Inadequate Chilling Research Articles

Hydrogen Cyanamide Induces Budbreak of Peaches and Nectarines Following Inadequate Chilling

Hydrogen cyanamide (Dormex) treatments were applied to 17 insufficiently chilled peach and nectarine cultivars ≈6 weeks after normal budbreak. Treatment effectively induced vegetative budbreak and reduced shoot dieback. The responses to Dormex treatments were linear, with the 2% rate being more effective than the 0 and 1% rates in most cases.

Effects of winter temperatures on flower development in two clones of kiwifruit ( Actinidia deliciosa (A. Chev.) C.F. Liang et A.R. Ferguson)

Winter temperature has a dramatic effect on flowering in kiwifruit. The clone ‘Hayward’ has a significantly higher chilling requirement than ‘Allison’. Flowering in both clones increased with increasing winter chilling. At Greytown, the coldest of three locations, where 872 h below 7.2°C (1354 Richardson units) were recorded, 400 ‘Allison’ and 154 ‘Hayward’ flowers were produced per 100 buds. At Kranskop, a climatically marginal location with 624 h below 7.2°C (959 Richardson units), 243 ‘Allison’ and 2 ‘Hayward’ flowers were produced per 100 buds. The warmest winter, with only 212 h below 7.2°C (222 Richardson units), was at Pietermaritzburg, where 35 ‘Allison’ flowers per 100 buds and no ‘Hayward’ flowrs were recorded. Increased chilling increased the reproductive budbreak percentage, the number of flowering nodes per flowering shoot and also the number of flowers per node. Seven stages were determined in the development of flower primordia. Stage III was reached in both cultivars in all three areas by autumn, but where inadequate chilling and high winter day temperatures occurred, further development was delayed during winter/spring and flower parts did not differentiate. Flower primordia that failed to differentiate, or aborted soon afterwards, ceased to function. Vegetative development from these positions, after the original buds had developed shoots on which each primordium became a bud, was from adventitious buds arising at the bases of the primordia. Where chilling requirements were satisfied, normal flower differentiation occurred in spring. Most flowers were formed around the fourth and fifth and fifth leaf primordia within ‘Allison’ and ‘Hayward’ buds, respectively.

Effect of hydrogen cyanamide on bud emergence in wine grapes

Hydrogen cynamide has been shown by other researchers to improve the amount and uniformity of budburst in grapevines in warm areas with inadequate chilling, such as California's Coachella Valley. A trial was conducted in 1985 to learn whether hydrogen cyanamide would also improve budburst in cooler areas, especially on cane-pruned vines of varieties that have budburst failure in the middle of the canes. The trial also included one Zinfandel vineyard to determine if the chemical would affect budburst on a spurpruned variety.

A survey of process hygiene in the Sri Lanka prawn industry.

AbstractA survey of process hygiene in the Sri Lanka prawn industry has shown that incoming raw materials had extremely high bacterial loadings, about 50% of samples analysed having total counts in excess of 107 g−1. Although deheading, washing and freezing reduced this loading, total bacterial counts on final products were often in the range 106‐107 g−1. Staphyloccocus aureus often exceeded 102 g−1 though most samples had levels of Escherichia coli of < 6 g−1. Of 262 personnel in export prawn plants in Sri Lanka, 137 (52%) were found to carry S. aureus on their fingers; between companies the prevalence of S. aureus ranged from 22–92%. Although five companies provided sanitiser hand‐dips this was found to be ineffective for the control of S. aureus. In addition, provision of hand‐washing facilities, protective clothing and toilet facilities was inadequate. Of the 15 export plants surveyed, only five were found to have a process which was adequately controlled. The most common process defects included inadequate chilling of prawns following the several washing stages, use of block ice to chill prawns, high prawn:ice ratios, and cross contamination between processed and raw products.

Vacuum-packaging of bovine edible offal

Edible offals are relatively perishable and may be frozen before leaving the abattoir, commanding a lower price on the wholesale market than fresh offals. Investigations are described in which a range of offals was vacuum-packaged in an effort to extend the shelf-life of the fresh material. Several visits to two abattoirs revealed that their offals after chilling were generally of rather poor microbiological quality, partly due to handling practices and, in one abattoir, to inadequate chilling. Reductions in the initial microbial load on hearts and tongues were achieved by immersion in water at 90°C, or with 100 ppm free chlorine or 1 % (v/v) lactic acid. However, these treatments offered no advantage over good production methods in extending the safe storage period in the vacuum-package. When offals produced under normal conditions were vacuum-packaged a storage period of 2–3 weeks at 1°C ± 1° was achieved which allowed a subsequent shelf-life of 3–4 days in air at 4°C. Offals produced with low initial numbers of contaminants gave the possibility of 1–2 weeks longer in the vacuum-package. A detailed investigation of the organisms growing on vacuum-packaged liver showed that a lactic flora developed during storage, but this did not inhibit potential spoilage organisms such as Pseudomonas or Alteromonas.