Influence of climatic factors on productivity of 'Williams' pear trees on different rootstocks

R. Zoppolo, P. Rodríguez, A. Uberti, A.S. Santana, A. Coniberti, D. Cabrera
Pear (Pyrus communis) is reasonably well-adapted to the average climatic conditions of southern Uruguay, but the climatic variables are not always agreeable for satisfactory production. The objective of this research was to evaluate the impact of climatic factors, on yield components (average fruit weight and productivity) of ‘Williams’ pears on two different rootstocks (‘OH×F40’ and ‘BA29’). The experiment was established in July 2003 at Instituto Nacional de Investigación Agropecuaria - INIA Las Brujas (34°67’S; 56°37’W). According to Köppen-Geiger classification, the climate of the studied region is ‘Cfa’ and the soil type is a Typic Argiudoll. To analyze the contribution of climatic factors on productivity of pear trees, a principal component analysis (PCA) was applied using the statistical software R. The correlations between yield components and precipitation, cold units, chill hours (≤7.2°C), relative humidity, evapotranspiration and average temperature were studied from the growing season 2014/15 until 2017/18. Climatic data were collected from the meteorological station at INIA Las Brujas, located less than 500 m from the trial plot. Climatic factors had a more significant effect on ‘Williams’ productivity than the rootstock factor. One main factor affecting seasonal productivity was chill hours. The average productivity values for the two rootstocks during the cycles 2015/16 and 2017/18 was zero and 7.2 t ha‑1, respectively. During the seasons where chilling was not the limiting factor (>500 chill hours), productivity was significantly higher (25.3 and 42.8 t ha‑1 on average for 2014/15 and 2016/17 seasons, respectively). Precipitation during fruit growth and flower induction and differentiation was another main factor affecting productivity in the current and next season. Even though cumulative yield was significantly higher in OH×F40 compared to BA29 (85.9 vs. 64.8 t ha‑1, respectively) no consistent differences were detected between rootstocks seasonally.
Zoppolo, R., Rodríguez, P., Uberti, A., Santana, A.S., Coniberti, A. and Cabrera, D. (2021). Influence of climatic factors on productivity of 'Williams' pear trees on different rootstocks. Acta Hortic. 1303, 251-258
DOI: 10.17660/ActaHortic.2021.1303.36
Pyrus communis, PCA, principal components analysis, alternate bearing, precipitation

Acta Horticulturae