Contribution of leaves to the yield of sunflowers - Gurley 2015-16
The information contained in this publication is based on knowledge and understanding at the time of writing (July 2017) and may not be accurate, current or complete. The State of New South Wales (including the NSW Department of Industry), the author and the publisher take no responsibility, and will accept no liability, for the accuracy, currency, reliability or correctness of any information included in the document (including material provided by third parties). Readers should make their own inquiries and rely on their own advice when making decisions related to material contained in this publication. The product trade names in this publication are supplied on the understanding that no preference between equivalent products is intended and that the inclusion of a product name does not imply endorsement by the department
To quantify the contribution of different sunflower leaves to yield and oil quality through applying 12 leaf defoliation treatments.
Sunflower yields were very low at this site in 2015–16, averaging 0.24 t/ha, and overall variability was very high.
The total removal of leaves at the budding stage had the largest impact on plant structures; plant height, head diameter and arc length.
Lead research organisation
Department of Primary Industries NSW
Host research organisation
Trial funding source
Trial funding source
DPI NSW DAN00197
Tactical agronomy for selected crops in the northern region (safflower, linseed, sunflower)
This experiment was part of the project Tactical agronomy for selected crops in the northern region (safflower, linseed, sunflower) (DAN00197), with joint investment by NSW DPI and GRDC. Thanks to Nuseed and Neil Weier for supplying experiment seed. Technical assistance provided by Delphi Ramsden, Angus Hombsch, Alice Bowler and Bronwyn Brennan (NSW DPI) is gratefully acknowledged. Thanks to Doug Clark, ‘Kyntyre’, Gurley for hosting the experiment.
Trial results Affect from defoliation treatments on sunflower plant structures
Head diameter (cm)
Head arc length (cm)
Plant height (cm)
Control - no leaves removed (0/3)
Budding - remove all leaves (3/3)
Budding - remove top 10 leaves (1/3)
Budding - remove top 20 leaves (2/3)
Budding - remove bottom 10 leaves (1/3)
Start of flowering - remove top 10 leaves (1/3)
Start of flowering - remove top 20 leaves (2/3)
Start of flowering - remove all leaves (3/3)
Start of flowering - remove bottom 10 leaves (1/3)
Flowering complete - remove top 10 leaves (1/3)
Flowering complete - remove top 20 leaves (2/3)
Flowering complete - remove all leaves (3/3)
Head arc length cm
Head diameter cm
Plant height cm
Site 3, Gurley NSW 2015
Observed climate information
Rainfall avg ann (mm)
Rainfall trial gsr (mm)
Derived climate information
Site 3, Gurley NSW
NOTE: Exact trial site locality unknown - Climate data may not be accurate
SILO weather estimates sourced from https://www.longpaddock.qld.gov.au/silo/
Jeffrey, S.J., Carter, J.O., Moodie, K.B. and Beswick, A.R. (2001). Using spatial interpolation to construct a comprehensive archive of Australian climate data , Environmental Modelling and Software, Vol 16/4, pp 309-330. DOI: 10.1016/S1364-8152(01)00008-1.
Loretta Serafin, Mark Hellyer and Peter Perfrement (NSW DPI)
Searching GRDC final reports...
Terms and conditions of use
Be advised that the data and information on this website:
may not be accurate, current or complete;
is subject to change without notice;
is continually being validated, enhanced and updated; and
is subject to the usual uncertainties of scientific research
To access this Online Farm Trials resource, please click the "Accept" button below.
The content of this website is provided for information purposes only. Access to the site is on the basis that you accept responsibility for assessing the accuracy of the data and information contained on the site. No responsibility will be accepted for any loss or damage, however caused, which you may directly or indirectly suffer in connection with your use of this website, nor do we accept any responsibility for any such loss arising out of your use of or reliance on information contained on or accessed through this website.
Use of Information
Except as set out otherwise in these terms and conditions, you are provided with access to this application only for your personal use and you may not without our written permission on-sell or rebadge information obtained from this website, or in any way represent that the information is from any source other than Online Farm Trials.
Copyright of materials presented on this website generally resides with the organisation that conducted the trial(s) (e.g. Grower Group, Research Organisation, Government Department), or may be shared with other collaborating research partners (e.g. research funders such as the GRDC), or by Federation University Austrailia. Apart from fair dealing for the purposes of private study, research, criticism or review, as permitted under copyright legislation, and apart from uses specifically authorised by these terms and conditions, no part may be reproduced or reused for any commercial purposes whatsoever.
Specifically, and other than for the purposes of and subject to the conditions prescribed under the Copyright Act 1968 and similar legislation which applies in your location, you may not in any form or by any means adapt, reproduce, store, create derivative works, distribute, print, display, perform, publish or commercialise any information, products or services obtained from any part of this website; without our written permission.
This website may contain links to linked websites. Those links are provided for convenience only and may not remain current or be maintained.
We are not responsible for the content or privacy practices associated with linked websites.
Our links to linked websites should not be constructed as any endorsement, approval, recommendation, or preference by us of the owners or operators of those linked websites, or for any information, graphics, materials, products or services referred to on those linked websites.
Security of Information
Unfortunately, no data transmission over the Internet can be guaranteed as totally secure. Whilst we strive to protect such information, we do not warrant and cannot ensure the security of any information which you transmit to us. Accordingly, any information which you transmit to us is transmitted at your own risk. Nevertheless, once we receive your transmission, we will take reasonable steps to preserve the security of such information.
Data and Systems Integrity
You acknowledge that we will not be responsible for any corruption or failed transmission of any information attributable to your computer system or to the system or any act or omission of your Internet Service Provider.
You agree that you will not use any device, software or routine to interfere or attempt to interfere with the proper working of the service or this site.
You acknowledge that access to the service or our website:
may not be continuous, uninterrupted or secure at all times; and
may be interfered with by factors or circumstances outside of our control.