HOW TO GET A GOOD HARVEST OF POTATOES IF THE DEFICIT OF PRECITATION IN THE REGION BECAME THE NORM, AND THE INTRODUCTION OF IRRIGATION IN THE FARM IS STILL (OR AT ALL) IMPOSSIBLE?
SPECIALISTS RECOMMEND TO PAY ATTENTION TO DROUGH-RESISTANT VARIETIES.
DROUGH RESISTANT OR HEAT RESISTANT?
First, let's deal with the terminology. As noted Evgeny Simakov, Doctor of Agricultural Sciences, Professor, Head of the Experimental Gene Pool Department of the FRC Potato named after A.G. Lorch, it is necessary to distinguish between the concepts of “drought-resistant varieties” and “heat-resistant (heat-resistant) varieties”. The first category includes those that can withstand both soil and air drought. "We are talking about varieties that can tolerate a complete lack of moisture for some time (but not the whole season!) - explains the scientist, - and heat-resistant varieties remain productive at high temperatures, but in the presence of irrigation". Heat-resistant varieties are widely represented on the market. "Colomba, Arizona, Impala, Riviera feel great, for example, in the Astrakhan region, on irrigation, - says Evgeny Simakov, - Favorit and Grand can serve as examples of domestic heat-resistant varieties.»
Drought-resistant varieties are much less. "in the Soviet years in the southern regions the Volzhanin variety was very popular, The expert recalls it was created by Stepan Afanasyevich Lezhepekov, breeder at the Ulyanovsk Experimental Station. This variety can be called a kind of drought tolerance standard. It is still grown now, but more often on private farms, where external appearance is not so important.ny type of tuber. Volzhanin loses contemporary leaders in optical parameters (rough skin, deep eyes) and yield indicators».
“Another well-known drought-resistant variety - Majestic (UK), - complemented by Professor Simakov, - in the south of Russia, it provided a yield of 15-20 t / ha when grown without glaze".
Modern varieties, of course, also exist, and they are grown today not only in traditionally hot regions.
THERE IS A CHOICE
In the Chelyabinsk region, for example, 7,2 thousand hectares are allocated for potatoes in the production sector, but irrigation equipment is installed only in some advanced farms. Meanwhile, drought for this region has long become commonplace.
«In the Urals, it is already becoming a rule that at least one of the summer months passes completely without rain, - states Alexander Vasiliev, Doctor of Agricultural Sciences, Chief Researcher of the South Ural Research Institute of Horticulture and Potato Growing (UNIISK), a branch of the Ural Federal Agrarian Research Center of the Ural Branch of the Russian Academy of Sciences. - We have recorded drought for four years in a row, and 2022, like the last one, we refer to the most difficult, since there was less precipitation during these periods than in 1975 (the driest year in the region during the observation period)". According to the scientist, one of the best drought-resistant varieties in the Southern Urals, capable of providing a decent result even in such harsh climatic conditions, is the Russian variety Tarasov. "He has the Nevsky variety in his parents - very plastic, - explains Alexander Vasiliev, - the habit of the bush is small, and it forms not so many large tubers. Mid-season. It has a very high productivity potential, under favorable conditions the yield can reach 3 kg per bush (about 120 t/ha), the average is 90 t/ha. If there is moisture at least at some point in the season, plants of this variety use it to the maximum».
Doctor of Agricultural Sciences, Professor, Head of the Experimental Gene Pool Department of the FRC Potato named after A.G. Lorcha:
“Back in 2010, we began to distinguish varieties in our line that are able to withstand both soil and air droughts, and according to the results of observations, ARIEL turned out to be the most drought-resistant, then SADON and METEOR. Every ten days during this season we have been dynamically harvesting, and these varieties showed at least a small increase, but. In other varieties under the same conditions, from a certain point in time, there was no increase in yield. ”.
In the experimental plots of YuUNIISK, in the dry seasons of 2019-2022, without irrigation, the Tarasov variety confidently provides a yield of about 40 t/ha. According to the expert, there are other varieties that show good results in heat and drought conditions, but so far they are not stable.
So, the Kashtak and Zakhar varieties showed themselves worthily in 2021, but in the next season the indicators dropped noticeably. The yield of the Spiridon variety in 2022 was 15% higher than a year earlier.
In the Moscow region, droughts are also no longer a rarity. "В this season, we planted behind the usual dates, the plants had a large supply of moisture from the winter, but then, throughout summer, not a single rain fell in our Shatursky district, says Evgeny Simakov.
Large agricultural holdings operating in the region grow potatoes under irrigation, but small farms suffer losses in dry years.
In the Samara region, famous for its hot and dry climate, they have compiled their own rating of varieties suitable for growing in conditions of extreme temperatures and lack of precipitation. In this region, scientific work to determine the most drought-resistant Russian varieties has been carried out for four years by the Samara Research Institute of Agriculture. N.M. Tulaykova - branch of the SamScience Center of the Russian Academy of Sciences.
«Our institute participates in ecological and geographicaltrial of new promising domestic varieties of potatoes (as part of the implementation of the Comprehensive Plan for Scientific Research on the Development of Potato Breeding and Seed Production), - explains Alexey Bakunov, Candidate of Agricultural Sciences, Leading Researcher of the Samara Research Institute of Agriculture, – theme of our research - "Grade varieties и hybrid material potato on resistance to biotic and abiotic stress factors in the conditions of the Middle Volga region. The work is carried out jointly with the Institute of Ecology of the Volga Basin of the Russian Academy of Sciences, all the necessary biochemical analyzes are carried out on the basis of the IEVB RAS».
The first three-year test cycle ended in 2021. Of the 45 varieties provided to the Samara Research Institute of Agriculture, scientists identified the two best (which demonstrated the highest yield and resistance to viral diseases throughout all seasons) - these are Krasa Meshchery and Siversky.
The highest yield of the variety was shown in 2019, when the growing conditions were quite favorable. The next two seasons were hot and dry, the air temperature in the summer months often exceeded 40°C, the soil temperature: 50°C. Potatoes in the experimental plots grew without irrigation. At the same time, the average yield of the Krasa Meshchery variety for three years was 30 t/ha, Siversky - 29 t/ha.
The decrease in yield from season to season (especially pronounced in the Siversky variety), according to scientists, was largely due not to weather conditions, but to the degeneration of tubers, the accumulation of viral diseases (this process is especially intense in hot weather).
The varieties Utro, Terra, Alaska, Debyut proved to be quite good during the tests, but their yield indicators fell three times from 2019 to 2022. All other varieties gave a good harvest only in the first growing season, then there was a sharp decline in performance.
But the main task of the Samara researchers was not just to name the leaders, but to determine which physiological and biochemical parameters of the potato plant may indicate its resistance to heat or drought, in order to be able to select such varieties according to “formal characteristics”, without conducting long-term tests.
«The main sign of resistance to heat and drought remains the yield, - reminds Alexey Bakunov, - we are trying to look for the relationship between the physiological and biochemical parameters of the plant with it. According to our observations, first of all, the course of the production process is influenced by the content of photosynthetic pigments, the level of lipid peroxidation, and the state of cell membrane systems.". During the test, scientists also came to the conclusion that potato varieties of different ripeness groups implement somewhat different adaptation mechanisms to adverse conditions.
«In early maturing varieties productivity is determined by high levelslack of photosynthetic pigments (chlorophyll b) and a low number of stomata per unit leaf area. In mid-season, the reverse pattern is observed: the level of photosynthetic pigments is slightly lower, and the number of stomata per leaf unit is higher. In addition, in the middle-early group, a high stability of the cell membrane system was revealed ahead of the increase in the mass of tubers (in July). And in mid-season varieties (as in varieties with the longest growing season) most high levels of proline (an amino acidyou who protect plant under stressful conditions) and minimal lipid peroxidation level”, – Alexei Bakunov shares his conclusions.
Based on the data obtained, the researchers were able to build experimental models of the dependence of the yield of potato varieties of different ripeness groups on hydrothermal cultivation conditions. In particular, scientists have determined that in early varieties, the yield depends more on air temperature than on soil moisture (they have time to capture spring moisture). On the contrary, mid-early and mid-ripening genotypes are more sensitive to the moisture content in the soil and less dependent on the increase in air temperature. At the same time, mid-ripening ones are more dependent on temperature than mid-early ones, since the process of tuberization is more extended in them.
These models can be used to predict the yield of different potato varieties. But the research is not over. Since 2022, the Samara Research Institute of Agriculture has moved to the next stage of work, now scientists will have to conduct a comprehensive test for drought resistance of 55 new varieties of potatoes. Does this mean that this criterion is becoming more and more important when growing a crop?
IT WILL BE HOT
Breeders have not yet noted an increased demand for drought-resistant potato varieties on the market and are cautious in their forecasts.
«Agricultural producers in our region suffer damage from recurring droughts from year to year, but a set of potato varieties that grown on farms, remains the same - tells Alexander Vasiliev, Chief Researcher of the South Ural Research Institute of Horticulture and Potato Growing, – with a request for droughtresistant potatoes we are mainly contacted by representatives of household plots. Perhaps that is why the level of potato productivity in the households of the population of the Chelyabinsk region is quite high and does not lag behind the level of peasant farms, although completely different technologies are used.cultivation gies.
Objectively drought-resistant varieties in the Southern Urals are needed now, but it is very difficult to make plans for the future. Given the pace of climate change, we cannot exclude the possibility that in 5-10 years it will be unthinkable to cultivate potatoes in our region without irrigation».
Evgeny Simakov assumes that the interest of agricultural producers in the main potato-growing regions of Russia in drought-resistant varieties will grow in the coming years.
«If the weather conditions in the non-chernozem belt, where the availability of irrigation for crop farms until recently was not a hard necessity, continue to change towards warming, and droughts become a constant phenomenon, agricultural producers will be forced to transfer most of the crops to irrigation, but it will not be easy to implement irrigation projects on a large scale because there are not so many sources of water, - the expert considers. In addition, do not forget about the costs, not every farmer can afford to purchase such equipment..
We will have to deal seriously with the selection of drought-resistant potato varieties, but we must understand that this process is quite lengthy. And it is necessary to be aware that the development of one feature, as a rule, is to the detriment of others.».
Samara Research Institute of Agriculture. N.M. Tulaykova, a branch of the SamRC RAS, thanks the staff of the Institute of Ecology of the Volga Basin RAS for their help in conducting the study “Evaluation of varieties and hybrid material of potatoes for resistance to biotic and abiotic stress factors in the conditions of the Middle Volga region”: O.A. Rozentsvet, E.S. Bogdanov, V.N. Nesterov.