Results 

Height analysis 

Three-way analysis of variance (ANOVA) showed that main effects of plant species (F5,143=1515。34, p<0。001), planting models (F1,143=78。73, p<0。001) and soil tilling intervals (F2,143=137。54, p<0。001); interactions of species with planting models (F5,143=20。93, p<0。001) and planting models with soil tilling intervals (F2,143=67。33, p<0。001) were highly significant for plant height。 Interactions of plant species with soil tilling intervals (F10,143=1。73, p=0。079) and species, planting models with soil tilling intervals (F10,143=0。81, p=0。620) did not significantly affect plant height。 Initial plant height did not significantly affect experimental error (F1, 143= 0。681, p=0。411)。 

Plants with turfgrass showed significantly taller height (221。95 cm) at 15 day STI than at 45 day STI (203。72 cm), (Table 1)。

Table 1。 Effect of soil working intervals on height and crown diameter of different varieties of plants planted in two plantation models

Plant species Mean Initial height in plantation models in 2006 (cm) Height / Crown diameter 2009 In (cm)

with turfgrass without turfgrass

15 days 30 days 45 days Mean 15 days 30 days 45days Mean Grand mean

Alstonia scholaris 87。93 320。80 / 318。00 / 296。80 / 311。87 / 286。20 / 280。00 / 280。20 / 282。13 / 297。00 /

- - - - - - - - 243。20 240。80 231。40 238。47 235。60 228。6 229。60 231。37 234。87

Bougainvillea glabra 59。17 268。60 / 263。80 / 228。80 / 253。73 / 253。40 / 249。40 / 241。60 / 248。13 / 250。93 /

- - - - - - - - 269。80 266。20 251。40 262。47 259。80 259。40 255。20 258。13 260。30

Ervatamia paricata