The campaign to eradicate the papaya fruit fly from north Queensland has been acknowledged by international scientists as a significant technical achievement. This is an account of the entire campaign since 1995 and also a practical "how-to" guide to combatting any future fruit fly pest incursion.

Growing cucumber fruit in a greenhouse at elevated temperatures during the day increased their tolerance to postharvest chilling. Fruit grown with an average day temperature of 32 +/- 1 degrees C (high temperature) had a storage life (i.e. time to loose 7% fresh weight) of 16 days at 10 degrees C and did not exhibit chilling injury, while fruit grown at 27 +/- 1 degrees C (control) developed symptoms of chilling injury (i.e. appearance of translucent, water-soaked areas in the mesocarp) after 12 days at 10 degrees C. The rate of fresh weight loss and the storage life (i.e. 7% water loss) of fruit from both treatments was 12 days when stored at 20 degrees C. Chilling-induced ion leakage from mesocarp disks was lower from high temperature grown fruit than from control fruit. During storage at 10 degrees, firmness, vitamin C content, and activity of superoxide dismutase (SOD; EC 1.15.1.1), and catalase (CAT; EC 1.11.1.6) were higher in high temperature grown fruit than in control fruit. Enhanced antioxidant enzyme activity in high temperature grown fruit may have contributed to increased chilling tolerance.

Genetic control of fruit shape in Cucumis melo was studied using QTL analysis in two Recombinant Inbred (RI) populations consisting of 163 and 63 individuals, respectively, obtained by crossing the same round-fruited parent with two different elongated-fruit lines. Fruit shape is mainly explained by fruit length in these two populations. Most QTLs for fruit shape and ovary shape detected were found to co-segregate, thus demonstrating early control of fruit shape during ovary development. A high level of correlation between fruit shape and ovary shape was also found in 14 unrelated genetic lines, a finding which suggests that control of fruit shape by gene(s) active early in the ovary is a general feature in C. melo. Two major flower genes, a (monoecious) and p (pentamerous), were shown to have major effectson fruit shape. Major tightly linked QTLs for fruit and ovary shape were found close to the a and p genes, probably reflecting their pleiotropic effect on fruit shape. Moreover, one of the two QTLs detected in the Védrantais x PI 414723 population wasals o found in the Védrantais x PI 161375 population. Variation of fruit shape in melon could be due to variations having quantitative effects on a large set of genes that are probably involved in ovary development. (Résumé d'auteur)

Cultivated tomato (Lycopersicon esculentum) encompass a wide range of fruit shape and size variants. This variation can be used to genetically dissect the molecular basis of ovary and fruit morphology. The cultivar Long John displays an extremely elongated fruit phenotype, while the wild relative Lycopersicon pimpinellifolium LA1589 produces fruit that are nearly perfect spheres, typical of wild tomatoes. Quantitative trait mapping of an F2 population between Long John and LA1589 revealed four fruit shape QTLs, located on chromosomes 2, 3, 7 and 11. The primary role of the fruit shape QTL located on chromosome 7, ljfs7, is to control pericarp elongation. The primary role of the fruit shape QTLs on chromosome 2, 3 and 11 (ljfs2, ljfs3 and ljfs11, respectively) is to control pear shape, measured as the eccentricity index. QTL map position and the effect of the loci on fruit shape suggested that ljfs2 and ljfs7 are allelic to the well-studied fruit shape loci ovate and sun, respectively. ljfs3 and ljfs11 map near the previously identified, but less characterized, fruit shape loci fs3.2 and fs11.1, respectively. This result suggests that most of the variation in tomato fruit shape is controlled by a few major QTLs. Although eccentricity and pericarp elongation were largely controlled by independent growth processes, significant interactions were detected between all four fruit shape loci in the control of eccentricity. This indicates that the three eccentricity loci, ljfs2, ljfs3 and ljfs11, epistatically control the same developmental process, while ljfs7 had a pleiotropic effect on eccentricity.

‘Springcrest' covers an important period in the regional peach season, but its good performance is not supplemented by a satisfactory fruit size. An experiment was carried out in order to evaluate the effects of different cultural practices on fruit quality, yield and crop distribution. The treatments consisted in the use; alone or combined, of flower thinning, conventional fruit thinning (Control), girdling and 2,4 diclorophenoxypropionic acid butilglycolic ester (2,4-DP). The evaluated variables were yield, fruit weight, percentage distribution of fruit size and for each harvest, skin color, overcolor percentage, total soluble solids content (TSS), flesh firmness and titratable acidity. Those treatments which included flower thinning affected yield negatively. Girdling appears as a factor that softens these effects. Only conventional fruit thinning did not increase the fruit percentage harvested the first time. A positive effect on fruit size was observed in all treatments in comparison to the control. The application of 2,4 DP did not harm the yield in comparison with the control but it affected acidity and TSS. No treatment affected the color of the fruits.

From 1994 to 1995 we [AMl] studied the effects of the light environment and pollen availability on fruit set and fruit maturation in the gynodioecious evergreen shrub Eurya japonica in a forest in central Japan dominated by Pinus densiflora and Quercus serrata. In E. japonica the number of immature fruits decreased dramatically immediately after the flowering period, and thereafter decreased gradually. In both 1994 and 1995, rates of fruit set on hand-pollinated branches were higher than those on control branches. Fruit set rates in open habitats did not differ significantly from those in the forest understory. Fruit set rates on control branches differed between 1994 and 1995. There were more seeds per fruit on hand-pollinated branches than on control branches. The reproductive investment in terms of the number of flower buds or fruits matured per unit length of branch was higher on branches in open habitats than in the forest understory. These data suggest that in E, japonica grown under canopies, the number of flower buds may be controlled by light intensity, while fruit set and the number of seeds per fruit may be controlled by the amount of pollen.

‘Climax’ rabbiteye blueberry (Vaccinium ashei Reade) with excessive fruit set often exhibits delayed vegetative bud emergence. A four year study was initiated to determine if spring fruit removal or pruning would enhance vegetative bud initiation and growth and if these one- time treatments would influence plant growth and fruiting characteristics over an extended period of time. Five methods of fruit removal/pruning were applied once in the spring of 1997. Removal was accomplished by 1) Cane removal, about 25% of plant density removed by cutting older canes from the base of the plant; 2) 25% Topping (T25), mechanical removal of approximately 25% of the plant top; 3) 50% Topping (T50); 4) Fruit removal, about 25% of green fruit removed; and 5) Control. By June 26, 1997, shoot number per stem and total shoot length had increased linearly with increased plant top removal. Plants with canes or fruit removed did not leaf out sooner or have vegetative growth greater than unpruned plants. In 1997, T50 plants produced one half the fruit yield of the control plants, while T25 plants showed no difference from the control plants in fruit yield. Plant top removal (either 25 or 50%) in the spring of 1997 resulted in increased vegetative coverage in 1998 and 1999. This influence was less in 1999 than in 1998. In 1998 floral bud development was delayed approximately 4-6 days in plants with either 25 or 50% of tops removed as compared to control plants. In that year, fruit yields were highest (approx. 2X control) in plants topped at 50%. Plants with 25% of their tops removed did not differ from control plants.. Regardless of treatments and resulting yields, berry size did not significantly differ in any year. Removing approximately 50% of the plant top resulted highest fruit yields of all treatments the second and third year after pruning. In 1998, and 99, ‘Climax’ plants were pruned on 3 dates (Mid-Feb, Mid-Mar, and Mid-April; 0 and 25% flower/fruit removal) to simulate late-freeze damage. One year after treatment, bud development and vegetative cover ratings were taken. Fruit yields were taken the year pruning treatment were applied and each succeeding year. Data taken in 1998, 1999, and 2000 shows no significant patters of vegetative growth, floral bud development, or fruit yields due to treatments. Data indicate vegetative growth in ‘Climax’ rabbiteye blueberries can be accelerated by removing about 25% of the plant top without reducing fruit yield.

Biological control of spider mites (Tetranychus urticae Koch and T. ludeni Zacher) in Australian field-grown strawberry crops using the predatory mite Phytoseiulus persimilis Athias-Henriot, has been practised commercially since 1984. Although adoption was slow in the early years, about 40% of growers now use the system. The adoption rate increased through the involvement of private consultants in pest monitoring and management. Growers have now embraced biological control of spider mites by implementing the pest in first (PIF) technique first proposed for the industry in 1984.