The Effect of Fertilizers and Growth Regulators on the Productivity of Safflower (Carthamus tinctorius L.) in the Dry Climate of Russia

The cultivation of safflower (Carthamus tinctorius L.) is aimed at stabilizing the collection of oilseeds in the arid zone of chestnut soils of the Lower Volga region of Russia for the production of vegetable oils. The center of origin of safflower is the Mediterranean (Leus, 2020; Gatske et al., 2023), the climatic conditions are characterized as hot and dry. This explains the peculiarities of the biology of safflower plants and its ability to tolerate hot and dry weather, so it is suitable for cultivation in the dry steppe climate of chestnut soils. Safflower is capable of forming a seed harvest in the driest conditions with a light yellow semi-drying oil content of about 37%, protein up to 19%, starch up to 25%. The resulting cake from safflower seeds contains 18 amino acids and can be supplemented in diets when feeding small and large ruminants and birds (Vasilenko et al., 2018). Currently, the demand for safflower seeds is increasing. Major consumers of safflower seeds in world food markets are China (60.7 thousand tons), the USA (12.2 thousand tons), European countries 77 (thousand tons).
       
The technologies for growing safflower and sunflower are in many ways similar, since both crops belong to the Asteraceae family (Eskova et al., 2015). Increasing the productivity of safflower in the technological cycle of seed production is inextricably linked with innovation and resource conservation, which will help improve their economic efficiency. In the direction of increasing the productivity of safflower, the seed production techniques using mineral, micro fertilizers and growth regulators in various ways is intended (Hiremath et al., 2023; Vidyashree et al., 2021; Amare et al., 2020). An analysis of the scientific literature on the use of fertilizers and growth regulators in technologies for growing safflower seeds in arid climates allowed us to conclude that the maximum effective dose of nitrogen fertilizers was N₅₀, seed yield 1.3 t/ha (Eskova et al., 2015). It has also been established that the use of nitrogen fertilizers in various doses in safflower crops does not greatly affect the yield of safflower (Polyakov et al., 2020) and the natural nitrogen content in the soil will make it possible to obtain 0.92 t/ha of safflower seeds and a dose of nitrogen of 0.25-0.5 kg/ha contributed to obtaining a seed yield of 1.18-1.3 t/ha, NSR_0.5 0.26. The integrated use of agrochemicals will allow the yield of safflower seeds to be 20.6-35.6% higher (Amangaliev et al., 2023; Keteku et al., 2019). It has been established that the use of additional mineral nutrition together with growth regulators in various phases of plants directly affects the morphological structure of plants, growth (formation of additional branches, baskets), seed development and their filling by 10.9-26.7% (Bogosoryanskaya, 2009; Polyakov et al., 2020; Prahova et al., 2022).
       
Agrochemical measures to improve the mineral nutrition of safflower plants, aimed at increasing productivity, will contribute to increased economic efficiency (Andriyuk 2014; Razumnova et al., 2018). However, not enough scientific publications have been devoted to the use of mineral, micro fertilizers and growth regulators in the zone of chestnut soils of the Lower Volga region, therefore, our research will complement the technological issues of growing safflower in a dry climate.
 
Purpose of the research
 
Determine the effect of the use of mineral, micro fertilizers and plant growth regulators Ultamag Bor micro fertilizer and Biostim on the yield and sowing qualities of seeds and methods of their use in safflower crops.

The experimental site is located in the right bank zone of the dry steppe of the river. Volga at 130 m above sea level. Geographical coordinates of the experimental site: 50°01' 39"N. w. 45°07'39"E. d. The soil is medium deep, heavy loamy. The humus content is 1.8-2.4%, in the 0-30 cm layer: gross phosphorus and nitrogen 0.11 and 0.06%.
       
The climate of the site is sharply continental, with a maximum summer temperature of +45 and a maximum winter temperature of -41°C. Snow cover forms and reaches a height of up to 22 cm in snowy winters (Sazhin et al., 2017).
       
In March, when the soil is physically matured, cover harrowing Is laid in two layers and pre-sowing cultivation were carried out and safflower was sown in the third ten days of April.
       
During the research years 2021-2023, While, the safflower growing season, an average amount was about 108.7 mm of precipitation fell and the average monthly air temperature was 19.0°C. During the growing season of 2021, the State Customs Committee amounted to 0.65; 2022 0.8; 2023 0.8., the weather conditions of the safflower growing season can be characterized as arid (Zinkovsky et al., 2018).
       
Safflower seeds, sorts Alexandrit and Volgogradsky 15 (reproduction OS) were sown during the research period in the third ten days of April. Safflower seeds of the Alexandrit and Volgogradsky 15 varieties (reproductive OS) were sown during the research period in the third ten days of April. Regional varieties were obtained as a result of breeding work at the Federal Scientific Center for Agroecology of the Russian Academy of Sciences, Volgograd, Russia. The varieties have good drought and heat resistance, so they were chosen for testing fertilizers in safflower crops. The potential yield of varieties is more than 1.3 t/ha, weight of 1000 grains is 39.9-51.5 g, oil content is 25.8-27.3% (Belyaev, 2021). When sowing safflower, complex fertilizer Nitroammofosk was applied at the rate of 50 kg/ha, containing up to 27% N to begin the growth of the safflower root system, K up to 20% and P up to 18% to maintain and stimulate metabolic processes. Before sowing safflower seeds, the seeds were treated with a tank mixture of fungicides Imidor Pro KS 10 g + Title Duo 10 g + micro fertilizer Biostim Star 10 g in 10 liters of water.
       
The leaves in the “budding” phase (Fig 1) were treated with safflower crops according to the following options:
1. Ultamag Bor micro fertilizer 30 g/10 liters of water.
2. Micro fertilizer Ultamag Bor 30 g + Biostim Growth 30 g/10 liters of water.
3. Control variant without cultivation.
 

       
All variants of the experiment and their threefold repetitions were placed in one field systematically and consistently. The area of the experimental plot is 300 m². The results of the experiment on the use of agrochemicals through foliar feeding in the “budding” phase were processed by the method of analysis of variance (Dospehov, 2014).

Intensification is the most cost-effective way to improve seed quality and increase crop yields. One of the ways to increase and improve the quality and quantity of agricultural products is the use of mineral, micro fertilizers and growth regulators. As a result of the research, the influence of agrochemicals on plant height, changes in yield indicators and the quality of safflower seeds of the Volgogradsky 15 and Alexandrite varieties were clarified. Elements of the yield structure of safflower varieties are reflected in Table 1.
 

       
The highest height of the safflower plant 15-76.1 cm was found in the Volgogradsky sort in the variant with foliar treatment with preparations in the “budding” phase with a tank mixture of Ultamag Bor 30 g+Biostim Growth 30 per 10 liters of water sown with the preliminary pre-sowing application of mineral fertilizers Nitroammofoska. In the Alexandrite sort, the tallest safflower plant- 63 cm was the same variant of foliar crop cultivation.
       
The largest number of baskets was found after using Ultamag Bor 30 g + Biostim Growth 30 g per 10 liters of water, for the Volgogradsky sort 15-412 pieces. The best indicator of the number of baskets for the Alexandrite sort was in the same variant of foliar treatment of crops - 410 pieces. Also, the number of grains per plant in this variant of foliar treatment was the best in the safflower variety Volgogradsky 15-115, in Alexandrit-124. The quality indicators of safflower seeds weighing 1000 grains in the experiment were in the Ultamag Bor 30 g + Biostim Growth 30 g per 10 liters of water, for the Volgogradsky 15 variety 36.7 g, for the Alexandrit variety 36.5 g. However, the highest biological yield of safflower seeds was for the Alexandrit variety with the foliar treatment option Ultamag Bor 30 g + Biostim Growth 30/10 liters of water-1.8 t/ha.
       
According to the research results, it was found that the best results of the structural elements (Table 1) of the yield of tinting safflower were in the variant with foliar treatment Ultamag Bor 30 g/l + Biostim Growth 30 g/10 liters of water, the biological yield of the sorts was Volgogradsky 15 -1 .7 t/ha, number of seeds per plant 115 pcs. and grain weight per 1 m2 is 253.5 g, for the Alexandrit variety the seed yield is 1.8 t/ha, 124 pcs and 293.7 g, respectively (Fig 2, Fig 3).
 

 

       
The obtained results of the experiment on testing mineral, micro fertilizers and growth regulators were processed by the method of analysis of variance and are presented in Table 2.
 

       
Analysis of variance showed that 87% of the experimental effects on safflower yield were caused by foliar fertilizing with mineral and micro fertilizers with growth regulators in the “budding” phase. In the study, the “sort” factor had an effect of only 0.62%; other agro technological conditions had an impact on seed yield of 11.8%. The small difference in the seed yield of safflower varieties can be explained by the fact that the properties of the seeds did not have a large influence on the results of the experiment (0.62%).
       
Calculations on the economic efficiency of using mineral, micro fertilizers and growth regulators are presented in Table 3.
       
Information on the economic efficiency of growing safflower using mineral and micro fertilizers in the Lower Volga region is presented in Table 3, where you can see that the most economically profitable option is the third one with treatment during the “budding” phase with a tank mixture of Ultamag Bor 30 g + Biostim Growth 30 g per 10 liters of water- the economic efficiency of seed production obtained with this option for the Alexandrit variety is 414.2%, Volgogradsky 15-385.7%. Using the Ultramag Bor treatment option, a harvest of safflower seeds was obtained from the Alexandrit and Volgogradsky 15 varieties with an economic efficiency of 361.2%.
 

Research in 2021-2023 on the use of mineral, micro fertilizers and growth regulators for the production of safflower seeds has established that the best option is to treat the leaf with a tank mixture of Ultamag Bor 30 g + Biostim Growth 30 g per 10 liters of water in the “budding” phase “ The best option yielded a yield of safflower seeds from the Alexandrit variety of 1.8 t/ha with a profitability of 414.2%, Volgogradsky 15 yield of 1.7 t/ha, a profitability of 385.7%.

The work was carried out within the framework of the State assignment FNFE-2022-0010 “Creation of new competitive forms, varieties and hybrids of cultivated, tree and shrub plants with high levels of productivity, quality and increased resistance to adverse environmental factors, new innovative technologies in seed production and nursery farming, taking into account varietal characteristics and soil and climatic conditions of arid territories Russian Federation”.

The authors declare no conflict of interest. All authors made equivalent contributions to the preparation of the article for publication.