PROBLEMS AND RESULTS IN ISRAEL 409 
sometimes of vital importance to hasten germination and seedling 
growth even by a few hours. 
The time of sowing is another problem. It is technically easier to 
sow before the first rain or flood, but there are reasons for not 
doing so: (1) crust formation; (2) the danger of the seeds being 
washed away with the top-soil by the first flood; (3) danger of 
germination after a small rainfall sufficient to bring about germina- 
tion but insufficient to maintain further growth; (4) on account of 
the rather erratic occurrence of effective rainfall, the impossi- 
bility of deciding on the species to plant until the rain has actually 
fallen. 
All these considerations lead to the conclusion that it is practica- 
ble to sow only after the soil has been wetted by flood. This raises 
the basic agrotechnical problem of methods of sowing in wet clay. 
This has to be done rapidly, and not be delayed even for one day 
as the drying of the topsoil is very rapid. 
Utilization of Available Saline Water 
Most of the available ground water is highly saline. There are, 
however, a number of plants which thrive on saline water. To 
cite only a few of the many species on which such work is being 
done: (1) Funcus maritimus as mentioned above; (2) Phoenix 
dactylifera, which is planted extensively at Revivim and along the 
salt marshes in Nahal Arava, between Yotvata and Elath on the 
Red Sea shore; (3) vegetables, such as beets and spinach; (4) salt- 
resistant strains of forage crops, such as alfalfa. 
Dew 
A yearly water balance of certain desert plants shows that they 
do not rely only on the water taken up from the soil (20, 22, 23). 
On the other hand, it seems today a well-established fact that dew 
is taken up by leaves, and may even be transported from the 
leaves to the roots where it can be secreted into the soil (16, 35). 
At the same time it seems to be certain that plants growing under 
arid conditions benefit decisively by the uptake of dew (16). Are 
there any practical conclusions to be drawn for desert agriculture 
from those facts? 
Based on ten years’ measurements of dew, made with Duvde- 
