Evaluation of Some New Navel Orange Cultivars Budded on Sour Orange and Volkamer Lemon Rootstocks

AFIELD EXPERIMENT was carried out in a private orchard at ….. Wady El-Mollak, El-Sharqia Governorate, Egypt during two successive seasons (2012 and 2013) to evaluate flowering, fruit set, fruit drop, yield, fruit quality, mineral and total carbohydrates content of some newly introduced Navel orange cultivars (New Hall, Navelina, Navelate, Lane Late, Cara Cara, Spring, Fisher, Parent, Fukumoto and Leng). These cultivars were grafted on two commercial rootstocks “Sour orange” (Citrus aurantium L.) and “Volkamer lemon” (Citrus Volkameriana L.). The present experiment comprises ten scions and two rootstocks. The experiment was laid out in factorial experiment in a randomized complete block design.
Results showed that, the effect of cultivars namely, Navelate, Lane Late, New Hall and Navelina gave the highest values of fruit set and the lowest values of fruit drop. Whereas, New Hall gave the highest values of fruit weight and yield/tree followed by Navelina and Lane Late but New Hall gave large fruit size which not accepted in export and local market. Meanwhile, New Hall and Navelina cultivars gave the highest values of TSS, TSS/acid ratio and the lowest values of acidity. On the other hand,
 “Cara Cara” “Spring” and “Leng” gave significant lower values of N content than other Navel orange cultivar. Navelate and Lane Late gave the highest values of P, K and Ca. Regarding the effect of rootstocks, Volkamer Lemon rootstock gave the significant highest values of flowering, fruit set, fruit drop, yield parameters, peel thickness, macro and micronutrients content (N, P, K, Ca, Mg, Fe, Zn, and Mn) as compared with sour orange rootstock. On the other hand, Sour orange gave the significant highest values of juice volume, TSS, TSS/acid ratio. Volkamer Lemon gave lower values of total carbohydrates consequently gave lower values of C/N ratio than Sour orange rootstock. Regarding the combination between cultivars and rootstocks, Lane Late and New Hall cultivars on Volkamer Lemon gave the highest values of flowering, fruit set percentages and lower values of fruit drop as compared with other combinations. New Hall budded on both rootstocks gave the highest values of yield followed by Lane Late on Volkamer Lemon. The highest values of TSS, TSS/acid ratio were obtained when New Hall and Navelina budded on sour orange followed closely by the same cultivars on Volkamer Lemon rootstock and the trend was reversed for acidity. The highest values of N, P, Ca, Mg, Fe and Mn were obtained
when Lane Late budded on Volkamer Lemon rootstock. All Navel orange cultivars budded on Volkamer Lemon rootstock gave lower C/N ratio than budded on Sour orange rootstock. In spite of Volkamer Lemon rootstock gave higher values of yield/tree than sour orange but with low fruit quality especially for peel thickness, TSS and TSS/acid ratio. Finally it could be concluded that, New Hall gave the highest values of fruit weight and yield/tree followed by Navelina and Lane Late but New Hall especially on Volkamer Lemon gave large fruit size which not accepted in export and local market. So, it could be recommended by budded Navelina and Lane Late cultivars on Sour orange rootstock for suitable yield with high fruit quality.