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1.
Summary

The effect of leaf area index (LAI) on canopy growth, light interception, yield, fruit growth and quality and return bloom of kiwifruit were examined in 1990 and 1991. Different LAIs were obtained in the 1990 season with defoliation treatment made precociously at different intensities, in a diffuse way, uniformly in the whole canopy. At the end of canopy development LAIs of 3.6,3.3,3.1,2.6 and 1.8 were obtained and evaluated. The kiwifruit vines with a bud load of 680?700 and LAIs of 3.3 and 3.6 in 1990, showed an optimum and constant yield (>90 kg per vine), good average fruit weight (>100 g) and high fruit quality in both years, and also good return bloom the following season. The reduction of LAI to 2.6 and 1.8 drastically reduced, in the year of LAI imposition, both yield (?18.5% and ?30%, respectively) and mean fruit weight (?18.6% and ?29.1%, respectively) compared with vines with an LAI higher than 3.1. In the same treatments, the soluble solids concentration in the fruit was significantly decreased and a great reduction in numbers of fruiting shoots and numbers of fruits per fruiting shoot were observed in the year following the LAI imposition. In vines with the same bud load, fruit number and an LAI of 3.1, small variations in yield and fruit weight in the year of defoliation treatments were recorded, but in the following season the yield was significantly reduced (?14 kg per vine) due mainly to a decrease in the number of fruiting shoots (?14%). In kiwifruit vines with low LAI (2.6 and 1.8) nearly all fruits present in the canopy ripen, with no significant fruit drop. At low LAI, the sink strength of the fruit was greater and more extended so that vine growth and the plants reserves were restricted. Under the conditions of this experiment, an LAI higher than 3.3, corresponding to a leaf area-fruit ratio higher than 600 cm2 per fruit, is necessary to obtain regular vine growth and yield, optimum fruit size and quality and return bloom the following season.  相似文献   

2.
Summary

A factorial combination of three cultural factors (± hand-pollination, ± growth retardant, ± fruit thinning) were evaluated for their effects on fruit set and fruit size of ‘Fuyu’ persimmon (Diospyros kaki L.) in subtropical Australia (Lat. 27° S). Treatments were applied to individual shoots on mature seven year old trees. Fruit set of pollinated flowers was high compared with non-pollinated flowers (91% vs. 47%). Pollinated fruit also grew faster at all stages of fruit development and, at harvest, fresh weights were 25% heavier. Palcobutrazol significantly (P<0.05) increased fruit weight by 7% compared with controls but did not increase fruit set. Irrespective of treatment, fruit weight was not correlated (r<0.3, n.s.) with shoot length, number of nodes per shoot, fruit nodal position, shoot dry weight, leaf area per shoot, and number of leaves per shoot. Fruit fresh weight was only poorly correlated with shoot base diameter (r = 0.41*). Pollinated fruit had significantly (P<0.05) higher concentrations of nutrients (N, K, Ca, and Zn).  相似文献   

3.
Summary

To multiply large number of male-sterile marigold plants for F1 hybrid seed production, an efficient protocol for in vitro cloning of field-grown differentiated male sterile plants has been developed. A comparative field performance study of tissue culture and seed-derived male sterile plants of two marigold genotypes was undertaken to test the possibility of using micropropagated plants in hybrid seed production. Tissue culture raised plants of both genotypes had superior field performance to the seed-derived counterparts. These plants were more vigorous in growth, i.e. in terms of plant height, number of secondary branches and number of leaves and plant spread, while the leaf chlorophyll contents were equal to that of seedling plants. Flowering was earlier by 2-3 weeks and the number of flowers per plant was also higher in such plants. Repeated hand pollination of sterile flowers with bagged flowers of cv. Pusa Narangi Gainda showed that seed set and bold seed yield were higher or almost comparable with the seed-derived plants. The results clearly indicate that the tissue culture can be adopted for the successful cloning of male-sterile plants, which could then be utilized for producing F1 seeds with higher quantities of bold seeds with better storability.  相似文献   

4.
单株留芽量及结果母枝剪留长度对猕猴桃结果性能的影响   总被引：3，自引：0，他引：3  
对栽植株行距3m×4m的美味猕猴桃秦美品种连续进行了3年试验,单株分别剪留250、300、350、400个芽处理后,平均单株新梢数、叶面积指数、落叶率与留芽数量呈正相关,叶幕下层的光强度、净光合率与留芽数量呈负相关;单株果枝数、果实数及单位面积产量均以留400芽处理最高,但平均单果重最小,88g以上的优质果产量最低。综合评价以单株剪留350个有效芽的效果最佳,优级果产量达到2102.7kg/666.7m2。结果母枝分别剪留7、12、17个有效芽处理后,平均每母枝的结果枝数、果实数、产量与留芽数量呈正相关,均以17芽处理最高,分别达到9.5个、30.4个和3.09kg,各处理间的单果重差异不显著。  相似文献   

5.
Abstract

Influence of initial transplant size on yield components was investigated using two strawberry cultivars over a three-year period. Plants were sorted into three groups according to crown size each fall before transplanting.

Fruits were harvested once a week over a ten-week period each year. There were marked differences between ‘Chandler’ and ‘Camarosa’ cultivars. Transplants of the ‘Chandler’ cultivar with larger crown diameters produced significantly greater early and total marketable yield than transplants with smaller crown diameters. Regression analysis of yield components against initial crown diameter revealed a positive relationship between total fruit numbers produced per plant and initial crown size for both cultivars. Total weight of marketable fruit produced per plant was positively associated with initial crown diameter of transplants. Relationships between initial crown diameter and early yield components were not as consistent among the two cultivars tested. Early yield components of ‘Chandler’ were all correlated to initial crown diameter of transplants. The size of the transplant did not influence early yield components of ‘Camarosa’ except for fruit size. There was a significant relationship between the postharvest dry weight of plants and initial crown diameter of transplants.  相似文献   

6.
Summary

Melon (Cucumis melo L.) ‘Arava’ was grafted onto 22 experimental Cucurbita rootstocks including intra- or interspecific hybrids to examine scion-rootstock compatibility and to correlate plant performance under greenhouse and field conditions. The commercial Cucurbita ‘TZ-148’ rootstock and non-grafted plants were used as controls. Numbers of leaves, stem length and plant fresh weights were recorded three weeks after planting. Vegetative growth of the grafted plants varied markedly, indicating differences in compatibility between the scion and rootstocks. A positive correlation was found between number of leaves, stem length and fresh weight of melon plants. No significant advantage in vegetative growth was found in melons grafted onto intra- or interspecific hybrid rootstocks. Stem diameter and number of vascular bundles of the rootstock did not correlate with scion plant fresh weight. Twelve selected rootstocks out of the 22 tested were grown in the field during the spring and autumn, to determine if there is an association between the plant performance in the greenhouse and fruit yield under field conditions. Positive and significant correlations were found between greenhouse growth parameters and fruit yield under field conditions. It is suggested that testing grafted melons under greenhouse conditions could be a useful tool for preliminary testing of scion-rootstock compatibility.  相似文献   

7.
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   

8.
Summary

Tomatoes were grown for 66 d in deep solution culture (a) without aeration, (b) with interplanted rice and (c) with air bubbled through the solution, in factorial combination with two electrical conductivities (4 and 8 mS cm?1). Root growth was seriously restricted in the poorly aerated solutions (a) and (b). Interplanted rice stimulated shoot growth compared with the un-aerated treatment, and increased the total dry weight, leaf area and fruit yield (fresh weight) by up to 26, 34 and 22% respectively. The total dry weight of plants grown with rice was only 60% of that of the aerated ones but the area of corresponding upper leaves was 73%. Water and nutrient uptake were reduced by poor aeration but, after allowing for the uptake by the interplanted rice, only the uptakes of P and Ca by tomatoes in that treatment were significantly higher than those of the un-aerated plants. The higher salinity reduced growth and the uptake of nutrients. No interaction between aeration and salinity was found.  相似文献   

9.
Summary

Young tomato plants were transferred to heated glasshouse compartments on 9 December at a density of 2.04 plants m-2 and grown as a conventional long-season tomato crop. Beginning in either the third, fifth, seventh or ninth week of the year, every other plant was allowed to retain one side shoot so as to increase the effective plant density to 3.06 plants m-2. Control crops were grown throughout at both the initial and the final densities. Two different patterns of taking the side shoots were tested in two sub-treatments: taking the required number of side shoots in four tranches over a period of six weeks was neither significantly better nor worse than taking them in two equal tranches, four weeks apart. The main effect of adding side shoots was to increase the number of fruit harvested per m-2, as compared with a control crop grown throughout at the initial density of 2.04 plants m-2. However, these additional fruit were not harvested until at least 80.d after the first side shoots had been allowed to grow. When side shoots were taken as early as week 3, a high proportion of the marketable fruit were in the preferred size (viz.47to57.mm in diameter, 50 to 90.g in weight, UK grade D) in all harvest periods. Thus, the additional side shoots enabled the crop to bear extra fruit and when the side shoots were taken early, the production of additional fruit coincided with the time when both the quantity of solar radiation incident per day and the concomitant assimilate production were increasing rapidly. Consequently, the supply of assimilates and the numbers of fruit available per m-2 were better matched for the purpose of continually producing fruit of one size. However, the presence of side shoots tended to reduce the number of marketable fruit carried on each truss. The addition of side shoots increased leaf area index and also significantly increased total fruit yield. The increased area of foliage served to shade more fruit from the heating effects of incident solar radiation and a smaller proportion of marketable fruit was downgraded to Class II in all side-shoot treatments. In general, the means of the four successive side-shoot treatments provided a graded series between those of the fixed low-density and the fixed high-density control treatments.  相似文献   

10.
A single foliar application of 2, 4 or 6% urea solution to ber cv Banarasi Karaka just before blooming in September significantly improved shoot growth, leaf number, area and weight, the best results being obtained following treatment with 4 or 6 % solutions. Flower number, fruit set and fruit retention were better in nitrogen-supplied plants. The size of the fruits and yield per tree increased with increasing concentration of urea and the highest yield (61 % greater than control) was recorded following 6 % spray treatment.  相似文献   

11.
Summary

Heirloom tomatoes (Solanum lycopersicum L.) such as ‘Cuore di Bue’ are highly appreciated by consumers for their outstanding quality and flavour. Nowadays, they are often grafted onto vigorous rootstocks in order to overcome several soil-borne diseases. The present study was conducted in 2007 and 2008 in Southern Italy. Plants of ‘Cuore di Bue’, an heirloom ‘oxheart’ tomato, were grown in a greenhouse either as non-grafted plants, or grafted onto two inter-specific (S. lycopersicum S. habrochaites) rootstocks (‘Beaufort F1’ and ‘Maxifort F1’) in order to evaluate their effects on vegetative growth, marketable yield, fruit quality, and the sensory properties of ‘Cuore di Bue’ tomato fruit. Growth analysis revealed that ‘Maxifort F1’ enhanced plant growth, particularly in terms of leaf area and leaf fresh weight. Grafted plants had higher leaf area ratios (by 13%) and higher leaf dry weight fractions (by 18%) compared to non-grafted ‘Cuore di Bue’ plants. Marketable yields increased by 20 – 25% in grafted plants in both years. However, total soluble solids (TSS) contents, titratable acidity (TA), and TSS/TA ratios were not significantly affected by grafting.Vitamin C contents decreased by 14 – 20% in both years in the fruit of plants grafted onto either rootstock. The sensory profiles of fruit were not modified by grafting, although taste panelists expressed a higher preference for purchasing fruit from plants grafted onto ‘Maxifort F1’. These results confirm that, when using the appropriate rootstock/scion combination, grafting can improve plant growth and the marketable yield of heirloom tomato fruit without reducing the sensory quality of the fruit or its biochemical parameters. However, grafting can reduce vitamin C contents and, thus, nutritional quality.  相似文献   

12.
Flower clusters were removed at full bloom from ten year old ‘Cox’s Orange Pippin’ trees on M.9 rootstocks, over the whole tree, on alternate branches or on whole sides. Mean fruit weight per tree at harvest was linearly dependent on leaf area per fruit and on light interception per fruit, both relationships accounting for over 90% of the variance. These relationships did not differ between treatments, implying either a mobile pool of carbohydrate or photosynthetic adjustment within the tree to crop load. Measurements of leaf photosynthesis in July and September showed no statistically significant differences in photosynthetic rate of spur or extension shoot leaves on bearing or non-bearing branches. Although the treatments caused no overall effects on shoot growth or leaf area per tree, sides of trees without fruit had greater leaf area and shoot growth than did sides bearing fruit. Fruit mineral composition and percentage dry weight were not affected by treatment except where the treatments significantly altered fruit size. In the following spring, although the treatments did not affect the total number of flower buds produced, branches that were deflowered in the previous spring carried significantly more flower buds than did branches which had cropped.  相似文献   

13.
Six-week-old tomato plants were subjected to 5 root-zone temperatures, ranging from 12 to 36°C, and 4 light levels in a factorial design. Large increases in shoot dry weight, leaf area and fruit development resulted from soil warming to 24°C when plants were grown under high light conditions. Shoot growth and fruit weight were reduced at 24°C root temperature under low light conditions. Total plant photosynthesis, leaf area index, net assimilation rates and leaf chlorophyll content were related to plant growth and flower development for the various treatments. Our experiments have shown an interaction between root-zone temperature and light levels for greenhouse tomatoes. Soil warming caused large increases in shoot dry weight and fruit development when light was not limiting plant growth, but had deleterious effects on flowering and fruit set under shaded conditions.  相似文献   

14.
Abstract

The optimum leaf number required for normal fruit growth in the regular bearing mango cultivar ‘Amrapali’ and the biennial bearing cultivars ‘Chausa’, ‘Dashehari’ and ‘Langra’ were studied by isolating individual fruits with known numbers of supporting leaves by shoot girdling at the time of fruit set. There were significant differences in the leaf area (249.01-1817.10 cm2), fresh weight (7.0-77.0 g) and dry weight (3.7-50.0 g) of leaves on shoots having 30, 20, 10 and 5 leaves as compared with control in different cultivars. In both types of cultivars, there was a progressive reduction in fruit size in terms of total fruit, pulp, peel, and seed weight with decreasing numbers of supporting leaves, however, a minimum reduction (2.4%) in fruit growth in ‘Amrapali’ was noticed with 30 supporting leaves. A nonsignificant difference in photosynthetic rate with varying number of leaves was found but its efficiency in leaves was higher in ‘Amrapali’ as compared with biennial bearing cultivars. Starch accumulation in the leaves was reduced by shoot girdling. The stomatal resistance of the leaves of girdled shoots was comparable with that of leaves on control shoots. In all the cultivars except ‘Amrapali’ it was observed that 30 leaves, the maximum retained on a shoot, could not support the growth of a single fruit to normal size. The data on rate of photosynthesis in different pool size of leaves and fruit growth in girdled and nongirdled shoots clearly show that fruit development depends not only on the current assimilates but also to a great extent on reserves. A 14CO2 feeding experiment showed a higher rate of carbon fixation in the leaves of girdled shoots than in the control shoots, but the translocation of 14C assimilated to the developing fruits on the girdled and control shoots was comparable. The results also indicated that developing fruits are major sinks for current photosynthates as more than 60 percent of the 14C exported from the treated leaf was found in the fruit in all instances.  相似文献   

15.
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   

16.
Summary

The apple cultivar Queen Cox on M.9 rootstock cropped more precociously when planted as two year old trees than when planted as one year old trees, even though there were no significant differences in the sizes (leader height and branch length) of the trees at the time of planting. However, the two year old trees had larger root systems at planting. As the trees aged, those planted as one year olds grew more vigorously and bore higher cumulative yields than those planted as two year olds. Annual root pruning of the trees, commencing 15 months after planting, reduced extension shoot growth, crown volume and grubbing weights (final fresh weights of scions) severely. In some seasons root pruning increased the number of spur and terminal floral buds produced and also the final sets and yield efficiencies on the treated trees. Planting trees within semi-permeable fabric membranes also reduced extension shoot growth and tree size, but less severely than the root-pruning treatment. Root restriction increased the efficiency of fruit set and yields and also improved the grades of fruits produced. Trickle irrigation treatments increased shoot growth and tree fresh weight at the time of grubbing, but had inconsistent and small effects on fruit set and yields. Interactions between tree age at the time of planting and the root manipulative treatments were significant.  相似文献   

17.
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   

18.
Examining the components of yield of black currant cultivars in 2 successive years indicated that the number of flowers per raceme, racemes per flower bud, and mean potential berry weight, although variable between cultivars, tended to vary little within any cultivar. These components combined gave a potential berry weight per bud which appeared to be relatively stable, and may be a genetic characteristic.Year-to-year variation in yield of single cultivars was closely correlated with changes in the number of fruiting buds per bush (the product of number of shoots and fruit buds per shoot). These components are determined at different times in the year before harvest and may indicate critical phases in development of the crop.In each year, all cultivars produced roughly the same proportion of their potential crop as actual crop, although the proportion was different in the 2 years. Thus the differences between cultivars in crops harvested were related to differences in crop potential developed in the pre-fruiting year, which are considered to be due to quantitative genetic differences in potential yields per bud and differences in response to conditions affecting fruit bud formation.  相似文献   

19.
The fig tree (Ficus carica L.) is widely cultivated in the Mediterranean region under warm climates. Fig yield is governed by the previous crop load and is strongly dependent on shoot length. Special cultural practices are required to stimulate new vegetative growth that will ensure regular and high productivity. The present study focused on the use of the rest breaking agent hydrogen cyanamide (HC) as Dormex to enhance vegetative growth, which influences the yield. A field trial was held in northern Tunisia (36° 49′ N; 9° 48′ E) on mature fig trees cv. Zidi. In reference to untreated trees as control, two hydrogen cyanamide treatments at 1% and 1.5% HC were considered. Bud break rate, vegetative growth, starch content of shoots, yield, and fruit characteristics were assessed. Results indicated that 1.5% HC significantly increased shoot length, fruit number per shoot, and yield. It advanced bud break by 10 days and fruit ripening by 7 days compared to the control. However, leaf number, leaf area, and starch content seem to be unaffected by hydrogen cyanamide treatments. Regarding fruit quality, a 1.5% HC dose significantly increased dry matter content, while fruit diameter and total soluble solids remain unaffected. In conclusion, hydrogen cyanamide could be used under warm conditions to improve vegetative growth of fig trees cv. Zidi and consequently fig productivity. Application of 1.5% HC 40 days before bud break was the most effective in increasing shoot length and yield.  相似文献   

20.
Summary

A crop-scale experiment between March and October 2000 investigated the effects of split-root salinity stress and rooting volume on the expansion of leaves, fruit yield and quality in two standard round fruited cultivars of tomato (Lycopersicon esculentumMill) Solairo and Espero, grown in rockwool. To implement the treatments, a split-root method was utilized whereby different levels of salinity (expressed as EC), adjusted by the addition of NaCl, was administered to two halves of a root system. The split-root high EC (2.8/8.0 dS m–1) treatment enhanced fruit quality by increasing the concentrations of sugar, acid, total soluble solids and reducing the incidence of visual defects such as uneven ripening and gold-spot. Split-root high EC did however reduce leaf area that corresponded with low K concentration in the leaf tissue. The split-root method utilized doubled the rooting volume compared with the standard single rockwool slab, but this extra rooting capacity had no detectable effect on leaf expansion, yield or fruit quality. Although there was little impact on yield for ten weeks after the imposition of the high EC split-root treatment, mean reductions in weekly yield occurred thereafter and were of the order of 9 and 13% for ‘Solairo’ and ‘Espero’ respectively through to the end of the experiment. The fall in yield was due, in part, to a decrease in fruit size. Whilst water uptake was reduced it was unclear how the effects on leaf growth and fruit yield were mediated in the shoot. Possible processes that coordinate responses to root-zone salinity stress are discussed. The potential use of the split-root system in commercial production is considered.  相似文献   

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