scholarly journals A MODEL TO DETERMINE QUANTITATIVE EFFECTS OF LIGHT AND TEMPERATURE ON ORGANIC TOMATO SEEDLINGS

2019 ◽  
Vol 18 (3) ◽  
Author(s):  
Hatice Şeyma Sarıbaş ◽  
Sezgin Uzun

The present study was conducted to determine the quantitative effects of light and temperature on growth and development of organic tomato (Solanum lycopersicum L.) seedlings in a glasshouse under ecological conditions of Samsun Province of Turkey. Seedlings were grown in four different periods (seeds sown on 29 September for 1st period; 2 December for 2nd period; 18 March for 3rd period and 6 July for 4th period). In order to create different light intensities, shading material having a shading capacity of 50% in 1, 2 and 3 layers was used in each period after seeding. The effects of light and temperature on plant growth and development (leaf area, stomatal conductivity, leaf chlorophyll content, plant height, stem diameter and total plant vegetative dry weight) and the number of days from sowing to plantation of seedlings, were investigated. Obtained results revealed decreasing number of days from sowing to seedling plantation with increasing light intensities. Finally, the number of days from sowing to seedling plantation to be used in organic tomato seedling production was modeled based on the variations in temperature and light intensity (r2 = 0.92).

2020 ◽  
Vol 19 (2) ◽  
pp. 3-15
Author(s):  
Iwona Ledwożyw-Smoleń ◽  
Mariya Halka ◽  
Sylwester Smoleń ◽  
Michał Kruczek

Salicylic acid is one of the regulatory compounds involved in numerous processes in plants. Previous studies indicated that also its halogen derivatives may exhibit similar roles. The aim of the work was to evaluate the influence of iododerivatives of salicylic acid such as: 5-iodosalicylc acid (5I-SA) and 3,5-diiodosalicylic acid (3,5diI-SA) on selected aspects of antioxidant capacity of tomato seedlings. The efficiency of improving iodine accumulation in tomato seedlings was also studied. No tested organoiodine compound had a negative effect on the growth and development of tomato seedlings. The presence of iodosalicylic acids in the nutrient solution led to a decrease of the content of salicylic acid, ascorbic acid and phenolic compounds in tomato seedlings. A modifying effect of tested organoiodine compounds on the antioxidant activity of tomato seedling extracts varied with respect to analyzed enzyme and applied assays. It has been confirmed that higher plants can take up and accumulate iodine from organoiodine compounds in levels not causing any symptoms of toxicity.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
María Micaela Pérez-Rodriguez ◽  
Patricia Piccoli ◽  
María Soledad Anzuay ◽  
Rita Baraldi ◽  
Luisa Neri ◽  
...  

Abstract In semiarid regions is important to use native strains best adapted to these environments to optimize plant-PGPR interaction. We aimed to isolate and characterize PGPR from roots and rhizosphere of a tomato crop, as well as studying the effect of its inoculation on tomato seedlings growth. We selected four strains considering their effectiveness of fixing nitrogen, solubilizing phosphate, producing siderophores and indole acetic acid. They belong to the genera Enterobacter, Pseudomonas, Cellulosimicrobium, and Ochrobactrum. In addition, we also analyzed the ability to solubilize Ca3(PO4)2, FePO4 and AlPO4 and the presence of one of the genes encoding the cofactor PQQ in their genome. Enterobacter 64S1 and Pseudomonas 42P4 showed the highest phosphorus solubilizing activity and presence of pqqE gene. Furthermore, in a tomato-based bioassay in speed-bed demonstrated that a sole inoculation at seedling stage with the strains increased dry weight of roots (49–88%) and shoots (39–55%), stem height (8–13%) and diameter (5–8%) and leaf area (22–31%) and were equal or even higher than fertilization treatment. Leaf nitrogen and chlorophyll levels were also increased (50–80% and 26–33%) compared to control. These results suggest that Enterobacter 64S1 and Pseudomonas 42P4 can be used as bio-inoculant in order to realize a nutrient integrated management.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 508e-508
Author(s):  
Bin Liu ◽  
Royal D. Heins

A concept of ratio of radiant to thermal energy (RRT) has been developed to deal with the interactive effect of light and temperature on plant growth and development. This study further confirms that RRT is a useful parameter for plant growth, development, and quality control. Based on greenhouse experiments conducted with 27 treatment combinations of temperature, light, and plant spacing, a model for poinsettia plant growth and development was constructed using the computer program STELLA II. Results from the model simulation with different levels of daily light integral, temperature, and plant spacing showed that the RRT significantly affects leaf unfolding rate when RRT is lower than 0.025 mol/degree-day per plant. Plant dry weight is highly correlated with RRT; it increases linearly as RRT increases.


Agronomy ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 157 ◽  
Author(s):  
Hye Kim ◽  
Seung Hwang

This study aimed to determine the effects of various light qualities (green (G), ultraviolet-A (UV-A), and far-red (Fr)) on the growth and development of tomato plug seedlings. The ‘Mini Chal’ tomato (Solanum lycopersicum L.) seedlings were used as the plant material to which various light qualities were supplied. Fluorescent lamp (FL), combined FL and diniconazole (Dini), and R3B7 (red (R):blue (B) = 30:70) were used as the control. The different light treatments for this experiment were as follows: two G light ratios added to R3B7 (G20 and G40), three UV-A light intensities added to R3B7 (UV 0.4, UV 0.6, and UV 0.8), and three Fr light ratios added to R3B7 (Fr1, Fr2, and Fr3). Plants grown in UV 0.4 and Dini were the shortest, followed by plants grown in R3B7. R3B7 induced higher specific leaf weight than G, UV-A, and Fr did. The position of the first flower cluster was the highest for plants in FL and Fr1, and the lowest for plants in R3B7 and UV 0.6. In conclusion, different light treatments heavily affected the growth and development of ‘Mini Chal’ tomato seedlings. R3B7 was the most effective light treatment for producing high quality seedlings in a closed-type plant production system that develop well after transplanting.


1965 ◽  
Vol 43 (3) ◽  
pp. 345-353 ◽  
Author(s):  
D. J. C. Friend

The number of spikelets on the differentiating inflorescence and the ear at anthesis was highest at high light intensities and at low temperatures. The length of the developing inflorescence and the ear, the height of the main stem, and the total plant dry weight at the time of anthesis were also greatest under these conditions.These results are related to differential effects of temperature and light intensity on the rates and duration of apical elongation, morphological development of the ear, and spikelet formation.


2016 ◽  
Vol 44 (2) ◽  
pp. 375-381 ◽  
Author(s):  
Hermann RESTREPO-DIAZ ◽  
Jorge BETANCOURT-OSORIO ◽  
Diego SANCHEZ-CANRO

Climate change has altered rainfall patterns causing waterlogging periods that often negatively affect the performance of horticultural crops in the Andean region in Colombia. An experiment was carried out under greenhouse conditions using three-month-old tamarillo (Solanum betaceum Cav.) seedlings, which were grown under two levels of nitrogen (N) (10 and 150 mg N∙L H2O). At 28 days after transplanting (DAT), waterlogging treatments were established when well-nourished plants (150 mg N L-1 H2O) significantly showed a higher shoot length than poor-nourished plants (10 mg N L-1 H2O) (~20 cm vs. ~10 cm, respectively). Three different periods of waterlogging were performed between 35 and 37, 51 and 55, and 64 and 70 DAT by covering the holes in the plastic pots to ensure a constant water depth. Results showed that well-nourished plants without waterlogging treatments through the experiment’s stress showed a greater shoot length (30 cm), total plant dry weight (7.95 g), Fv/Fm ratio (0.62) and leaf chlorophyll content (37.51 SPAD units) than poor-nourished plants without stress condition (15 cm, 5.57 g, 0.5 and 12.69 SPAD units, respectively) at the end of the experiment. Overall, waterlogging reduced leaf area and nitrogen use efficiency (about 75% and 50%, respectively) in both N levels. However, periods of waterlogging enhanced dry matter partitioning to stems (around 30-35%) in both N levels. This study showed that tamarillo plants are susceptible to landscaping situations where periods of waterlogging can be expected regardless of their N nutritional status.


2014 ◽  
Vol 65 (1) ◽  
pp. 71-77
Author(s):  
Ghazala Nasim ◽  
Sobia Mushtaq ◽  
Irum Mukhtar ◽  
Ibatsam Khokhar

AbstractPenicilliumspp. are well known to produce a variety of beneficial metabolites for plant growth and survival, as well as defend their hosts from attack of certain pathogens. In this study, effects of culture filtrate of differentPenicilliumspp. were tested on tomato seeds. On the whole, presoaking of seeds in filtrates of the ninePenicilliumisolates tested, significantly increased seed germination when compared with the control seeds. Cultural extracts ofP. expensumandP. billiwere highly effective in growth promotion up to 90%. It was also observed thatP. implicatumandP. oxlalicamsignificantly enhanced the root growth in tomato seedling as compare to other species. In case of shoot length,P. verrucosum(3.38),P. granulatum(2.81) andP. implicatum(2.62) were effective. HoweverP. implicatumwas quite promising to increase shoot and root length in tomato seedlings. Where asP. simplicissimiumandP. citrinumwere leas effective on seedling growth. The plant growth promoting ability ofPenicilliumstrains may help in growth permotion in other plants and crops.Penicilliumspp. are already known for producing mycotoxin and enzymes. Plant growth promoting ability ofPenicilliumspp will open new aspects of research and investigations. The role ofPenicil-liumspp. in tomato plant growth requires further exploration.


2008 ◽  
Vol 34 (1) ◽  
pp. 29-40
Author(s):  
Glynn Percival ◽  
Ian Keary

The aims of this study were to determine the influence of nitrogen (N) fertilizers on tree tolerance under prolonged waterlogging conditions and investigate the effect of N fertilization on aiding tree recovery from waterlogging damage using containerized English oak (waterlogging-intermediate) and European beech (waterlogging-sensitive) as test species. English oak proved to be more waterlogging-tolerant than European beech. Tree vitality as measured by chlorophyll fluorescence, photosynthetic rates, leaf chlorophyll content, stomatal conductance, leaf and root protein concentration, and foliar N content was consistently higher in trees in which N fertilizers were added to the waterlogged solutions compared with trees waterlogged with tapwater only for 18 days. Measurement of light absorbance, light trapping, electron transport, and dissipation fluxes per leaf cross-section of photosystem II after the 18-day waterlogging period indicated a beneficial influence of N fertilization on leaf photosynthetic processes at the cessation of the waterlogging period. Addition of N induced greater resource allocation in favor of roots over shoots in both tree species. At the cessation of the 18-day waterlogging period and after a 10-day regeneration period, growth (leaf area, shoot, root, total plant dry weight) was constantly higher in N waterlogged trees compared with non-N waterlogged ones. In a separate study, recovery rates of trees as measured by chlorophyll fluorescence, photosynthetic rates, leaf chlorophyll content, and stomatal conductance over a 6-week period after the cessation of 18 days waterlogging were 30% to 50% higher in N-fertilized trees compared with non-N-fertilized trees irrespective of species. In all cases, nonfertilized trees had the least capacity for recovery. In addition, leaf area, shoot, root, and total plant dry weight were higher in N-fertilized trees compared with nonfertilized ones. Results of this investigation indicate 1) applications of N fertilizers enhance the tolerance of trees under prolonged waterlogged conditions; and 2) applications of N fertilizers after waterlogging stress would be of benefit to improve tree recovery rates and growth. From a practical point of view, N fertilization 14.5 g (0.51 oz) or greater N per liter (0.26 gal) of water is tentatively suggested based on preliminary results of this study.


2002 ◽  
Vol 127 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Kirk W. Pomper ◽  
Desmond R. Layne ◽  
Snake C. Jones

The North American pawpaw [Asimina triloba (L.) Dunal] has great potential as a fruit crop or as a landscape plant. The influence of incident irradiance on pawpaw seedling growth and development in containers was examined in the greenhouse and outdoors. Root spiraling can be a problem for container-grown pawpaw seedlings; therefore, the influence of paint containing cupric hydroxide [Cu(OH)2] at 100 g·L-1 applied to the interior of containers on plant growth was also examined in a greenhouse environment. In pawpaw seedlings grown outdoors for 11 weeks, low to moderate shading levels of 28%, 51%, or 81% increased leaf number, total leaf area, and total plant dry weight (DW) compared to nonshaded seedlings. A shading level of 81% decreased the root to shoot ratio by half compared to nonshaded plants. Shading of 98% reduced leaf number, leaf size, and shoot, root, and total plant DW. Shading increased leaf chlorophyll a and b concentrations for pawpaw seedlings grown outdoors, while it decreased average specific leaf DW (mg·cm-2). In a separate greenhouse experiment, pawpaw seedlings subjected to shade treatments of 0%, 33%, 56%, 81%, or 98% did not respond as greatly to shading as plants grown outdoors. Greenhouse-grown plants had greater total and average leaf area under 33% or 56% shading than nonshaded plants; however, shading >56% reduced root, shoot, and total plant DW. Total shoot DW was greater in greenhouse grown plants with 33% shading compared to nonshaded plants. Pawpaw seedlings in control and most shade treatments (33% to 81%) in the greenhouse environment had more leaves and greater leaf area, as well as larger shoot, root, and total plant DW than seedlings in similar treatments grown outdoors. The greenhouse environment had a 10% lower irradiance, a 60% lower ultraviolet irradiance, and a significantly higher (1.23 vs. 1.20) red to far-red light ratio than the outdoors environment. Treatment of container interiors with Cu(OH)2 decreased total and lateral root DW in nonshaded seedlings, and it adversely affected plant quality by causing a yellowing of leaves and reduction of chlorophyll levels by the end of the experiment in shaded plants. Growth characteristics of pawpaw seedlings were positively influenced by low to moderate shading (28% or 51%) outdoors and low shading (33%) in the greenhouse. Seedlings did not benefit from application of Cu(OH)2 to containers at the concentration used in this study. Commercial nurseries can further improve production of pawpaw seedlings using low to moderate shading outdoors.


Author(s):  
. Shilpa ◽  
Y. R. Shukla ◽  
Priyanka Bijalwan ◽  
Kuldeep S. Thakur

In this study we evaluated the effects of two different types of mulches (black mulch, silver/black) on weed control and yield in tomato (Solanum lycopersicum L.) production. Field studies were carried out during 2017-2018 and 2018-2019. The treatments consisted in the study were planting methods (raised bed/flat bed), polythene mulching applications (black mulch, silver/black and unmulched plots) and training systems (two stem and three stem). Tomato seedlings were transplanted in the plots, where mulch application had already been done prior transplanting.The results indicated thatmarketable tomato yield from the treatments consisting of black mulch, was higher compared to the other unmulched plots for both the years of study. In unmulched plots there was reduction of tomato yield. Mulch treatments reduced the number of weeds, weed intensity, and above ground biomass (fresh weight and dry weight of weeds) as compared to control plots. At tomato harvest weeds were well suppressed by black mulch above the entire where black mulches have been used. In mulch plots there was consistent reduction in weed intensity also. The black mulch seems to be a suitable for assuring an effective weed suppression and high yield in tomato grown in raised beds compared to the plants grown on flat beds without using any mulch material.


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