Blossom-end Rot Research Articles

Effect of gypsum, deep ripping, and irrigation on determinate tomatoes

Treatments of gypsum, deep ripping, and level of irrigation were applied to alluvial soils at Carnarvon, Western Australia, to assess the effect on yield of determinate tomatoes. Yield was increased (P<0.05) from 3 1.9 to 41.5 t/ha when gypsum (5 t/ha) was applied and increased (P<0.05) with level of irrigation (65.6 t/ha at 699 mm v. 14.9 t/ha at 270 mm). Blossom end rot and total soluble solids in fruit were significantly (P<0.05) higher at low and medium irrigation (355 mm) levels than at the high level. Total soluble solids increased significantly (P<0.05) when gypsum was applied to deep-ripped treatments. Dispersion of soil colloids was significantly (P<0.05) reduced by gypsum. Deep ripping to 0.6 m removed the soil hardpan but had no effect on tomato yield or dispersion.

果実送風によるトマト尻腐れ発生防止とそのメカニズムの解明

Occurrence of blossom-end rot of tomato fruits is serious problem in tomato cultivation in greenhouses and is considered to be caused by lack of calcium. In order to prevent occurrence of blossom-end rot, effect of air flow to fruits was tested and the mechanism of prevention of occurrence of blossom-end rot was analysed.Data were collected in the experiment of zone cooling with cold water or fog, the results of which were reported in previous paper (Cho et al., SHITA JOURNAL, 4 (1) : 30-39, 1992). Average relative humidity in cold water cooling was 67-68% and that in fog cooling was 75-76%. Tomato plants (Lycopersicum esculentum MILL. cv. House momotaro) were cultivated in hydroponics with nutrient solution of EC of 0.4 S-m-1.The results were as follows.(1) Percentages of occurrence of blossom-end rot of tomato fruits in cold water cooling with air flow to fruits, in cold water cooling, in fog cooling with air flow to fruits and in fog cooling were 0%, 4%, 0% and 55%, respectively. Air flow to fruits was effective for prevention of occurrence of blossom-end rot.(2) Solar radiation, water uptake rate and calcium uptake rate showed similar changes (Fig. 1 and Fig. 2), indicating that calcium movement follows water movement in tomato plants. Fig. 2-A indicates that occurrence of blossom-end rot in this experiment was not due to decrease in calcium uptake from nutrient solution.(3) Air flow to fruits was effective for increasing distribution ratio rather than concentration of calcium in dry matter of fruits (Table 1 and Table 2).(4) Blossom-end rot occurred about 8-12 days after anthesis, when diameter growth rate of fruits was fastest (Fig. 4).(5) Occurrence of blossom-end rot was affected by humidity. High humidity leads to decrease in transpiration of tomato plants, which would result in occurrence of blossom-end rot. The mechanism of the effect of air flow to fruits is considered that air flow to fruits promotes transpiration from fruit surface and inflow of water and calcium into fruits.

Uptake and Transport of Calcium and the Possible Causes of Blossom-end Rot in Tomato

The possible causes of blossom-end rot (BER) in tomato fruit were investigated by comparing the uptake of calcium by the roots, the distribution of 45 Ca within the fruit and the vascular bundle network in the fruit of susceptible cultivars (Calypso and Spectra) with those of a less susceptible cultivar (Counter) grown in a range of salinities (electrical conductivity of 5, 10 and 15 mS cm -1 ). The daily calcium uptake rates at 5 mS cm -1 , as estimated from the xylem exudation of the decapitated stem stump in young plants of Calypso and old plants of Spectra, were lower than that of Counter

Salinity effects on the network of vascular bundles during tomato fruit development

The development and distribution of the conducting tissue of tomato fruit in relation to salinity was studied by recording the number of vascular bundles in different layers of the fruit tissues at different growth stages in fruit grown at three levels of salinity (electrical conductivity, 5,10 and 15 mS cm'1). The uptake of safranin through the pedicel was used to locate the lignified xylem tissue in the bundles. Pericarp and placenta were supplied by separated vascular networks. Both the number and the density of vascular bundles (per cross sectional area of fruit tissue) were higher in pericarp than in placenta. The number of bundles decreased from the proximal (pedicel) half to the distal (blossom-end) half of the fruit, more so in the placenta than in the pericarp. The average density of bundles decreased from 1.7 and 0.6 bundles mm-2 in pericarp and placenta, respectively, to less than 0.1 bundles mm'2 during fruit expansion from dl4 to d31. The average density of bundles in layer 5 of the placenta was 2.5 times lower than that of the pericarp throughout fruit development. Salinity reduced the number of both total and stained bundles especially in the distal layer of the placenta. Therefore, xylem tissue development in the distal fruit tissue was substantially retarded at high salinity and this may be the anatomical basis for the initial Ca deficiency symptom of blossom-end rot in the distal placenta.

Blossom–end Rot of Pears: Systemic Infection of Flowers and Immature Fruit by Botrytis cinerea

A histological study was made of the systemic growth of Botrytis cinerea from styles, stamens and sepals to the flower receptacle and mesocarp of immature pear fruit. In most styles, hyphal growth ceased in the upper portion at the onset of stylar senescence, which occurred at about 1 wk after full bloom. Hyphae never passed through styles into the carpel. Unlike the styles, hyphae in filaments grew without restriction and progressed within 4 days, via vascular tissue, through sepals into tissues of the upper end of the flower receptacle, or of the mesocarp adjoining the sepals, without causing symptoms. Filaments remained green to partly green until harvest. B. cinerea entered filaments and spread into the receptacle or mesocarp at any time between blossoming and harvest and then became latent in these tissues. Filaments were, however, more susceptible at the flowering stage. After 2 months floral tubes were closed, and the stamens protected from infection. Careful inspection of ripe, cold–stored fruit showed that decay invariably spreads from mesocarp tissue adjoining the sepals, outward along the vascular bundles, but not from secondary inoculum in the floral tube. The behaviour of the pathogen suggests that control of blossom–end rot could be achieved if pears are sprayed with fungicide at 75—100% petal fall (when most stamens are exposed) and a month later (before floral tubes started to close). Kelchbasisfäule von Birnen: Die systemische Infektion von Blüten und unreifen Früchten durch Botrytis cinerea Das sytemische Wachstum von Botrytis cinerea von den Blütengriffeln, den Staubgefäßen und den Kelchblättern ab, bis zu dem Blütenstandboden und dem Mesokarp unreifer Früchte der Birne wurde einer histologischen Untersuchung unterzogen. Bei Beginn des Absterbens der Blütengriffel, etwa eine Woche nach voller Blüte, hörte der Wachstum der Hyphen in der proximalen Region in den meisten Blumengriffeln auf. Hyphen wuchsen niemals durch das distale Ende der Blumengriffel in das Fruchtblatt hinein. Im Gegensatz zu den Blütengriffeln, entwickelten sich die Hyphen unbegrenzt in den Staubfäden und wuchsen innerhalb von vier Tagen durch das Leitungsgewebe der Kelchblätter, in das Gewebe des proximalen Endes des Blütenstandbodens hinein, oder in den Mesokarp neben den Kelchblättern, ohne Symptome zu verursachen. Filamente blieben grün, zum Teil grün bis zur Ernte. Staubgefäße waren mehr anfällig in dem Blütenstadium, aber B. cinerea konnte in die Filamente hinein wachsen und sich in dem Blütenstandboden oder Mesokarp zu irgend einer Zeit zwischen Blüte und Ernte verbreiten und dann latent in diesen Geweben vorhanden sein. Nach zwei Monaten waren die Blütenkelche geschlossen und Staubgefäße gegen Infektion geschützt. Vorsichtige Untersuchung von reifen, kalt gelagerten Früchten zeigte, daß Fäule von dem Mesokarpgewebe neben den Kelchblättern in den Leitbündeln nach außen verbreitet und sich nicht von einem sekundären Inokulum im Blütenkelch entwickelt. Das Verhalten des Pathogens deutet darauf, daß Kelchbasisfäule kontrolliert werden könnte, wenn Birnen zu dem Zeitpunkt, an dem 75--100 % der Blütenblätter abgefalien sind (wenn die meisten Staubgefäße freigelegt sind), und wieder nach einem weiteren Monat (bevor die Blütenkelche anfingen zu schließen) mit einem Fungizid gespritzt werden.

CROP ROTATION AND NITROGEN RATE INFLUENCE PROCESSING TOMATO QUALITY

A study was conducted from 1989 to 1991 to examine the effects of continuous tomato cropping, short-term crop rotation and, nitrogen fertilization rates on processing tomato quality. Research was conducted at two sites in southwestern Ontario, Leamington and Dresden, in split-plot experimental design. The rotations included tomato (Lycopersicon esculentum) - winter wheat (Triticum aestivum) (underseeded with red clover (Trifolium pratense), tomato-winter wheat-soybean (Glycine max), tomato-alfalfa (Medicago sativa), and tomato-rye (Secale cereale). Nitrogen fertilization rates of 0, 45, 90 and 135 kg/ha were used. Processing tomato cv. Heniz 9230 and Nabisco Brands Ltd. 7107 were assessed for colour, % soluble solids and total solids, and blossom end rot [BER]. In most instances, continuous tomato [C-T] had significantly poorer colour, soluble solids, and total solids than fruit from the various crop rotations. High nitrogen rates for C-T at Leamington, resulted in improved soluble solids and total solids, but had no significant effect on colour. A lower incidence of BER consistently occurred with low rates of nitrogen. Our results indicate that short-term crop rotation and nitrogen management in processing tomatoes can enhance fruit quality when compared to C-T.

The susceptibility of modern tomato cultivars to blossom- end rot in relation to salinity

Three cultivars, Counter, Calypso and Spectra, were grown in NFT at a range of salinities (electrical conductivities of 5,10 and 15 mS cm-1) in two successive crops during the year. The incidence of blossom-end rot (BER) in ‘Calypso’ and ‘Spectra’ was substantially higher than in ‘Counter’ at all salinities. In the early crop, ‘Calypso’ had the highest incidence of BER at 10 mS cm-1, of which the proportion of international BER was greater than in ‘Spectra’. In the late crop, ‘Spectra’ had a higher incidence of BER than ‘Calypso,’ and a higher proportion of external BER. In the early crop, the incidence of BER in both cultivars grown at 10 mS cm"1 was higher than those at 15 mS cm-1, mainly due to an exceptionally high incidence of internal BER. In the late crop, however, the reverse was true. ‘Counter’, which is not susceptible to BER, had a higher shoot dry weight than the two BER susceptible cultivars. Nevertheless, ‘Calypso’ and ‘Spectra’ set more fruit in the lower and upper trusses respectively. A high incidence of BER was related to a high number of fruit set in the susceptible cultivars. Both the Ca content and the daily rate of Ca accumulation in the fruit were reduced by salinity, but no differences between cultivars were observed. The distal placenta and locular tissues had the lowest Ca content in the whole fruit and appeared to be the site of the earliest symptoms of BER. The interaction between cultivar and salinity affecting the Ca content of these tissues was not significant. The causes of susceptibility to BER in tomato are discussed.

高カルシウム濃度培養液処理で起こるトマト果実の尻腐れとその原因

Blossom-end rot of tomato fruits occurred when tomato plants (Lycopersicon esculentum Mill. cv. Momotaro) were grown in Ca-rich nutrient solution by using the nutrient film technique. Concentrations of Ca ions were high in both stems and leaves of plants yielding fruits having blossom-end rot. However, Ca concentrations in fruits suffering from blossom-end rot were significantly lower than normal fruits. This indicates that Ca ion diffusion from stems to fruits was physiologically inhibited, resulting in blossom-end rot in fruits. This phenomenon was associated with reduction of photosynthesis. Because plants yielding blossom-end rot absorbed significantly higher concentrations of Mn and Zn ions than healthy plants, it may be possible that enzymes related to calcium transport and photosynthesis might be inhibited with the higher concentrations of heavy metal ions.

自然光利用型植物工場の夏期昼間の局所冷房 トマトの尻腐れとの関連も含めて

In this study, air cooling in the zone only around plants in greenhouse in the daytime in summer was investigated.Two types of air cooling systems were constructed in a greenhouse in Ehime University. One was the system which used cold water and water-air heat exchanger (cold water cooling system), and the other was the system which utilized heat of vaporization of fog (fog cooling system). Schematic diagrams of these systems are shown in Fig. 1 and Fig. 2.The results of air cooling on a fine day are shown in Fig. 4, Fig. 5 and Fig. 6. Furthermore, Fig. 7 shows the effectiveness of system identification in analysis and control in cold water cooling system.The effect of environment of above-ground part on occurrence of blossom-end rot of tomato plants was also investigated. The effect of air flow to fruits was also examined using the system shown in Fig. 3. The results are shown in Fig. 8 and Table 1.

Early and Late-season Blossom-end Rot of Tomato following Mulching

Paper mulch and black plastic mulch were compared with no mulch on tomatoes (Lycopersicon esculentum Mill. `Better Boy' and `San Marzano') for incidence of blossom-end rot (BER) in the field during 1988–90. Early season (late July to late August) harvest had more BER than in later pickings. Black plastic mulch significantly increased early season BER in `Better Boy' relative to paper or no mulch. Late-season BER in `San Marzano' was decreased with paper or black plastic mulch relative to no mulch.

Sodium chloride salinity in fruit vegetable crops in soilless culture.

Tomatoes, cucumbers and sweet peppers (capsicums) were grown in hydroponic systems in which the nutrient solutions were recirculated. The EC of the nutrient solution was maintained at values of 2.5, 3.7 or 5.2 dS m-1 (25 degrees C) in the different treatments. In some of the treatments, the EC values mentioned were achieved by addition of nutrients, and in others by addition of a combination of nutrients and NaCl. Yields of all 3 crops were adversely affected by increased EC values. Most fruit quality characteristics, on the contrary, were favourably affected. However, the incidence of blossom-end rot in tomatoes and capsicums increased at higher EC values. For capsicums, this was especially the case with NaCl addition. Apart from that, only slight specific NaCl effects were noticed. Salinity threshold values for the different crops lay between 2.3 and 3.5 dS m-1 and salinity yield decrease values ranged from 2.3 to 7.6% for each dS m-1. The absorption of Na and Cl differed with crop and with the Na and Cl concentration. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Import of calcium by tomato fruit in relation to the day-night periodicity

The day-night periodicity in calcium (Ca) transport into fruits of tomato ( Lycopersicon esculentum Mill.) was investigated by growing plants with two trusses in aerated nutrient solution labelled with 45Ca for 11 h either during the day or at night. The import of Ca by tomato fruits was favoured at night, although it also occurred during the day, but at a much lower rate. The rates of Ca absorption and translocation from roots to shoots did not differ between the day and the night. Withholding the oxygen supply to roots at night, which is a cause of blossom-end rot of tomato fruits in hydroponics, greatly inhibited both the absorption of Ca from roots to shoots.

THE INFLUENCE OF SOIL CALCIUM LEVEL ON GROWTH AND YIELD OF WATERMELON AND CALCIUM CONCENTRATION OF WATERMELON RIND TISSUE

Three cultivars of watermelon (Citrullus lanatus), `Crimson Sweet', `Charleston Gray' and `Tri-X Seedless' were grown in combination with 4 levels of soil applied calcium (0, 280, 560, 1120 kg Ca/ha). Gypsum was incorporated into 6 m plots on 5 m centers then covered with black plastic mulch. Irrigation requirements were provided through a hi-wall drip system and soil water status monitored with tensiometers. Transplants were spaced 1.2 m apart in-row spacing allowing for 5 plants per plot and replicated 3 times. Melons were harvested at 7, 14, 21 days from anthesis and at full maturity. Rind tissue was analyzed for total and extractable Ca, Mg, K, Mn, Zn and Fe. Leaf samples were taken 6 weeks from transplanting for similar analysis, Yield, vine growth and the incidence of blossom-end rot were recorded. The study was conducted at 2 locations during the 1989 and 1990 growing seasons. Data will be presented at the meeting,

THE INFLUENCE OF SOIL CALCIUM LEVEL ON GROWTH AND YIELD OF WATERMELON AND CALCIUM CONCENTRATION OF WATERMELON RIND TISSUE

Three cultivars of watermelon (Citrullus lanatus), `Crimson Sweet', `Charleston Gray' and `Tri-X Seedless' were grown in combination with 4 levels of soil applied calcium (0, 280, 560, 1120 kg Ca/ha). Gypsum was incorporated into 6 m plots on 5 m centers then covered with black plastic mulch. Irrigation requirements were provided through a hi-wall drip system and soil water status monitored with tensiometers. Transplants were spaced 1.2 m apart in-row spacing allowing for 5 plants per plot and replicated 3 times. Melons were harvested at 7, 14, 21 days from anthesis and at full maturity. Rind tissue was analyzed for total and extractable Ca, Mg, K, Mn, Zn and Fe. Leaf samples were taken 6 weeks from transplanting for similar analysis, Yield, vine growth and the incidence of blossom-end rot were recorded. The study was conducted at 2 locations during the 1989 and 1990 growing seasons. Data will be presented at the meeting,

Fertilizer Placement Effects on Soil Nitrogen and Use by Drip-irrigated and Plastic-mulched Tomatoes

The effects of fertilizer placement and soil moisture level on soil N movement, uptake, and use by tomato plants (Lycopersicon esculentum Mill) grown with drip irrigation and plastic mulch were evaluated at two locations on two types of sandy soils. Broadcast or band fertilizer placement had no effect on fruit size, fruit number, or total yield. Fruit size was increased at one location, and the incidence of blossom-end rot was decreased by increased frequency of irrigation. Nitrate-N distribution within the bed was not affected by initial N placement. In the soil with a rapid infiltration rate, NO3-N levels in the center of the bed were always low, with highest concentration observed in the areas of the bed most distant from the drip tube. In the soil with the slower infiltration rate, NO3-N concentrations were more uniform throughout the bed, with highest concentrations in the bed center: Increasing soil moisture levels (–20 kPa vs. –30 kPa) resulted in increased leaching and reduced NO3-N concentration throughout the bed. Foliage N concentration was not affected by N placement, but decreased seasonally. Total N uptake by the above-ground portion of the plants was not affected by fertilizer placement or soil moisture level.

ETHYLENE EVOLUTION BY FRUITS OF TOMATO STRESSED BY AMMONIUM NUTRITION

Studies were made of ethylene evolution by `Heinz 1350' tomato fruits from plants that had received nitrogen nutrition from ammonium or nitrate salts in soil-based media. Fruits of plants receiving ammonium nutrition had higher ammonium concentrations, higher occurrences of blossom-end rot, and higher rates of ethylene evolution than fruits from nitrate-grown plants. Fruits showing blossom-end rot had higher ammonium concentrations and higher rates of ethylene evolution than normal fruits only if the plants received ammonium nutrition. Ethylene evolution increased as fruits from nitrate-grown plants ripened but without a concurrent increase in ammonium concentrations in the fruits. Ammonium accumulation in fruits apparently induces blossom-end rot and enhances ethylene evolution, but ammonium accumulation does not appear to be a naturally occurring phenomenon in ripening fruits or in fruits that have blossom-end rot arising from other casual factors.

Uniconazole controls growth and yield of greenhouse tomato

Tomato ( Lycopersicon esculentum cultivar ‘Summer Flavor’) seedlings received a single uniconazole soil drench at 0, 12.5, 25, 50, 100, 200 or 400 μg per plant at the five-leaf stage. After 2 weeks of growth, plant height, length and area of the fifth leaf, and plant fresh and dry weights progressively decreased with increasing rates of uniconazole. The rate of leaf production was unaffected at low rates of the retardant. Another group of seedlings received soil drenches at the above rates at the onset of flowering. Uniconazole applied at both stages resulted in short final plant height at all rates. Total fruit yield was reduced by uniconazole at the 12.5 μg per plant rate, with further reduction as rates increased. Yields of large fruits (≥ 110 g) increased at the two lower rates of uniconazole. The incidence of blossom-end rot (BER) was nearly eliminated by this retardant at all rates. Foliar application of uniconazole at the flowering stage with rates of 0, 25, 50, 100, 250, 500, 750 or 1000 μg per plant had less control on plant height compared with their respective rates as a soil drench. Total fruit yield was not affected until the rate exceeded 100 μg per plant. The incidence of BER decreased sharply with increasing rates of uniconazole. The number and weight of fruits ≥ 110 g were doubled at rates between 25 and 250 μg per plant. Plant fresh and dry weights were lower as a result of uniconazole foliar spray. Fruit number was reduced regardless of the rate and stage of uniconazole application.

EFFETS DE LA COMPOSITION DU SUBSTRAT TOURBEUX ET DU VOLUME DES SACS DE CULTURE SUR LA PRODUCTIVITÉ DE LA TOMATE DE SERRE

A large-fruited greenhouse tomato cultivar (Lycopersicon esculentum Mill. ’Dombello’) was grown in 12-, 24- and 36-L bags containing three types of peat:perlite substrates (85:15, 70:30 and 55:45, vol:vol). The control consisted of 36-L bags containing peat only. Plant density was three plants per bag, i.e. 3.22 plants m−2. Early and total yields of marketable and nonmarketable fruits were measured. Early yields were higher for plants grown in 12- or 24-L bags as compared to those grown in 36-L bags, although blossom-end rot followed the same trend. Seasonal cumulative yields were not influenced significantly by bag size and substrate composition. Reduced perlite content and bag size increased the incidence of blossom-end rot. The incidence of blossom-end rot and average fruit weight indicate that reduction of root-zone volume and air porosity increased water stress. Greenhouse tomatoes can be grown successfully in smaller bag sizes containing peat substrate amended with more than 15% perlite.Key words: Tomato, peat-lite substrates, root-zone restriction, blossom-end rot, fruit weight, grow bag

Postharvest Fungi of Lowbush Blueberry Fruit

The major fungi isolated from 50 processor or market samples of lowbush blueberry fruit were Botrytis cinerea, Glomerella cingulata, Gloeosporium minus, Alternaria spp. and Penicillium. Gloeosporium, an incitant of leaf spots, stem cankers and blossom-end rot on highbush blueberries, has not previously been reported as a disease of lowbush blueberry. The incidence of Glomerella and Alternaria was significantly higher in fields pruned by mowing than in those pruned by burning

Fruit set in the pepino ( Solanum muricatum Ait.)

Fruit set and seed number per fruit of glasshouse-grown plants were increased by transfer of pollen by brush from anthers to stigmas or by vibration of inflorescences. Chlorflurenol applied to whole plants increased fruit set of flowers that were at anthesis or that opened after application. These fruit were small, seedless and developed blossom-end rot. In the field, where there was greater plant movement, vibrator or brush treatments did not increase fruit set and each inflorescence set only 0–2 fruit. Pollen viability and pollen transfer were not limiting fruit set in the field.