of good quall
this report a
POL 65-1 September 23, 1964
INFLUENCE 0 LCff7ENG POTATO PRODUCTION
D. R. Hens 1Aoc ate S s Chemist in Charge
:ets of pot.ato. product ust be combined to produce potatoes
ity. Factor.- production which are discussed in
Lre: use of ro cover and soil improvement crop and
Rotations: When potato land which has been in continuous potato
production for many years becomes less productive, consideration should
be given to rotational soil improving crops.
Results from pangolagrass experiment indicate that improved yields
could be expected for two years or more. Potatoes in the following experi-
ment were fertilized with three different rates of 6-8-8, two separate
sidedressing applications, and were placed in three different rotations.
2 yrs. after
1 yr. after
50# N & K20
Response to sidedressing was greater on the lower rate of fertilization
following either one or two years after pangolagrass.
Winter Cover Rotations: Winter cover crops can also be included in
a rotation plan. The winter cover crops should be established in the
late fall. In the following spring, they should be plowed under and a
summer cover established. Results in the following table show that yields
can be increased by this method. However, the effects of this type of
rotation appear to be shorter lived than other methods.
k I - -
In the following table, increase in yields due to all cover crops
except rye grass were noted for 1963. However in 1964, differences were
Treatment 1963 1964
Continuous 180 206
Rye grass 28* 214
1Teat 235 214
*Volunteer ryegrass couldd not be controlled by or- dnary weed control methods.
Potassium. So.rces and Placement: A large cam-ont of work has been
done to estabil:'.h -'.: hbes source of potassium for: potatoes. With the
possibility of using potassium nitrate (13-0-443 *,. place of potassium
sulfat, and potassium chloride, comparisons betw,-,n the three sources
Potassium All | Bands Bands
Source Banded Broadcast Sidedressed
Sulfate 253 263 218*
Chloride 272 260 223*
SChloride 278 279 233*
N03 N 208 234 230
NH4 N 237 230 246
*Sidedressed with nitrate of soda potash (15-0-14).
Potatoes which were fertilized with sulfate and chloride sources
of potassium yielded more than those fertilized with potassium nitrate.
No significant differences between methods of placement were noted.
Specific gravity measurements were taken on the marketable size A
tubers. Specific gravity of potatoes fertilized with potassium nitrate
was highest which was followed by sulfate of potash. Lowest specific
gravity readings came from potassium chloride source.