Dan G.,Fruit Storage Research Laboratory |
Dan G.,Migal Institute |
Dan G.,Tel-Hai Academic College |
Ruth B.-A.,Fruit Storage Research Laboratory |
And 2 more authors.
Scientia Horticulturae | Year: 2015
The changes in ripening parameters of 'Spadona' pears were monitored from 95 days after full bloom (DAFB) until the end of the harvest season in 2 orchards during 3 years, in an attempt to predict the timing of the pre-climacteric minimum (PCM), as a tool for determining the optimum harvest maturity for extended controlled atmosphere (CA) storage.A model based on the pre-harvest rates of changes of fruit weight, firmness, starch degradation and seed colour was found to predict the timing of the PCM with an accuracy of 24h of its occurrence (R2=0.9925). Changes in soluble solid content (SSC) and titratable acidity (TA) did not improve the model. Fruit quality assessed at removal from CA storage after 6 months, followed by 2 weeks of shelf-life at 20°C, verified that the optimal time for harvest of 'Spadona' pears was at the PCM. © 2015 Elsevier B.V. Source
Sharon R.,Migal Institute |
Sharon R.,Ohalo College |
Harari A.R.,Israel Agricultural Research Organization |
Zahavi T.,Extension Service |
And 7 more authors.
Plant Pathology | Year: 2015
A stolbur-type phytoplasma is the putative pathogen of grapevine yellows disease that causes economic damage to vineyards in most growing areas around the world. The pathogen is known to be transmitted to vines by two planthoppers, Hyalesthes obsoletus and Reptalus panzer; the latter is found in Europe but has not yet been observed in Israel. The establishment of a vector-pathogen-plant relationship requires that the pathogen and the vector meet on a shared host plant. This does not happen in the ecosystem examined here, where two different principal host plants for the obligate pathogen and its vector exist: the pathogen is established on vines, while its vector, H. obsoletus, develops on Vitex agnus-castus. The present study verified that: (i) the vector cannot complete its life cycle on vines; (ii) V. agnus-castus does not grow in the immediate vicinity of vines, and does not harbour the pathogen; and (iii) the pathogen is not vertically transmitted from mother to offspring. Moreover, in a thorough search of plants in vine growing areas, no other plants were found that host both the vector and the pathogen. However, it was found that the planthopper can acquire the phytoplasma from infected vines. Nonetheless, this does not prove the ability of the planthopper to further transmit the pathogen to vines and does not explain the presence of the vector on the non-preferred vines. Thus, the enigma of the pathogen-vector-host triangle in this system remains unresolved. © 2014 British Society for Plant Pathology. Source