Pasture Pest Problem Less Serious

Press, Volume CVIII, Issue 31772, 31 August 1968, Page 10

Pasture Pest Problem Less Serious

Pasture pests have caused much less damage in the province this winter than they did a year ago. In the main, granulated D.D.T. superphosphate, which became available for the first time last autumn, has given good control.

These were two of the main points to emerge from a discussion of the incidence of the pests this winter, and control measures, at a meeting of the pasture pests control committee of North, Mid and South Canterbury Federated Farmers in Christchurch this week.

The chairman of the committee (Mr A. F. Wright) said that with production of granulated D.D.T. superphosphate from the Hornby fertiliser works running at about 700 tons a week it had only been sufficient to keep pace with orders. Even at this stage, with 500 to 700 tons being made a week, the works were just meeting orders and there was no surplus. Farmers had proved to the company that if it went into production of granulated D.D.T super they would support it, he said. Before inviting members of the committee to review the pest position and control situation in their own areas, Mr Wright, who comes from Annat, referred to the position in his own area. He said a large tonnage of granulated D.D.T. fertiliser had been used and while in certain areas there had been no reaction to it, good control had been obtained in other areas. He felt the majority opinion would be that reasonably good control had been obtained. This had been particularly against porina caterpillars as grass grubs did not constitute so great a problem in his area.

Mr Wright said he was uncertain whether climatic conditions had anything to do with lack of successful control where that had occurred. In the last month it appeared as if there might hot have been enough moisture for grass grub control. He did, however, feel that the pests were moving inland on to the higher country. He mentioned the Hawarden-Wai-kari area and said that some grass grub and porina damage had been noticed and in these areas people might have to start using D.D.T. super. Mr P. G Morrison, of Sheffield, said he thought most people would be happy with the control results they had achieved. He had heard no complaints said Mr A. L. Mulholland, of Darfield, and he had heard a number say granulated D.D.T. super had controlled porina. A number had also not been able to put it on soon enough because of the excessive growth. Mr Mulholland said, however, that in a paddeck treated six weeks earlier some grubs were still alive, (Mr J. M. Kelsey, officer in charge of the Lincoln substation of the Entomology Division ’of the Department of Scientific and Industrial Research, said after the meeting that this was not unusual as in the first year the D.D.T. did not kill grubs outright but partially immobilised them so they did not move far and did not eat much plant growth). The granulated D.D.T. superphosphate had not been released specifically

for control of porina, said Mr W. N. Dunlop. The Agricultural Chemicals Board had made it plain that it considered the organophosphates would control the porina situation and the granulated D.D.T. was for grass grub control. Where it had been used in his area it had been very good and the only complaint had been of mechanical troubles in applying it.

“I have had no unfavourable reports about of this material against grass grubs. This really justifies all that has been done," he said. “We have not had the problem raised at every meeting this year and that is significant,” said Mr J. G. Humm, chairman of the meat and wool section of Mid-Canter-bury Federated Farmers. There were one or two areas in his district where there were definite problems of resistance to control and there had been some mechanical problems with the new material, “but by and large it has been a considerable improvement on last year.” He added that a late start had to be made with treatments this year because the granulated D.D.T. super was not available earlier and there had been some wet weather. “In our area there are some who are not 100 per cent happy,” said Mr R. W. Johnston, another Mid-Canterbury representative, “but these are areas with a possibility of some resistance. I also know that a lot of granulated D.D.T. has been used quite successfully and I think it is probable that it would be highly effective if put on at the right time." Both porina and grass grub seemed to be moving back into the higher-rainfall foothill area, said Mr D. J. Huiston, of Waimate, chairman of the South Canterbury meat and wool section of Federated Farmers. “I think we can thank the Lord that we have got granulated D.D.T. available.”

Mr W. J. Penno, another South Canterbury representative, also from the Waimate

area, said It had been a most unusual year in his district. When the porina had been breeding it had been extremely dry and then during the winter the paddocks could be seen only when the water had drained off. “We do not know whether the water drowned them out.” With the removal of the fines from the material, Mr Mulholland said that the mechanical problems mentioned had been eliminated. This made the material better to apply. Discussing the amount of damage done by pasture pests this winter, Mr Dunlop said there was no comparison with last year.

It seemed that in general there was satisfaction with granulation, said Mr Wright in summarising the discussion. It seemed that in most areas control had been very good and where it had not been so good this could be because of several factors and not necessarily the material. J Taking into account that the granulated D.D.T. had not been available until late in the season, it seemed that there where it could be applied at the right time there would be a most effective con trol over almost the whole area.

Mr Wright reported later in the meeting that the terms of issue of permits for applica tion of D.D.T. to dairy farm pastures had been tabled. It was quite obvious, he said, that dairy farmers would have to apply very early if they wished to treat pasture, as the machinery involved for issue of permits could take some time to carry out. Earlier Mr Dunlop said there could be quite a problem on dairy farms. This was an area where there were grass grubs and Tasmanian grass grubs and dairy farmers would suffer considerable loss of pastures as counts of insects had to be high before the granting of a permit would be considered.

As already reported in the general news columns earliei in the week, the committee also reaffirmed an earlier decision asking the Agricultural Chemicals Boards to introduce a system of permits for all D.D.T. fertilisers for use on farms other than dairy farms The granting of permits would be automatic, but the objective would be to make it possible for the Department ot Agriculture to have a complete record of all D.D.T superphosphate distributed. The committee made a similar proposition at the end of last year.