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Effects of foliar sprays of methanol on growth of some greenhouse plants
SCENTIA HORTlCulTuM ELSEVIER
Scientia Horticulturae 64 (1995) 187-191
Short Communication
Effects of foliar sprays of methanol on growth of some greenhouse plants Leiv M. Mortensen Department of Horticulhue
and Crop Science,The Agricultural
* University of Norway, 1432 is, Norway
Accepted 16 August 1995
Abstract Foliar sprays of either 20% methanol or 20% methanol + nutrients (Carbonkick) in water, were applied weekly to greenhouse roses, tomato and cucumber during 4-6 weeks. The plants were grown at 18.7”C air temperature in growth chambers placed in a greenhouse compartment, and supplied with a photosynthetic photon flux density of 175 pmol m-* s-’ for 18 h day-‘. No effects of the two foliar spray treatments were found on any of the species, as compared to control plants grown either in the same chamber or in a separate chamber. Foliar sprays of aqueous methanol, at least so far, can not be recommended for greenhouse crops under supplementary lighting during winter. The present results are discussed in relation to the positive effects of methanol previously found in field and greenhouse crops. Keywords:
Greenhouse plants; Growth; Methanol
It has been reported that foliar sprays of lo-50% aqueous methanol increase the and development of cut roses and tomato (Nonomura and Benson, 1992; Rowe et al., 1994) as well as in different field crops (Nonomura and Benson, 1992; Devlin et al., 1994). Mitchell et al. (1994), however, found no effect of methanol on growth of peppermint. Although methanol frequently caused leaf injuries due to nutrient deficiency, these injuries were eliminated by adding of a source of nitrogen in the spray (Nonomura and Benson, 1992). Some greenhouse growers in Scandinavia now use methanol sprays supplemented with nutrients to roses and tomato, and a mixture of 20% methanol and nutrients (‘Carbonkick’) is produced by the Finnish company KekkilB: OY (Tuusula, Finland). ‘Carbonkick’ contains glycerophosphate, urea, ureaphosphate and Fe-chelate. In view of the interest in this method of increasing plant growth an growth
* Corresponding address: The Norwegian Crop Research Institute, Sorheim Research Center, 4062 Klepp Stasjon, Norway. 0304-4238/95/$09.50 0 1995 Elsevier Science B.V. AU rights reserved SSDI 0304-4238(95)00841-l
188
L.M. Mortensen /Scientia
Horticulturae 64 (1995) 187-191
experiment was carried out with some important greenhouse species in order to evaluate the effect of methanol application. Seeds of Lycopersicon esculentum (tomato) cv. Liberto and of Cucumis sativus (cucumber) cv. Ventura, were sown on 2 and 13 September 1994, respectively, in standard fertilized peat (Floralux, Nittedal industrier, Norway) in 0.5 1 pots, and one plant was allowed to grow per pot. After 12 and 9 days from sowing in tomato and cucumber respectively, the pots were placed in growth chambers previously described by Mortensen and Nilsen (1992). Plants of Rosa cv. Souvenir (in 2.0 1 pots) were cut above the first five-leaflet leaf, and placed in growth chambers on 14 September. Two shoots were allowed to develop per pot. The chambers were placed in a greenhouse compartment. In addition to the daylight (7.3 mol mm2 day-’ on average), supplementary light was given at a photosynthetic photon flux density (PPFD) of 175 pmol rnp2 s-l for 18 h day-’ (11.3 mol m-2 day-‘) from high pressure sodium lamps (Philips SON-T Plus, The Netherlands). The mean air temperature throughout the experiment was 18.7 + 0.3”C, the relative air humidity 75 f 3%, and the CO, concentration 355 f 30 pmol mol-‘. The pots were watered regularly with a complete nutrient solution (Mortensen and Nilsen, 1992) to maintain the electrical conductivity at about 3.0 mS cm-‘. Two methanol spray treatments were given, either 20% methanol in water or 20% methanol + 0.8% ‘Carbonkick’ from Kekkila OY (Tuusula, Finland). The spray solutions contained 250 ppm of the wetting agent Citowett (BASF, Germany). The plants were sprayed to run off once a week, and this was done outside the chambers on single plants in order to avoid spraying other plants. Control plants were placed in the same chamber as the two methanol treatments and, in addition, also in a separate chamber in order to avoid any effect from the methanol-sprayed plants. Each treatment included eight plants of roses (altogether 16 shoots), and six plants of tomato and cucumber. One chamber was used for each of the three species and a fourth chamber contained the control plants of all three species. The pots of the different treatments were randomized in each chamber. The rose shoots were harvested at the saleable stage, the tomato plants were harvested at flowering of the first truss, and the cucumber plants after 28 days in the chambers. Days until flowering, shoot fresh and dry weights, shoot length and number of leaves were recorded. All data were subjected to an analysis of variance (SAS Institute Inc., Carey NC, USA). No significant effects (p > 0.05) of foliar sprays of methanol alone or in combination with ‘Carbonkick’ were found either on flowering of roses and tomato, on the dry weight and shoot length of the three species (Fig. 1) or on the number of leaves in cucumber (Fig. 1) or tomato (data not presented). Nonomura and Benson (1992) concluded that foliar sprays of methanol strongly enhanced plant growth in arid and warm (up to about 40-45°C) environments. They observed that methanol sprays increased plant turgidity and prevented wilting of the leaves in direct sunshine (high-light conditions) in dry and warm environments, and this may have resulted in the increased growth rates and yields of greenhouse roses and some field crops. In the present experiment, however, the plants were not exposed to any drought stress or extreme temperatures, which may explain why no effects were found. Nonomura and Benson
L.M. Mortensen /Scientia Horticulturae 64 (1995) 187-191
_6rA’
L B
I
189
DAYS UNTIL DRY WEIGHT
•m Carbonkick
q
Methanol
I ~Control1 Control
2
HEIGHT
TIME UNTIL FLOWERING
m Carbonkick
14
r
H
Methanol
?
Control
1
q
Control
2
=. DRY WEIGHT
NO. OF LEAVES
Fig. 1. The effect of 20% methanol only (Methanol) or in combination with nutrients (‘Carbonkick’) on growth (*SE) and flowering of roses (A), tomato (B) and cucumber CC). Control 1 = control plants in the same growth chamber, and Control 2 = control plants in a separate chamber. No significant differences at p = 0.05 level were found between the four treatments in any of the three species.
190
L.M. Mortensen /Scientia
Horticulturae
64 (1995) 187-l 91
(1992) also found that a methanol solution with glycine and glycerophosphate stimulated plant growth indoors under artificial lighting at a PPFD of 75-100 pmol m-’ s-‘. The level of photosynthetic active radiation in the present experiment was not much lower than in a greenhouse during mid-summer in Scandinavia, which again is not much different from that in southern Europe (Wallen, 1970). No leaf injuries were observed in the present experiment yet Nonomura and Benson (1992) found that leaf injuries readily developed when either glycine or glycerophospate was not added. The methanol concentration which causes leaf injuries has been reported to differ between species (Nonomura and Benson, 19921, and it is possible that the 20% methanol solution applied to the present species was below the critical concentration for leaf injuries under the present climate regime. However, Mitchell et al. (1994) observed no leaf injuries in peppermint even at methanol concentrations above 90%. In addition to the effect on the turgidity of plants, Nonomura and Benson (1992) suggested that the long-term stimulation of growth by methanol may be related to the inhibition of photorespiration of plants as they found that positive effects were observed in C, plants (with photorespiration) but not in C, plants (without photorespiration). This was supported by the findings of Devlin et al. (1994) where methanol stimulated the growth of some C, species (wheat, radish and pea) but not the growth of corn (a C, species). CO, enrichment is a standard method of increasing plant growth and yield in greenhouses (Mortensen, 19871, and elevated CO, concentrations are known to inhibit photorespiration and to increase photosynthesis and growth of C, species such as chrysanthemum (Mortensen and Moe, 1983a) and cut roses (Mortensen and Moe, 1983b). It should be of little interest, therefore, to apply methanol during periods of high CO, concentrations in the greenhouse. The present experiment was carried out at low CO, concentrations in order to test the methanol effect on plants under conditions where photorespiration was not inhibited. Nevertheless, no effect of methanol was found. Methanol treatments of greenhouse plants might be of interest under water stress conditions in the greenhouses, i.e. during periods of sunny weather (high temperatures and high water vapour deficits) in late spring and summer, especially as photorespiration is known to increase with increasing temperature (Laing et al, 1974; Mortensen, 1983). At present, however, methanol application can not recommended for greenhouse crops under artificial lighting during winter.
Acknowledgement The author thanks Mr. E. Braut and Ms. R.L. Rosland for their technical assistance. This work was supported by the R.J. Svinningen Nursery and the National Research Council of Norway.
References Devlin, R.M., Bhowmik, P.C. and Karczmarczyk, Quarterly, 22: 102-107.
J., 1994. Influence
of methanol
on plant growth.
PGRSA
L.M. Mortensen/Scientia
Horticulturae
64 (1995) 187-191
191
Laing, W.A., Ogren, W.L. and Hageman, R.H., 1974. Regulation of soybean net photosynthetic CO, fixation by the interaction CO,, 0, and Ribulose 1.5diphosphate carboxylase. Plant Physiol., 54: 678-685. Mitchell, A.R., Crowe, F.J. and Butler, M.D., 1994. Plant performance and water use of peppermint treated with methanol and glycine. J. Plant Nutr., 17: 1955-1962. Mortensen, L.M., 1983. Growth responses of some greenhouse plants to environment. IX. Effect of CO, on photosynthesis of Chrysanthemum morifolium Ramat. at different light, temperature and 0, levels. Meld. Nor. LandbrHogsk., 62(11): 1-12. Mortensen, L.M., 1987. Review: CO, enrichment in greenhouses. Crop responses. Scientia Hortic., 33: l-25. Mortensen, L.M. and Moe, R., 1983a. Growth responses of some greenhouse plants to environment. V. Effect of CO,, 0, and light on net photosynthetic rate in Chrysanthemum morifolium Ramat. Scientia Hortic., 19: 133-140. Mortensen, L.M. and Moe, R., 1983b. Growth responses of some greenhouse plants to environment. VII. The effect of CO, on photosynthesis and growth of roses. Meld. Nor. LandbrHogsk., 62(13): 1-15. Mortensen, L.M. and Nilsen, J., 1992. Effects of ozone and temperature on growth of several wild plant species. Norw. J. Agr. Sci., 6: 195-204. Nonomura, A.M. and Benson, A.A., 1992. The path of carbon in photosynthesis: Improved crop yields with methanol. Proc. Natl. Acad. Sci., USA, 89: 9794-9798. Rowe, R.N., Farr, D.J. and Richards, B.A.J., 1994. Effects of foliar and root applications of methanol or ethanol on the growth of tomato plants (Lycopersicon escdentum Mill.). New Zealand J. Crop HOI?. Sci., 22: 335-337. Wallen, CC. (ed.), 1970. World Survey of Climatology. Volume 5: Climate of Northern and Western Europe. Elsevier, Netherlands, 239 pp.
Scientia Horticulturae 64 (1995) 187-191
Short Communication
Effects of foliar sprays of methanol on growth of some greenhouse plants Leiv M. Mortensen Department of Horticulhue
and Crop Science,The Agricultural
* University of Norway, 1432 is, Norway
Accepted 16 August 1995
Abstract Foliar sprays of either 20% methanol or 20% methanol + nutrients (Carbonkick) in water, were applied weekly to greenhouse roses, tomato and cucumber during 4-6 weeks. The plants were grown at 18.7”C air temperature in growth chambers placed in a greenhouse compartment, and supplied with a photosynthetic photon flux density of 175 pmol m-* s-’ for 18 h day-‘. No effects of the two foliar spray treatments were found on any of the species, as compared to control plants grown either in the same chamber or in a separate chamber. Foliar sprays of aqueous methanol, at least so far, can not be recommended for greenhouse crops under supplementary lighting during winter. The present results are discussed in relation to the positive effects of methanol previously found in field and greenhouse crops. Keywords:
Greenhouse plants; Growth; Methanol
It has been reported that foliar sprays of lo-50% aqueous methanol increase the and development of cut roses and tomato (Nonomura and Benson, 1992; Rowe et al., 1994) as well as in different field crops (Nonomura and Benson, 1992; Devlin et al., 1994). Mitchell et al. (1994), however, found no effect of methanol on growth of peppermint. Although methanol frequently caused leaf injuries due to nutrient deficiency, these injuries were eliminated by adding of a source of nitrogen in the spray (Nonomura and Benson, 1992). Some greenhouse growers in Scandinavia now use methanol sprays supplemented with nutrients to roses and tomato, and a mixture of 20% methanol and nutrients (‘Carbonkick’) is produced by the Finnish company KekkilB: OY (Tuusula, Finland). ‘Carbonkick’ contains glycerophosphate, urea, ureaphosphate and Fe-chelate. In view of the interest in this method of increasing plant growth an growth
* Corresponding address: The Norwegian Crop Research Institute, Sorheim Research Center, 4062 Klepp Stasjon, Norway. 0304-4238/95/$09.50 0 1995 Elsevier Science B.V. AU rights reserved SSDI 0304-4238(95)00841-l
188
L.M. Mortensen /Scientia
Horticulturae 64 (1995) 187-191
experiment was carried out with some important greenhouse species in order to evaluate the effect of methanol application. Seeds of Lycopersicon esculentum (tomato) cv. Liberto and of Cucumis sativus (cucumber) cv. Ventura, were sown on 2 and 13 September 1994, respectively, in standard fertilized peat (Floralux, Nittedal industrier, Norway) in 0.5 1 pots, and one plant was allowed to grow per pot. After 12 and 9 days from sowing in tomato and cucumber respectively, the pots were placed in growth chambers previously described by Mortensen and Nilsen (1992). Plants of Rosa cv. Souvenir (in 2.0 1 pots) were cut above the first five-leaflet leaf, and placed in growth chambers on 14 September. Two shoots were allowed to develop per pot. The chambers were placed in a greenhouse compartment. In addition to the daylight (7.3 mol mm2 day-’ on average), supplementary light was given at a photosynthetic photon flux density (PPFD) of 175 pmol rnp2 s-l for 18 h day-’ (11.3 mol m-2 day-‘) from high pressure sodium lamps (Philips SON-T Plus, The Netherlands). The mean air temperature throughout the experiment was 18.7 + 0.3”C, the relative air humidity 75 f 3%, and the CO, concentration 355 f 30 pmol mol-‘. The pots were watered regularly with a complete nutrient solution (Mortensen and Nilsen, 1992) to maintain the electrical conductivity at about 3.0 mS cm-‘. Two methanol spray treatments were given, either 20% methanol in water or 20% methanol + 0.8% ‘Carbonkick’ from Kekkila OY (Tuusula, Finland). The spray solutions contained 250 ppm of the wetting agent Citowett (BASF, Germany). The plants were sprayed to run off once a week, and this was done outside the chambers on single plants in order to avoid spraying other plants. Control plants were placed in the same chamber as the two methanol treatments and, in addition, also in a separate chamber in order to avoid any effect from the methanol-sprayed plants. Each treatment included eight plants of roses (altogether 16 shoots), and six plants of tomato and cucumber. One chamber was used for each of the three species and a fourth chamber contained the control plants of all three species. The pots of the different treatments were randomized in each chamber. The rose shoots were harvested at the saleable stage, the tomato plants were harvested at flowering of the first truss, and the cucumber plants after 28 days in the chambers. Days until flowering, shoot fresh and dry weights, shoot length and number of leaves were recorded. All data were subjected to an analysis of variance (SAS Institute Inc., Carey NC, USA). No significant effects (p > 0.05) of foliar sprays of methanol alone or in combination with ‘Carbonkick’ were found either on flowering of roses and tomato, on the dry weight and shoot length of the three species (Fig. 1) or on the number of leaves in cucumber (Fig. 1) or tomato (data not presented). Nonomura and Benson (1992) concluded that foliar sprays of methanol strongly enhanced plant growth in arid and warm (up to about 40-45°C) environments. They observed that methanol sprays increased plant turgidity and prevented wilting of the leaves in direct sunshine (high-light conditions) in dry and warm environments, and this may have resulted in the increased growth rates and yields of greenhouse roses and some field crops. In the present experiment, however, the plants were not exposed to any drought stress or extreme temperatures, which may explain why no effects were found. Nonomura and Benson
L.M. Mortensen /Scientia Horticulturae 64 (1995) 187-191
_6rA’
L B
I
189
DAYS UNTIL DRY WEIGHT
•m Carbonkick
q
Methanol
I ~Control1 Control
2
HEIGHT
TIME UNTIL FLOWERING
m Carbonkick
14
r
H
Methanol
?
Control
1
q
Control
2
=. DRY WEIGHT
NO. OF LEAVES
Fig. 1. The effect of 20% methanol only (Methanol) or in combination with nutrients (‘Carbonkick’) on growth (*SE) and flowering of roses (A), tomato (B) and cucumber CC). Control 1 = control plants in the same growth chamber, and Control 2 = control plants in a separate chamber. No significant differences at p = 0.05 level were found between the four treatments in any of the three species.
190
L.M. Mortensen /Scientia
Horticulturae
64 (1995) 187-l 91
(1992) also found that a methanol solution with glycine and glycerophosphate stimulated plant growth indoors under artificial lighting at a PPFD of 75-100 pmol m-’ s-‘. The level of photosynthetic active radiation in the present experiment was not much lower than in a greenhouse during mid-summer in Scandinavia, which again is not much different from that in southern Europe (Wallen, 1970). No leaf injuries were observed in the present experiment yet Nonomura and Benson (1992) found that leaf injuries readily developed when either glycine or glycerophospate was not added. The methanol concentration which causes leaf injuries has been reported to differ between species (Nonomura and Benson, 19921, and it is possible that the 20% methanol solution applied to the present species was below the critical concentration for leaf injuries under the present climate regime. However, Mitchell et al. (1994) observed no leaf injuries in peppermint even at methanol concentrations above 90%. In addition to the effect on the turgidity of plants, Nonomura and Benson (1992) suggested that the long-term stimulation of growth by methanol may be related to the inhibition of photorespiration of plants as they found that positive effects were observed in C, plants (with photorespiration) but not in C, plants (without photorespiration). This was supported by the findings of Devlin et al. (1994) where methanol stimulated the growth of some C, species (wheat, radish and pea) but not the growth of corn (a C, species). CO, enrichment is a standard method of increasing plant growth and yield in greenhouses (Mortensen, 19871, and elevated CO, concentrations are known to inhibit photorespiration and to increase photosynthesis and growth of C, species such as chrysanthemum (Mortensen and Moe, 1983a) and cut roses (Mortensen and Moe, 1983b). It should be of little interest, therefore, to apply methanol during periods of high CO, concentrations in the greenhouse. The present experiment was carried out at low CO, concentrations in order to test the methanol effect on plants under conditions where photorespiration was not inhibited. Nevertheless, no effect of methanol was found. Methanol treatments of greenhouse plants might be of interest under water stress conditions in the greenhouses, i.e. during periods of sunny weather (high temperatures and high water vapour deficits) in late spring and summer, especially as photorespiration is known to increase with increasing temperature (Laing et al, 1974; Mortensen, 1983). At present, however, methanol application can not recommended for greenhouse crops under artificial lighting during winter.
Acknowledgement The author thanks Mr. E. Braut and Ms. R.L. Rosland for their technical assistance. This work was supported by the R.J. Svinningen Nursery and the National Research Council of Norway.
References Devlin, R.M., Bhowmik, P.C. and Karczmarczyk, Quarterly, 22: 102-107.
J., 1994. Influence
of methanol
on plant growth.
PGRSA
L.M. Mortensen/Scientia
Horticulturae
64 (1995) 187-191
191
Laing, W.A., Ogren, W.L. and Hageman, R.H., 1974. Regulation of soybean net photosynthetic CO, fixation by the interaction CO,, 0, and Ribulose 1.5diphosphate carboxylase. Plant Physiol., 54: 678-685. Mitchell, A.R., Crowe, F.J. and Butler, M.D., 1994. Plant performance and water use of peppermint treated with methanol and glycine. J. Plant Nutr., 17: 1955-1962. Mortensen, L.M., 1983. Growth responses of some greenhouse plants to environment. IX. Effect of CO, on photosynthesis of Chrysanthemum morifolium Ramat. at different light, temperature and 0, levels. Meld. Nor. LandbrHogsk., 62(11): 1-12. Mortensen, L.M., 1987. Review: CO, enrichment in greenhouses. Crop responses. Scientia Hortic., 33: l-25. Mortensen, L.M. and Moe, R., 1983a. Growth responses of some greenhouse plants to environment. V. Effect of CO,, 0, and light on net photosynthetic rate in Chrysanthemum morifolium Ramat. Scientia Hortic., 19: 133-140. Mortensen, L.M. and Moe, R., 1983b. Growth responses of some greenhouse plants to environment. VII. The effect of CO, on photosynthesis and growth of roses. Meld. Nor. LandbrHogsk., 62(13): 1-15. Mortensen, L.M. and Nilsen, J., 1992. Effects of ozone and temperature on growth of several wild plant species. Norw. J. Agr. Sci., 6: 195-204. Nonomura, A.M. and Benson, A.A., 1992. The path of carbon in photosynthesis: Improved crop yields with methanol. Proc. Natl. Acad. Sci., USA, 89: 9794-9798. Rowe, R.N., Farr, D.J. and Richards, B.A.J., 1994. Effects of foliar and root applications of methanol or ethanol on the growth of tomato plants (Lycopersicon escdentum Mill.). New Zealand J. Crop HOI?. Sci., 22: 335-337. Wallen, CC. (ed.), 1970. World Survey of Climatology. Volume 5: Climate of Northern and Western Europe. Elsevier, Netherlands, 239 pp.