Evaluation of key meteorological determinants of wintering and flowering patterns of five rubber clones in Xishuangbanna, Yunnan, China

Abstract

All rubber tree clones (Hevea brasiliensis) exhibit regular annual wintering characterized by senescence and abscission of leaves. After 3-4 weeks, this is followed by the onset of new leaves. It is likely that the timing of leaf onset affects the susceptibility of rubber trees to rubber powdery mildew disease, as this predominantly infests young leaves. However, little information is available on the phenological behavior of different rubber clones, or how meteorological factors affect such behavior. We assessed the wintering and flowering patterns of five rubber clones in Xishuangbanna, southwest China, based on observations made from 1978 to 2011, and evaluated how these patterns responded to different meteorological factors. Partial least squares regression was used to analyze the timing of defoliation, refoliation, and flowering. Our results showed that the two clones RRIM 600 and GT1 defoliated during the last week of December and refoliated in the last week of January, and clones Yunyan 277-5, Yunyan 34-4, and PR 107 defoliated during the first week of January and refoliated in the second week of February. The number of hours of sunshine during both the rainy season and the cold dry period in the dry season were important determinants of phenological changes in the rubber trees. Similarly, higher temperatures tended to delay the onset of defoliation and refoliation, and were a triggering factor for the onset of flowering. These results may help rubber cultivators to schedule appropriate disease control measures, as well as to design hybridization programs aiming at the production of clones which are resistant to foliar disease.

The powdery mildew disease of rubber (Oidium heveae) mainly controlled by the winter temperature in the Xishuangbanna, China

“…The highly joint and undisentangled effects of temperature variables and duration of leaf maturation indicated that the powdery mildew infection is strongly influenced by both extrinsic and intrinsic factors, as that found for oak trees which are highly affected by the winter temperature and phenology (Marcais and Desprez-Loustau, 2014;Marcais et al, 2017). The study on rubber trees showed the infection of powdery mildew varied with rubber clones (Fang et al, 2013;Liyanage et al, 2019), and the species dependence of oak trees to the infection of powdery mildew was also detected (Marcais and Desprez-Loustau, 2014;Marcais et al, 2017). We assumed that the response variations between rubber clones might relate to rubber phenologies (both defoliation and refoliation phenologies), with different sensitivity to winter temperature (Fig.…”

Global Assessment of Climate-Driven Susceptibility to South American Leaf Blight of Rubber Using Emerging Hot Spot Analysis and Gridded Historical Daily Data

“…As an alternative, metadata gathered from studies that report both refoliation dates and the corresponding geographical coordinates from different locations should serve as an alternative for producing a time map for refoliation. The existing literature which report both refoliation dates and coordinates [58][59][60][61][62][63][64][65][66][67] are not abundant enough and the indicated refoliation dates are often formulated in too much a loose range to be applicable to our purpose. As a result, the map which summarizes the situation over the refoliation period (Figure 2b) inevitably suffers from overgeneralization of the time frame.…”

Foreword for IJB Special Issue on Asian Biometeorology

“…The further two phenological papers were for studies of subtropical evergreen broad-leaved forest phenological changes, which posed great challenges for people in the past few decades (Morellato et al 2013), from Prof. Jianchu Xu's group. Zhai et al (2017) brought a fresh viewpoint telling minimum temperature in December was found to be the critical factor for the leaf phenology development of rubber trees, and Liyanage et al (2018) investigated wintering and flowering patterns of five rubber clones in Xishuangbanna, southwest China, based on observations made from 1978 to 2011, and found the number of hours of sunshine during both the rainy season and the cold dry period in the dry season were important determinants of phenological changes in the rubber trees; besides, higher temperatures tended to delay the onset of defoliation and refoliation and were the triggering factors for the onset of flowering. Their conclusions further improved our understanding of the phenological changes of subtropical plants and helped the development of predictive models that could be applied to early warning systems of rubber powdery mildew disease.…”