FEW GRASS GRUBS ARE INJURED BY PASTURE ROLLING

Bay of Plenty Beacon, Volume 15, Issue 45, 17 May 1950, Page 4

FEW GRASS GRUBS ARE INJURED BY PASTURE ROLLING

Forming part of their programme on combating damage by grass grubs, research workers of New Zealand have issued recommendations to farmerc on the compaction of soil and the consolidation of pasture plants damaged by grass grubs. At the present time the grubs are very near the soil surface, they are approaching the fully-fed state after which injury of roots de-» creases, and there is then adequate soij. moisture for consolidation of injured pasture and compaction of soil. Furthermore, root growth takes place readily during this period because of the moisture, although on the surface the pasture shows no noticeable growth. Stock should be left' off rolled pastures for three weeks after rolling otherwise they will/tend to pull up tufts of grass before the injured plants have re-rooted. If rolling is carried out much earlier than June, the new roots on the plant are likeiy to be destroyed by the grubs, many of which are actively feeding at the earlier period. If rolling is carried out after August, when dry months occur in riiany parts of New Zealand, the soil becomes hard and the injured pasture dries up and is blown away. It is pointed out that very few grubs are injured by rolling, but that if the soil is compacted during the period when few grubs are actively feeding new roots grown from the plant will become established. It has also been shown that irrigation does not drown grass grubs except in depressions where water lies for more than 12 hours.