Correlation Between Nut Traits and the Early Development of Pecan Rootstocks

Pecan (Carya illinoinensis [Wangenh.] K. Koch) is a species native to the United States and Mexico, commercially cultivated in several countries, including southern Brazil. Commercial production of seedlings in Brazil occurs exclusively through grafting the cultivars of interest onto rootstocks obtained from seeds. Despite the great diversity of pecan trees in the country, there are no records of which genotypes are most suitable for producing rootstocks. Thus, this study aimed to evaluate the biometric diversity of nuts from 40 genotypes and their relationship with the growth and development of seedlings intended for rootstocks. The genotypes analyzed came from the state of Rio Grande do Sul and were considered based on the morphological characteristics of the nuts. After biometric evaluation and stratification, the nuts were sown in a nursery. Seedling emergence was monitored weekly until the 11th week, and seedling height and stem diameter were measured at 16 months. Principal component analysis grouped the genotypes into three groups, highlighting 16 with superior characteristics. However, the results indicated that the biometric characteristics of the nuts are not related to the growth and development of seedlings in the nursery. Therefore, the selection of rootstocks should not be based exclusively on biometric attributes of nuts, but rather on characteristics intrinsic to the genetics of individuals, which should be evaluated individually.