GRASS GRUB MENACE

Wanganui Chronicle, Volume 75, Issue 151, 29 June 1932, Page 9

GRASS GRUB MENACE

DIFFICULTY OF CONTROL HIGH COST OF TREATMENT IMPOSSIBLE ON ARM LANDS. AUCKLAND, June 26. To exterminate the grass grub, which has been causing serious damage in the Te Aroha district, would be so costly as far as farm lands are concerned as to be practically prohibitive, according to the opinion expressed yesterday by Air. P. 8. Smallfiold, fields superintendent of the Department of Agriculture, Auckland. “The grub can be controlled in 'awns, but the cost of treatment is quite outside the bounds of possibility in the case of farming areas,” said Mr. Smallfield. “The indications are that the attacks of the grub are worst in the shallow-rooted grasses, particularly ryegrass, but that good perennial strains of ryegrass are less susceptiole than the short-lived strains. Pasture Management. “Under farming conditions the only useful method of control is good pasture management, that is. avoidance of rank growth on the pastures in the summer. That can be done by saving as much of the surplus growth as possible as ensilage and, after cutting the ensilage, keeping the pastures well grazed. Beyond that, there is no practicable method of control under farm conditions, owing to the cost of treatment. “It would cost £lO or £l2 an acre at th** very leaqt for material,” said Mr. Bmalllield, “and that expenditure might have to be incurred every year. As the land produces only about £4 or £5 an acre yearly, the impracticability of incurring such heavy expenditure can readily be appreciated.” The grass grub eats the root of the grass and the beetle of the grub eats the leaves of trees. The grub is really only dormant toward the end of October and in November, when it is turning into the beetle, and there are grubs in the ground virtually the whole year through. The beetle is on the wing usually in November, December and January. The ravages of the grub are worst in a dr/ season, &uch as was experienced last summer. Other Areas Infested. So far as the Department of Agriculture is aware, the Cawthron Institute has not been successful iu finding a parasite which will attack the grass grub. It is stated that other parts of the South Auckland area, beside the Manawaru and Shaftesbury districts, near Te Aroha, specially mentioned yesterday, are infested with the grub, which has been, in evidence in the North Island for a good many years. The Cambridge district was mentioned by Mr. Smallfield as one from which complaints had also been received. No indication can be given in Auckland as to the possibility of the department giving financial assistance toward the cost of controlling the pest. However, a report on the situation has been sent to the Minister. For the treatment of lawns, bowling greens, golf courser and the like, affected by the gruofl grub, carbon bisulphide or a proprietary preparation of coal tar, containing an unusually high percentage of high boiling tar acids, is recommended. The plant research station, at Palmerston North has interested itself in the problem and some hopes are held that the cost for large-area treatment may bo reduced sufficiently to enable its economical application to farming lands.