Dry-matter production in a tomato crop: comparison of two simulation models

TOMSIM(l.O) and TOMGRO(l.O) are two dynamic models for tomato growth and development. Their submodels for dry matter production are compared and discussed. In TOMSIM(l.O), dry matter production is simulated by a modified version of SUCROS87 (Spitters et al., 1989). Single leaf photosynthesis rates are calculated separately for shaded and sunlit leaf area at different depths in the canopy, according to the direct and diffuse components of light; daily crop gross assimilation rate (A) is computed by integration of these rates over the different depths and over the day. In TOMSIM(l.O) leaf photochemical efficiency (e) and potential leaf gross photosynthesis rate at saturating light level (Pgmax) both depend on temperature and C02 level. In TOMGRO(l.O) crop gross photosynthesis rate is calculated by the equation of Acock et al. (1978); e is a constant and Pg max is a linear function of C02. In both models leaf photosynthesis characteristics are assumed to be identical in the whole canopy. Maintenance respiration (Rm) and conversion efficiency (Cf) are taken into account in the same way, except that root maintenance respiration is neglected in TOMGRO(l.O). For both models a sensitivity analysis was performed on the input variables (light intensity, temperature, C02 and leaf area index (LAI)) and on some of the model parameters. Under most conditions considered, simulated A was found to be 5-30% higher in TOMSIM(l.O) than in TOMGRO(l.O). At temperatures above 18°C Rm was also higher in TOMSIM(l.O), and C, was 4% higher in TOMGRO(l.O). The two models were very sensitive to changes in e and to a lesser extent to changes in the light extinction coefficient, whereas the scattering coefficient of leaves had hardly any effect on the simulated A. TOMGRO(l.O) appeared to be rather sensitive to the C02 use efficiency, whereas at ambient C02 level mesophyll resistance was quite important in TOMSIM(l.O). Four sets of experimental data (differences in cultivar, C02 enrichment and planting date) from Wageningen (The Netherlands) and Montfavet (southern France) were used to validate the models. Average 24 h temperature and average daily C02 concentration values were used as input to the models. For the Wageningen experiments, hourly PAR values were calculated from the daily global radiation sum by TOMSIM(l.O) and used as input in both models. For the Montfavet experiment, average hourly PAR measurements were used. Also measured LAI, dry matter distribution and organ dry weights (for calculation of Rm) were input to the simulation. In the Wageningen experiments, total dry matter production was simulated reasonably well by both models, whereas in the Montfavet experiment an under-estimation of about 35% occurred. TOMGRO(l.O) and TOMSIM(l.O) simulated almost identical curves in all four experiments. Strong and weak points of both models are discussed.     

同步叶片修剪对温室番茄干物质优化分配的影响

 研究了同步叶片修剪对温室番茄品种‘Capita’干物质优化分配的影响。结果表明, 在每穗果实数修剪为6个时, 一方面会减少营养生长库强, 显著降低了叶面积指数(LA I) 和植株总干质量; 另一方面有利于干物质分配到果实, 显著提高果实累积干物质分配率, 补偿因植株总干质量降低而引起的果实干质量的降低。在合理增加植株密度时, 同步叶片修剪可以显著提高LA I与单位面积植株总干质量, 从而显著提高单位面积果实干质量。     

Growth characteristic and sink strength of fruit at different CO2 concentrations in a Japanese and a Dutch tomato cultivar

The aim of the present study was to elucidate how fruit growth was limited by the source and sink capacities in a Japanese (‘Momotaro York’) and a Dutch (‘Dundee’) tomato cultivar. The two cultivars were grown hydroponically with a high-wire system in greenhouses for 25 weeks, and the growth characteristics and sink strength of fruit were determined. Fruits were pruned to four (4F) or one (1F) per truss. The latter were used to determine potential fruit growth, an indicator of fruit sink strength. Growth was also determined under normal (LC) and enriched (HC, 700 μmol mol⁻¹) CO₂ concentrations to examine the effect of source enhancement on fruit production. In both cultivars under normal CO₂, the growth rate of fruit pruned to 4F per truss was lower than that in 1F, indicating that maximum potential fruit growth was not achieved. Under HC conditions, fruit growth rate of ‘Dundee’ achieved in 4F trusses was lower than that in 1F. In ‘Momotaro York’ in HC, fruit growth in 4F trusses was close to potential. This implies that fruit growth was source-limited irrespective of CO₂ concentrations in ‘Dundee’ cultivar while fruit growth in ‘Momotaro York’ under normal and enriched CO₂ conditions was limited by source and sink strengths, respectively. Adjustments of cultural practices including increasing fruit number per truss and/or genetic approaches to enhancing fruit sink strength by breeding may improve fruit yields of Japanese cultivars under high source/sink conditions.     

Influence of sub-optimal temperature on tomato growth and yield: a review

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.     

不同茬口日光温室番茄干物质生产与分配

 以番茄的果穗和果穗下的三片叶及其相应的茎作为一个源库生长单位，对不同茬口日光温室番茄的干物质生产与分配规律进行了研究。结果表明：植株在前7穗果同时存在的情况下，从下到上不同源库生长单位内果实所分配到的干物质比例在42.6%～98.6%之间，即随着果穗数从下而上的不断增加，每产生一穗果实，各源库生长单位果实的干物质分配率下降约6%。不同茬口日光温室番茄受外界环境影响显著，干物质生产表现出明显的季节性差异，果实干物质分配率在越冬茬、早春茬和春夏茬分别为72%、62%和59%，春夏茬果实干物质分配率最低，这与其生长后期遭遇高温，坐果率降低有关；越冬茬生长前期100 d的干物质积累量只有后100 d的1/3，与其生长期内低温弱光有关。     

Effect of electrical conductivity,fruit pruning,and truss position on quality in greenhouse tomato fruit

Summary

The combined effects of electrical conductivity (an EC of 2.5 dS m^–1 or 8 dS m^–1 in the root zone) and fruit pruning (three or six fruit per truss) on tomato fruit quality were studied in a greenhouse experiment, planted in January 2005. Taste-related attributes [dry matter content (DM), total soluble solids content (SSC), titratable acidity (TA), glucose, fructose and citric acid content] and health-promoting attributes (lycopene, βcarotene, vitamin C, and total anti-oxidant activity) of tomato fruits harvested on the vine from the fifth or tenth truss positions were determined. The quality of tomato fruits was improved by high EC. A high EC in the root zone increased the DM content, total SSC, TA, as well as glucose, fructose and citric acid contents. A significantly higher lycopene and βcarotene content was also observed [on a fresh weight (FW) and dry weight (DW) basis] with a high EC in the root zone. The accumulation of different compounds that determine tomato fruit quality differed between the fifth and tenth truss. In particular, the lycopene content was reduced, whereas the βcarotene content was increased in the tenth truss with respect to the fifth truss, most likely because of higher temperatures during ripening of the tenth truss. Fruit pruning increased fruit FW by 42% and positively influenced the DM content and total anti-oxidant activity, while a negative effect was observed on lycopene and citric acid contents (on a FW and DW basis). EC and fruit pruning both had a strong effect on fruit size; however, EC had a much stronger impact on taste and health-related fruit quality attributes. A small interaction between EC and fruit pruning was found for marketable yield, fructose and glucose content, fruit firmness, and P and Ca concentrations in fruits.     

保护地黄瓜新品种‘旺世’

 ‘旺世’为耐低温弱光,适于鲜食切片型黄瓜新品种。植株生长势强,耐低温弱光,早熟,主蔓节瓜为主,平均单瓜质量200 g,产量可达150 t · hm-2。瓜棒形,长约35 cm,平均横径2.8 ~ 3.0 cm,果形指数约12,瓜把短。瓜皮深绿色,稍有光泽,无棱,瘤小,刺密。果实脆甜清香,硬度10 kg · cm-2。高抗枯萎病、白粉病,较抗霜霉病。适合河南、山东、河北、安徽、江苏、湖北、湖南等黄瓜产区早春保护地和秋延后保护地栽培。     

不同整枝方式对管棚越夏栽培番茄生长的影响

在管棚田间状况下,对越夏栽培的番茄进行单秆整枝、双秆整枝及连续摘心处理,测定番茄的生长、产量及品质指标,研究不同的整枝方式对越夏栽培番茄生长的影响.研究结果表明,连续摘心处理的植株在株高、茎粗、产量、叶绿素含量及根系活力指标方面均优于单秆整枝和双秆整枝处理;双秆整枝处理的植株叶片中丙二醛含量最高,番茄果实中VC含量也有...     

Fruit growth and pseudoembryo development affected by uniconazole,an inhibitor of gibberellin biosynthesis,in pat-2 and auxin-induced parthenocarpic tomato fruits

Morphological changes during the development of pseudoembryos in parthenocarpic fruits of the genetic parthenocarpic tomato cultivar, ‘Severianin’, were observed. Pseudoembryos that originated from division of the innermost integument cells were formed in the ovule cavity. These cells were highly stained with toluidine blue O and actively divided until 20 days after anthesis. Uniconazole, an inhibitor of gibberellin biosynthesis, applied at anthesis decreased the setting ratio of fruits and inhibited the development of pseudoembryos. Uniconazole applied at 3 days after anthesis inhibited fruit growth entirely and suppressed pseudoembryo development. Gibberellin treatment at 2 days after uniconazole treatment reversed the inhibitory effect of uniconazole on fruit growth and pseudoembryo development in ‘Severianin’. The inhibitory effect of uniconazole on fruit growth and pseudoembryo development in auxin-induced fruits of ‘Kyouryoku-Kyokkou’, a commercial cultivar without genetic parthenocarpy, was weaker than that in ‘Severianin’. Application of gibberellin also reversed the inhibitory effect of uniconazole in this cultivar. Well-developed pseudoembryos were always observed in the well growing fruit in both cultivars. These results indicate that the development of pseudoembryos is closely related to the growth of parthenocarpic fruit.     

外置式秸秆反应堆对日光温室番茄生长发育的影响

以番茄"魁冠108"为试材,研究了外置式秸秆反应堆在越冬茬栽培过程中对晴天温室内CO2含量和番茄植株营养生长及叶片叶绿素含量以及番茄坐果数、果实产量和品质的影响。结果表明:外置式秸秆反应堆能有效缓解日光温室内CO2亏缺现象;使营养生长期和结果期番茄植株净光合速率分别提高了19.5%和27.8%;显著提高番茄植株在营养生长期和结果期叶片叶绿素含量,促进番茄植株的生长;单果重增加32.59g,产量增加1 303.8kg/hm2。     

Competition effects between fruit trusses of the tomato plant

There were 6 treatments in each of 2 series covering the range from 1–6 fruit trusses per plant. The terminal growing-points were removed 2 leaves above the last inflorescence of each treatment in the “limited-stem” series, and 2 leaves above inflorescence 6 with inflorescences removed as necessary in the “full-stem” series.The yield of trusses 2–5 in the “full-stem” and of truss 2 in the “limited-stem” series was reduced by the presence of subsequent trusses. Similar trends were apparent with trusses 3–5 of the “limited-stem” series. It was suggested that the reduction in yield was due to competition between trusses for assimilates resulting in smaller and/or fewer fruit per truss.Data is presented to suggest that the net assimilation rate in the tomato plant can be reduced due to lack of fruit load and that fruit yield can be limited simultaneously by lack of both source and sink strength.     

Effects of fruit characteristics and climatic conditions on tomato transpiration in a greenhouse

Summary

Experimental data of the transpiration and surface temperature of detached tomato fruits were collected to study and analyse how tomato fruit transpiration (E) was related to fruit characteristics, growth stage and climatic conditions. The measurements were carried out (i) in controlled conditions on fruits weighing between 10 and 140 g and (ii) during several summer days on fruits of 60–100 g under two greenhouse compartments with contrasted (high and low) levels of air vapour pressure difference (VPD_a). The transpiration rate, when expressed on a fruit area basis (g cm^–2 h–1 ), showed only a very slight dependence upon weight. Linear models relating E in unit area to (i) VPA_a and (ii) VPD (fr-a) (fruit-to-air vapour pressure difference) by means of a total conductance to water vapour (g_t), were proposed and their parameters were identified for fruits grown under the high and low VPD regimes. These models were able to explain a significant part of the observed variation in fruit transpiration. The parameters of the model differed with respect to growth conditions. The results evidenced the role of both fruit characteristics and climatic conditions on fruit transpiration and that the response of fruit transpiration to VPD could be separated into two components: (i) a short-term and reversible response which seems to be related to instantaneous changes in cuticular hydration linked to the prevailing VPD conditions and (ii) a long-term and irreversible response due to cuticle characteristics which depend on the average level of VPD experienced by the fruit during its growth.     

Relations Between Growth of Leaves,Fruit and Shoot of Glasshouse Tomato Plants

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%.     

Responses of leaf photosynthesis and plant growth to altered source–sink balance in a Japanese and a Dutch tomato cultivar

We investigated the effects of altered source/sink ratio by leaf or fruit pruning on leaf photosynthetic characteristics and whole-plant growth of ‘Momotaro York’, a Japanese cultivar, and ‘Dundee’, a Dutch cultivar and verified a hypothesis for sink-limitation of plant growth proposed by Tanaka and Fujita (1974). Plants were grown hydroponically with a high-wire system in a greenhouse for 11 weeks. Light-saturated photosynthesis of young, fully expanded leaves measured at atmospheric CO₂ partial pressure of 37 Pa and at an intercellular CO₂ partial pressure of 20 Pa was not influenced by alteration of source/sink ratio for either cultivar. Although soluble sugars were accumulated in leaves under high source/sink conditions, the amount of ribulose-1,5-bisphosphate carboxylase/oxygenase, a rate-limiting factor for CO₂-limited photosynthesis, was not affected by the altered source–sink balance. Net assimilation rate of a whole plant increased with decreasing source/sink ratio, but this can be accounted for by the changes in light interception per unit leaf area, without taking the source–sink relationship into consideration. It was concluded that the altered source/sink ratio did not change leaf photosynthetic capacity and the sink-limitation hypothesis cannot be applied to either cultivar under the conditions of the present study.     

菏泽市樱桃番茄日光温室栽培关键技术

为了充分发挥樱桃番茄观赏性强、营养价值高、菜果兼宜且经济效益突出的特点,满足广大消费者和种植户的热切需求,积极开展新品种选育、深入研究高效栽培管理技术具有重要的现实意义。在栽培面积不断增加、产量及品质出现瓶颈的情况下,对菏泽市多个樱桃番茄大棚种植园进行了实地调研,从品种选择、播种、培育壮苗、定植、田间管理、病虫害防治、果实采收等方面归纳总结出了菏泽市樱桃番茄日光温室栽培关键技术,以期为当地种植户实现促产增收提供依据。     

芡实新品系苏芡杂2号品种特性比较试验

对苏芡杂2号植株的叶、花、萼片、果实、籽粒等主要植物学性状进行了比较研究。试验结果表明,除花色、萼片形状基本相同外,苏芡杂2号的营养生长强于对照紫花苏芡,始花期早于对照5～9 d,且采收期较对照延长5 d左右;综合抗叶瘤病强于对照;苏芡杂2号的单株平均结果数为13个,多于对照的12个;其籽粒米仁直径平均为1.0 cm,较对照的0.85 cm大15%;其单株产量高于对照11.1%;平均667 m^2产量达77.8 kg,高于对照14.1%。     

不同生长调节剂对秋季番茄穴盘壮苗指标及丰产性状的影响

于苗期采用灌根处理的方法,研究了碧护、生根粉、超级矮丰王、金云大-120、复硝酚钠、甲壳素对秋季番茄幼苗生理指标、植株营养生长以及产量的影响。结果表明,生根粉处理后番茄秧苗质量显著增加;碧护、金云大-120、复硝酚钠、甲壳素处理,均不同程度地增加了番茄幼苗的株高、茎粗、叶面积、根冠比、G值、壮苗指数及叶绿素含量。定植后,各生长调节剂处理均可促使植株生长势增强,增加现蕾数;生根粉处理显著增加番茄前期产量、平均单果质量及总产量。因此,番茄越冬茬栽培中,为培育壮苗,于幼苗1叶期施用生根粉100倍液效果最佳。     

Effects of CCC on the occurrence of tomato puffy fruits and the endogenous cytokinin activities

CCC treatment at flowering time suppressed the occurrence of tomato fruit puffiness in solution culture. Root application, truss spraying and whole plant spraying of CCC were all effective in correcting fruit puffiness, and truss spraying did not decrease fruit weight, unlike the other two treatments. For practical use, truss spraying might be the best method to control tomato fruit puffiness.Cytokinin contents in the xylem sap of tomatoes increased when CCC was applied to roots. This suggests that cytokinin biosynthesis in roots was increased by CCC treatment. Cytokinin activities in tomato fruits at an early developmental stage were also markedly increased by CCC treatment to roots. These results suggest that the CCC effect on the control of tomato fruit puffiness might be partly due to increased cytokinin activity in the developing fruit.     

冬季温室气温调控对番茄和黄瓜生长的影响

采用四段变温管理,即揭棉被—13：00、13：00—盖棉被、盖棉被—19：00、19：00—次日揭棉被,以贝美番茄和津早一号黄瓜为材料,研究了冬季温室气温调控对其生长的影响。研究结果表明,在冬季温室生产中,采用透光率较高的PO膜覆盖和适当较高的四段变温管理,即4个时间段下番茄和黄瓜的温度指标分别为26℃—24℃—18℃—12℃和28℃—25℃—19℃—13℃时,更有利于番茄和黄瓜植株生长,株高、茎粗、叶面积的相对生长量增加,坐果率和果实膨大速度增加,叶片叶绿素含量增加及净光合速率增强。     

Essential and non-essential element composition of tomato plants fertilized with poultry manure

Poultry manure (PM) must be disposed of from poultry farms, but is a potentially valuable source of macro- and micronutrients for plant growth. The objective of this study was to examine the effects of poultry manure on the growth of tomato (Lycopersicon esculentum) plants. Yields of fruits and vegetative material of plants grown in soil with 0, 10, 20 and 40 g kg⁻¹ PM added were measured. Concentrations of N, P, K, Ca, Mg, S, Fe, Zn, Cu, Mn, Mo, Cl, Si, Br, Rb, Sr and Ba in leaves at flowering and at final harvest and in fruits were determined by polarized energy dispersive X-ray fluorescence (PEDXRF). Poultry manure fertilization improved tomato shoot growth and also fruit yield and increased leaf N concentrations at the harvest stage. In addition, P concentrations of the leaves and fruits were increased as the application rate of PM was increased. Fruit Ca and Mg were significantly reduced by increased rate of PM application, but not to the extent to cause the calcium deficiency disorder blossom end rot. Applied high levels of PM slightly increased the concentrations of leaf Mo and Br at the harvest stage. Poultry manure applications had a positive effect on the concentrations of leaf Zn, Cu, Cl and Rb at both sampling stages, but leaf Si concentration was reduced by PM treatments. The concentrations of Zn and Rb were increased in the fruits by PM treatments, but the concentrations of Br were decreased. Applied PM levels had no significant effects on the concentrations of K, S, Fe, Sr or Ba in tomato plants. It is concluded that the increased fruit yield, and the increased concentration of Zn (an element required in the human diet) and the lowered concentration of potentially harmful Br in the fruit make poultry manure a valuable growing medium for tomato production.