02463naa a2200169 a 450000100080000000500110000800800410001910000220006024500980008226000090018052019320018970000250212170000170214670000220216370000220218577300860220716519272004-04-16       1998    bl uuuu     u00u1 u    #d1 aSARMENTO, S. B. S  aGrowth rate, starch and fiber content in cassava store root as an indication harvesting time.  c1998  aAbstract: The final harvest of cassava store root may be established by the initiation time for the storage root formation and by the growth rate store root (SR). Both characteristic are determined by either genetic factors as well as environment and their interaction. The present study analyzed the variation among commercial clones used for industry by the means of the store root growth rate (SRGR) and by their capacity to convert structural and non-structural carbohydrate in the SR. Four commercial clones of divergent agronomic performance in the State of São Paulo were harvested monthly after the twelfth month of planting. Store root fresh weigh and dry weight, as well as dry matter, starch and fiber content were evaluated. The average SR weight was ranked higher for the clone Mico (847.2 gSR/plant) followed by Fibra (600 gSR/pant), Branca da Santa Catarina (407 gSR/plant) and lastly by IAC 12-829 (349.3 gSR/pant), while the number of SR (7.3 SR/plant) did not vary among  clones. The SRGR during the linear growth phase indicated values of 97, 53, 43 and 28 gSR/plant/month for clones Mico, Fibra, IAC 12-829 and Branca da Santa Catarina respectively. Store root dry matter content was also higher in clones Mico and Fibra than the others two clones. Two patterns of fiber and starch accumulation were observed during the experimental period. In the first one the fiber accumulation starch accumulation stays constant while starch accumulation remains increasing in a linear fashion for clones Mico and IAC 12-829. In the second pattern both fiber and starch accumulation rearch a plateu after the third harvest for the clones Fibra and Branca de Santa Catarina. The fiber:starch content ratio is proposed as a reference for the harvesting date after planting and the diversity of the genetic bakground of the different clones are discussed as factor controlling the precocious harvest of cassava store root.1 aCARVALHO, L. J. C. B1 aCEREDA, M. P1 aPENTEADO, M. V. C1 aPIEDADE, S. M. S.  tRevista Brasileira de Mandioca, Cruz das Almasgv.17, p.62, nov, 1998.Suplemento.