Sugar beet is the most productive and economically advantageous crop of field rotation in the Forrest-steppes of Ukraine. However, they are among the most finical to growing conditions and require high level of soil fertility and fields culture, primarily to its sanitary condition. Thus, other harmful factors can destroy the crop yield. One of the  features of sugar beet  is its long germination period, soil surface shooting  before the roots molt, which occurs in the second phase and is completed in third phase of true leaf pairs), can last from 16–26 to 18–29 or more days depending on several reasons.

During this period of plants growth and development sugar beet is the most vulnerable and exposed to all pests and diseases. To create productive sugar beet crops it is necessary to reach on the optimal parameters and biological optical density which depends on field seed germination, plant loss, duration of the phases and the phytosanitary condition. Thus, sugar beet crops monitoring is topical in relation to specific areas of sugar beet sowing.

Comprehensive system of monitoring and evaluation of sugar beet crops was conducted during the 2009-2014 on the farm of Yarmolynetskiy district, Khmelnytskiy region. The sugar beet productivity was determined depending on the weather conditions of the growing season. Laboratory analyzes and accounting of the plants samples were conducted in the laboratory of soil agrochemical analysis in Bila Tserkva NAU.

The plot total area was 16.2 m², accounting area – 13.5 m², repetition – quadruple. Sugar beet diploid pelleted seed hybrid: Ukrainian ChS 72 was used for the research.

Phenological observations and biometric accounting was carried out in accordance with the conventional method of field experiment and methodical instructions of the Institute of Sugar Beet of UAAS.

Soil and climatic conditions of Khmelnytskiy region are generally favorable for sugar beet growing. Thus, it has long been renowned for its high yields of this crop and occupied its rightful place in the region for the gross yield of raw sugar. However, in recent years, the economic crisis that struck the agricultural sector has resulted in a sharp decline in sugar beet and sugar production. Reducing the sugar beet sowing areas, insufficient provision of material resources in the sector, inadequate relationship between sugar beet producers and processors, as well as violation of growing technology have made the industry unprofitable.

In 2009–2013, on the average, the area of sugar beet growing was 2 thousand ha in Yarmolinetskiy district, the crop average billet was 91thousand tons. It should be mentioned that for 2001–2005 these indexes were 4.5 thousand/ha and 197.1 thousand tons, and for the 1991–1995 – 6.3 thousand ha and 257.7 thousand tons respectively.

The sugar beet crops productivity was different during the 2009–2014.

The highest productivity in sugar beet crops for a 6-year period were in 2012 and 2014. Area moistening, phytosanitary status of the growing season (cercosporosus infestation was 40 %) contributed to a fuller using of the system of farming practices in createing high-productivity crops. The average yield in 2012 was 51.6 t/ha, for example. The lower yields of sugar beet is marked in 2009 (41.3 t/ha) and 2011 (42.0 t/ha), as compared to other years.

To establish the relationship between the studied traits of plant productivity and climatic conditions we have conducted correlation and regression analysis.

The obtained mathematical models are of linear character and describe the experimental data with rather high precise measurement (approximation coefficients respectively at 0.85, 0.81 and 0.69). Thus, plant density before harvesting, yield and sugar yield  can be predicted according to the GTC index for sugar beet growing season the by the graphs or regression equations:

y = 13,37x + 93,174,

y = 12,266x + 31,178 and

y = 2,1902x + 4,713.

It has been found out that the most informative indicator for predicting the field germination and density of plants at the time of the full shoots phase is the GTC for the period of sowing-shoots. Developing mathematical models with this index allows to get the maximum rate of approximation (i.e., the model describes experimental data the most accurately) and high correlation coefficients.

Key words: sugar beet, hydrothermal conditions, growing season, yield, sugar content, sugar yield.