No-rust poplars issued

Taupo Times, Volume 23, Issue 50, 25 June 1974, Page 8

No-rust poplars issued

The free issue to catchment authorities of the rust-resistant poplar species "flevo" has been authorised by the Soil Conservation and Rivers Control Council. Last year the council recommended the removal of large quantities of poplar trees susceptible to the American and European rust diseases spreading throughout the country. The rusts have caused significant delays in catchment authority programmes _ for planting poplars, which are extensively used for soil conservation work. iJt A full season of exposure - to the rust has made it clear that certain types of widely-used poplar can no longer be effectively cultivated and their use is being phased out. The effects of the rust on shelter belts is of great concern to orchardists and nurserymen who depend on such trees for crop protection. Spraying has had some benefits but it is likely that shelter belts planted with rust-prone trees will be progressively replaced as disease conditions become more firmly established. r * As public awareness of the poplar rust increases, many samples from othor trees have been sent to the Ministry of Works and Development's plant materials centre in Palmerston North. This draws attention to the fact that there are other types of rust in New Zealand, which have been around for some years, arid willow rust, for example, is not the new disease that was introduced to the country last year. Only poplars are attaclted by the poplar rust. Over the years mo^t catchment authorities have established large "stool bed" nurseries for soil conservation use. The most comrnon poplar clones appear to be seriously affected by the rusts and the soil council is anxious for these to be . replaced as soon ^s possible. Although the "flevo" . variety has not been widaly tested under New Zealand conditions,' its immediate release is based on definite resistance to both American and European rusts, and the knowledge that full testing could take up to five years. In addition to the free issue of "flevo", the Soil Conservation Council will approve individual grants to catchment authorities for the removal and disposal of rejected poplar stools, including shelter belts, and for the cultivation and replanting with resistant clones of the cleared areas. Certain other authorities (such as Government d£--partments) with suitable nurseries will be considered on the same basis. wThe nursery trade will be* supplied next year as stocks become more widely available.