Fig 5 - uploaded by Anderson Carlos Marafon
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Average stage of floral bud development of ‘Abate Fetel’ ( Pyrus communis ) in Pelotas during the growth period in 2007.
Source publication
The flower formation in fruit trees is in the spring but actually begins in the previous summer. Flowers are induced in the apex of the buds, which were vegetative previously. After flower induction, which is still an unknown process, successive steps of physiological processes occur and morphological differentiation, when the apex becomes organize...
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The commercial exploration of the pear culture in Brazil has little expression, due to the low productivity of the plants, being the internal consumption supplied by imports. The lack of adaptation and flower bud abortion (bud jump or floral bud drop), are the main problems for the development of the crop. The aim of this work was to evaluate the o...
Citations
The results in the present paper are part of the scientific research project 'Autochtonous genetic resources of pears in the Republic of Macedonia'. Flower bud differentiation was examined in five traditional pear varieties ('Carigradsko Avche', 'Letna Kajkushka', 'Vodenka', 'Zimska Kajkushka' and 'Zimnica') in the region of Skopje. In the region of Skopje, the differentiation of mixed flower buds in the traditional pear varieties starts in summer. The primordia of calyx and corolla are formed in the period from the second half of October to early November. In midNovember, stamen primordia are formed, while in late November the primordia of carpels are formed. In winter months, the archesporial tissue develops and microsporogenesis occurs. In the period from January to March, microgametogenesis and pollen grain development take place. The earliest differentiation of flower buds (approximately 7-10 days) and the earliest blooming (about 3-4 days) are tipical of the variety 'Carigradsko Avche', compared to the latest varieties 'Zimska Kajkushka' and 'Zimnica'.
Pear is among the fruits of major commercial interest in the world and one of the most imported in Brazil. Brazilian production is very small and the fruit quality is low, due to production problems. The success of culture in the country, among other factors, may be linked to the choice of cultivars, pollinating and rootstocks better adapted to local conditions, and thus depend on the particulars of an agricultural zoning. The aim of this study was to identify, in southern Brazil, homogeneous climatic zones with potential for growing of European and Asian pears, through climate risk studies. The regions were defined by the seasonal availability of chilling hours (<7.2 °C) accumulated during the period from May to September and the monthly risk of drought. The analysis allowed the recognition of four homogeneous areas for the production of pears in southern Brazil.
Flowering is a complex process which starts with the induction and development of the flower buds. For azalea (Rhododendron simsii hybrids), flower induction was hastened by the application of chlormequat and took place within 11 days after treatment. Subsequent flower bud differentiation was not altered by the application rate of the plant growth regulators (PGR) chlormequat and paclobutrazol, nor by temperature or light sum. There were however, large genotypic variations in flower bud differentiation rate. For all cultivars a linear phase until flower primordia were fully differentiated and the style started to enlarge (flower bud stage 7), was followed by a slower final development (to stage 8). The linear phase was fastest for the semi-early flowering cultivars (textquoteleftMont Blanctextquoteright, textquoteleftM. Marietextquoteright and textquoteleftOttotextquoteright), requiring only 46 or 48 days to reach flower bud stage 7 after the first PGR treatment. Two late flowering cultivars (textquoteleftTheslatextquoteright and textquoteleftSachsensterntextquoteright) had the slowest differentiation, requiring 64 days to reach stage 7. The early flowering cultivars (textquoteleftH. Vogeltextquoteright sports) and two late flowering cultivars (textquoteleftMw. G. Kinttextquoteright and textquoteleftTamiratextquoteright) required 54 and 52 days, respectively, after the first PGR treatment to reach stage 7. To reach flower bud stage 8, a similar trend in velocity was seen, the semi-early flowering cultivars requiring the least amount of days (17 to 18 days), the late flowering cultivars textquoteleftTheslatextquoteright and textquoteleftSachsensterntextquoteright requiring the highest amount of days (24) and the early flowering cultivars and the late flowering cultivars textquoteleftMw. G. Kinttextquoteright and textquoteleftTamiratextquoteright requiring an intermediate number of days (20 to 22 days).
