At densities between 5 × 5 and 12 × 12 cm plant?1 the relative growth rate (Rw) decreased with increasing density. A difference in the Rw values between the two seasons was probably partly caused by differences in the stocks used for the experiments. The highest weight increase was found at a density of 214 bulbs m?2 in 1969 and 229 bulbs m?2 in 1970.  相似文献   

8.
Summary

Virus-tested stocks of Narcissus pseudonarcissus cv. Carlton were compared in the field with commercial stocks which were at least 97% free from plants with visually obvious virus symptoms. Despite planting bulbs of similar weight and apparently uniform anatomical structure the number of growing points in the comparative stocks sometimes differed depending on the locality in which the bulbs were produced. Consequently, leaf number in year one, which is related to the number of growing points was used to adjust flower and bulb yield. After adjustment where necessary, the mean bulb yield of virus-tested stocks was 9-20% greater than that of commercial stocks. Increased bulb yield of virus-tested compared with visually healthy commercial stocks resulted from greater mean bulb weight. Virus infection apparently had no effect on bulb number. Virus-tested stocks flowered three to four days earlier than the commercial stocks but no clear differences in flower quality or number were detected.  相似文献   

9.
Solar heating (solarisation) of the soil, by means of mulching with transparent polyethylene sheets in the hot season, is used for disease control. The effect of soil solarisation, under different agricultural practices, on incidence of pink-root disease caused by Pyrenochaeta terrestris, and on onion yield and quality was investigated. Onions were seeded in beds of non-infested, either non-solarised or solarised, soil and transplanted into growth containers filled with soil either non-infested or infested with the pink-root pathogen. Growth of plants pre-grown in solarised beds was improved as compared to plants originated from non-infested beds. Plants grown in the infested soil suffered considerably, as expressed in leaf number and length, root quantity and bulbing-process. In a field experiment, early sowing resulted in a higher disease incidence than later sowing. Soil solarisation controlled the disease, improved seedling survival and increased yield in most cases. Delay in harvest to 100% falling tops increased yields and reduced percentage of undersized bulbs. At high plant-population density (170 plants m?2), percentage of small bulbs was higher and rates of double bulbs were lower than at low plant density (90 plants m?2). Soil solarisation resulted in effective disease control and higher yields and facilitated accurate planning of plant population in the field, extension of the growing-season and higher yields of better quality.  相似文献   

10.
Changes in endogenous abscisic acid and soluble sugars levels during dormancy-release of lily bulbs of Lilium rubellum were investigated. Shoot emergence and flowering of the bulbs stored for 14 weeks at 4 °C occurred more synchronously, and the time span from first to last flower in the plants was shorter than those of bulbs stored for 10 weeks at 4 °C. Longer duration of bulb storage showed accelerating effects of increasing leaf number and stem length but negatively affected flower size. Flower number per plant was not much influenced by bulb storage duration. Concentration of endogenous abscisic acid (ABA) level in the bulbs during bulb storage decreased as storage duration increased, and it remained at a constant level after being stored for 10 weeks. This result suggests that the decrease in the endogenous ABA level during bulb storage is correlated with dormancy-release. Concentrations of soluble sugars also changed during bulb cold storage. Sucrose concentration increased as the chilling term increased to 10 weeks but decreased afterward. Glucose and fructose increased from the beginning of chilling to the end of a 14-week cold storage.  相似文献   

11.
Summary

The influence of plantation age and plant density on pseudostem size, canopy cover and vegetative growth characteristics of banana cv. Williams was investigated over four cropping cycles at Burgershall Research Station, in the subtropical Eastern Transvaal. Densities were 1000, 1250, 1666 and 2222 plants ha?1. Over all densities, pseudostem height, lamina area, numbers of functional leaves at flowering and LAI increased with plantation age up to the second ratoon (R2). This increase in canopy cover caused vegetative and total cycle intervals to be extended progressively from plant crop to R3. Within cycles, higher density had little effect on plant height or lamina length, but induced thinner plants with significantly narrower leaves than at low density. Peak ratoon LAI at flowering almost doubled between 1000 and 2222 plants ha?1. At 1000 plants ha?1, four cropping cycles were completed in the same period as three cycles at 2222 plants ha?1. Annual leaf emergence rate was significantly reduced by up to five leaves with an increase in plant density from 1000 to 2222 plants ha?1, which was also accompanied by a 3–4°C reduction in pseudostem temperature. Up to six more leaves per plant were produced at 2222 plants ha?1 and only 14% of the available radiation was transmitted through the primary canopy compared with 30% at 1000 plants ha?1. Crop cycle interval is an important component of annual yield at different densities.  相似文献   

12.
Summary

We assessed whether adding inoculum of the vesicular-arbuscular mycorrhizal fungus (VAMF) Glomus intraradices into growing medium of three Zephyranthes spp (White Rain Lily [WRL], Z. candida; Pink Fairy Lily [PFL], Z. robusta; Yellow Zephyr Lily [YZL], Z. sulphurea) alters aspects of flower and bulb production. Shoots of inoculated plants emerged 7–13 d earlier than those of non-inoculated plants. Inoculation slightly delayed the emergence of flower buds on WRL and PFL, but did not delay the time of flower opening of WRL. Inoculated YZL flowered 4–11.d earlier than non-inoculated plants. The number of flowers produced by YZL was consistently increased by inoculation, while the inoculation with VAMF increased flower production by WRL and PFL only when plants were growing in pasteurized soil. Leaf biomass of inoculated WRL was larger than non-inoculated plants, while leaf biomass was generally smaller in inoculated PFL and YZL. Partitioning of biomass to bulbs and offsets varied with species, soil pasteurization, and inoculation. Inoculation increased the combined weight of bulbs and offsets at the end of the second growing cycle by 50–150%. Inoculated YZL and WRL consistently produced more offsets in the second growing season after inoculation. For all species, inoculation increased phosphorus and carbohydrates and decreased nitrogen and amino acids in bulbs. Adding VAMF into the growing medium of Zephyranthes altered aspects of plant development and biomass partitioning important to flower and bulb production during the first growing cycle after inoculation, and most effects of VAMF inoculation are more pronounced in the second growing cycle after inoculation. Of the three species examined, Z. sulphurea showed the most consistent responses to inoculation.  相似文献   

13.
Summary

Ashwagandha (Withania somnifera L. Dunal; Solanaceae) is being cultivated around the world mainly for its root which has rejuvenative properties. Field experiments during 1999–2001 under semi-arid tropical conditions of Hyderabad, India studied the effect of tillage depths (15 and 30 cm) and plant population densities (20, 40, 60 and 80 plants m–2) on root morphology, yield and quality and cultivation economics of ashwagandha. Preparatory tillage to 30 cm depth in combination with a density of 60 plants m–2 gave the highest root yield of 1.2 t ha–1 which was 50% higher than that following 15 cm tillage depth and the same density. This is attributed to the favourable effect of the former treatment leading to 33, 37 and 21% increases in plant height, number of branches per plant and shoot biomass yield, respectively. Further, this treatment produced most (68%) best quality root pieces. Main root length, length of lateral roots and diameter of lateral roots were significantly increased, while the diameter of main root and the number of laterals decreased. Furthermore, increase in plant density from 20–80 plants m–2 increased production of best quality roots from 42% to 59% under shallow tillage and from 53% to 71% of root yield under deep tillage. The implications of change in root morphology are discussed in the light of production of different grades of roots, their market preferences and economics. Deep tillage was equally advantageous for seed production, but plant population density for maximum seed yield (211 kg ha–1) was lower at 40 than at 60 plants m–2 for maximum root yield. Maximum gross and net returns and benefit-cost ratio occurred following the highest root yield.  相似文献   

14.
探讨了不同品种及栽培条件对大蒜鳞茎中大蒜素含量的影响。结果表明,不同大蒜品种大蒜素含量差异显著,其中兰州紫皮大蒜素含量最高,为10. 52μg·g-1。密度、土壤相对含水量、土壤类型及采收期都对鳞茎中大蒜素含量有一定的影响。其中,密度以每公顷52. 5万株最为适宜,此时大蒜素含量为8. 39μg·g-1,比常规对照高出8. 1 %;当土壤相对含水量达40 %时,大蒜素含量较高,为6. 03μg·g-1;砂壤土有利于鳞茎中大蒜素含量的提高;为提高鳞茎中大蒜素含量,不宜提早采收大蒜。  相似文献   

15.
Summary

The effects of different mean growing season temperatures and C02 concentrations during bulb production on postharvest bulb sprouting in a common storage environment at Reading, UK, was examined in two cultivars of the Rijnsburger type of onion (Allium cepa L.). Crops were grown in the field in temperature gradient tunnels maintained at either 374 or 532 ppm C02. At crop maturity, cohorts of bulbs were harvested, transferred to a constant temperature room (at an average of 11.6°C) and the subsequent duration to sprouting recorded. The duration to the onset of sprouting (expressed as days in storage until the first bulb sprouted) was not affected by cultivar, mean growing season temperature or CO2 concentration, and was 165 d. The subsequent rate of sprouting (expressed as bulbs per day) was a positive linear function of mean growing season temperature, but no effects of CO2 or cultivar were detected. Mean rate of sprouting increased from an average of 0.036 bulbs per day at 12.3°C to 0.093 bulbs per day at 18.6°C. Rapid sprouting in storage was associated with lower levels of total non-structural carbohydrate in the bulbs at the time of harvest. Thus, postharvest susceptibility of onion bulbs to sprouting in storage is expected to increase in warmer crop production temperatures.  相似文献   

16.
Changes in the fresh and dry weights of the component parts of plants of tulip cv. ‘Apeldoorn’ were followed in bulbs kept at low and high temperatures (9 and 18°C respectively) from the time of completion of flower differentiation until anthesis.There were marked differences between shoot dry weights at the two temperatures. At 9°C the stem, leaves and flower grew exponentially throughout the whole period, but at 18°C the specific growth rate of the stem and leaves declined throughout the period of the experiment. At 9°C the proportion of total dry weight in shoots and daughter bulbs was higher than at 18°C, and the proportion in the mother bulb was correspondingly smaller.At both temperatures the fresh weightdry weight ratios of the mother bulb, shoot and daughter bulbs declined during dry storage, the decline being greater at 9°C. After planting, the ratio for all plant parts increased at 9°C, but scarcely changed at 18°C.These results are discussed in relation to dormancy, to the low-temperature requirement for successful and rapid flowering and to flower quality.  相似文献   

17.
SUMMARY

Nitric oxide (NO) is an essential endogenous plant signalling molecule involved in a wide range of plant developmental processes. To investigate the effect of NO on breaking dormancy in bulbs, bulbs of Oriental lily (Lilium orientalis) ‘Siberia’ were treated with various concentration of the NO donor, sodium nitroprusside (SNP; 0.0,1.0,3.0, or 5.0 mM). The results showed that the effect of NO was dose-dependent, with the maximum biological response at 1.0 mM SNP. When applied exogenously, the 1.0 mM SNP treatment reduced the time required to release dormancy in Oriental lily bulbs. Meanwhile, 1.0 mM SNP significantly increased the shoot length:bulb height ratio. In addition, 1.0 mM SNP significantly lowered starch concentrations and increased water soluble carbohydrate (WSC) and reducing sugar concentrations. These results indicate that NO treatment, at the correct dose, reduced the time required to release dormancy in bulbs by accelerating the degradation of starch and increasing the accumulation of WSC and reducing sugars in Oriental lily bulbs.  相似文献   

18.
Asiatic hybrid lilies, Lilium × elegans Thunb., ‘Red Carpet’ and ‘Sunray’ were used to investigate the effect of bulb vernalization at 2.5 °C on plant growth, flowering, and CO2 production (respiration), and to use the CO2 production pattern to monitor the time of flower bud initiation and development. Lily shoot emergence and flowering were accelerated when bulbs received 2.5 °C bulb vernalization; however, flowering was delayed when bulbs were stored at 20 °C before treatment at 2.5 °C; this indicated that bulbs were de-vernalized. The maximum CO2 level, and the minimum level, reached in 78 h in non-vernalized bulbs and in 110 h in 6 weeks of 2.5 °C (6 weeks/2.5 °C) treated bulbs, was increased as the 2.5 °C duration was increased; this indicated that CO2 level can be an useful parameter to measure the cold stimulus (i) accumulated in bulbs following bulb vernalization. The respiration rate higher than the predicted values of the best-fit curves derived from the quadratic equations was designated as Blip A and this was correlated to the time of flower bud initiation and development. Shoot elongation may follow the rise in carbon dioxide levels after reaching the minimum level. It is proposed that increased carbon dioxide levels higher than the predicted levels (Blip A), was correlated to the time of flower bud initiation and development. Measurement of carbon dioxide production upon receipt of bulbs may be a useful technique to provide important information for optimum vernalization treatments for bulbs that have accumulated different levels of low temperature stimulus after bulb vernalization.  相似文献   

19.
The effects of six cultural treatments on (a) marketable yield, (b) percentage marketable plants and (c) percentage perfect quality curds produced, were studied on representative varieties of three groups of autumn cauliflower in experiments carried out over a period of five years. The treatments included a comparison of the use of graded and ungraded seed, transplanting and direct-drilling of the crop, different transplant ages, selection for uniformity at planting or thinning time, and plant density and nitrogen levels during the early seedling stage of growth.

In general the yields and quality of drilled and transplanted crops were similar with all varieties each year and neither the use of graded seed nor the nitrogen treatments had any significant effect on yield or curd quality. Both increasing plant density in the seedbed and increasing age of transplant caused a reduction in yield on most occasions. The effects of the treatments on yield and quality are discussed in relation to their effects on the maturity characteristics of the crops.  相似文献   

20.
Two varieties of tulip, Golden Harvest obtained from Cornwall and Lincolnshire and Krelage’s Triumph from Cornwall, were grown in sand culture with deficiency, normal and high levels of major nutrients in various combinations.

Symptoms produced by deficiencies of nitrogen, phosphorus, potassium and magnesium mainly resembled those recorded previously with the variety Rose Copland.

Leaf measurements and bulb yields showed nitrogen deficiency to have the most significant effect on growth, and symptoms were evident several weeks before flowering.

Leaf areas and bulb yields were apparently closely related for Nil, nitrogen and phosphorus deficiency treatments but were less clearly related for other treatments, especially in Krelage’s Triumph.

Cornish stock of Golden Harvest tulip was more sensitive than Lincolnshire stock to deficiencies, especially of phosphorus. Krelage’s Triumph was also less sensitive on the whole, and especially in terms of leaf area, than Golden Harvest from the same source, even though the fanner had the smaller-sized bulbs.

High levels of sodium produced succulent growth and soft bulbs. There were no marked effects of high levels of nitrogen, phosphorus, or potassium on yields, although leaf area of Cornish bulbs particularly was decreased by some of these treatments, possibly in relation to high nitrogen level.  相似文献   

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