Journal Articles

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    Effects of Abiotic Stress Associated with Climate Change on Potato Yield and Tuber Quality Under a Multi-environment Trial in New Zealand
    (Springer Nature, 2024-03-06) Siano AB; Roskruge N; Kerckhoffs H; Sofkova-Bobcheva S
    In the 2018/19 growing season, a multi-environment trial in Opiki, Hastings, and Ohakune located in three different regions of the North Island of New Zealand was conducted to evaluate responses of selected potato cultivars to abiotic stress associated with climate change. Heat and drought stresses were evident with supra-optimal temperatures (> 25 °C) in Opiki and Hastings and sub-optimal rainfall (< 500 mm) in Opiki, which influenced the different morpho-physiological characteristics of the potato crop, ultimately affecting yield and tuber quality. These abiotic stresses also increased the incidence of malformation, growth cracks, and second growth in tubers reducing the total and marketable tuber yields by 43% and 45%, respectively. In addition, the genotype × environment analysis showed that Ohakune had the most favourable environmental conditions for potato production since all cultivars in this site had superior marketable tuber yields. ‘Taurus’ was the most stable and adaptable cultivar across trial sites (wide adaptation), whilst ‘Hermes’ and ‘Snowden’ were more adapted under Opiki and Hastings conditions (specific adaptation), respectively. As established in this study, heat and drought stresses have significant effects on the morpho-physiology, yield, and tuber quality of commercial potato cultivars in New Zealand.
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    Genetic variation in surface temperature measured using infra-red thermography and genetic associations with production traits in grazing dairy cattle
    (Taylor and Francis Group, 2024-01-01) Douie JS; Lopez-Villalobos N; Dukkipati VSR; Udy G
    Increasing global temperatures and the incidence of extreme weather conditions will result in heat stress becoming a greater issue in production animals. Genetic selection and breeding for heat-tolerant animals have been promoted as a possible mitigation strategy in dairy cattle. The objectives of this study were to obtain in-field skin temperature measurements of the eye, muzzle and udder using infra-red thermography to examine the genetic variation in skin temperature within cows of a dairy herd and to estimate the genetic correlations between skin temperature and production traits. Thermal images and herd test records were obtained for the dairy herd at Massey University’s dairy farm 1. Estimates of (co)variances were obtained using the JWAS program with univariate and bivariate animal models. The heritability estimates for the eye, muzzle and udder temperature were low to moderate at 0.20, 0.24 and 0.39, respectively. All genetic correlations between production and temperature traits were positive except for eye temperature with milk yield and protein yield which was negative and weak. These results indicate that it may be possible to select for a greater skin temperature, however, these results need to be validated using a larger sample size.