Agriculture Reference
In-Depth Information
Results of our researches (Table 5.3) revealed that in the phase of full plant fl ow-
ering, the most optimum area of the leaf surface occurred in cultivar Vladikavkazsky
(34.3,000 m
2
/ha) on the second time of planting. At the same variant at cultivars
Volzhanin and Predgorny, the assimilating surface was 32.1 and 33.4,000 m
2
/ha, re-
spectively.
TABLE 5.3
Top mass and assimilating surface of various potato cultivars depending on the
time of planting
Volzhanin
Vladikavkazsky
Predgorny
As-
similating
surface
(thou-
sand m
2
/
ha)
Time of
plant-
ing
Assimilating
surface
(thousand
m
2
/ha)
Assimilating
surface
(thousand m
2
/
ha)
Mass
(g/bush)
Mass
(g/bush)
Mass
(g/bush)
1
370
30,1
490
29,9
390
31,3
2
440
32,1
580
34,3
470
33,4
3
360
28,3
470
27,4
350
29,7
In agricultural literature, a lot of contradictory statements concerning the effi cien-
cy of planting time per potato tuber yield have been recorded. This is probably because
the climatic conditions and the cultivar role in determination of their infl uence on pro-
ductivity are not always considered. On soils with various mechanical compositions,
spring high-plastic condition and its warming up do not occur at the same time—from
5 to 20 days. In areas with prevalence of light sandy and sandy loam soils, the high-
plastic condition comes earlier than the accepted recommendations [3].
As a rule, yield loss because of the delay of potatoes planting to 20 and more days
is not compensated with the increase in planting density and additional application of
fertilizers [2, 3]. One of the important arguments against early potato planting is the
fear of sprouts getting damaged because of late spring frosts. However, in the larger
territory of the Central Nonchernozem Region, plants seldom come under frosts at ear-
ly planting, but decrease in yields because retarded planting is observed annually [6].
Potato planting in different calendar days practically does not infl uence expenses,
but productivity rate from return at early plantings promotes increase of relative net
profi t of 44-49 percent [1, 6].
High effi ciency of crops can be received at the optimum combination of all factors
infl uencing the formation of productivity. Therefore, agrotechnical actions have to be
strictly specifi ed for certain soil-climatic conditions, and cultivated cultivars as well.
In our experience, more stable and rather high yield of tubers in all the three stud-
ied cultivars have been noted.
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