الفهرس 
ENHANCEMENT OF ORCHARD PERFORMANCE FOR “COSTATA” PERSIMMON SEEDLINGS BY GROWTH REGULATORSOnly 14 pages are availabe for public view
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Abstract
The present investigation was conducted during the 2018 and 2019 growing seasons on
one-year-old “Costata” persimmon grafted on “Seedy” and “Tarabouls” rootstocks grown ElTarh region, El-Behera Governorate. Fifty seedlings (25 on “Seedy” and 25 on “Tarabouls”
rootstocks) were selected as uniform as possible to study the effect IBA or k-NAA dipping at
3000 mg l-1 for 5 seconds or soaking at 500 mg l-1 for 24 hours on enhancement the orchard
performance. The seedlings were treated in February of both growing seasons then planted. After planting, the seedlings were treated with the same horticultural practices as on the orchard.
The experimental design was as split plot, the rootstocks being the main plot and the chemical treatments are the subplot (2 rootstocks × 5 treatments × 5 replicates = 50 seedlings).
The obtained data could be summarized as follows: Regarding the main effect of K-NAA and IBA, the obtained results showed a significant
increase in vegetative growth, root biomass and leaf chlorophyll and mineral content of the “Costata” seedlings by all K-NAA and IBA applications as compared with the water in both
seasons, except the IBA dipping treatment did not significantly differ between them in the leaf nitrogen and potassium ‘in the first season’ and iron content ‘in the second season’. The highest values of sprouting buds’ percent‘ during April, June and August’, average shoots number, trunk
cross-sectional area and canopy volume were recorded with the K-NAA soaking at 500 mg l-1for 24 h. K-NAA either dipping or soaking and IBA dipping gave the same results. The results of both seasons indicated that, the K-NAA soaking or dipping applications recorded the highest values of average shoot length and length increment percent, stem diameter increment percent and the survival percent. Furthermore, the IBA soaking gave the 100% survival percent in the first season only. During both seasons the K-NAA and IBA dipping and K-NAA soaking applications, increased leaf area. Additionally, the K-NAA soaking at 500 mg l-1 for 24 h gave the highest significant values of root biomass in the first season. The highest value of the leaf chlorophyll content was recorded with K-NAA and IBA soaking in the first season. K-NAA soaking at 500 mg l-1
for 24 h gave the highest values of leaf N, P, K, Fe, Mn and Zn of “Costata”
seedlings in both seasons.
As for the main effect of rootstocks, regardless of the applications, as for the main effect
of rootstocks, regardless of the applications, the obtained results showed that the persimmon
seedlings on “Seedy” rootstock surpassed “Tarabouls” rootstock in all vegetative growth
parameters and root biomass. While, the seedlings on “Tarabouls” rootstock superior seedy
rootstocks in their leaf nitrogen, phosphorus, manganese and zinc content.
With regard to the interaction effect between auxin applications and rootstock, the
obtained results of both seasons indicated that the seedlings on “Seedy” rootstock, have the
highest values of sprouting buds percent “in April, June and August” average shoots number, and
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leaf area and canopy volume when soaking in K-NAA at 500 mg l-1
for 24 h. Whereas, in the
second season, the K-NAA dipping for 5s at 3000 mg l-1
gave the highest bud sprouting percent
in April only. The highest values of average shoot length and length increment and stem diameter
increment were obtained when soaking in K-NAA treatments in the first season. While, in the
second season these values were obtained with K-NAA dipping only. The K-NAA soaking and
IBA dipping gave in the highest cross-sectional value in first season only. All auxin applications
recorded a 100% survival in the first season, while in the second season; the K-NAA only
recorded 100% survival. Moreover, the highest value of the root biomass was recorded with KNAA soaking at 500 mg l-1
for 24 h in the first season only. The highest values of leaf nitrogen,
phosphorus, potassium, manganese, iron and zinc content were recorded with K-NAA soaking at
500 mg l-1
for 24 h. In addition, all K-NAA and IBA applications significantly increased all the
vegetative growth parameters, root biomass and leaf chlorophyll and mineral content of the
“Costata” seedlings grafted on “Seedy” rootstock as compared with the water in both seasons.