The effect of regulated de®cit irrigation (RDI) on fruit growth was studied for pear trees (Pyrus communis L. `Barlett') grown in 120 l isolated containers. Two irrigation treatments were applied in consecutive seasons (1996 and 1997) but on different trees each year. The Control treatment was watered to non-stress conditions using stem water potential (Cstem) and Penman ETo as a guide for the ...

Pear (Pyrus pyrifolia L.) has an S-RNase-based gametophytic self-incompatibility (SI) mechanism, and S-RNase has also been implicated in the rejection of self-pollen and genetically identical pollen. However, RNA degradation might be only the beginning of the SI response, not the end. Recent in vitro studies suggest that S-RNase triggers mitochondrial alteration and DNA degradation in the incom...

Inorganic copper is used as a broad-spectrum fungicide and bacteriocide on a variety of agricultural crops. After application, the copper residue typically accumulates in the upper 15 cm of soil. Data from the California Pesticide Use Reports were used to estimate the augmentation of copper in the soil that resulted from pesticide applications for the six years from 1993 to 1998 on 12 crops tha...

The influence of scoring during the flower induction phase was investigated. Pear trees, Pyrus communis L. cv. Doyenne du Comice, Forelle and Rosemarie were used in the study, conducted in the Western Cape, South Africa. The yield of ‘Doyenne du Comice’ increased by 38% in scored trees compared to the control. The increase in yield was due to 50% more fruits on the scored trees than on the cont...

In order to investigate the physiological role of ethylene in the initiation and subsequent progression of softening, pear fruit were treated with propylene, an analogue of ethylene or 1-methylcyclopropene (1-MCP), a gaseous inhibitor of ethylene action at the preclimacteric or ripening stages. The propylene treatment at the pre-ripe stage stimulated ethylene production and flesh softening whil...

Fingerprinting information can be used to elucidate in a robust manner the genetic structure of germplasm collections, allowing a more rational and fine assessment of genetic resources. Bayesian model-based approaches are nowadays majorly preferred to infer genetic structure, but it is still largely unresolved how marker sets should be built in order to obtain a robust inference. The objective ...