الفهرس 
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Abstract
Two field experiments were conducted in the Research and
Experimental Farm of Nubaria Agricultural Research Station during
1997/ 98 and 19981 99 seasons. The aim of this study was to
investigate the response of sugar beet crop variety ”Tarios” to
different levels and application time of phosphorus and potassium in
calcareous soil. Each experiment included 36 treatments which were
the combination of 3 levels of P, 4 levels of K and 3 times of fertilizer
application .
Factors under study were:
1_ Phosphorus fertilizer at 0, 16 and 32 Kg P2051 fad.
11_ Potassium fertilizer at 0, 40, 80 and 120 Kg K20/ fad.
111_ Application time at sowing (T1), after thinning (T2) and after 30
days from thinning (T3) .
The design was a randomized complete plock with four
replications in both seasons. Results could be summarized as follow:
I..Effect of phosl!!lorus fertilizer:
1-The total number of leaves! plant after six months from sowing did
not affect by different levels of P fertilizer until 32 Kg P20s/ fad. in
both growing seasons.
2- Phosphorus fertilizer until 32 Kg P2051 fad. significantly increased
root length, root diameter, fresh and dry weight of leavesl plant, fresh
. and dry weight of root! plant, total fresh and total dry weight! plant
after 6 months from sowing in both growing seasons.
3- Phosphorus fertilizer significantly increased ~,lAl and SlA as
compared with unfertilized treatment in both growing seasons. High
level of applied P (32 Kg P205’ fad.) significantly decreased LWR
and had no significant effect on LAR in both growing seasons.
4- At harvesting time, increasing the level of applied phosphorus from
o to 16 and 32 Kg P2051 fad. caused a significant continuous
increase in root length, root diameter, fresh weight of root! plant, root
yield (Toni fad.), top yield (Toni fad.), biological yield (TonI fad.) and
sugar yield (Toni fad.) in both growing seasons.
5- The highest root yield (TonI fad.) was obtained by using 32 Kg
P205! fad. and increased the root yield by about 39% and 46% in the
first and second season, respectively as compared with control
treatment.
6- The average increases in biological yield (Toni fad.) by using P
fertilizer at rates of 16 and 32 Kg P20s/ fad. amounted to 16.5% and
280/0 over unfertilized treatment, respectively .
7- The highest rate of P fertilizer (32 Kg P20s/ fad.) gave the highest
value of sugar yield (Toni fad.). This increment reached 48% and
20/0 over the control treatment in the first and second season,
_ Phosphorus fertilizer significantly increased sucrose% in both
easons and purity% in the first season only. Total soluble solids’i
did not affect by increasing P level up to 32 Kg P20sI fad. in both
growing seasons-
11_Effect of l!olassium fertilizer:
1- All potassium levels had no significant effect on number of leaves!
plant as compared with control treatment after 6 months from sowing
in both growing seasons .
2- Root length, root diameter, fresh and dry weight of leaves! plant,
fresh and dry weight of root! plant, total fresh and total dry weight!
plant increased gradually and significantly with increasing K-fertilizer
levels up to 120 Kg K201 fad. after 6 months from sowing in both
growing seasons. The highest values were resulted from higher
potassium rate (120 Kg K20! fad.) .
3- Potassium fertilizer significantly increased LA, LAI and SLA as
compared with unfertilized treatment in both growing seasons. The
highest values were obtained by the highest K- fertilizer level .
4- All level of K- fertilizer had no effect on LAR and significantly
decreased LWR in both growing seasons as compared with check
treatment.
5- All potassium rates, i, e., 40,80 and 120 Kg K201 fad. significantly
increased root length, root diameter, fresh weight of rootl plant, root
yield (Ton/ fad.), top yield (TonI fad.), biological yield (TonI fad.) and
sugar yield (TonI fad.) at harvesting time in both growing seasons.
_ Application of K at rates 40, 80 and 120 Kg K201 fad. increased
he root yield (TonI fad.) over the control treatment by more than
370/0,480/0and 61% in the first season and 24%, 35% and 48% in the
second season, respectively.
7- Potassium at 40, 80 and 120 Kg K201 fad. increased biological
yield (TonI fad.) over the control treatment by about 25%,33
%
and
400/0 in the first season and about 16%, 250/0and 33% in the second
season I respectively .
8- The increments of sugar yield (TonI fad.) by increasing K level
from 40, 80 and 120 Kg K201 fad were 45%, 580/0and 75% in the
first season and 27%, 41% and 55% in the second season as
compared with unfertilized treatment. respectively .
9- Total soluble solids% and sucrose’l significantly increased by all
K levels as compared with unfertilized treatment in both growing
seasons.
10- Potassium fertilizer had no significant effect on purity% in both
seasons.
Ill..Effect of aMliestio” time of fertilizer:
_ The application of P and K fertilizer after thinning (40 days from
owing, T2) gave the highest values of root length, root diameter,
resh weight of leavesl plant, fresh weight of rootl plant and total
resh weight after 6 months from sowing as compared with T 1 (at
sowing) and T3 (70 days from sowing) in both growing seasons.
2- After 6 months from sowing, number of leavesl plant, dry weight of
rootl plant and total dry weight! plant were insignificant affected by
different application date of P and K fertilizer in both growing
seasons.
3- The difference between T 1 and T3 was not significant on leaf
characters .
4- The highest value of LAI was obtained by T2 treatment and
significantly higher as compared with T3 .
5- Concerning LA, LWR, LAR and SLA did not significantly affected
by different application time of P and K fertilizer .
6- At harvesting time, the highest values of root length, root diameter,
fresh weight of rootl plant, root yield (Toni fad.), top yield (Toni fad.),
95.
biological yield (Toni fad.) and sugar yield (Toni fad.) were obtained
by the application of P and K fertilizer after thinning (T2. 40 days from
sowing) in both growing seasons.
7~ The difference between the applied of P and K at sowing (T 1) and
70 days from sowing (T3) was not significant on root length and
iameter, fresh weight of root/ plant, root yield, (Toni fad.) top yield,
onl fad.) biological yield (Toni fad.) and sugar yield (Toni fad.) in
oth growing seasons.
_ The effect of applied date of P and K fertilizer on technological
quality, namely, total soluble solids%, sucrose% and purity% was not
significant in both growing seasons.
IV...Effect of the interaction:
1- After 6 months from sowing the greatest values of root length, root
diameter, fresh weight of leavesl plant, fresh weight of root! plant,
total fresh weight! plant. dry weight of leavesJ plant (in second season
only), dry weight of root! plant and total dry weight! plant (in both
growing seasons) were obtained by high levels of applied P (32 Kg
P20S’ fad.) with the high two levels of applied K (120 and 80 Kg
K201 fad.).
2- The highest values of LA in both growing seasons, LAI and SLA in
first season were obtained by the highest rate of P (32 Kg P20S’
fad.) and highest two levels of K (120 and 80 Kg K201 fad.) .
3- The greatest value of leaf weight ratio (LWR) was reported by
unfertilized treatment (0 P20S + 0 KZOI fad.) in the second season
only.
4- At harvesting time, fertilization with highest levels of both
fertilizers, P + K recorded the greatest values of root length, root
diameter, root weight! plant, root yield (TonI fad.), biOlogical yield
(TonI fad.) and sugar yield (TonI fad.) in both growing seasons.
5- Phosphorus and potassium at highest rate (32 Kg PZOS+ 120 Kg
K201 fad.) gave about double values from root diameter, root yield
(Ton’ fad.). biological yield (fonl fad.) and sugar yield (fonl tad.) as
compared with unfertiHzed treatment.
6- Sucrose% was higher by applied highest levels from P and K
fertilizers in first season only.
7_ The treatments with high levels of both P and K gave higher
values of purity0/o as compared with lower rates of P and K, except
only the unfertilized treatment in the first season only .
8- Higher level of P fertilizer (32 Kg P20sJ fad.) with the application
time after thinning (T2. 40 days from sowing) gave the higher values
of total fresh weight! plant in the second season, root yield (TonI tad.)
in the first season and biological yield (TonI fad.) in the both growing
seasons.
9- The greatest values of fresh weight of leavesl plant, total fresh
weight! plant, LAI, root yield (TonI fad.) and biological yield (TonI fad.)
were obtained by highest level of K (120 Kg K201 fad.) and
application time after thinning (T2, 40 days from sowing) in the first
season only.
1o- The greatest values of root yield (TonI fad.) in the first season
and biological yield (TonI fad.) in the both seasons were obtained by
treatments of high levels of P and K with application time of fertUizer
after thinning (T2, 40 days from sowing) .