Photosynthetic activity of chicory root plants

Abstract

Annotation. The article highlights the dynamics of the area formation of the root chicory plants leaf surface depending on the timing of sowing during the growing season in the conditions of the Right-Bank Forest-Steppe of Ukraine.

Methods Phenological observations, biometric studies were carried out according to B.A. Dospekhova, V.F. Moiseichenka. The research material was the soil of the experimental field - medium-loamy black soil on loess-like loams. Root chicory plants were used as the research object. The studies were conducted on the experimental field of the Khmelnitsky State Agricultural Experimental Station of the Institute of Feed and Agriculture of the Podillia of the NAAS during 2014-2016.

Results. It was established that the period from the second decade of July (July 20) to the second decade of August (August 20) according to the winter sowing period (November 15–20) was characterized by the highest level of leaf surface area during all years of research. So, in 2014, the leaf surface area was - 40.6-48.1 thousand m2 / ha, in 2015 - 13.9-14.5 and in 2016 - 30.8-33.4 thousand m ²/ ha .

It should be noted that in 2014 the greatest average area of leaf surface was 30.2 thousand m² / ha in the winter term, with photosynthetic potential amounting to 3326 thousand. M² × days / ha. While in 2015 and 2016 the area of leaves was 9.0 and 17.9 thousand m² / ha, the photosynthetic potential of 1045 and 1971 thousand. M² × days / ha, respectively.

Slightly lower indicators of leaf surface area were obtained from early spring sowing dates (1.04-4.04). On average, during the growing season, the largest leaf area was in 2014 and amounted to 20.5 thousand m² / ha, photosynthetic potential - 2250 thousand M² × days / ha. In 2015 and 2016, there was a sharp decrease in leaf surface area compared to 2014. So, on average, during the growing season, the leaf area in 2015 was 12.1 thousand m² / ha, AF - 1329 thousand M² × days / ha, in 2016 - 11.5 thousand m² / ha, AF - 1271 thousand. m² × days / ha, respectively. This is primarily due to the climatic conditions of the year, namely, the change in rainfall during the growing season

According to summer sowing (1.06-4.06), the largest leaf surface area of chicory plants on average during the growing season was in 2016 - 9.1 thousand m² / ha, photosynthetic potential of 1003 thousand m² / day / ha. Analysis by accounting periods showed that the highest leaf area in 2016 was at 1.09, this is primarily due to the large amount of rainfall in August. In 2014 and 2015, the average leaf surface area during the growing season was 5.1 and 6.6 thousand m² / ha, while the photosynthetic potential was 558 thousand M² × days / ha and 733 thousand M² × days / ha, accordingly . We also noted that over the summer sowing in chicory crops there is a significant loss of letters in the early growing season.

It was established that in chicory plants in the unfertilized area in the first and second variant, at the beginning of the growing season, the assimilation surface increased more intensively with increased soil moisture of 80% of the total moisture capacity. So, for the period the second decade of June (June 20) - the first and decade of July (5.07), the leaf surface area of chicory plants was 1965 cm² / plant and 3090 cm² / plant, 242 cm² / plant less compared with the first option for the accounting period 20.06 , and 54 sm² / plant less for the accounting period 5.07.

Starting from the third decade of July, chicory plants in the second variant began to lag behind in growth from the plants of the first variant, which were grown at 60% soil moisture. So for the period of July 25, the leaf area in an unfertilized plot in the variant with soil moisture 60% exceeded 459 sm² / plant for the second variant (humidity 80% without fertilizers). A similar trend was observed in subsequent periods of the account until the end of the growing season. This fact indicates that at a low concentration of nutrients, plants react more strongly to a higher soil moisture of 80% compared to a lowered 60%, the optimal humidity for chicory root crops on less fertile soil approaches 60% moisture.

The use of fertilizers has a positive effect on the increase in leaf area. It should be noted that the largest leaf surface area was on fertilized varieties and with high soil moisture of 80% during the growing season in all accounting periods. This, in turn, was reflected in the level of the crop, both plants and root crops. The greatest mass of the root crop was noted on the fertilized version with soil moisture of 80% and amounted to985 g, respectively, which exceeded the first option

Thus, to ensure a high leaf surface area and, as a result, a high yield of chicory root crops, it is necessary to carry out fertilizers and maintain soil moisture at 80%.