The aim of onion bulb storage is to meet consumer demand for extended availability of onions whilst maintaining product quality. The principal biological factors leading to onion bulb deterioration are respiration, resumption of growth and pathogen attack. In onion bulbs a dormant period, when sprouting and rooting cannot be induced, is followe...d by a period of internal changes that prepare the bulb for breaking of dormancy and subsequent growth. Out of storage, the bulb then proceeds towards flowering and seed production. Two successive winter seasons of 2008/2009 and 2009/2010 were conducted under sandy soil conditions to study the effect of spraying with 12 commercial compounds on yield and yield components of onion seeds and storage The seed yield of each commercial compounds plot from previous experiment was divided into two groups, storage under room temperature and 5°C. Seeds transferred immediately after drying to Increasing Export Competition of Some Vegetable Crops Project Laboratory located in Faculty of Agriculture, Cairo University. The effects of storage temperature, storage period and foliar with some commercial compounds on onion seed quality were considered. Storage in 5°C had the higher germination percentage than storage in room temperature. Results indicated that as storage period increased the germination percent decreased. The treatment with boron or amica in the first season had the highest germination percentage. While, the treatment with union Zn, union feer, union Mn, boron, elga 600, caboron, amica, hummer or amino X had the highest germination percentage in the second season. Storage in 5°C resulted in higher moisture content than storage in room temperature. Regarding the effect of storage period on moisture content, the water content was significantly increased with prolongation of storage period. The lowest values of water content were recorded for treatments with union feer, shams K or boron in the first season, and union feer, shams K, boron, magnesium, shetocare or hummer in the second one. Catalase activity was significantly decreased as storage period increased. The treatment with shams K, boron, shetocare or amino X had the highest catalase activity in both seasons. Peroxidase activity was significantly decreased as storage period increased. Foliar application with boron had the highest peroxidase activity in both seasons. Seed stored in room temperature had the higher malondialdehyde content than those stored in 5°C in the second season. The malondialdehyde content increased as storage period increased. The treatment with magnesium, caboron and the control in the first season, and the treatment with magnesium and the control in the second season had the highest malondialdehyde content.
Vegetative propagation by hardwood cuttings is a very simple and cheap method for production of plum rootstocks. The aim of this study was to examine if this propagation technique is suitable for practice of three plum rootstocks and find the time or period when the percent of rooted cuttings is maximal. Based on our results, hardwood cuttings...of the rootstocks tested have the rooting potential acceptable for practice, however, for Fehér besztercei in the previous literature leafy cuttings are recommended. Fehér besztercei reached 74.0% rooting, cuttings of Sainte Julien GF 655/2 rooted in as high percentage as 78.3%, and Marianna GF 8-1 had 88.3% rooted cuttings. Rooting potential of hardwood cuttings depends on more factors, one of them can be their dissimilar sensitivity for the diverse environmental circumstances at the different propagating dates, affecting through the internal biochemical changes that can be in relation with the differences in their dormancy.
The cuttings of Marianna GF 8-1 take root easily, but in some years the conditions were less favourable for reaching maximal rooting. For taking cuttings the period from the beginning of October until December was optimal. For Fehér besztercei the optimal date of cutting collection was around the end of October, but in some years the rooting in the middle of December was also high. Sainte Julien GF 655/2 definitely rooted best in October. The treatments with different IBA concentrations in two years affected differently the rooting percentage. The rooting of Marianna GF 8-1 and Sainte Julien GF 655/2 is barely influenced by the different hormone dose in both years. Hardwood cuttings of Fehér besztercei rooted definitely better when treated with 2000 ppm IBA in comparison to untreated ones, while in 2001-2002 there was no difference between 2000 and 4000 ppm.