%0 Journal Article
%T Sunspots Are Correlated With Foliar Ph in Grapevines - Sunspots Are Correlated With Foliar Ph in Grapevines - Open Access Pub
%A Alberto Cugnetto
%A Giorgio Masoero
%A Giuseppe Sarasso
%A Giusto Giovannetti
%A Marco Nuti
%J OAP | Home | Journal of Agronomy Research | Open Access Pub
%D 2018
%X Foliar pH is a specific multifaceted parameter that is sensitive to a deficit in soil water and to temperature variations. It also represents a tool that can be used to rapidly phenotype the symbiosis induced in several crops by bio-fertilizers containing Arbuscular Mycorrhizal Fungi. Yearly decreases in foliar pH, which dropped from 3.73 in 2015 to 3.15 in 2017 and then stabilized at around 3.13, have been observed in an experimental vineyard near Torino (Italy) in six grapevine cultivars. In this paper, these curious, original results have been paired with the average sunspots of the 24th sun cycle, proximal to its endpoint. The paired values were highly correlated (r 0.95 P< 0.01), with close parabolic patterns. A lowering in foliar pH has been correlated with a modification of the leaf composition, as characterized by the higher hydration and reinforced wall. An increase in the circulating acidity of the plants has been hypothesized to interfere in a diminution in the general predisposition to block parasite attacks. From this perspective, the retrieval of several historic outbreaks and the long-term systematic monitoring of mud and Erwinia amylovora frequencies have suggested that the hypothesis that links the solar minima with dysfunctions of the plant-pest relationships cannot always be rejected. Cosmic influences pertaining to UV variations are poorly understood in plant physiopathology. Foliar pH appears to be a rapid and simple tool to unveil high-level mechanisms. It is this simple parameter that physiologists and geneticists, but also agronomists, are asked to consider. DOI10.14302/issn.2639-3166.jar-19-3116 The monthly average of the sunspot (S) numbers oscillates around a cycle, called the ¡°solar cycle¡±, which was decoded in 1843 by Heinrich Schwabe. Sunspots arise quickly and fall more slowly over an irregular cycle that lasts about 11 years. These cycles have been numbered since 1750. Currently, the 24th cycle is unfolding, from the minimum (1 S) in December 2008, passing through the cyclic maximum, which occurred in February 2014 (146.1 S), towards the next minimum which will possibly occur around 2020, since a value of zero was measured in November 2019. In 1801, Herschel 1 called attention to an apparent relationship between sunspot activity and the price of wheat, a parameter that was considered as a gold standard for economists. The theory was then invalidated after Love¡¯s 2 (2013) overall mathematical recalculation. However, Gorbanev 3(2015) revisited evidence on the influence of solar activity on the economy, and examined whether
%U https://www.openaccesspub.org/jar/article/1227