scholarly journals The Effect of Temperature and Mean Cumulative Daily Light Intensity on Fruiting Behavior of Greenhouse-grown Tomato

2007 ◽  
Vol 132 (4) ◽  
pp. 459-466 ◽  
Author(s):  
Sezgin Uzun

Determinations were made of the effect of mean daily temperature and cumulative daily light intensity related to planting date on fruiting behavior of greenhouse-grown tomato (Lycopersicon esculentum Mill.). Time to first flowering (FT), flower bud number per cluster (BN/C), fruit number per cluster (FN/C), mean fruit weight, fruit growth period (FGP), and fruit production rate (FPR) in tomato were plotted against mean daily temperature (11 to 28 °C) and mean cumulative daily light intensity (2 to 8 MJ·m−2·d−1) obtained from different planting dates. The FT was negatively related to mean daily temperature at any given mean cumulative daily light intensity. Mean cumulative daily light intensity had a negative sharp and slight curvilinear relationship to FT at lower and higher mean daily temperatures, respectively. At the highest cumulative daily light intensity, BN/C was the greatest at the lowest mean daily temperature, whereas at lower cumulative daily light intensities, BN/C was curvilinearly related to mean daily temperature with the optimum mean daily temperature for BN/C between 13 and 19 °C. Mean cumulative daily light intensity had a positive curvilinear relationship to BN/C at any given mean daily temperature. FN/C increased linearly with mean cumulative daily light intensity with a steeper slope at low mean daily temperatures. At each cumulative daily light intensity, FN/C declined curvilinearly with mean daily temperature. Mean fruit weight was curvilinearly related to mean daily temperature at all mean cumulative daily light intensities. Mean fruit weight was greatest at the highest mean cumulative daily light intensities. There was a curvilinear relationship between mean cumulative daily light intensity and FGP at all mean daily temperatures. The FGP increased curvilinearly as mean daily temperature and mean cumulative light intensity increased. There was a curvilinear increase in FPR with mean cumulative daily light intensity at any given mean daily temperatures. Mean daily temperature also had a curvilinear effect on FPR such that FPR increased up to 25 °C for the lowest cumulative daily light intensity and 22 °C for the highest cumulative daily light intensity and declined thereafter as mean daily temperature increased. Optimum mean daily temperatures for FPR declined as mean cumulative daily light intensity rose. It can be said that the relationships produced in this study can be incorporated into the climate control and fertigation programs of greenhouse tomatoes.

1971 ◽  
Vol 49 (1) ◽  
pp. 21-25 ◽  
Author(s):  
Praim N. Sood ◽  
W. E. Sackston

Light intensity from 2200 to 43 000 lux during production of urediospores of Puccinia helianthi had little influence on germinability of fresh spores. The higher light intensities had an adverse effect on germinability of spores stored at −16 °C for 2 months. Daylength had little consistent effect on germinability of fresh or stored spores. Spores produced at day temperatures of 16, 21, and 27 °C showed no effect of temperature on germinability when fresh. After 2 months storage at −16 °C germination was highest for spores produced at 21°. Spores of races 1 and 3 germinated well after 1218 days of storage at −16°, and a small percentage germinated after storage at 4 °C. Races 2 and 4 germinated well after 1136 days storage at −16 and 4 °C. Races 2 and 4 survived longer than races 1 and 3 at 30° and at 23 °C, but not at 13 °C. Race 3 appeared more susceptible than race 1 to effects of light, temperature, and storage.


1985 ◽  
Vol 104 (2) ◽  
pp. 325-329 ◽  
Author(s):  
D. A. C. Pink ◽  
D. G. A. Walkey

SummaryPlants of Cucurbita pepoL. cvs Cinderella, Cobham Bush Green and Goldrush were inoculated with cucumber mosaic virus (CMV) and some grown at each of three temperatures (15, 20 and 25 °C) and three light intensities (13, 40 and 120 W/ma). Symptom severity in all three cultivars decreased with increased temperature but only for ovs Cinderella and Cobham Bush Green when the light intensity was raised. In general ov. Cinderella was most resistant and cv. Goldrush most susceptible, except at 25 °C, when most plants were symptomless.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 459d-459
Author(s):  
Fumiomi Takeda ◽  
Paul R. Adler ◽  
D. Michael Glenn

Strawberry plants (cvs. Camarosa, Chandler, Sweet Charlie, Primetime, Jewel, and Tribute) were grown in soilless culture systems in a greenhouse from October to May. Fresh-dug and runner-tip Aplug® plants were transplanted into two systems: vertically stacked pots (24 plants/m2) containing perlite and horizontal nutrient film technique troughs (13 plants/m2). Plants were fertigated continuously with recirculating nutrient solution. In a 7-month production cycle, the plug plants bloomed earlier and produced more fruit during the first month of harvest (December) than the fresh-dug plants. Higher yields from plug plants were a result of more fruit numbers and not larger fruit size. Fruit production averaged 6.0 and 3.5 kg/m2 in the trough and pot systems, respectively. The vertical growing system allows greater plant densities, but light intensity reaching the plants in the lower sections of the tower can be less than 20% of levels measured at the top. Establishment costs of protected culture systems are higher, but production is earlier and labor costs are typically reduced. Greenhouse hydroponic culture systems could extend the winter strawberry production to more northern locations.


2021 ◽  
Vol 13 (14) ◽  
pp. 8060
Author(s):  
Mehmet Ramazan Bozhuyuk ◽  
Sezai Ercisli ◽  
Neva Karatas ◽  
Halina Ekiert ◽  
Hosam O. Elansary ◽  
...  

The Rosa is one of the most diverse genera in the plant kingdom and, in particular, its fruits have been used for multiple purposes in different parts of the world for centuries. Within the genus, Rosa canina and Rosa dumalis are, economically, the most important species and dominate Rosa fruit production. In this study, some important fruit and shrub traits of ten Rosa canina and ten Rosa dumalis ecotypes collected from rural areas of Kars province, located in the east Anatolia region of Turkey were investigated. We found significant differences among ecotypes in most of the morphological and biochemical traits. The ecotypes were found between 1446–2210 m altitude. Fruit weight and fruit flesh ratio ranged from 2.95 g to 4.72 g and 62.55% to 74.42%, respectively. SSC (Soluble Solid Content), Vitamin C, total phenolic, total flavonoid, total carotenoid, and total anthocyanin content of the ecotypes ranged from 16.9–22.7%, 430–690 mg per 100 g FW (fresh weight), 390–532 mg gallic acid equivalent per 100 g FW, 0.88–2.04 mg per g FW, 6.83–15.17 mg per g FW and 3.62–7.81 mg cyanidin-3-glucoside equivalent per kg, respectively. Antioxidant activity was determined to be between 19.7–34.7 mg ascorbic acid equivalent per g fresh weight. Rosa ecotypes contained chlorogenic acid and rutin the most as phenolic compound. Our results indicated great diversity within both R. canina and R. dumalis fruits.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Jingying Zhang ◽  
Changhai Sui ◽  
Huimin Liu ◽  
Jinjiao Chen ◽  
Zhilin Han ◽  
...  

Abstract Background ‘Regal Splendour’ (Hosta variety) is famous for its multi-color leaves, which are useful resources for exploring chloroplast development and color changes. The expressions of chlorophyll biosynthesis-related genes (HrHEMA, HrPOR and HrCAO) in Hosta have been demonstrated to be associated with leaf color. Herein, we isolated, sequenced, and analyzed HrHEMA, HrPOR and HrCAO genes. Subcellular localization was also performed to determine the location of the corresponding enzymes. After plasmid construction, virus-induced gene silencing (VIGS) was carried out to reduce the expressions of those genes. In addition, HrHEMA-, HrPOR- and HrCAO-overexpressing tobacco plants were made to verify the genes function. Changes of transgenic tobacco were recorded under 2000 lx, 6000 lx and 10,000 lx light intensity. Additionally, the contents of enzyme 5-aminolevulinic acid (5-ALA), porphobilinogen (PBG), chlorophyll a and b (Chla and Chlb), carotenoid (Cxc), superoxide dismutase (SOD), peroxidase (POD), malondialdehyde (MDA), proline (Pro) and catalase (CAT) under different light intensities were evaluated. Results The silencing of HrHEMA, HrPOR and HrCAO genes can induce leaf yellowing and chloroplast structure changes in Hosta. Specifically, leaves of Hosta with HrCAO silencing were the most affected, while those with HrPOR silencing were the least affected. Moreover, all three genes in tobacco were highly expressed, whereas no expression was detected in wild-type (WT). However, the sensitivities of the three genes to different light intensities were different. The highest expression level of HrHEMA and HrPOR was detected under 10,000 lx of illumination, while HrCAO showed the highest expression level under 6000 lx. Lastly, the 5-ALA, Chla, Cxc, SOD, POD, MDA, Pro and CAT contents in different transgenic tobaccos changed significantly under different light intensities. Conclusion The overexpression of these three genes in tobacco enhanced photosynthesis by accumulating chlorophyll content, but the influential level varied under different light intensities. Furthermore, HrHEMA-, HrPOR- and HrCAO- overexpressing in tobacco can enhance the antioxidant capacity of plants to cope with stress under higher light intensity. However, under lower light intensity, the antioxidant capacity was declined in HrHEMA-, HrPOR- and HrCAO- overexpressing tobaccos.


In a tank filled with a suspension of indian ink in tap water, a population of Daphnia magna will undergo a complete cycle of vertical migration when an overhead light source is cycli­cally varied in intensity. A ‘dawn rise’ to the surface at low intensity is followed by the descent of the animals to a characteristic maximum depth. The animals rise to the surface again as the light decreases, and finally show a typical midnight sinking. The light intensities at the level of the animals in this experiment are of the same order as those which have been reported in field observations; the time course of the movement also repeats the natural conditions in the field. The process is independent of the duration of the cycle and is related only to the variation in overhead light intensity. At low light intensity the movement of the animal is determined solely by positive photo-kinesis; the dawn rise is a manifestation of this, and is independent of the direction of the light. At high light intensities there is an orientation response which is superimposed upon an alternating positive (photokinetic) phase and a negative phase during which movement is inhibited. The fully oriented animal shows a special type of positive and negative phototaxis, moving towards the light at reduced light intensities and away from it when the light intensity is increased. In this condition it follows a zone of optimum light intensity with some exactness. Experiments show that an animal in this fully oriented condition will respond to the slow changes of intensity characteristic of the diurnal cycle, while being little affected by tran­sient changes of considerable magnitude.


1969 ◽  
Vol 47 (7) ◽  
pp. 1153-1156 ◽  
Author(s):  
J. A. Ekundayo ◽  
R. H. Haskins

Cultures of Botryodiplodia theobromae Pat. produced pycnidia abundantly on several media under continuous irradiation with fluorescent light. The fungus did not sporulate when grown in darkness. Irradiation of cultures with a light intensity of 15 foot-candles for 4 days was sufficient to stimulate pycnidial production, but for appreciable sporulation to occur over the same exposure period, higher light intensities are required. Irradiation of cultures through glass color filters showed that long-wave ultraviolet radiation stimulated sporulation.


1982 ◽  
Vol 54 (1) ◽  
pp. 329-339
Author(s):  
ELIZABETH SMITH ◽  
PAUL R. FISHER ◽  
WARWICK N. GRANT ◽  
KEITH L. WILLIAMS

The speed of sustained migration of Dictyostelium discoideum slugs was similar in a temperature gradient and at different light intensities, including a light intensity sufficient to cause significant disorientation of slugs. No change was observed in slug speed in the presence of high levels of Slug Turning Factor (STF), a low molecular weight compound through which phototaxis and thermotaxis are mediated. Thus orientation of D. discoideum slugs is not mediated by a sustained changed in slug speed and we propose that slug movement is not directly coupled to tactic responses. Slug speed depended on the size, age and genotype of slugs as well as the nature of the substratum (charcoal-containing water agar versus water agar).


2012 ◽  
Vol 72 (2) ◽  
pp. 343-351 ◽  
Author(s):  
MC. Bittencourt-Oliveira ◽  
B. Buch ◽  
TC. Hereman ◽  
JDT. Arruda-Neto ◽  
AN. Moura ◽  
...  

Cylindrospermopsis raciborskii (Woloszynska) Seenayya et Subba Raju (Ordem Nostocales) is one of the most troublesome bloom-forming species in Brazil. Understanding the population dynamics of the different morphotypes of C. raciborskii (straight and coiled) could assist in the prediction of favourable conditions for the proliferation of this potentially toxin-producing species. The aim of the present study was to assess the effects of two different light intensities and temperatures on the growth rate and morphology of the trichomes of the straight and coiled morphotypes. For such, two non-toxin producing strains of C. raciborskii were used - one with a coiled trichome (ITEP31) and another with a straight trichome (ITEP28). The strains were cultured in BG-11 medium in a climatic chamber under controlled conditions. Two light intensities (30 and 90 µmol.m-2.s-1 ) were combined at temperatures of 21 and 31 °C and the growth rate and morphological changes were analysed. The morphotypes responded differently to the different temperatures and light intensities. Both strains exhibited faster growth velocities when submitted to higher light intensity and temperature. The lower temperature and higher luminosity hampered the development of both strains. Variations in cellular morphology and an absence of akinetes in both strains were related to the lower temperature (21 °C). The coiled morphotype demonstrated considerable phenotype plasticity, changing the morphology of trichome throughout its growth curve. Although molecular analysis does not sustain the separation of the morphotypes as distinct species, their different eco-physiological responses should be considered further knowledge of extreme importance for the population control of these potentially toxic organisms.


1955 ◽  
Vol 33 (5) ◽  
pp. 821-829 ◽  
Author(s):  
Moyra J. Smith ◽  
Patricia M. Beatty ◽  
J. A. Pinder ◽  
D. J. Le Roy

The mercury (3P1) photosensitized hydrogenation of ethylene has been studied at room temperature as a function of ethylene concentration, mercury concentration, and light intensity. In addition to combination and disproportionation, ethyl radicals have been shown to take part in the reaction[Formula: see text]The conditions favoring this reaction have been established and anomalous values previously found for the ratio of ethane to butane have been explained. The value obtained for the ratio of the rate constants for the disproportionation and combination of ethyl radicals, 0.15 ±.01, is in excellent agreement with the values obtained by other methods. Hexane formation is of some importance at low light intensities and high ethylene concentrations, and is adequately accounted for by the reactions[Formula: see text]


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