Possibilities of using RGB-based image analysis to estimate the chlorophyll content of micropropagated strawberry plants

An image analysis method based on RGB features for rapid estimation of the chlorophyll content of leaves of micropropagated strawberry plants (2 cultivars) was presented in the study. An algorithm describing the relationship between the absolute values of chlorophyll content and the colour components of a leaf image captured with a conventional scanner was developed and tested. The accuracy of the proposed method was compared with that of an optical greenness meters designed for assessing leaf chlorophyll content. The chlorophyll content in the strawberry leaves was correlated with the results of measurements recorded by the two optical meters (SPAD-502, CCM-200) and with RGB values of scans of these leaves. The highest values of correlation coefficients were obtained between the chemical analysis results and mean values of the red colour (R) of the scans. However, varietal differences were evident here, which indicates the need for individual calibrations. In the case of the green colour (G), the accuracy was slightly lower; however, no varietal differences were found, thus one calibration can be used for both cultivars. Three formulas: (R-G)/(R+G), (R-G)/(R+G+B), and R/(R+G+B) were selected and their relationship with the changes in chlorophyll content was tested. These variables did not explain the changes in chlorophyll content better than the variable R. The study confirmed the possibility of using the image capture method for the detection of chlorophyll status in strawberry plantlets cultured in vitro.

Estimation of genotypic features of effects of plant treatment with growth regulators on canopy parameters and yield of winter wheat

Aim. A study of the effects of growth regulators derived from natural raw materials on the photosynthetic apparatus surface and the yield of winter wheat. Methods. Morphometric, spectrophotometric, statistical. Results. An increase in the value of canopy chlorophyll index (ChlI) of Smuhlianka and Astarta varieties under the treatment of plants with Stimpo growth stimulator was established at anthesis, a positive effect of the regulator Regoplant – only for Smuhlianka variety at milk-wax ripeness. Chlorophyll photosynthetic potential (ChlP) during the period anthesis – milk-wax ripeness increased significantly under the use of growth regulators in both varieties, while the efficiency of treatments had varietal differences: growth was greater (11–18% compared to control) in the variety Smuhlianka than in the variety Astarta (6–7%). A positive correlation was established between the yield and ChlP during the period anthesis – milk-wax ripeness. Under the action of treatment of plants with growth regulators, the increase in grain yield was significant (0.29–0.45 t/ha) only in the variety Smuhlianka. Conclusions. The positive effect of treatments of plants with growth regulators, obtained from natural raw materials, on the value of canopy ChlI at anthesis and ChlP during period anthesis – milk-wax ripeness was established. A positive correlation between the winter wheat yield and ChlP during the period anthesis – milk-wax ripeness was found. Varietal differences in the effect of growth regulators treatment of plants on ChlP and yield were found. Keywords: Triticum aestivum L., grain productivity, chlorophyll index, chlorophyll photosynthetic potential, growth regulator.

The effect of meteorological factors on apple tree productivity in the Piedmont zone of Crimea

Приведены результаты изучения четырех сортов яблони (Красное Раннее, Виста Белла, Киммерия, Таврия), на основании которых сорта были распределены по срокам цветения. Продолжительность цветения изменялась по годам и имела сортовые различия. В среднем цветение занимало от 8 до 14 дней. Конец цветения у всех изученных сортов при накоплении суммы эффективных температур выше 5С - от 216 до 260С. Среднесуточная температура воздуха варьировала от 7,1 до 14,8С. Периодические весенние заморозки повреждают генеративные почки, степень их воздействия значительна. В результате проведенных исследований установлено, что имеется корреляционная связь между среднесуточными минимальными температурами и урожайностью раннецветущих сортов яблони. Большое влияние оказывают среднесуточные и минимальные температуры воздуха на раноцветущие сорта, а для поздноцветущих сортов определена корреляционная зависимость от суммы осадков. За исследуемый период были отмечены ночные заморозки до -2С, что повлияло на завязываемость плодов и урожайность сортов, заморозки наблюдались в 2011, 2015, 2017 гг. Урожайность яблони была определена как совокупный показатель, зависящий от количества генеративных почек, числа цветков в соцветии, среднего количества завязавшихся плодов и их массы, а также степени адаптивности сорта к стресс-факторам. Также было отмечено, что урожайность изученных сортов яблони была нестабильна и имела сортовые различия, наивысшее значение данного показателя за период исследования было отмечено у сорта Таврия (66,6 т/га). The results of study of four apple varieties (‘Krasnoye Ranneye’, ‘Vista Bella’, ‘Cimmeria’, ‘Tavria’) are presented. On its basis the varieties are classified by the time of flowering. The duration of flowering of the studied apple varieties was changing over the years and had varietal differences. On average the period of flowering timed 8 - 14 days. The end of flowering in all studied varieties with the accumulation of the sum of effective temperatures above 5 °C was registered with values from 216 to 260 °C. The average daily air temperature varied from 7.1 to 14.8 °C. Periodic spring frosts damage the reproductive buds, the degree of their impact is significant. As a result of the conducted studies, a correlation between the average daily minimum temperatures and cropping capacity of early-flowering apple varieties was found. The average daily and minimum air temperatures have a great impact on early-flowering apple varieties, and for late-flowering apple varieties the correlation dependence on the amount of precipitation is determined. During the study period, night frosts of up to -2 °C, affecting the setting and cropping capacity of varieties, were observed. Frosts were registered in 2011, 2015 and 2017. The apple tree cropping capacity was determined as a cumulative indicator that depends on the number of reproductive buds, the number of flowers in inflorescences, the average number of set fruits and their weight, as well as the adaptability degree of the variety to stress factors. It was also noted that cropping capacity of the studied apple varieties was unstable and had varietal differences, the highest value of this indicator during the study period was noted in the ‘Tavria’ variety (66.6 t/ha).