Control measures for the encroacher shrub Seriphium plumosum

Figures & data

Table 1 : Application rates (kg ha⁻¹) of the different fertiliser (kg ha⁻¹ or g fertiliser shrub⁻¹) and soil-applied suspension herbicide (Molopo – active ingredient tebuthiuron) (ml shrub⁻¹) treatments. Fertiliser was applied as calculated for an application area of 0.5 m×0.5 m around the stem of a Seriphium plumosum shrub. LAN = Limestone ammonia nitrate

Lime		Nitrogen		Sodium chloride		Phosphorus		Molopo
(kg lime ha^−1)	(g lime shrub ^−1 )	(kg N ha^−1)	(g LAN shrub^−1)	(kg NaCl ha^−1)	(g NaCI shrub^−1)	(kg P ha^−1	(g super-phosphate shrub^−1)	(ml shrub^−1)
1 000	25	30	2.7	100	2.5	5	1.20	0.5
2 000	50	60	5.4	200	5.0	10	2.50	1.0
5 000	125	120	10.7	300	7.5	15	3.75	2.0
		200	17.9	600	15			4.0
		500	44.6	1 000	25
		1 000	89.2	2 000	50
		2 000	178.4	4 000	100

Table 2 : Seriphium plumosum death (%) in response to different fertilisers and a soil-applied suspention herbicide (Molopo: active ingredient tebuthiuron), as grouped in different height classes. Cost per shrub is also indicated for each treatment. Means (n = 4) within a plant height class with different superscript letters indicate significant (P ≤ 0.01) differences among treatments based on Tukey's test

	Height size (mm)
Concentration	600	500	400	300	200	Cost shrub^−1 (cents)
	N (kg ha ^−1 )
30	0	0	52^c	77^b	100	2
60	0	0	73^b	100^a	100	3
120	0	22d	100^a	100^a	100	6
200	0	48c	100^a	100^a	100	10
500	0	71b	100^a	100^a	100	24
1 000	44^b	100^a	100^a	100^a	100	48
2 000	100^a	100^a	100^a	100^a	100^a	96
	NaCI (kg ha ^−1 )
100	0	0	100	100	100	0.2
200	0	0	100	100	100	0.4
300	0	0	100	100	100	0.6
600	0	48c	100	100	100	1
1 000	52^c	73^b	100	100	100	2
2 000	71^b	100^a	100	100	100	4
4 000	100^a	100^a	100	100	100	8
	Molopo (ml shrub ^−1 )
0.5	0	0	89	100	100	1.5
1	47^c	71^b	92	100	100	3
2	82^b	100^a	100	100	100	6
4	100^a	100^a	100	100	100	12

Table 3 : Mean ± SE sodium absorption ratio (SAR) in response to different NaCl applications, as measured on the foot slope at the end of the trial (March 2009). Means (n = 10) with different superscript letters indicate significant (P < 0.01) differences based on Tukey's test

NaCl ratio
Control (no NaCl)	100	200	300	600	1 000	2 000	4 000
0.17±0.03^g	1.00±0.20^f	3.41±0.11^e	4.82±0.09^e	8.55±0.14^d	15.58±0.22^c	21.00±3.61^b	36.13±4.66^a

Table 4 : Mean ± SE root:shoot ratio for different age Seriphium plumosum plants as measured in the greenhouse. Means (n = 10) with different superscript letters indicate significant (P < 0.01) differences based on Tukey's test

Plant age (months)
1	2	3	4	12
0.11±0.02^e	0.18±0.03^d	0.23 ±0.04^c	0.29±0.04^b	0.66±0.08^a