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1.
The annual growth of an apple tree in the vegetative condition is distributed in a definite pattern between leaves, stems and roots ; when a crop is borne, this constitutes an additional end-point for growth materials. The disturbances in the pattern of vegetative growth caused by this additional region of utilization are described. Two-year-old apple trees were deblossomed at flowering or defruited on 30th May, and their growth was compared with that of cropping trees. The increments in weight were estimated by samples taken at treatment times.

After deblossoming, the trees made extra growth in terms of dry weight, more and larger leaves, and longer stems. The periods of greatest and least growth were the same as for cropping trees. Defruiting also resulted in extra growth, but this came later, and so was out of phase with the growth of fruiting trees. This extra vegetative growth (including more trunk thickening and root growth as well as leaves and new shoots) weighed more than the crop on the fruiting trees. Defruiting had slightly less effect than deblossoming.

The diversion of metabolites to the crop changed the pattern of growth in the rest of the tree. Cropping trees had 50% more leaf proportionate to total vegetative increment, and 50% less root, than deblossomed ones. The intervening regions varied roughly according to their position. Despite this greater leafiness of cropping trees, they produced significantly more total dry matter (vegetative growth plus crop) per unit area of leaf.

These results are attributed to the greater demanding power of the growing crop in diverting photosynthates from the lower parts of the tree and in increasing the rate of removal of photosynthates from the leaves.  相似文献   

2.
Ozone (O3) and sulphur dioxide (SO2) are widespread pollutants in many of the areas in which petunias are grown as bedding-plants. Controlled environment experiments were conducted to evaluate the sensitivity of ‘Capri’, ‘White Magic’ and ‘White Cascade’ to separate or combined O3 and SO2 at 2 growth stages. Relative cultivar sensitivity was the same for O3, SO2 or O3 + SO2, with ‘Capri’ leaves least injured and ‘White Cascade’ leaves most injured. Visible injury symptoms were similar in all cultivars. Leaves of intermediate age were most sensitive, but early vegetative plants were more sensitive to O3 than plants in immediate prefloral stage. Severity of leaf injury was generally greater from the combined gases than from the single gases, and the combination treatment at the early vegetative stage significantly reduced plant growth and flower weight 4 weeks later.  相似文献   

3.
Application of 2,4-D and 2,4,5-T at concentrations ranging from 5 to 20 mg l?1 to 5-year-old ‘Pant Lemon-1’ (Citrus limon Burm) trees reduced the vegetative growth in terms of height, spread, shoot length, number and size of the leaves in the autumn flush. Various NAA treatments (5–20 mg l?1), however, enhanced growth, but not to the extent that was observed after GA3 treatments. Application of GA3 at 10–40 mg l?1 significantly enhanced all aspects of growth, and the effects were most pronounced at 20 and 40 mg l?1. Nutritional status of the leaves showed a slight variation in relation to vegetative growth under various treatments.Some 2,4-D- and 2,4,5-T-treatments increased the fruit yield over the control, which could suggest mobilization of foods even at the expense of reduced vegetative growth. On the other hand, NAA, particularly at 10 mg l?1, increased both vegetative growth and yield, suggesting that the transport of the photosynthates from the leaves to the fruits was not at the expense of new growth extension. Due to excessive growth enhancement under higher concentrations of GA3 (20 and 40 mg l?1), comparatively fewer nutrients were translocated to the fruit “sinks”, thereby resulting in a non-significant decrease in yield.  相似文献   

4.
Summary

The effects of temperature on growth, development and yield of tomato (Lycopersicon esculentum) are reviewed with special emphasis on cultivar differences. The focus is on sub-optimal temperatures, above the level where chilling injury occurs. Temperature has a large effect on all aspects of development. Leaf and truss initiation rates decrease linearly with decreasing temperature. Although these rates may be different for different cultivars their response to temperature is the same. Young plants grown at sub-optimal temperatures produce thicker leaves, so they intercept less light and therefore have a lower relative growth rate. There was no interaction between temperature and cultivar for relative growth rate and related traits. In a crop producing fruits, this aspect is less important as most of the light is intercepted anyway. At sub-optimal temperatures, fruit set is reduced as a result of poorer pollen quality. The period between anthesis and ripening of the fruit increases and, as the growth rate of the fruit at a certain developmental stage is independent of temperature, fruits become larger at sub-optimal temperature. Higher temperature leads to an increase in early yield, at the cost of vegetative growth, but may also cause a delay in later trusses. Total yield over a whole season might be equal at lower temperatures, but higher tomato prices early in the season do not make it economically profitable to reduce the temperature in the greenhouse. Short-term effects might thus be different from long-term effects. In the literature, the link between yield and whole plant growth is often missing, limiting the possibilities of studying the underlying processes that contribute to changes in yield. Breeding for cultivars with equal production at lower temperatures is hampered by the limited variation for temperature response in cultivated tomato. Therefore breeders have to look for other sources of variation, as in related wild Lycopersicon species.  相似文献   

5.
Summary

Two levels of humidity, high, 0.1 kPa vapour pressure deficit (vpd) and control 0.5 kPa vpd, and four nutrient feed K/Ca mM ratios (4/7, 10/7, 4/2 and 10/2) were applied in all factorial combinations to a nine-week old tomato (Lycopersicon esculentum Mill.) crop for 63 d. The effect on gas exchange, water relations, vegetative growth, yield and accumulation of Ca and K in the shoot was examined. High humidity had a deleterious effect on leaf expansion, delayed truss and fruit maturity and reduced fruit yield. Water uptake was reduced and the Ca concentration of leaf and fruit tissue was increased under high humidity compared with plants grown under control humidity; K accumulation was unaffected. The accumulation of K and Ca in the shoot appeared to be poorly related to the rate of transpiration. The high (10/2 mM) K/Ca ratio nutrient feed had little effect on vegetative growth and yield compared with the low (4/7 mM), but restricted Ca uptake to the fruits at both the high and the control humidity. During the measurement period, 0900–1300 hours, stomatal conductance and leaf water status remained high at elevated humidity, compared with a progressive reduction in leaf water status and low stomatal conductance in the control humidity. A/ci gas exchange analysis where A is the net CO2 assimilation rate and ci is the intercellular partial pressure of CO2 suggested that, at high humidity, the photosynthetic capacity of the leaves was reduced because of a lower in vivo carboxylation efficiency. However, the mechanism(s) responsible for reduced leaf expansion remains unclear. The complex interrelations between physiological responses, leaf expansion and the uptake and distribution of K and Ca to the shoot, are discussed.  相似文献   

6.
Aqueous sprays containing either (1) micronutrients (Fe, Mn, Cu, Zn, B) at a concentration of 5 × 104M, (2) 2, 4-D at 1 ppm or (3) the micronutrients and 2, 4-D together were applied to 2-week-old plants of green bush bean, Phaseolus vulgaris. Measurements of juvenile growth were made 5, 10 and 15 days after treatment; of green pod yield and ascorbic acid content 6 weeks after treatment; and of seed yield when the plants were 13 weeks old. The use of 2, 4-D and of the 2, 4-D-micronutrient sprays resulted in significant (P = 0.05) increases in stem height, leaf number and area, and fresh and dry weights of roots, stems and leaves at all three times of harvest. The yield of green pods, in terms of number and fresh weight per plant, and the pod vitamin C content at harvest and after 4 days’ storage were significantly larger in the treated plants. In all cases the greatest stimulation resulted from the use of the solution containing both the 2, 4-D and microelements. Application of the solution containing only microelements produced values which did not differ significantly from those of control plants.  相似文献   

7.
The weekly rates of shoot extension and total growth in leaf length of the glasshouse tomato variety Potentate increased from germination until soon after the start of ovary swelling. It is postulated that when, or soon after, the first flower primordia were initiated, an internal reaction was stimulated that eventually resulted in the cessation of the progressive increase in the rates of shoot extension and growth in leaf length. Increase in the rate of vegetative growth ceased soon after the start of ovary swelling, but this occurred even when no ovaries were allowed to swell.

The diameter of the shoot was unaffected by removal of leaves but increased when no fruits were allowed to develop. Conversely, shoot extension growth was unaffected by removal of fruit but decreased when alternate immature leaves were removed, although the removal of mature leaves had no effect on shoot extension growth.

Removal of leaves was associated with a reduction in total fruit volume and an increase in total leaf length.

Removal of immature fruit was associated with an increase in total leaf length. Removal of alternate immature fruits had little effect on total fruit . volume ; the difference between normally fruiting plants and plants from which alternate fruits had been removed was less than 0?5%.  相似文献   

8.
Lentil plants of the Beladi type were grown at various NaCl levels under laboratory, greenhouse and field conditions with the object of determining the salt tolerance limits. Salt tolerance was much higher during germination than during subsequent growth. A 50% reduction in germination occurred at about 20.0 mmhos cm-1. Seed yield was reduced to 50% at soil salinity of about 3.9 mmhos cm-1. Plant survival, pod formation and seed quality were adversely affected by higher salt levels. Total nitrogen in the kernel decreased with rising soil NaCl levels while that of the husk increased.  相似文献   

9.
SUMMARY

The growth and photosynthesis of Oncidium ‘Goldiana’, a popular tropical orchid for cut flower production, were studied. Four main developmental stages were identified: bud stage, plantlet stage, unsheathing stage and pseudobulb stage. Pseudobulb formation occurred during the unsheathing stage which was closely followed by the formation of an inflorescence. The pseudobulb is of the heteroblastic type (arising from a single node) and lacks stomata. It is a G, shade plant based on chlorophyll a/b ratio, C02 compensation point, post-illumination C02 outburst and light response curves. The formation of new sinks such as inflorescence and axillary bud have a significant effect on the rate of photosynthesis of certain leaves. The photosynthetic rates of leaves L2 and L3 increased during the development of the axillary bud and inflorescence respectively. Pseudobulbs have high water content and contain chlorophyll but show no sign of gas exchange in light and dark. However, fixation of C02 is possible in light with partial removal of the underlying cuticle.  相似文献   

10.
The conjunctive use of a compost tea (CT) and an inorganic fertiliser (NPK) on the growth, yield and terpenoid content of Centella asiatica (L.) urban was evaluated. CT and NPK applied at half the recommended concentration resulted in the significant enhancement of vegetative growth, yield and antioxidant content. The synergistic effect of CT50 and NPK50 was highly pronounced on the bioactive components Asiatic acid, madecassoside and asiaticoside. The distribution of the total antioxidants was highest in roots (80%), followed by leaves (66%) and petioles (54%). There was a strong positive correlation (r = 0.990) between fertility and total antioxidant content, suggesting an enhanced synthesis of bioactive components resulting from the treatment. This response by C. asiatica to the integrated experimental treatment suggests a viable option for the commercial cultivation of the herb. Augmenting the vegetative biomass production and bioactive components will increase the availability of this medicinal herb for the treatment of various human ailments.  相似文献   

11.
Hibiscus sabdariffa L. was found to show an ambiphotoperiodic reaction, flowering both in short days and in extremely long days, but remaining vegetative (at least at 21–25° C) in a 16 h day. Flowering had a dual effect on growth. When floral induction was strong, lateral buds developed into flowers and the number of branches was proportionally reduced. The first stage of floral induction, however, was accompanied by a decrease of apical dominance. Plants shifted to long days after only a short stay at an inductive daylength, and plants moved to short days after a prolonged stay in long days, formed many more branches and a much greater vegetative mass than plants grown in continuous short days or long days.Plants were already sensitive to daylength in the cotyledon stage. Floral induction was not carried over from short days into long days. After marginal induction, floral buds reverted to vegetative shoots, or aborted and were replaced by a shoot from the axil of a bract.In short days, seedlings form shallowly three-lobed leaves until the generative stage, when only entire leaves are formed. In long days, the leaves are deeply five-lobed, also when the plant flowers.  相似文献   

12.
Summary

This study addresses vegetative growth and the uptake of nutrients and their accumulation in the vegetative and reproductive tissues of pepino (Solanum muricatum Ait.). The study was conducted in soilless plastic house conditions, with a planting density equivalent to 25.000 plants ha–1 during two seasons (1997–98 and 1998–99). The plants were sampled, fractionated into leaves, stems, fruits and roots, then dried and weighed and the macronutrient content was analysed every 30.d for 300.d after transplanting. The yield obtained was 2.kg of fruit per plant, which is 30% of the total dry weight. The relative growth rate (RGR) ranged from 0.0028 to 0.0451.d–1. The highest N, K, Ca and Mg concentrations were recorded in the leaves, and the highest P concentration in the roots. The nutrient accumulation of this yield was 10.64, 1.12, 16.06, 10.0 and 1.58.g of N, P, K, Ca and Mg per plant respectively. The highest accumulation of all nutrients was found in the leaves. The nutrient with the highest specificuptake rate was K, which ranged from 0.0037 to 0.0838.g g–1 d–1.  相似文献   

13.
Lettuce plants were sprayed with gibberellin (GA3) or water at the rosette (8-leaf) stage and subsequently with water or CCC (500 or 1500 ppm) at the onset of bolting. GA3 induced rapid bolting and increased seed yield, but seed stalks were longer and thinner than those that had been sprayed with water at the same stage. Treatment with CCC (500 ppm) at bolting decreased the flower stalk height of plants that had been sprayed with water at the rosette stage, but not that of GA3 treated plants. CCC (500 ppm) increased the number of inflorescence branches per plant as well as seed yield in the autumn sown crop, but had no effect on the winter sown crop. When a higher concentration of CCC (1500 ppm) was applied at bolting, flower stalk height decreased, irrespective of whether the plants had been previously treated with GA3 or not, and seed stalk diameter increased. However, 1500 ppm CCC reduced the number of inflorescence branches per plant and mean seed yield. It is concluded therefore that although the application of 500 ppm CCC at the onset of bolting may increase seed yield in the autumn sown crop, this treatment does not improve the seed stalk strength (e.g. increasing diameter or reducing height) of GA3 treated plants. On the other hand, whereas a higher concentration of CCC (1500 ppm) improves seed stalk characteristics, it reduces seed yield.  相似文献   

14.
Treating three cultivars of Vicia faba L. with ethephon led to reduced vegetative growth and enhanced abscission of leaves, flowers and immature pods. No clear pattern emerges of changes in the levels of endogenous auxin and inhibitors as a result of treatment with the growth regulator. Cytokinin levels in leaves of treated plants were much higher than in the controls but no changes occurred in stem tissue. The results are discussed in relation to senescence, abscission and flowering.  相似文献   

15.
以豇豆品种"青豇909"为试材,利用甲基磺酸乙酯(EMS)进行种子诱变处理并进行田间栽培试验,研究了EMS不同处理浓度对豇豆种子活力、生育期、农艺性状和经济性状等方面的影响,以期为豇豆EMS突变体库的建立和种质创新提供参考依据。结果表明:EMS不同处理对种子活力影响明显,随着处理浓度的增大,种子活力呈递减趋势;各处理出苗期差异明显,但从全生育期来看,与对照相比差异不明显;各处理间农艺性状和经济性状差异明显,第一开花节位总体比对照降低,0.2%的处理最低,单株分枝数0.1%的处理最多;单株结荚数0.5%的处理最多;0.1%的处理荚长最长,单株干荚总质量最大,平均干荚质量0.2%的处理最高。综合考虑,EMS处理浓度为0.1%时,种子活力、出苗率、荚长、荚粗、单株干荚总质量等方面优于其它处理,可作为筛选优质、高产豇豆新品种的EMS处理浓度。  相似文献   

16.
In order to optimise production of the edible flower buds produced by myoga (Zingiber mioga Roscoe) a greater understanding of the growth and development of the plant and factors influencing flower initiation and development are required. The vegetative growth phase in myoga was characterised by a distinct period of pseudostem development from the planted rhizome piece followed by an extended period of rhizome growth from both the base of pseudostems and the planted rhizome piece. The transition from pseudostem formation to the initiation of rhizome growth occurred at the same time as the dry weight of the planted rhizome piece ceased to decline. Flower bud initiation and development occurred over an extended period, beginning soon after the commencement of new rhizome growth and ending prior to foliage senescence. Flower buds were observed at the terminal meristem of first, second, third and fourth order rhizomes. Increasing temperatures stimulated both increased vegetative growth and flower bud initiation and development. Low flower bud yields recorded under conditions of low temperature were the result of reduced rate of floral initiation and not abortion of flower buds. Increased shading of plants grown under glasshouse conditions resulted in reduced flower bud yield and similarly the response resulted from decreased initiation rather than abortion.  相似文献   

17.
Pot culture experiments were conducted to assess the extent of growth, photosynthetic capacity, sennoside concentration and yield attributes of Senna plant under the individual as well as combined influence of NaCl and CaCl2. Six treatments, i.e. NaCl (80 and 160 mM), CaCl2 (5 and 10 mM) alone and a combination of NaCl + CaCl2 (80 + 10 and 160 + 10 mM) were given to the growing Senna plants at pre-flowering (45 DAS), flowering (75 DAS) and post-flowering (90 DAS) stages. Significant reductions were observed in pod biomass, leaf area, stomatal conductance, photosynthetic rate and sennoside concentration and yield, with each NaCl treatment. On the contrary, individual CaCl2 treatments had a favourable effect. Under the effect of combination treatments, although these parameters were reduced, the extent of reduction was much less than one caused by NaCl treatments. The combined treatments thus mitigated the adverse effects caused by NaCl.  相似文献   

18.
Experiments were conducted to observe the effects of foliar application of gibberellic acid on vegetative growth, flowering, fruiting and various disorders in ‘Chandler’ strawberry. GA3 (75 ppm) was applied to the strawberry plants either during mid-November (at fruit bud differentiation stage), or mid-February (pre-flowering stage) or at both times. Fruit under control were sprayed with tap water only. Observations were recorded on vegetative attributes like crown height, crown spread, petiole length, leaf number, leaf area; flowering and fruit set, fruit size; production of albino, malformed and button berries, total yield and marketable fruit yield and quality parameters, like juice content, TSS, ascorbic acid contents, acidity etc. Results indicated that GA3 (75 ppm) spray either during mid-November or mid-February or at both times has favourably influenced all vegetative attributes of ‘Chandler’ strawberry over control. Similarly, fruit set was increased, and production of malformed and button berries was reduced, but albinism remained unaffected. Although individual berry weight was reduced slightly, but fruit number, total as well as marketable yield was increased tremendously over control with no adverse effect on fruit quality parameters. In all, spraying GA3 both during mid-November and mid-February was much more effective in achieving the desirable results than single application of GA3 either during mid-November or mid-February.  相似文献   

19.
The effects of different manurial treatments on the yield and mineral composition of early potatoes are described. The crops were grown annually from 1954 to 1964 in a rotation of vegetable crops in a factorial manurial experiment on a sandy loam at Wellesbourne and, in i960 only, on a very fine sandy loam at Efford.

At Wellesbourne, farmyard manure (20 tons per acre per crop) with fertilizers consistently produced much higher yields than mineral fertilizers alone, and the relative effect of FYM increased from 1954 to 1959 but not subsequently. In years when moisture supplies were adequate, the larger part of the increase in yield could be attributed to effects of FYM on the early growth of the plants, and a smaller part to the increased rate of bulking of the tubers on the FYM plots. In dry years, however, growth during the harvest period was much slower on the fertilizer plots than on the FYM plots and the additional relative increase in yield on the latter during this period caused the overall effect of FYM to be larger than in the wetter years.

In the absence of FYM, each of the major nutrients N, P and K gave significant yield increases, but the need for adequate applications of phosphate and potash fertilizers together was emphasized by a marked interaction between their effects on yield. Applications of phosphate fertilizers had a particularly important effect early in the bulking period, whereas the effects of the nitrogenous fertilizers were greater at the later stages. In the presence of FYM, the fertilizer applications had significant effects only at the later stages of bulking, but at this time the amounts needed to give maximum yields were similar to those needed in the absence of FYM (124 lb. N, 36 lb. P2O5 144 lb. K2O (estimated), each per acre).

At Efford, applications of up to 4 cwt. per acre of sulphate of ammonia and 2 cwt. per acre of superphosphate (18% P22O5) gave significant increases in yield, and higher rates would probably have given still higher yields. Potash fertilizers did not affect yields although they markedly increased the potash contents of the plants. The differences between the responses at the two sites are discussed in relation to soil conditions.

The leaves of plants manured with FYM (Wellesbourne) contained much more potassium and slightly more phosphorus than leaves from unmanured plants and, while the differences in potassium content were larger towards the end of the bulking period than at the beginning, the reverse was true of the phosphorus contents. Thus, to use leaf composition data to indicate possible shortages of nutrients in the soil, the samples of leaves for chemical analysis must be taken at several different times during the growth of the crop. The value, if any, of extra nutrients for FYM-manured plants cannot at present be assessed.

At Efford, applications of sulphate of potash increased the potassium content of the leaves to levels approaching those found in the manured plants at Wellesbourne and higher than those in the unmanured plants. Because of marked interactions between the effects of the phosphate and potash fertilizers at Wellesbourne and indications that phosphate applications at Efford may have been too low to ensure maximum yields, it does not seem possible to combine the data from the two experiments in order to suggest levels of the major nutrients in the potato leaves, at any particular stage or stages, which may be considered adequate for maximal yield production.

At Wellesbourne the standard error per plot was smaller for the manured series (8·1%) than for the unmanured (12·9%), indicating that growth was more uniform on the former.  相似文献   

20.
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