Nutritional Status and Yield Efficiency of Navel and Valencia Orange Trees as Affected by Used Rootstocks
This study was carried out during 2007-2008 and 2008 – 2009 seasons on Navel and Valencia orange cultivars budded on Sour orange and Volkamer lemon rootstocks. Results indicated that, leaves of Valencia orange on Volkamer lemon rootstock recorded the highest N and Mg content, Naval orange on Volkamer lemon recorded the highest P content and Naval orange on Sour orange showed the highest K and Ca content. Navel orange significantly improved P and K content in roots of Volkamer lemon rootstock compared to Valencia orange on Sour orange rootstock. Valencia orange increased N, Ca and Mg content in roots Sour orange rootstock. Valencia orange significantly increased N and Ca content in Sour orange bark and P, K in Volkamer lemon bark. Navel orange enhanced Mg in Sour orange bark. Volkamer lemon rootstock was more effective in increasing N and K content in bark of both cultivars than Sour orange rootstock which significantly increased Ca and Mg in Valencia orange bark and P in Navel orange bark. Tree yield efficiency as weight was the highest for Valencia orange on Sour orange in the first season and Volkamer lemon in the second one. Meanwhile, tree yield efficiency as number of fruits was the highest for Navel orange on Volkamer lemon in the first season and Valencia orange on the same rootstock in the second one. Generally, Volkamer lemon rootstock was more effective in improving yield efficiency of both cultivars than Sour orange rootstock.