Diseases caused by Bipolaris sorokiniana, expressed as leaf spot blotch (SB) and common root rot (CRR), continue to limit spring wheat production, particularly in dry regions where yield losses may reach 35-40%. This study evaluated resistance to SB and CRR in fifty spring wheat genotypes at both seedling and adult plant stages and identified genetic sources of resistance using molecular markers linked to the Sb1 and Sb2 genes. Field trials were conducted in 2023 and 2024 in the Aktobe region under natural infection, artificial inoculation, and a fungicide-treated background. Based on leaf spot blotch severity quantified as the area under the disease progress curve (leaf AUDPC) under natural infection, nine genotypes displayed stable resistance across both years, while fungicide-treated plots revealed twenty-three resistant genotypes in 2023 and eighteen in 2024. Artificial inoculation identified five resistant lines in 2023 and one in 2024. Resistance to common root rot (CRR) was assessed independently based on subcrown internode (SCI) browning at the adult plant stage. Seedling assays confirmed consistent resistance in six genotypes, all of which carried Sb1, Sb2, or their combination. In total, Sb genes were detected in thirty-six of the fifty accessions, including genotypes from Kazakhstan, Russia, and several other countries. The presence of Sb1 or Sb2 was associated with reduced disease severity, particularly at the seedling stage. These findings identify valuable germplasm for breeding wheat with improved resistance to B. sorokiniana in Kazakhstan.
The article evaluates the role of remote sensing in the precision farming system. It has been found that plant and soil diagnostics of nitrogen and phosphorus nutrition play a primary role in the differentiated application of fertilizers. Spectral indices directly dependent on the level of nitrogen nutrition in winter wheat have been identified. Increasing the rate of applied mineral nitrogen from 60 to 180 kg/ha increased NDVI values from 0.64 to 0.72. The residual effect of manure application at 20–60 t/ha altered these values within a narrower range, from 0.62 to 0.67. Potassium fertilizers had little effect on NDVI values, with a slight tendency to decrease as application rates increased. The correlation between nitrogen and chlorophyll content in plants and grain yield was calculated, based on which nitrogen sufficiency indices and "greenness" indices were obtained for different grain yield levels. With the help of portable photometers of NDVI indices obtained with portable photometers is comparable to traditional methods of nitrogen nutrition diagnostics and can be effectively used in precision farming to quantitatively assess the degree of in-field heterogeneity and the nitrogen needs of winter wheat crops.
Tan spot of wheat, caused by the fungus Pyrenophora tritici-repentis (Ptr), is one of the most destructive foliar diseases of wheat worldwide and in Kazakhstan. Expansion of wheat plantings, the adoption of no-till methods, and the use of ineffective fungicides contribute to the accumulation of inoculum and the spread of the pathogen. Despite the important role of fungicides in plant protection, data on the susceptibility of Ptr populations in Kazakhstan are lacking. This study, for the first time, assessed the susceptibility of Ptr isolates from various regions of Kazakhstan to QoI and DMI fungicides. A predominance of genotypes associated with ToxA (82.9%) was found, with a limited distribution of ToxB (7.9%). Propiconazole demonstrated the highest efficacy, inhibiting mycelial growth by an average of 70.85%, followed by pyraclostrobin (69.04%), while azoxystrobin demonstrated lower efficacy (41.47%). Molecular analysis revealed the widespread prevalence of the G143A mutation in the cytochrome b gene, associated with resistance to the QoI fungicide. These results indicate the emergence of strobilurin resistance in Ptr populations in Kazakhstan and highlight the need for regular monitoring of fungicide susceptibility and the development of effective resistance management strategies.
Kazakhstan possesses considerable potential for the development of organic agriculture. In organic production systems, the use of chemical plant protection products is restricted or completely excluded, making the cultivation of genetically resistant wheat lines to major fungal diseases one of the most effective approaches for maintaining stable grain production. The current study aimed to evaluate disease resistance in wheat genotypes by integrating phenotypic screening and marker-assisted selection and their validation under organic farming conditions. A total of 50 facultative and introgressive wheat lines were evaluated under an artificial infection background for resistance to yellow rust, leaf rust, stem rust, and common bunt. Molecular marker analysis was performed to identify resistance-associated alleles. Integrated phenotypic and molecular analyses enabled the identification of three promising genotypes, namely 1675-52, 1723-32, and 1716-24. They combined a high level of resistance to yellow rust and common bunt with the presence of resistance-associated alleles. These selected genotypes were subsequently validated under organic field conditions. The results demonstrated that these lines maintained stable resistance to yellow rust and common bunt and produced seed yield ranging from 5.45 to 5.94 t/ha, exceeding that of the standard cv. Almaly (4.88 t/ha). The obtained results confirm the effectiveness of integrating phenotypic screening with marker-assisted selection for identifying wheat genotypes with complex disease resistance. These genotypes represent promising prebreeding resources for organic agriculture, subject to validation across a wider range of environments.
Efficient nutrient management is essential for enhancing flax productivity under semi-arid conditions. A two-year field experiment (2024–2025) was conducted in southeast Kazakhstan to evaluate the effects of integrated foliar fertilization with macro- and micronutrients and biofertilizers on the growth, seed quality, and yield of flax (Linum usitatissimum L.). The experiment was arranged in a randomized complete block design with five treatments: T1 (control, absolute zero fertilization (N0P0K0), i.e., soil without any additional nutrient applications), T2 (N60P60K60), T3 (N60P60K60 + foliar macro–micronutrients), T4 (biofertilizer), and T5 (N60P60K60 + foliar macro–micronutrients + biofertilizer). Integrated foliar fertilization significantly increased nitrogen, phosphorus, and potassium concentrations in vegetative biomass and seeds, leading to higher nutrient uptake and improved nutrient use efficiency compared with mineral fertilization alone. Treatments combining foliar macro- and micronutrients with biofertilizers (T3 and T5) enhanced plant establishment, biomass accumulation, and dry matter allocation to reproductive organs. Seed yield increased from 0.58 to 0.89 t ha−1, while protein and oil contents ranged from 27.0 to 28.4% and 39.8–41.8%, respectively. The combined foliar treatment showed the highest and most stable performance, likely due to improved nutrient uptake and plant growth. These findings indicate that integrated foliar fertilization is an effective and sustainable strategy for improving flax yield stability, nutrient efficiency, and seed quality under semi-arid conditions.
