New Zealand Journal of Crop and Horticultural Science, 2008, Vol. 36: 285–294

0014–0671/08/3604–0285 © The Royal Society of New Zealand 2008

H08024; Online publication date 2 December 2008

Received 13 March 2008; accepted 24 October 2008

PDF file of entire paper: Print-quality (526K) | screen-quality (314K)

New Zealand Journal of Crop and Horticultural Science abstracts

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Growth and essential oil yield of rose-scented geranium (Pelargonium capitatum × P. radens ‘Rose’) as affected by withholding irrigation at different times during regrowth

B. K. Eiasu

J. M. Steyn

P. Soundy

Department of Plant Production and Soil Science

University of Pretoria

Pretoria, 0002, South Africa

email: puffy.soundy@up.ac.za

Abstract Response of plant growth and essential oil yield of rose-scented geranium (Pelargonium capitatum × P. radens ‘Rose’) to withholding irrigation at different times of regrowth cycles was investigated at Hatfield Experimental Farm of the University of Pretoria, South Africa, from 2004 to 2007. No-stress (control), and 1-month withholding irrigation periods during the 2nd, 3rd, or 4th month of regrowth were applied as treatments. Herbage yield showed a significant reduction when the water stress period was imposed during the 3rd or 4th month of regrowth. A remarkable essential oil yield loss was observed only when the plants were stressed during the 4th month of regrowth. Essential oil content (% oil on fresh herbage mass basis) apparently increased in the stressed treatments, but total oil yield dropped as a result of lower herbage mass. Essential oil composition changes in response to irrigation withholding treatments were not consistent. Water-use efficiency was not significantly affected by withholding irrigation in the 2nd or 3rd month of regrowth. With a marginal oil yield loss, c. 330–460 m³ of water/ha per regrowth cycle could be saved by withholding irrigation during the 3rd month of the regrowth cycles. The overall results highlighted that, in water scarce regions, withholding irrigation during either the 2nd or 3rd month of regrowth could improve water productivity in rose-scented geranium.

Keywords essential oil composition; essential oil content; herbage mass; water-use efficiency; water stress period

 

New Zealand Journal of Crop and Horticultural Science, 2008, Vol. 36: 285–294

0014–0671/08/3604–0285 © The Royal Society of New Zealand 2008

H08024; Online publication date 2 December 2008

Received 13 March 2008; accepted 24 October 2008

PDF file of entire paper: Print-quality (526K) | screen-quality (314K)

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