EFFECT OF ROOTSTOCK ON GROWTH AND PRODUCTIVITY OF SOME GRAPE CULTIVARS

Abstract

This work was devided into three separate experiments.The first experiment was designed to evaluate some grapevine cultivars grafted on different root stocks comparing with the own rooted cultivarsto resistanceof root-knot nematodeMeloidogyne incognita under green house condition at National Research Center, Giza, Doki. The obtained results revealed that Flame cultivar was highly susceptible to the infestation with M. icognita than other cultivars.On the other hand the rootstocks of Saltcreek and Freedom were extremely highly resistance than the own rooted cultivars. M. incognita infestation caused a significant reduction in growth of the own rooted grapevine cultivars Flame, Early sweet, Red Glob and Superior comparing with grafted ones on the nematode resistant rootstocks, Salt creek and Freedom. The fiber fraction (ADL, Hemicellulose and Cellulose) recorded the highest percentage in cultivars grafted on Salt creek and Freedom rootstocks comparing with the own rooted ones. Proline and free amino acid were extremely higher in the own rooted cultivars than the rootstocks ones. Under field condition,grape vine varieties grafted on Salt creek and Freedom produced the highest average yield with nematode infestation, in the opposite own rooted ones produced the lowest average yield with nematode infestation.The second experimentwas designedas a pot culture experimentto examine the tolerance of different cultivars under study to salinity as affect by different rootstocks.Different levels of salinity of irrigationwater (1000, 2000 and3000 ppm) were used. Results showed that vine growth properties (vine length, inter-node length and number of leaves per vine) were significantly decreased with the increase of salinity levels among all vines. At the highest salinity level (3000 ppm), the survival vine percentage was zero% for own rooted vines, except, the own rooted Flame seedlessthat recorded 50 percent of vine survival. Among the scion-rootstock vines, about 70-80% vine survival was observed with the vinesgrafted on Salt creek and 60-65% in vines grafted on Freedom rootstock. Increasing salt concentration significantly reduced the N, P and K contents in the leaf petioles. On the contrary, leaf proline, Na and Ca content were increased with increasing the salinity level. Based on the gained results, all cultivars grafted on Salt creek rootstock were more tolerant to irrigation with the studied salinity treatments. The third experiment was carried out during three seasons (2011- 2013) on Flame seedless, Superior seedless and Early sweet cultivars grafted onto Salt Creek, Freedom and Harmony rootstocks, while Thompson seedless cultivar grafted only onto Salt Creekand Harmony rootstocks.In addition, the same cultivars were grown on own rootsand served as control. Results revealed that leaf chlorophyll a and b (mg/gm fresh wt), Leaf Nitrogen, Phosphorus and Potassium content (%) were significantly increased in grafted vines onto all the three rootstock compared with ungrafted vines. Yield (kg)/vine, cluster weight (gm), length and width of cluster (cm) of Flame seedless, Superior seedless and Early sweet cultivars were markedly increased in grafted vines compared with ungrafted ones. Superior seedless and Early sweet cultivars grafted onto Harmony rootstock resulted in a significant higher values in berry weight (gm), berry size (cm3), length/ diameter ratio of berry and Juice volume of 100 berry (cm3) compared with other rootstocks and grown on own rooted. On the other hand Flame seedless cultivar grafted onto Freedom rootstock gave the best results. Chemical berry characteristic including SSC percentage, low acidity and high SSC/acid ratio were generally noticed when Flame seedless cultivar grafted onto Harmony rootstock and Superior seedless grafted onto Salt Creek rootstock. Early sweet cultivar grafted onto Harmony followed the similar trend except for juice acidity which recorded high percentage values compared with other grafted rootstocks. Flame seedless and Early sweet cultivars recorded higher fruiting bud percentage when grafted onto Harmony rootstock compared with other rootstocks and own rooted ones. Meanwhile, highest bud burst percentage and fruiting bud percentage of Superior seedless cultivar was obtained when grafted onto Salt creek rootstock. The own rooted Thompson seedless vinesresulted in a significant higher values of yield, cluster weight, some physical properties of berries. Chemical berry characteristic including SSC percentage, low acidity and high SSC/acid ratio were generally noted withown rooted vines of Thompson seedless. Thompson seedless cultivar recorded higher fruiting bud percentage withungrafted vines compared with the other rootstocks. Meanwhile, highest bud burst percentage was obtained when Thompson seedless cultivargrafted onto Salt creek rootstock. Generally, yield, cluster and berry characteristics of grafted vines i.e. Flame seedless, Superior seedless and Early sweet cultivars on Salt creek, Freedom and Harmony rootstocks were better when compared with own rooted vines. On the other hand, yield, cluster and berry characteristics of own rooted vines of Thompson seedless were best when compared with vines grafted onto rootstocks under this study.

Key word:Grapevine,vitis vinifera,Rootstock, Nematode resistance,M. incognta, Salinity tolerance, Growth properties, Yield, Fruit quality, Nutrient content,