Gilberto Luiz Putti

Temperaturas efetivas para a dormência da macieira(Malus domestica Borkh)

Apple tree cultivars demand several requirements in cold but theres a little of information about what temperatures are the most efficient. Apple tree cultivars Condesa, Baronesa, Daiane, Imperatriz, Fuji and Gala were studied on quantity of cold and different temperatures for shooting inducement. Experimental delineation was full casualized on the factorial system, with six cultivars, five levels of cold unities and three temperatures. Average time for shooting was minor when the cultivars were exposed to 1,500 cold unities independently of the temperature. Effective temperature in order to accumulate cold ranges according to the cultivar, and it is able reaching until 15oC in case of cultivar of lower demand in cold.

Efeito da intensidade do frio no tempo e percentagem de gemas brotadas em macieira

Apple tree demands periods of low temperatures (4oC to 10oC) during autumn and winter, otherwise the tree will keep under dormancy or will present an irregular shooting and blooming. Without low temperatures during autumn and winter, apple tree buds keep under dormancy during a longer period and present an irregular shooting and blooming. In order to measure the quantity of cold needed to subject the dormancy, it was used the method of number of cold unities according to the Modified Model of the North Carolina. In stakes with length from 20cm to 25cm, and in stakes of isolated knots, which received from zero to 530, 1,060 and 1,590 cold unities during the dormancy. Tried cultivars were Condensa, Baronesa, Daiane, Imperatriz, Gala and Fuji. Cultivars differed themselves on the number of days for the shooting of the buds, taking place the minor time for shooting when they were subjected to 1,590 cold unities, for all the cultivars, what showed that theres a tie between the average time of the shooting and the deepth of the dormancy. The percentage of shoot buds was also larger when the stakes were exposed to 1,590 cold unities, being Condensa the cultivar that showed the largest percentage of shooting, what confirms that it is really, among the studied cultivars, that of minor demand in cold.

Evolução do estado fisiológico da parte aérea do morangueiro durante a armazenagem em câmara frigorífica

The aim of this work was to know the physiological state of the aerial part of strawberry plants (varieties Gariguette and Elsanta) during storage in cold chamber (-2oC) from January until August. According to the biological test (petiole test), the growth capacity was kept up without significant evolution. The flow of metabolic heating (Q) and the respiratory intensity (RCO2) of the apical zone tissues measured at the exit of the cold chamber did not change significantly. Their values measured after 48 and 72 hours of acclimatization at 20oC were higher than at the exit of the cold chamber. The differences between the values without acclimatization and after acclimatization increased during the first weeks of storage, showing an evolution in the apex of the plant. There was a strict parallelism between the values of Q and RCO2 and of the tissues water contents (UP). The growth capacity of the aerial part of the plants seemed to keep up even after 8 months of storage.