Sowing Depth Research Articles

Characterization of Cytoskeletal Profilin Genes in Plasticity Elongation of Mesocotyl and Coleoptile of Maize Under Diverse Abiotic Stresses.

The plasticity elongation of mesocotyl (MES) and coleoptile (COL) largely determines the morphology of maize seedlings under abiotic stresses. The profilin (PRF) proteins play a pivotal role in cytoskeleton dynamics and plant development via regulating actin polymerization. However, little is known about whether and how the expression of the ZmPRF gene family regulates MES and COL elongation in maize under adverse abiotic stresses. Here, a total of eight ZmPRF gene members were identified in the maize genome. They were mainly located in the cytoplasm, chloroplast, and mitochondrion, and clearly divided into four classes, based on phylogenetic analysis. Segmental duplication was the main driver for the expansion of ZmPRF genes. Ka/Ks analysis indicated that most ZmPRF genes were intensely purified and selected. Promoter cis-element analysis suggested their potential roles in response to growth and development, stress adaption, hormone response, and light response. The protein-protein interaction network and two independent RNA-sequencing analyses revealed that eight ZmPRF genes and their thirty-seven interacting genes showed varied expression patterns in MES and COL of three maize genotypes under different sowing depths, 24-epibrassinolide application, and light spectral-quality treatments, of which ZmPRF3.3 was a potential core conserved gene for breeding application. Moreover, the quantitative real-time PCR (qRT-PCR) verified that the relative expression levels of most ZmPRF genes in MES and COL under above treatments were significantly correlated with the plasticity elongation of MES and COL in maize. Therefore, these results perform a comprehensive overview of the ZmPRF family and will provide valuable information for the validation of the function of ZmPRF genes in maize development under diverse abiotic stress.

Modeling the response of crop emergence to sowing depth and soil water deficit in direct-seeded rice

Abstract Background and aims Dry direct seeding of rice in the tropics often suffers from poor crop establishment owing to soil water deficit. A potential solution is sowing deeply to utilize residual soil moisture farther below the surface. We evaluated rice emergence under various sowing depths and soil moisture conditions and tested a model framework of it as a simultaneous function of sowing depth and soil moisture. Methods We combined data from three field experiments and one growth chamber experiment to collect emergence data for four rice cultivars (Dontokoi, Dular, Rc222 and Rc420). We independently parameterized the relationships between emergence and sowing depth or soil water tension using logistic functions. We expressed the final emergence as the product of the two functions. Results Emergence responses to sowing depth and soil moisture fitted the cultivar-specific logistic functions well. For Dular, a cultivar that tolerates deep sowing, emergence was greatest when sown at 4 to 5 cm below the surface under soil water deficit, versus 1 to 2 cm under wet conditions, and our combined model successfully reproduced this result. Conclusion Our emergence model framework supports adjustment of sowing depth to account for available soil water, making the model a powerful new tool for drought adaptation in direct-seeded rice.

Field investigation of soil moisture profile in the seedbeds of clayey paddy fields composed of large clods (aggregates)

ABSTRACT Unstable germination and emergence of upland crops in clayey paddy fields is a pressing issue. As tillage leads to the formation of large clods measuring a few centimeters, the soil moisture content in the seedbed markedly decreases, potentially inhibiting germination of seeds. Although the effect of the clod size on the soil moisture profile was confirmed experimentally, the validity of this effect has not been tested in the field. In this study, we aimed to clarify the effect of clod size on the moisture profile and water balance in the seedbeds of clayey paddy field. We developed an apparatus for measuring soil moisture content in the soil layer with clods. This apparatus used a laser displacement sensor and large transparent plate horizontally fixed above the soil surface. Temporal changes in the soil moisture profile (0–10 cm depth) and evaporation rate of clayey paddy fields with different clod sizes were monitored during the sowing period of soybeans. We found that the larger the mean clod diameter (MCD), the greater the decrease in soil moisture content near the soil surface. In addition, soil moisture loss at the sowing depth (5 cm) was positively correlated with MCD. In terms of the water balance, the estimated upward water flux at a depth of 5 cm was less than 1 mm d−1 across all the plots and periods. By contrast, the estimated ratio of the apparent to molecular diffusion coefficient of water vapor in the dry soil layer of clayey paddy field with an MCD of 2.5 and 1.8 cm were 5.1 and 2.0, respectively. These results suggest that more significant soil moisture loss causing reduction of germination and emergence rate can occur in a clayey paddy field with large clods, likely owing to the increased enhancement of water vapor movement. To increase the germination and emergence rate, therefore, a numerical model that can evaluate the moisture profile of soil layer with clods should be developed and the sowing depth should be optimized based on the MCD.

Soil Moisture Detection and Linear Deceleration Control Strategy Enhancing Trenching Depth Precision and Stability for Rapeseed Sowing

Sowing depth significantly affects the germination of rapeseed, and different soil moisture conditions require corresponding sowing depths. However, most current trenching devices do not account for soil moisture content, and commonly used hydraulic or constant-force trenching equipment also exhibits deficiencies in stability and consistency. To address these challenges, this study developed an automatic depth adjustment control system based on soil moisture content. A soil moisture detection device and an innovative sliding mechanism that maintained the soil moisture sensor in a relatively stationary position relative to the soil during seeder movement were introduced. An automatic sowing depth adjustment device was designed to modulate the sowing depth. A control strategy that incorporated the Kalman filtering algorithm and linear deceleration equations was conducted. At an observation noise covariance matrix (Q/R) of 0.001, a deceleration range of 40 mm and a minimum speed of 10, the control system exhibited minimal overshoot (approximately 4%) and steady-state error (approximately 3.2 mm). It effectively adjusted the trenching depth while operating at speeds ranging from 2 to 3.6 km/h, successfully adapting to variations in soil topography. The system performance tests revealed that the control system adjustment time (ts) was 534 ms and the steady-state error remained within 1 mm. Under three different soil moisture content conditions, the sowing depth qualification rate and stability coefficients consistently surpassed 90% and 80%, respectively. This research offers a sowing depth adjustment control system based on soil moisture content, contributing to more precise depth regulation for rapeseed sowing.

Sowing Depth Monitoring System for High-Speed Precision Planters Based on Multi-Sensor Data Fusion

High-speed precision planters are subject to high-speed (12~16 km/h) operation due to terrain undulation caused by mechanical vibration and sensor measurement errors caused by the sowing depth monitoring system’s accuracy reduction problems. Thus, this study investigates multi-sensor data fusion technology based on the sowing depth monitoring systems of high-speed precision planters. Firstly, a sowing depth monitoring model comprising laser, ultrasonic, and angle sensors as the multi-sensor monitoring unit is established. Secondly, these three single sensors are filtered using the Kalman filter. Finally, a multi-sensor data fusion algorithm for optimising four key parameters in the extended Kalman filter (EKF) using an improved sparrow search algorithm (ISSA) is proposed. Subsequently, the filtered data from the three single sensors are integrated to address the issues of mechanical vibration interference and sensor measurement errors. In order to ascertain the superiority of the ISSA-EKF, the ISSA-EKF and SSA-EKF are simulated, and their values are compared with the original monitoring value of the sensor and the filtered sowing depth value. The simulation test demonstrates that the ISSA-EKF-based sowing depth monitoring algorithm for high-speed precision planters, with a mean absolute error (MAE) of 0.083 cm, root mean square error (RMSE) of 0.103 cm, and correlation coefficient (R) of 0.979 achieves high-precision monitoring. This is evidenced by a significant improvement in accuracy when compared with the original monitoring value of the sensor, the filtered value, and the SSA-EKF. The results of a field test demonstrate that the ISSA-EKF-based sowing depth monitoring system for high-speed precision planters enhances the precision and reliability of the monitoring system when compared with the three single-sensor monitoring values. The average MAE and RMSE are reduced by 0.071 cm and 0.075 cm, respectively, while the average R is improved by 0.036. This study offers a theoretical foundation for the advancement of sowing depth monitoring systems for high-speed precision planters.

Association mapping of mesocotyl and coleoptile length in rice using various genome‐wide association study models

AbstractThe mechanized direct seeding of rice (Oryza sativa L.) is a major trend nowadays. The elongation of rice mesocotyl and coleoptile can facilitate the rapid emergence of seedlings under deep mechanized sowing. Currently, most of the cultivated rice accessions have short mesocotyls or coleoptiles, with only a few related genes cloned. However, understanding and enhancing the ability of rice seedlings to rapidly emerge from deep sowing depths is crucial. Herein, we assessed 745 core rice germplasm accessions sown under a soil cover depth of 10 cm and found few long mesocotyl and coleoptile germplasms. We conducted genome‐wide association study using six models to obtain three or more multi‐model co‐localization candidate regions and calculated Fst between the phenotypes of extreme samples to determine genetic differences. The candidate regions associated with mesocotyl and coleoptile lengths were identified by integrating Fst and multi‐model localization results. This multi‐model localization method may accelerate the mining of genes related to the mesocotyl and coleoptile, providing valuable targets for functional validation and marker‐assisted selection in rice breeding programs.

Sowing depth control strategy based on the downforce measurement and control system of ‘T’-shaped furrow opener

Sowing depth is a critical factor in crop growth and is determined by both the soil conditions and the force of the opener. The trend for the future is to control sowing depth based on soil dynamic parameters. Therefore, this paper developed a downforce measurement and control system based on the ‘T’-shaped furrow opener and investigated the influence of soil dynamic parameters and opener downforce on sowing depth. A test-rig was constructed and the accuracy of the system in measuring downforce and controlling downforce and sowing depth was verified. The study shows that at different sowing depths, soil moisture, bulk density and their interaction have a significant effect on downforce (P < 0.01). As the moisture content decreases and the bulk density increases, the required downforce increases for the same sowing depth. A mathematical model of downforce-sowing depth-soil bulk density-soil moisture content was established using experimental data, with an R2 of 0.916, VIF <5 and a Durbin-Watson value of 1.628. Field experiments show that, at an operating speed of 6 km h−1, the control strategy based on the soil dynamic parameters predicted by downforce theory significantly outperformed the strategy of adjusting the downforce in response to perceived changes in downforce. This indicates that after dynamic and rapid measurement of soil bulk density and moisture content during field operations, sowing depth can be accurately controlled based on the directed downforce of the opener. The mathematical model provides a theoretical basis for sowing depth control based on soil dynamic parameters.

Sowing depth stability analysis and test verification of no-tillage planter parallel 4-bar row unit

The sowing depth stability and consistency of the no-tillage planter, particularly the high-speed operation, are poor. A reason for this is that the structure and parameter selection of no-tillage planter row unit profiling mechanism are unreasonable. The stability and consistency of sowing depth is beneficial when the upper and lower links of the parallel 4-bar profiling mechanism (PFPM) are parallel to the ground, but this principle is not satisfied on the uneven no-till soil. To improve the stability of gauge wheels downforce (GWD) and sowing depth of no-tillage planter row unit. The variation law of spring additional downforce (SAD) with tilt angle of parallel 4-bar profiling mechanism (PFPM) and connection offset of spring is discussed by constructing the steady state analysis matrix equation of PFPM. Additionally, the influence of tilt angle of PFPM and SAD on the stability of the sowing depth was analyzed. Based on the single factor control variable test method, bench and field tests were conducted. The test results show that the SAD increases nonlinearly with the increase in the degree of tilt of PFPM from downward to upward. Under the condition that four springs are installed and the tilt angle of PFPM is between (−20°–20°), the maximum SAD is 485.95 N, 1236.64 N, and 2258.05 N when the spring connection offset is 44 mm, 79 mm, and 115 mm, respectively. When the tilt angle is 8° upward, the GWD increases by 429 N, 575 N, and 984 N, GWD stability increases by 42.31 %, 56.16 %, and 50.29 %, and ditching depth stability increases by 30.00 %, 12.50 %, and 30.00 % compared with that of the control group at the sowing speed of 8, 10, and 12 km/h, respectively. At the sowing speed of 10 km/h, when the PFPM is operated with spring-free and additional springs, the average GWD increases by 353 N, and the stability of GWD and ditching depth increases by 34.38 % and 20.00 %, respectively. The results showed that the tilt upward of PFPM and SAD were beneficial to improve the stability of the GWD and sowing depth of the no-tillage planter row unit. The results not only verify the correctness of theoretical analysis, but also provide theoretical basis for the design and application adjustment of high-speed no-tillage planter.

Design and experiment of a stereoscopic vision-based system for seeding depth consistency adjustment

The basic process of corn sowing includes seed selection, land preparation, fertilization, sowing, and soil compaction. Soil compaction is an important step in the sowing process, playing a crucial role in protecting the seeds, promoting germination and root development, and providing a stable growth environment for corn. Currently, mainstream soil compaction devices used in corn sowing employ non-active adjustment structures, which cannot regulate the amount of soil covering and the compaction force for individual seeds during the sowing process, making it difficult to ensure consistent sowing depth. To address these issues, this study investigates the soil compaction device on a corn planter and proposes a soil compaction device that utilizes a binocular structured light camera to detect the opening depth of the planter and flexibly adjust the soil covering and compaction force for each seed. Experimental evaluations of the device’s performance were also conducted. The design of the sowing depth consistency control system includes the selection and application of the design, motor, gearbox, binocular structured light camera, dust removal device, user interface, electric-driven soil compaction device, and control system. The experimental results showed that when the system detects a variation in trench depth of around 2 cm, the average response time of the system is 2.23 s with a standard deviation of 0.042 s. When the system detects a variation in trench depth of around 4 cm, the average response time of the system is 4.68 s with a standard deviation of 0.078 s. This suggests that the system’s response time fluctuates within 0.1 s, indicating good stability of the system. The average error of the planter’s opening depth, as measured by the binocular structured light camera, is approximately 6 mm, the success rate of detection can be maintained above 70 % under different trench depths. The dust removal device’s performance meets the requirements of the detection system. The research demonstrates that the sowing depth consistency control system developed in this study can accurately detect the planter’s opening depth during operation and adjust the soil covering, compaction force appropriately based on the depth information provided by the soil compaction device.

Rice encrusting with small‐seeded native species for reintroduction in agroecosystems: a case study in Lindernia procumbens

Seed coating is commonly applied in agricultural seed industry to alleviate biotic and edaphic barriers and improve seed germination, seedling emergence and establishment. Recently, this seed enhancement technology has been tested and applied to seeds of native species for ecological restoration and conservation. This work presents a novel application of seed coating for the reintroduction of species with dust‐like seeds that render direct seeding and cultivation unfeasible. Here we have used seed coating on Lindernia procumbens (Krocker) Philcox (Linderniaceae), a threatened annual species of paddy fields. Lindernia procumbens seeds were encrusted to the surface of rice seeds that acted as carrier to spread the species along rice sowing. We first tested how two selected concentrations of binder affected L. procumbens germination, then we investigated sowing depth (i.e. surface level—light, and buried—darkness) effect. Rice encrusting is a feasible and valuable tool for preserving threatened species with tiny seeds, since binder did not limit L. procumbens germination. Light increased L. procumbens seedlings emergence compared to buried conditions. Although L. procumbens emergence was limited in a paddy field trial, we promoted the formation of a soil seed bank for the species. As such, this should not discourage the possibility to reintroduce rare species with tiny seeds in agroecosystems. This pioneering technique can be extended to ecological restoration, where there is an urgent need for new seed‐based approaches and seed‐coating technologies to improve seedling establishment and restoration efficacy.

The effect of different sowing depth on the yield and yield-forming elements of maize

On a global scale, maize is an important food, feed and industrial crop, with an increasing production area (Nagy, 2007 and 2021). Among the environmental impacts, extreme weathering factors caused by climate change are causing serious problems for crop stability, and maize is no exception. Precision farming is today's most innovative agrotechnical approach, which can greatly increase crop safety and reduce costs by exploiting the genetic potential of our soils and the hybrids we use (Torres, 2012). Sowing is one of the most important agrotechnical elements, and with good seeding we can ensure that we have all the requirements of a high yielding, high growing crop (Pepó, 2019). In the case of sowing, it is important to place the seed in moist soil to provide the optimum environmental conditions for the crop to ensure uniform emergence (Széles et al., 2020; Shrestha et al., 2018). Precision planting is the market leading technology in precision planters in the United States, and when cooperating with them we looked for methods to optimise the depth of sowing and to monitor the effect on yield by studying the initial development of the plants. The seeder was equipped with the company's SmartFirmer soil scanner integrated into the seed drill. Automatic seed depth adjustment based on soil moisture is an exceptional solution for uniform emergence and drought protection.

Organic amendment composition and sowing depth in coffee Arabica: Effects on seedling growth biometrics

There is a significant production of coffee in the Gedeo zone, southern Ethiopia, which has could generate a huge amount of coffee husk wastes that have polluted the environment. However, organically enriching the soil is an effective method to enhance the development and productivity of coffee. Thus, this study aims to understand the effects of the interaction between sowing depth and organic amending practices. Three sowing depths and sixteen different organic amendment compositions were tested in a complete randomized design with three replications. Coffee seedling growth biometrics was measured, and R-program was used to calculate the statistical difference at a 5 % significance level. The organic amendment composition with 3:2:1 (topsoil: forest soil: sand) sown at a depth of 2 cm had statistically higher values of seedling stem height, leaf length, and taproot length by 82.82 %, 93.35 %, and 85.41 % than in the topsoil at a depth of 3 cm. Likewise, the main effect of organic amendment with 3:2:1 (topsoil: forest soil: sand) in internode length, number of nodes per seedling stem, number of true leaves per seedling, and leaf width were also higher by 70.42 %, 63.16 %, 92.23 % and 91.80 % than seedlings grown in topsoil solely. Interestingly, the days of 50 % emergence in 3:2:1 (ratio of topsoil: forest soil: sand) organic amendment composition were earlier by 62.11 days than using topsoil. This could be because of the accessibility of a significant quantity of organic carbon, primary macronutrients, alkaline nature of the growth media in addition to having low bulk and particle densities in the forest soil that could increase coffee seedling growth biometrics by improving soil porosity, aeration and nutrient uptake capacity, producing important soil microbes and neutralizing organic acids in comparison with the topsoil.

Response of late-sown wheat (Triticum aestivum) to limited irrigation, seed rate and depth of sowing

A field experiment was conducted during the winter (rabi) season of 2014–15 and 2015–16 at New Delhi, to study the effect of limited irrigation, seed rate and depth of sowing on growth, yield, water-use parameters and economics of late-sown wheat (Triticum aestivum L.). The experiment comprised 3 factors, viz. 3 irrigation levels [(I1 , irrigation at crown-root initation (CRI) stage; I2 , irrigation at CRI stage + 0.2 irrigation water: cumulative pan evaporation (IW : CPE) ratio; and I3, irrigation at CRI stage + 0.4 IW : CPE ratio), 3 seed rates (S1, 75; S2, 100 and S2, 125 kg/ha) and 2 depths of sowings (D1, 5 cm and D2 , 10 cm). The field experiment comprising 18 treatment combinations, replicated thrice, was laid out in strip-plot design. Interactions between irrigation levels and seed rates, and irrigation levels and depths of sowing for grain yield were significant during 2014–15. Irrigation levels, seed rates and depths of sowing also significantly affected plant height, yield attributes, grain yield, straw yield and harvest index. Irrigation at CRI stage + 0.4 IW : CPE ratio resulted in significantly the highest plant height (86.3 cm), effective tillers/m2 (407.82), spike length (14.40 cm), spikelets/spike (17.43), grains/spike (44.20), grain weight/spike (2.05 g), 1,000-grain weight (48.95 g), grain yield (4.22 and 3.75 t/ha during 2014–15 and 2015–16) and harvest index (0.497 and 0.477 during respective season). Seed rate of 125 kg/ha resulted in significantly the highest plant height (82.7 cm), effective tillers/m2 (416.66), spike length (14.62 cm), spikelets/spike (17.53), grains/ spike (40.20), grain weight/spike (2.06 g), 1,000-grain weight (47.80 g), grain yield (3.63 t/ha during 2015–16) and harvest index (0.496 and 0.456 during respective year). Sowing depth of 10 cm resulted in significantly the highest plant height (82.2 cm), effective tillers/m2 (382.64), spike length (13.94 cm), spikelets/spike (16.44), grains/spike (38.21), grain weight/spike (1.90 g), 1,000-grain weight (46.24 g), grain yield (3.95 and 3.49 t/ha during both the years) and harvest index (0.456 and 0.443 during both the years).

高速作业种肥播深可控的花生播种机的设计与试验研究

Aiming at the traditional peanut planter seed and fertilizer sowing depth inconsistency caused by seed burning and injury, fertilizer waste and low seed emergence rate, the design of a peanut planter with high-speed operation and controllable seed and fertilizer sowing depth was performed. The laser sensor is added to detect the height of the ridge and the furrow opener position feedback, and the speed sensor detects the operating speed of the peanut planter. The mechanical analysis of the four-link rod clarifies the control principle, improves the PID algorithm of the integral term, designs the control strategy based on the operating speed of the planter, controls the electro-hydraulic system, and realizes the sowing and fertilizing depth adjustment of the furrow opener. Through the design of three-factor three-level orthogonal simulation test, it is concluded that the vehicle speed and height deviation value are significant factors affecting the sowing and application depth, and under the verification of the field test, it is obtained that when the sowing depth is 50 mm under the speed of 3 km/h, the dynamic sowing depth qualification rate is 96.26%, and the maximum coefficient of variation of the sowing depth is 2.58%, which improves the effect of the existing control of the sowing depth of the peanut by 6.05%, and reduces the variation of the sowing depth by 2.85%. The research has demonstrated superior performance compared to traditional mechanical adjustment in regulating the planting depth of peanuts, thereby achieving the intended design objective.

Genome-Wide Association Study Uncovers Genomic Regions Associated with Coleoptile Length in a Worldwide Collection of Oat.

The length of coleoptile is crucial for determining the sowing depth of oats in low-precipitation regions, which is significant for oat breeding programs. In this study, a diverse panel of 243 oat accessions was used to explore coleoptile length in two independent experiments. The panel exhibited significant variation in coleoptile length, ranging from 4.66 to 8.76 cm. Accessions from Africa, America, and the Mediterranean region displayed longer coleoptile lengths than those from Asia and Europe. Genome-wide association studies (GWASs) using 26,196 SNPs identified 34 SNPs, representing 32 quantitative trait loci (QTLs) significantly associated with coleoptile length. Among these QTLs, six were consistently detected in both experiments, explaining 6.43% to 10.07% of the phenotypic variation. The favorable alleles at these stable loci additively increased coleoptile length, offering insights for pyramid breeding. Gene Ontology (GO) analysis of the 350 candidate genes underlying the six stable QTLs revealed significant enrichment in cell development-related processes. Several phytochrome-related genes, including auxin transporter-like protein 1 and cytochrome P450 proteins, were found within these QTLs. Further validation of these loci will enhance our understanding of coleoptile length regulation. This study provides new insights into the genetic architecture of coleoptile length in oats.

Development of a Solar Powered Seeder for Pea Seeds

One of the most profitable vegetable crops for farmers to plant is peas. Pea seeding by hand is still one of the most tedious techniques farmers use today. Pea seed sowing requires a more significant number of skilled workers. The soil is dug by one person, and the pea seeds is sown there by another. Regarding farmers, the availability of skilled labor is still another issue. Egypt has many small farms; hence, it is necessary to produce small-scale farming machinery. Thus, this research manufactures a solar-powered seeding mechanism exclusively for small farmers at a low cost to overcome the problems of a lack of labor skills, sowing times, labor cost, accurate seeding, and seed losses. Increase profit for farmers who plant vegetable crops. The machine is provided with an accurate system to achieve accurate seed distribution. A complex gear mechanism is replaced with a sensor to make seeding simpler. There is an input LCD screen to sow at various distances between seeds. The distance between rows can be maintained. Also, there is a solar tracking system, which is essential for receiving more direct sunlight. Also, the motors used are 12 volts, so they are compatible with the electricity produced from the solar panel without the need for a voltage converter, which reduces costs. Also, both fuel costs and air pollution do not exist. The study includes two experimental variables: four theoretical hill spacings of 15, 18, 21, and 24 cm and four sowing depths of 2, 3, 4, and 5 cm. The measurements include the plant's longitudinal dispersal, lateral dispersal, emergence percentage, and operating costs. The minimum values of longitudinal and lateral dispersal and the highest value of emergence percentage were obtained at a theoretical hill spacing of 24 cm and a sowing depth of 5 cm. The developed machine can lower the operational cost by 94.96%, as one skilled worker can adequate complete the seeding operation. Therefore, it is suggested to use the solar-powered system for seeding pea seeds in small-scale farming.

The Effect of Three Depths of Mechanical Seed Drill (Gaspardo SC-250) on the Performance of Vicia Faba L. Bean for Yield Characteristics and Components

Current study was conducted on a farm in two sites: the center of Kirkuk Governorate and Hawija District, during the 2022–2023 agricultural season. It focused on two factors: the seeding depths of the Gaspardo SC-250 machine (at 2, 3, and 6 cm) and three varieties (local, Yildiz, and Aquadulce). The land was divided according to a randomized complete block design (RCBD) according to a split-plot system with three replicates. The study allocated the sowing depth factor to the main panels and the variety factor to the secondary panels. The findings showed a notable improvement in yield characteristics and components when sowing depths were increased at both sites. It was observed that the total yield of dry seeds was significantly influenced by sowing depths at both sites, with D3 showing superior results, producing 2074.91 kg/ha and 7854.71 kg/ha, respectively. We observed that the Aquadulce variety had the highest yield rate, producing 5503.64 kg/ha and 7441.37 kg/ha, respectively. There was a significant impact of sowing depths and varieties on this trait at both sites. Specifically, at the Kirkuk site, the Aquadulce variety had the highest yield at depth D1, with 8413.83 kg/ha. At the Hawija site, the Aquadulce variety outperformed the other varieties at depth D3, yielding 9863.83 kg/ha. This superior performance was attributed to the quality of its components, resulting in a significant increase in the final yield.

Physiological evaluation of Sonchus oleraceus L. seeds with different pre-germinative treatments under high tropical latitudinal conditions

Sonchus oleraceus L. is an invasive species that negatively affects the quality and yield of different crops. This research aimed to evaluate the physiological behavior of seeds from the weed S. oleraceus L., which were subjected to different treatments in three experiments. In experiment 1, different gibberellic acid (GA) concentrations were applied (0, 200, 400, and 600 mg L-1). In the second experiment, apical, basal, and apical-basal cut treatments were carried out on the seeds. In a third experiment, seeds were placed at different sowing depths (0.5, 1, 2, 5, and 10 cm) in peat as the substrate. The results indicated that GA at concentrations higher than 200 mg L-1 inhibited seed germination and, consequently, seedling growth. Germination was similar between the 200 mg L-1 GA treatment and the control, but germination occurred faster in the control. The apical-basal cut in the seeds generated the highest percentage of germination, the highest average speed of germination, and a significantly lower time of germination than the control; however, the longest shoot was observed in the seeds without a cut, and the longest root was detected in the seeds with the basal cut. Seedling emergence was affected by sowing depth, where it was significantly greater at 0.5, lesser at 2 cm, and, at greater depths, seedlings did not emerge.

ОБОСНОВАНИЕ РЕЖИМОВ РАБОТЫ ТРАКТОРА К-735 С ПОЧВООБРАБАТЫВАЮЩЕ-ПОСЕВНЫМ КОМПЛЕКСОМ КУЗБАСС ПК 6.1

Modern crop production is characterized by the introduction of resource-saving methods of processing and cultivation of crops aimed at preserving and increasing soil fertility. The purpose of the research is to determine traction and energy indicators and substantiate the operating modes of a machine-tractor unit based on a K-735 wheeled tractor with a Kuzbass PK 6.1 sowing complex. Based on research, it was found that the pulling force in sowing varies from 19.0 kN to 37.43 kN, the output hook power ranges from 40.11 to 124.26 kW and depends on the speed of the unit, the depth of sowing and the weight of the bunkers. The modes of operation of the unit are justified: at a depth of 5 cm in the second mode, 3 gears at a speed of rotation of the diesel crankshaft 1900 min–1 , after unloading the seeds 50 % transition to the 4th gear of the second mode at a speed of rotation of the diesel crankshaft in the range from 1730 to 1750 min–1 ; at depths of 7 and 9 cm on the second in the 3rd gear mode at a speed of rotation of the diesel crankshaft 1900 min-1 , after unloading the seeds 75 % transition to the 4th gear of the second mode at a speed of rotation of the diesel crankshaft in the range from 1730 to 1750 min–1 .

USING BLACK WALNUT ROOTSTOCK FOR CREATING HIGH-YIELDING WALNUT PLANTATIONS

The comparative analysis of seed germination and growth of walnut and black walnut seedlings in the conditions of the Right-Bank Forest-Steppe of Ukraine was carried out. It was found that in rows with a sowing depth of 10 cm and 13 cm, the germination rate of walnut had the highest rates and amounted to 70% and 63%, respectively, and black walnut - 80% and 84%. The lowest germination rate was observed at a sowing depth of 17 cm for walnut and 6 cm for black walnut, 46% and 39%, respectively. The influence of the position of the walnut seeds on their germination was determined. In particular, when sown by the "top up" and "on the edge" methods, the germination rate was 70% and 72%, which is 24-26% higher than the "top down" and "side by side" methods. The germination energy of black walnut seedlings was found to be higher than that of walnut seedlings. The first signs of germination of black walnut were observed 7 days earlier than in field crops of walnut. It was found that the main growth of seedlings in height began from the end of the first decade of June and lasted until the first decade of August. The average height of black walnut seedlings was 50 cm, while the average height of walnut seedlings was 19 cm lower and amounted to 31 cm. The yield of standard black walnut seedlings was recorded at 69% of the total number of seedlings, while in walnut this figure was only 12%. The compatibility of the varieties 'Webu-6', 'Chandler' and 'Kazaku' with black walnut and walnut during the cultivation of grafted seedlings was studied. It was found that the selected experimental varieties of walnut, which were grafted onto black walnut seedlings, showed approximately the same formation of callus tissues, except for the variety 'Vebu-6'. This once again confirms the information that not all walnut varieties can participate in interspecific combinations. It was found that the length of the central root of the black walnut at the end of the first year of cultivation is 15 cm longer than the length of the central root of the walnut and averages 43 cm. The main branching of lateral roots in walnut occurs at a depth of 10 to 20 cm. The number of main skeletal roots is generally 3-4 units. At the end of the first year of cultivation, the seedlings had a significantly smaller root system compared to black walnut. The root system of standard black walnut seedlings is on average 60% larger than that of walnut. The main branching of lateral roots is on average at a root length of 7 to 30 cm. Similar to the walnut, the root system of black walnut has 2-3 tiers. The number of skeletal roots averages 8-10 pieces, and the length of the main skeletal roots ranges from 15 to 30 cm. According to the research results, it can be concluded that walnut seedlings grafted on black walnut seedlings have prospects for further introduction into production as they can bear fruit faster, have relatively restrained growth, allow for the formation of a crown at the 3rd year of life and have a more powerful root system.