VARIATION IN NATURALISED MEDICAGO POLYMORPHA COLLECTED FROM INLAND EASTERN AUSTRALIA: 11 - QUEENSLAND
D.L. Lloyd¹, R.R. Young², K.C. Teasdale³, B. Johnson¹ and M. O’Neill^4
1Department of Primary Industries, PO Box 102, Toowoomba, Qld 4350
²NSW Agriculture, RMB 944, Tamworth, NSW 2340
³Department of Primary Industries, Hermitage Research Station, Warwick, Qld 4370
⁴NSW Agriculture, Condoblin, NSW 2877

Naturalised burr medic (Medicago polymorpha) occurs widely on clay soils in the northern wheat belt of Australia providing useful forage in wetter winters and having the potential to improve the nitrogen fertility of cropping soils. A more complete rationale for collecting and studying representative populations of Medicago polymorpha from this area has been described (1). This paper describes the variation in flowering time of the collection from 11 geographic regions in Queensland.

MATERIALS AND METHODS

The collection and growout protocols in the Queensland component of the study were similar to those in New South Wales (1).

RESULTS AND DISCUSSION

All regional populations were characterised by wide but similar diversity in the 26 attributes measured (including vigour, seed production, leaf mark, pod spininess, habit and flowering time). The largest proportion of plants in all regions flowered between 100 and 109 days (Table 1) but in the drier environments, more flowered early than late. The converse was true in the wetter regions which included the Darling Downs and all regions east of the Great Divide.
Table 1. Flowering times of Medicago polymorpha populations in the 11 regions.

Region	Key	Seasonal	% Plants flowering by (days)
	Town	Rainfall1	<90	90-99	100-109	110-119	>119
South Burnett Moreton	Kingaroy	237/533	0.0	19.0	50.4	25.6	5.0
North Central Burnett	Monto	218/524	1.6	16.5	55.9	25.2	0.8
Central Queensland	Biloela	202/486	4.1	19.3	44.4	21.1	11.1
Central Highlands	Emerald	190/465	2.8	23.9	52.1	21.1	0.0
Central West	Blackall	156/349	12.8	16.4	49.0	20.0	1.8
South West	Morven	151/278	4.3	31.9	55.3	8.5	0.0
Maranoa North	Roma	193/379	4.2	25.2	50.4	17.7	2.5
Maranoa South	St George	188/328	8.5	22.0	48.8	20.8	0.0
Western Downs North	Miles	214/448	5.2	25.6	50.8	17.4	1.0
Western Downs South	Moonie	204/373	8.8	31.8	43.2	15.1	1.1
Darling Downs	Warwick	228/455	3.0	17.3	38.1	35.0	6.6

¹ Seasonal Rainfall = April-September/October-March (mm)

REFERENCE

1. Young, R.R., Lloyd, D.L., O’Neill, M., Teasdale, K. and Johnson, B. 1996. Proc. 8th Aust. Agronomy Conf., Toowoomba. (in press).