Nineteen locally selected potato lines were screened for water stress
tolerance by measuring the growth parameters in vitro. The stress was achieved
by adding 4% of sorbitol to the growth medium. Plant height and diameter,
leaf area, number, lengt
h and diameter of roots and plant fresh and dry weight
were measured. The results showed a difference in the response of the studied
lines to water stress, cluster analysis, based on the sum of all growth
parameters relative values of the lines showed that the lines were divided into
three groups according to water stress tolerance: The tolerant group, the
moderate tolerant group and the sensitive group. The results indicated the
possibility to use the in vitro method to screen the potato lines for water stress
tolerance.
In this research, protoplast isolations were obtained from the leaves of
Potato Binella cultivar at the laboratories of Agriculture College- Damascus
University in order to determine factors affecting the yield and viability of
protoplast isolation. Results indicated that the best yield percentage of isolated
protoplast.
This study was conducted at Abo Jarash farm, Faculty of Agriculture,
Damascus University In order to determine the response of three local varieties
of potato (Sponta, Draja, Diamont) to salinity stress with different
concentration of NaCl solutio
n (0,50, 100, 150, 200 mM). The results indicated
that the existence of a inverse correlation between increased concentrations of
salts in the solution and the rate of plant height, leaf area, and the percentage of
leaf dry weight, and the proportion K+/ Na+., and the productivity was declined
with a proportional rate 22< 32, and 48% for the varieties of Sponta, Draja,
Diamont, respectively. Results indicated the existence of reverse relationship
between increasing salt concentration in the medium and plant height, Leaf
area, dry weight of the leaves and K+/Na+ ration in addition to the decline in the
productivity of studied varieties. The results also showed variations in the
extent of tolerance between studied varieties to salinity stress where Sponta
was the most tolerant, followed by Draja and Diamont was the less tolerant and
this was reflected in terms of higher germination and increasing the mean of
plant height, Leaf area and dry weight of plant.
This search carried out to study the effect of treatment with some fungicides
(mancozeb + metalaxyl - M, chlorothalonil ،azoxystrobin and mancozeb) in
control late blight (Phytophthora infestans Mont.) on potato va. Spunta and
yield in homs during
two seasons 2008 and 2009. The results showed that the
use of a mixture of fungicides (mancozeb + metalaxyl - M) gave the superior
efficacy in controlling the disease during two seasons compared with other
treatments. The percentage of effect (74.32% and 57.24%) during 2008 and
2009, respectively. While, the fungicides (mancozeb) gave the lowest effect in
controlling the disease during two seasons, where as the percentage of effect
(31.95% and 40%), respectively. Recorded results showed that spray of potato
plant with tested fungicides increase the yield compared with untreated plants.
The mixture fungicides (mancozeb + metalaxyl-M) increase in yield (35.55%
and 32.285) during 2008 and 2009, at respectively. We can arrange the tested
fungicides according to their the efficacy in controlling the disease and in
increase the yield such as following: mancozeb +metalaxyl-M> chlorothalonil>
azoxystrobin> mancozeb.
Effect of organic and bio fertilizers (Azotobacter and phosphate solubilizing
bacteria) on production of potatoes and some soil properties was studied in
Tartous.
The experiment consisted of 4 treatments (control soil, soil+manure, soil+
bioferti
lizer and soil+manure+biofertilizer) each replicated four time, for 2004
and 2005 seasons.
Total N, available P, available K, and organic matter in soil were
determined.
Significant increases were observed in most of the inoculated and organic
fertilized treatments compared with the control. However, the treatment
(soil+manure+biofertilizer) was the best and showed significant increases in
potato yield compared with other treatments especially in the next season.
However, the second season was better in yield increase in all treatments
than the first seacon.
