Distribution of Swiss needle cast in New Zealand in relation to winter temperature

Abstract

Abstract. Phaeocryptopus gaeumannii, the causal agent of Swiss needle cast disease, is widely distributed throughout New Zealand, where the disease may cause significant growth losses in Douglas-fir (Pseudotsuga menziesii) plantations. In western Oregon, where the pathogen is native, pathogen abundance and disease severity are correlated with mean daily winter temperatures and spring moisture, enabling the development of climate-based disease prediction models. The distribution of P. gaeumannii and severity of Swiss needle cast was surveyed in 16 Douglas-fir plantations throughout New Zealand in 2005. Retention of foliage was assessed in the field and samples of 1-and 2-year-old needles were collected for assessment of P. gaeumannii abundance. Foliage retention and abundance of P. gaeumannii varied across sites. Less colonisation by P. gaeumannii and greater needle retention was found in the South Island. Abundance of P. gaeumannii was found to be positively correlated with August minimum temperature and June average temperature, and showed a similar relationship to winter temperature as observed in western Oregon. These data will be used to derive a disease prediction model for Swiss needle cast in New Zealand that can be used to guide further research and provide short-and long-term disease risk predictions and cost/benefit analyses.

Phaeocryptopus gaeumannii, patógeno causante del “swiss needle cast” en Pseudotsuga menziesii: antecedentes de su biología, medidas de control y situación en Chile

“…en zonas donde se desarrolla naturalmente P. menziesii, las tempe raturas de inviernos pueden alcanzar -18 °C, y el aumento de las temperaturas hacia la primavera es lenta y gradual. Esta condición podría estar afectando la maduración de los pseudotecios y podría explicar la diferencia de liberación anticipada de ascosporas en Nueva Zelanda, que presenta un clima templado con influencia marina (Ford y Morton 1971, Stone et al 2007). …”

“…En plantaciones forestales jóvenes y adultas de P. menziesii, se han utilizado productos con ingredientes activos como el clorotalonil, carbendazima y cobre, aplicando de forma aérea y reduciendo la infección entre un 55 y 93 % (Hood y Van der Pas 1979. Estos resultados demuestran un control eficaz de P. gaeumannii; sin embargo, la aplicación prolongada de químicos en el tiempo y lo extenso de las superficies re sulta económicamente inviable, y ambientalmente podrían traer consecuencias nocivas para el ecosistema natural (Hansen y Lewis 2003, Stone et al 2007). …”

Assessments of Population Structure, Diversity, and Phylogeography of the Swiss Needle Cast Fungus (Phaeocryptopus gaeumannii) in the U.S. Pacific Northwest

“…In this case, climate (i.e., temperature and precipitation gradients) may be an important factor influencing the different distribution patterns of the two lineages across the landscape. There is strong evidence that climatic variables such as winter temperature and precipitation in the spring and early summer influence the abundance of P. gaeumannii, and thus disease [22][23][24][25][26]. The western Oregon Coast Range is particularly suited to support abundant populations of P. gaeumannii because it receives greater spring precipitation, and has generally milder winter, and cooler summer, temperatures than the rest of the region.…”

Developing breeding and deployment options for Douglas-fir in New Zealand: breeding for future forest conditions

“…Douglas-fir in New Zealand can be badly affected by Swiss needle cast (SNC) (HOOD et al, 1990;KNOWLES et al, 2001). This foliage disease, caused by Phaeocryptopus gaeumannii (Rohde) Petrak, is widely distributed in New Zealand plantations, and both pathogen abundance and disease severity have been shown to be associated with mild mean daily winter temperatures (August minimum and June average) and spring moisture (STONE et al, 2007). Swiss needle cast has serious implications for the New Zealand Douglas-fir breeding population, for example, the need for selection of resistant genotypes for the North Island, and the consideration of separate selections for the South Island, in areas where the disease is not as prevalent.…”