Spraying aids tree establishment

Press, Volume CXV, Issue 33928, 22 August 1975, Page 6

Spraying aids tree establishment

A combined woodlot-shelter plantation of about 16 hectares or 40 acres established just over a year ago on the “Lynton” property of Mr P. W. Smail at Hororata is a notable example of the success of chemical spraying of the turf before planting. The trees have got off to a wonderful start, and are looking extremely healthy.

Mr Smail is certain that this is the way to establish trees. The site selected for the trees was a pretty bony piece of undeveloped country — a Lismore stony loam in browntop and fescue and dead manuka carrying a meagre 2.5 ewe equivalents per hectare. Strips a metre or 39 inches wide and 3.75 metres or 12 ft apart were sprayed with simazine, “Downpon” and amitrole and after three weeks the trees (Pinus radiata) were planted mechanically two metres, or a title over 6ft apart in the rows. This gave some 1500 stems an acre. At the same time six rows were planted in the same way where the ground had not been sprayed. Following a normal winter and an unusually good spring, establishment was about 99 per cent successful. In early November measurements showed that the trees had grown 21.7 p?r cent better on the sprayed area compared with the unsprayed, but none of the trees looked under stress at that stage. But in November and December there was next to no rain and a graphic change took place. Eighty per cent of the trees in the unsprayed rows died but there was still a 99 per cent survival in the sprayed rows. Mr Smail said that the grass in the unsprayed strips, having established itself, utilised all of the moisture and also transpired through the foliage. The few surviving trees in the unsprayed strips were in slight depressions, where they gained some moisture and benefited from some shelter.

through the life of a tree, just as good growth at the hogget stage had an important bearing on the subsequent standard of a sheep. After successful establishment, every tree has

Had the ground been scalped, and not sprayed, no doubt survival rate in the unsprayed area might have been better, but the short term effect of this as a result of grass establishment would have left the trees stunted. Bv the end of April, when the trees were only 11 months old. those in the spraved strips were reckoned to be the equivalent of two-year-old planted stock. Having tried numerous other methods of establishment — cultivation, planting in a furrow and ripping — Mr Smail said that there was no doubt in his mind that use of a desiccant spray before planting was the most effective method of establishment. If a mechanical planter was not available, then ripping of the sprayed strip was recommended. The initial establishment of trees was most important, . being compounded

since been topdressed by hand at a rate equivalent to 4cwt of superphosphate, lewt of slow release nitrogene, 51b of copper per acre, and 0.2 grams of boron per tree. About two tons of the mixture has been sufficient to treat about 20,000 trees. The planting is dual-pur-pose, being both a woodlot and shelter. Seven paddocks open on to the area so that stock can move in during critical periods. A chain and a half margin has been left unplanted so that it will afford shelter from every direction. The trees will also be pruned so that stock can move down the rows.