Agriculture Reference
In-Depth Information
Various cultivars reacted differently to the developed weather conditions, clearly
owing to the biological features. The highest yields in all the three cultivars were
recorded on the second planting. In our experience, the cultivar Predgorny appeared
to be the most high-yielding plant (25.8 t/ha) and Vladikavkazsky (24.3 t/ha) slightly
less. On the fi rst planting time, yields were 2.2-3.1 t/ha less, than on the second.
Various tuber marketability is noted on cultivars. The lowest is on the cultivar
Volzhanin, fl uctuations of which depend on planting times made 4-8 percent. By opti-
mum variant its marketability reached 82 percent.
Researches showed that the cultivar Predgorny had higher marketability than other
cultivars, thus maximum was received on the second planting time, 96 percent. In oth-
er cultivars, this indicator did not reach even the lower limit of the cultivar Predgorny.
One of the main quality indicators of potato tubers is starch and dry matters, which
are determined by a number of factors: varietal features, climatic conditions, agrotech-
nology, rate, form and relation of fertilizers, degree of tubers maturity, etc.
A certain correctional connection between the content of dry matters and starch in
the tuber is determined. Depending on the varietal features and early ripening of the
cultivar, the difference between the content of dry matters and starch reaches 4.6-11.0
percent. Deviations depending on the cultivar of one ripening group reached 6.0-7.0
percent [7].
S. T. Prokoshev [8] determined that mid-ripening and late-ripening potato cultivars
always have higher content of starch than early-ripening cultivars, irrespective of the
applied agrotechnology.
Contradictory opinions about infl uence of planting time on tuber starchiness are
encountered in the literature. Thus, the majority of authors state that the maximum
starch accumulation is in variants with early planting [5-8].
In the process of plant growth and development, accumulation of dry matters is
unstable as a result of fl uctuations of weather and other conditions.
According to Table 5.3, the content of dry matter and starch in tubers do not sig-
nifi cantly differ according to the variants or the cultivars. For all cultivars, optimum
according to these factors was the early planting.
The largest amount of dry matters and starch were accumulated by the cultivar
Predgorny, 19.3 and 14.2 percent, respectively. The cultivar Volzhanin during the third
planting accumulated less, 15.4 and 11.3 percent of dry matters and starch, respec-
tively.
The cultivar Vladikavkazsky accumulated dry matters and starch 0.5-0.7 percent
more than the cultivar Volzhanin and 0.3-0.9 percent less than the cultivar Predgorny.
Summing up according to the content of dry matters and starch, we conclude that
the studied cultivars according to these indicators can be referred to table cultivars.
5.4 CONCLUSIONS
1. Studying the influence of planting time of various potato cultivars on indica-
tors of their morphological development, efficiency, and quality revealed that
for each cultivar the choice has to be individual and applicable to concrete
climatic zones.
 
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