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8PHOTOSYNTHETIC ACTIVITY OF POTATO LEAVES AS A COMPONENT OF IMPROVING CROP YIELDS IN THE UDMURT
REPUBLIC
Hrameshin R.A.,
1st year Master Student of Agricultural Engineering Faculty,
Enders M.A.,
2nd year Master Student of Zoological Engineering Faculty,
Hrameshin A. V., Ph.D., Associate Professor of the Department of Public Safety,
Arslanov F.R.
Ph.D., Associate Professor of the Department of Equipment Maintenance and Repair. Federal State Budgetary Educational Institution of Higher Education Izhevsk State Agricultural Academy
ABSTRACT
The article analyses the influence of the photosynthetic activity of potato leaves on crop under the particular conditions of Udmurtia. We consider the impact of photosynthetically active radiation on potato varieties during the crop management.
Keywords: potatoes, leaf, surface, variety, crop, radiation.
Introduction
In the context of the Udmurt Republic potato is one of the major food and feed crops. The constant growth of its consumption requires an increase of the production and one of the areas of this process without the extension of areas is the seed production, the development of new varieties with high feed and nutritional value [2], the improvement of cultivation technologies and the subsequent post-harvest handling, [1].
The review of the available sources indicates a relatively poor knowledge of photosynthetic potato indicators in Udmurtia, reflecting the necessity of filling the gaps in that regard.
The studies of mechanisms of potato crop formation in both: seed and ware potato, remain relevant. It depends on trends in the behaviour of physiological processes. The structure and the activity of the photo-synthetic apparatus and the root system are also of great relevance.
The purpose of this work is to study the main indicators of different potato varieties under the conditions of the Udmurt Republic, to identify the most viable varieties based on their productivity and to analyse the structure of the photosynthetic apparatus of potatoes during the tuber formation and growth in order to detect the maximum contribution of different parts of plants on the size and mass tuber characteristics during their further cultivation.
Conditions, resources, methods.
The objects of study are the new, locally - adapted potato varieties in pilot sites of Zavyalovo and Vot-kinsk regions in Udmurtia.
The preparation of planting material for the experiment included the bulkhead, sorting and selection of the middle fraction of 45-55 mm and its further germination in wooden boxes under a layer of moistened peat in greenhouses carried out in mid and late May.
The potato planting was made at the beginning of the first decade of June under the scheme (70 + 30) * 25 cm. The area of the plots was of 10 m2. The plant
care included the following: one pre-emergence loosening and two post - emergence loosening and hilling up with simultaneous weed removing and fertilizing every bush with 1-3 g of AN and after that, with urea. The crest height is 25 to 30 cm.
There was no use of herbicides, insecticides or desiccants because, as it has been shown before, the amount of leaf surface varied depending on the type, the dose and the combination of their application irrespective of the weather conditions and the population rate.
The harvesting was taking place during the second and third decades of September gathering the data from the entire area of each accounting plot.
In 2011-2016 the studies of 5 potato varieties were carried out (Rosara, Red Scarlett, Nevsky, Chaika, Leader). There were early varieties, the mid-early and the middle ones (the late harvest varieties were not taken into account as not relevant to the conditions of Udmurtia with its early autumn frosts and rainy weather conditions).
It was found that an important component of yield potential is the leaf photosynthetic rate. It may vary significantly from year to year, depending on the leaf surface and the leaf chlorophyll content. There is another value directly linked to the leaf surface that is the pho-tosynthetic potential (PP) which characterizes the area of the assimilating planting surface and its duration.
Photosynthetically active radiation (PAR) is the part of the solar radiation which can be absorbed by chlorophyll in photosynthesis. PAR is the wave spectrum from 380 to 710 nm made up of direct sunlight and ambient light with the intensity equal to 1/3 of the direct solar radiation. In the scattered light the PAR constitutes up to 90% and it means that the stray light, in contrast to the direct sunlight, can be absorbed almost entirely by the plant [3, 4].
The information obtained during the years of study (2011-2016) allows remarking on some features of the PP formation during the potato cultivation. In the first
two periods (germination - tillering and tillering - beginning of flowering) it's possible to notice how the photosynthetic potential grows due to the increasing of the leaf surface.
It's in the phase of flowering when PP reaches its highest values and then, begins to decline gradually. During the harvesting period the PP index in all the groups decreases more than twice that is associated with the natural dying off of the leaf blades. However, in some dry years (summer 2016) the process starts to progress, therefore, the 79 ... .96% of the overall development of the assimilation surface during the growing season depend on the characteristics of the year.
During the period of the investigations there were manifestations almost of all kinds of the weather conditions specific to the region of Udmurtia. The samples were taken according to their development phases within 4 repetitions of 10 plants.
Calculation of the leaf surface (a leaf blade) was made according to the formula (1) of V. V. Anikeev and F.F. Kutuzov:
S=L*D*0.76, (1)
where S - is the leaf surface, cm2 ;
L - is the leaf length, cm;
D - is the leaf width, cm;
0,76 - is the conversion factor.
The photosynthetic potential (PP) that characterizes the intensity of work of the specific leaf area during the same period of time (cm2 / day), is calculated according the formula (2) of A.A. Nichiporovich:
1 1 1
PP = (-*(S1+ S2))*H1 +(-*(S3+ S4))*H2+(-2 2 2
*(Sn+ Sn+1))*Hn, (2)
where PP - is the plants'photosynthetic potential, cm2 / day;
Hn - is the number of days;
Sn - is the leaf area during the respective development phases cm2.
The results were categorized by variance analysis methods.
Results and discussions
The crop forming management is quite a complex process because of the plant cenosis that means its changing during the vegetation and its interaction with other complex systems such as soil organisms, pathogens, weeds, pests.
It is almost impossible to control some of environmental factors - the temperature, the rainfall etc. while the other factors can be regulated very well. For instance, it is possible to change the mineral nutrition conditions, to prevent the weeds, pests and diseases.
In the specific context the plant photosynthesis may be determined by the ratio of such conjugate indicators as the photosynthesis rate, the leaf surface and the life expectancy of the leaves of different tiers. The absorption of the photosynthetically active radiation (PAR) depends on the size of the photosynthetic surface.
During the budding phase (the beginning) the leaf surface per plant totalled 40.28 ... .45, 86 cm2 on average per group. At the same time, the most extensive leaf surface was observed in the Nevsky variety (a standard one) and reached up to 75.67 cm2 with the additional pre - plant germination in a peat-humus mass. The lowest index of this value (without any additional germination) was reflected in the varieties called Rosario and Chaika and was equal to 38.14 cm2.
According to our observations, the increasing foliage growth during the budding period and at the beginning of flowering was possible due to the maximum rainfall at this time in recent years.
When the flowering begins, the lower tiers leaves die, so, during this period, the assimilating surface decreases up to 50.87... .67, 94 cm2 on average per group
The dying of the leaves damaged due to the impact of working machines during the inter-row cultivation or due to diseases and pests remains during all the growing season and affects the tuber formation and the productivity in general.
The result of two-factor analysis displayed that the development of the assimilation surface during the growing season up to 85.45 ... 97.64% is determined by the "year" factor. The "variety" factor contributes to the total variability and equals, depending on the vegetation phase, from 1.76 to 12.96%. The interaction "grade * year" totals between 2.35% and 4.99%.
The yield formation management needs a systematic monitoring of plant development and the direction of the crop photosynthetic activity in accordance with the predetermined parameters (which may be different even for the neighbouring areas of the Udmurt Republic).
In addition to the maintenance of the recommended temperature and humidity levels, it is also important to arrange the optimum plant placement. For better lighting, the plant rows should be located from east to west or from north-east to south-west. The crop amount strongly depends on the correct landing structure.
One of the priority goals of potato farming is the use of varieties that could develop a greater photosyn-thetic surface and thus obtain high photosynthesis productivity. Obtaining a final product which would be a useful biomass accumulation, i.e. net photosynthesis productivity, represents the greatest interest.
Table 2
Table 1
Biological potato yield by varieties (2011-2016)
Variety Tubers' weight g / bush Number of tubers, pcs. / bush The average weight of a tuber, g Biological yield, t / ha
Early varieties
Lider (st) 630 8,9 71 36,8
Red Scarlett 726 8,6 92 42,4
Rozara 921 14,2 137 55,8
Mid - early varieties
Nevsky (st) 804 12,4 73 45,9
Mid - maturing varieties
Chaika (st) 776 8,8 91 44,8
Particle size distribution of potato tubers by varieties (2011-2016)
Variety The size of tubers in a crop, %
small < 30 mm for seed production 30-60 mm big > 60 mm good presentation, total
Early varieties
Lider (st) 5 73 22 95
Red Scarlett 5 66 29 95
Rozara 2 51 47 98
Mid - early varieties
Nevsky (st) 7 68 25 93
Mid - maturing varieties
Chaika (st) 6 70 24 94
On the basis of the analysis of the climatic factors it is possible to choose the varieties that adapt to specific conditions and to offer the cultivation technology that would develop its full yielding potential under specific circumstances.
References
1. Adaptive technologies as a tool for yield forecasting and the size, weight and quality characteristics of root crops. / R.A. Hrameshin, A.V. Hrameshin / Science, education and society: Trends and Prospects, The
collection of scientific papers on the materials of the International scientific-practical conference: 7 parts. Ltd. "Ar-Consult". Moscow, 2014. pp 157-161.
2. The quality of potatoes can be improved. / A.V. Hrameshin, F.R. Arslanov, A.N. Vasiliev / Storage and processing of agricultural raw materials. 2012. № 11. pp. 41-44.
3. The technique of photosynthetically active radiation measurement./ H. G. Tooming, B.I. Gulyaev -Moscow, 2002;
4. A plant and the Sun./ Shulgin I.A. - L., 1993.
GENERATION OF POWER RECTANGULAR NANOSECOND PULSES BASED ON SUMMATOR OF QUASI-HARMONIC
OSCILLATIONS
Kladukhin S. V., Khramtsov S.P.
Institute of Electrophysics of the Ural Division of the Russian Academy of Sciences (IEP UD RAS), Russia,
Ekaterinburg
ABSTRACT
An approach to synthesize generators of power nanosecond high-voltage pulses with short front based on its Fourier representation is presented. The design of the experimental generator of subgigawatt power level built on
