Cold shock in early growth cotton

Bange, M. and Milroy, S.ORCID: 0000-0002-3889-7058 (2003) Cold shock in early growth cotton. In: 11th Australian Agronomy Conference: Solutions for a better environment, 2 - 6 February 2003, Geelong, Victoria

Abstract

A previous analysis of the rate of cotton development has shown that minimum temperatures below 11C delay the development of cotton seedlings compared with the expected rate based on the accumulated day degree sum. Events where the minimum daily temperature fall below this value are referred to as ‘cold shocks’. The number of cold shocks occurring in the early parts of the cotton growing season are used by growers and advisors in assessing retardation of crops in their areas. However, this ‘cold shock’ effect has not been tested explicitly.

The aim of this work was to empirically assess impacts of cold shock on crop growth and development. Cotton seedlings were grown under natural light conditions in controlled temperature glasshouses. To impose cold shock plants were transferred to cold chambers ranging from 3 to 22C during the night period for durations from 3 to 10 d. In order to generate some effect, plants grown in 30/22C day/ night temperatures had to be exposed to 10? C for 10 d to delay time to first square and first flower, but this effect did not translate into differences in leaf area or total dry matter measured just after flowering. Plants exposed for a similar duration at the same temperature that had been grown in a 23/15C day/ night regime showed no significant differences in any parameter measured, possibly indicating some degree of cold acclimation. In one experiment a significant reduction in leaf photosynthesis was measured the day after the initial cold shock at 3C, but this did not impact on crop time to flowering or total dry matter measured at flowering.

This work is intended to improve understanding of the impacts of temperature extremes on cotton growth and development to help develop more functional decision support tools and field management strategies which will enable both research and management to be done more accurately in scenarios where extremes of temperature are likely.

Item Type:	Conference Paper
Conference Website:	http://www.agronomyaustraliaproceedings.org/images...
URI:	http://researchrepository.murdoch.edu.au/id/eprint/57332

Item Control Page

Downloads