POTATOES
. Effect of Planting Distances and Use of Fertilizers.
At the Matanuska station an experiment was carried on in
1939 to determine the best distance in the row to plant seed potatoes
for production of maximum quality, early maturity, and highest yield
of marketable potatoes. White Bliss potatoes were planted. xhe seed
was treated with a mercuric disinfectant for disease and sprouted
before planting. time of planting a 4-6-10 complete fertilizer
was applied at 300 pounds per acre. They were kept free from weeds,
cultivated twice, ridged for better drainage, and rogued for disease.
In harvesting, they were dug by hand and each hill kept separate.
Sixteen hills of potatoes at each planting distance were weighed
for purposes of comparison. Comparative results are shown in Table VI.
TABLE VI
Distance Average weight Total yield Percent by weight
in rows
inches
8
12
16
20
30
per hill
pounds
1.84
2.0
2.2
2.9
3.1
per acre
bushels
339.2
245.2
203.1
211.6
175,7
unmarketable
potatoes
14.3
12.6
10.1
7.7
6.2
There was no noticable difference in maturity betvw en the
different planting distances as evidenced by slipping of skin.
To determine the effect of phosphate fertilizers on maturing,
ripening yield and quality triple super phosphate was applied to a
part of the field at the rate of 100 pounds per acre on July 1st,
August 1st and September 1st. The ground was given shallow cultiva
tions after each application. Table number VII shows average weight
per hill, yield per acre, and percentage of unmarketable -potatoes
for each of the planting distances.
TABLE VII
distance average Total
in rows weight yield
inches per hill per acre
8 1.58 364.6
12 2.93 335.8
16 3.1 286.2
20 3.42 252.7
30 3.90 182.2
Percent by weight
of unmarketable
potatoes
12.4
11.7
9.5
6.9
6.1
A comparison of labile number VI and VII indicates first,
that there is much higher yield of total crop where the phosphate was
applied at regular intervals during the growing season. Second, plant
ing at a shorter distance in both cases produced a higher yield both
of total crop and marketable potatoes. Third, the per hill v, ’ght of
potatoes at the longer planting distances in the row is much higher
and the unmarketable percentage is much lower than at the shorter dis
tances. Fourth, the smaller number of hills per acre lowered the total
yield at the longest planting distance an average of 48^ for the two
trials. There is a lower percentage of unmarketable potatoes where
the additional phosphate was applied during the growing season. The
potatoes treated with phosphate appeared more firm and the skin slipped
less than on the untreated row.