Phenology and Principal Economic Characteristics of Indigenous Superior Walnut Cultivars in Baoshan Municipality

A study was carried out to observe the phenology, to survey the principal economic characteristics as well as to determine the chemical contents of 8 superior indigenous walnut cultivars distributed in Baoshan Municipality from 2007 to 2009 in order to conserve and rationally utilize the local superior walnut cultivar resource and to meet the demand of superior cultivar diversity for industrialization of walnut production. The results showed that Tengchong and Songshan walnut cultivars were periodical homogeneity of female and male flowers, while the other cultivars were male priority. The fruit development duration for the 8 cultivars was quite different, it took 210 days for ‘Minguangzi’ fruits to get mature, whereas 120 days for ‘Tengchong’ fruits to ripen, and it took 160-180 days for the fruit development of the other cultivars. There was extremely significant difference (p<001) in nut yield per unit canopy area, which varied from 2101g/m2 to 353g/m2 among the 8 cultivars. The individual nut of the cultivars weighed between 90g to 207g. The walnut shell thinness differed from 04mm to 10mm, and the nut ratio changed from 540% to 679%. The gross fat content was between 64195% and 74266%, the gross protein content varied from 11091% to 15949%, the content of unsaturated fat acid changed from 9383% to 9651%, P from 0217% to 0425%, Fe from 2186mg/kg to 2888mg/kg, Zn content changed between 398-676mg/kg. Apart from the above nutrients, walnut also contained other 7 kinds of amino acid essential to human beings.