The present study was conducted during two consecutive 2014 & 2015 experimental seasons on two citrus
rootstocks namely: Cleopatra mandarin (citrus reshnii L.) and Rangpur lime (citrus limonia L.), to investigate
the effect of treating their seeds with some pre-sowing soak solutions. It was aimed to shorten the duration
needed for producing standard transplants through accelerating / hastening & raising germination process, as
well as seedlings vigour (plant height) and survival percentage of transplanted seedlings, which certainly would
be reflected positively in improving their suitability for carrying out budding / grafting. Hence seeds of each
citrus rootstock were subjected to soaking for 24 hours in one of either GA3 or ZnSO4 solutions (each at 500,
1000, 1500 and 2000 ppm), beside tap water as control for investigating their effect on two germination
parameters (total number of germinated seeds & germination percentages) after 6 weeks from sowing (planting)
and two growth measurements (average plant height just before transplanting and survival % of translocated
seedlings after two weeks). Data obtained during both experimental seasons revealed obviously that all presowing
soak treatments increased significantly both germination measurements (total germinated seeds &
germination %) and two parameters of induced seedlings (average plant height & survival % of translocated
seedlings) as compared to control (soak for 24 hours in tap water) with both citrus rootstocks. However, soaking
in the highest concentrated solutions (2000 ppm) of either GA3 or ZnSO4 particularly later one was/were
statistically the most effective in this concern. In spite of pre-sowing soak of two citrus rootstocks seeds in GA3
& ZnSO4 solutions at the least concentration (500 ppm) were statistically the inferior from one hand, but both
resulted in a significance increase over control with four investigated measurements. In addition, other GA3 &
ZnSO4 solutions came significantly in between the aforesaid two extremes with a noticeable tendency showed a
relative more efficiency always coupled with the higher concentration of a given chemical solution even within
such intermediate category. |
