Main Shoot Research Articles

Selection of cucumber for parthenocarpy for spring greenhouses

Scientific relevance. Currently, in the protected ground, the main areas are occupied by parthenocarpic hybrids of cucumber of foreign origin. Therefore, the selection of domestic cucumber hybrids of the parthenocarpic type is very relevant.Material and conditions. The experience was laid in 2018-2022 in the Odintsovo district of the Moscow region in the conditions of a spring film ground greenhouse of the "Block" type on the basis of the head institution of the FSBSI FSVC. Agrotechnics of cultivation is generally accepted for the conditions of spring film greenhouses. In breeding nurseries where there were no bees, the degree of parthenocarpy was determined as the ratio of the fruit set to the number of female flowers formed on the plant, as a percentage. The records were carried out from the 5th to the 20th node inclusive, only on plants of the female type of flowering. On the basis of the laboratory of breeding and seed production of pumpkin crops, 27 collectible and more than 50 breeding samples of parthenocarpic cucumber were studied.Results. During three years of research, 7 hybrids of cucumber of the parthenocarpic type of foreign breeding were selected based on the sum of economically useful traits.These hybrids were distinguished by a high degree of parthenocarpy. With their participation, as a result of multiple selections and self-pollination, more than 50 breeding lines were created. Analysis of the obtained material showed that the degree of manifestation of parthenocarpy on the plant (the arithmetic mean between the indicators of parthenocarpy on the main and lateral shoots) in the best half of the samples in 2021 was in the range of 30-50%, whereas in 2022 it already reached 50-70%. The parthenocarpy severity coefficient above 70% was noted only in 2022 in 4% of samples. About half of the samples showed a fairly low parthenocarpy: in 2021 no more than 30%, and in 2022 no more than 50%. Most of them were rejected. The parthenocarpy of the best breeding samples in 2022, compared with 2021, increased by an average of 17.7%. Breeding lines obtained even from the same collection sample often differed greatly, sometimes by 4 times, in the degree of parthenocarpy. The families of the most stable parthenocarpy samples had differences on this basis in 2021 only 3-6%, and in 2022 – 10-11%. Families with the greatest severity of this trait were selected annually. It can be concluded that the degree of parthenocarpy in cucumber strongly depends on both the genotype of the sample and the growing conditions. 3 breeding lines were selected, characterized by high indicators of the degree of manifestation of parthenocarpy in 2021 (61.5-70.5%) and the stability of the manifestation of this trait by families and years.

Effect of elevated temperature on phenology, growth, yield components and seed yield of Brassica juncea grown in temperature gradient tunnels (TGT)

Elevated temperature is one of the major production constraints of Indian mustard. The present study was aimed to estimate variations in phenology, yield attributes and seed yield under elevated temperature (ET) in temperature gradient tunnels (TGT) and open field for heat tolerance. Fourteen genotypes consisting of introgression lines and the mustard varieties were sown in TGT and open field for two consecutive winter seasons (2017-2019).The phenophases were shortened due to elevated temperature in TGT as compared to control except physiological maturity which was trailed by 17-18 days during both the years. Temperature affect was most severe on siliqua formation and seed filling. Among growth parameters only length of main shoot suffered reduction whereas yield contributing parameters like siliqua on main shoot, siliquae plant-1, seeds siliqua-1 and 1000 seed weight along with biomass, seed yield and harvest index suffered significant decline in TGT. Average temperature had positive correlation with all phenological parameters except flowering completion, growth parameters except number of primary and secondary branches while yield attributes only with 1000 seed weight, biomass and seed yield under TGT. Interestingly, number of primary branches had significant negative correlation with average temperature under both control (r=-0.59*) and TGT (-0.61*). Phenological traits had strong relationship with seed yield under TGT. However, seed yield had strong relationship with growth parameters, yield attributes under control except for number of primary branches. Biomass had strong relationship with seed yield under both TGT (R2= 0.51) and control (R2= 0.43). Two years testing revealed introgression lines (JA24 and JA53) and varieties (JD6 and Giriraj) tolerant to heat stress.

Influence of lightculture on obtaining planting material of Ipomoea batatas (L.) in vitro

The current article presents the results of the influence of lighting conditions on the morphogenetic potential of Ipomoea batatas (L.) microcuttings in vitro. The studied objects were 4 sweet potato cultivars - Jewel, Purple, Porto Rico, Vinnitsa pink. Microcuttings of I. batatas were cultivated in vitro. We used nutrient medium with mineral salts (according to the prescription of Murashige and Skoog (MS)) and medium only with distilled water (without mineral salts). All nutrient media contained sucrose 2% and agar 0.7%. Hormones were not added to the nutrient media. We studied the influence of the different red (R) and far red (FR) ratios, as well as the red and blue light spectrum on the formation of microshoots and the root system. It was shown that the lighting regimes (R and FR ratio) had a stimulating effect on the roots and shoots growth regardless of the medium composition. Moreover, significant results were obtained under conditions of complete nutrition (mineral salts according to MS) in contrast to the control treatment (fluorescent lamps) and the treatment without salts. The best results were obtained at the R=FR treatment. This light treatment can be recommended for inclusion in the technology of clonal micropropagation of sweet potato. When red and blue spectra were added to normal illumination in different proportions, it did not lead to an increase in the morphogenetic potential of cultivated explants. The growth rate (μ) of the main shoot from axillary buds was about 2 times less than in the control treatment.

Liguleless narrow and narrow odd dwarf act in overlapping pathways to regulate maize development and metabolism.

Narrow odd dwarf (nod) and Liguleless narrow (Lgn) are pleiotropic maize mutants that both encode plasma membrane proteins, cause similar developmental patterning defects, and constitutively induce stress signaling pathways. To investigate how these mutants coordinate maize development and physiology, we screened for protein interactors of NOD by affinity purification. LGN was identified by this screen as a strong candidate interactor, and we confirmed the NOD-LGN molecular interaction through orthogonal experiments. We further demonstrated that LGN, a receptor-like kinase, can phosphorylate NOD in vitro, hinting that they could act in intersecting signal transduction pathways. To test this hypothesis, we generated Lgn-R;nod mutants in two backgrounds (B73 and A619), and found that these mutations enhance each other, causing more severe developmental defects than either single mutation on its own, with phenotypes including very narrow leaves, increased tillering, and failure of the main shoot. Transcriptomic and metabolomic analyses of the single and double mutants in the two genetic backgrounds revealed widespread induction of pathogen defense genes and a shift in resource allocation away from primary metabolism in favor of specialized metabolism. These effects were similar in each single mutant and heightened in the double mutant, leading us to conclude that NOD and LGN act cumulatively in overlapping signaling pathways to coordinate growth-defense tradeoffs in maize.

Performance of Turmeric (Curcuma longa L.) Variety Megha Turmeric-1 in Various Districts of Assam

Aim: An experiment was conducted in the farmers’ field of various locations representing four agro climatic zones of Assam to assess the performance of Turmeric variety Megha Turmeric-1.
 Place and Duration of the Study: The study was conducted by the Krishi Vigyan Kendras of Karbi Anglong, Udalguri, Barpeta, Darrang, Dibrugarh, Sivasagar and Sonitpur under Assam Agricultural University.
 Results: The study revealed that the plant was 175.24 cm tall with 10 numbers of leaves on main shoot. Additionally, the leaf lamina length and width were found to be 54.08 cm and 15.18 cm respectively from the study. The leaf disposition was erect with distant venation and wavy leaf margin. Moreover, the rhizomes were found to have distant inter nodal pattern along with tertiary rhizomes. The crop recorded higher yield 249.63 quintal per hectare against the local varieties in all the locations.
 Conclusion: From the study, it can be inferred that the farmers may adoptMegha Turmeric-1 over their local varieties for better yield and returns.

Pre-Sowing Laser Light Stimulation Increases Yield and Protein and Crude Fat Contents in Soybean

Pre-sowing laser light stimulation is a method commonly used to increase the productivity of legume species. However, it has not been proved that single-laser light stimulation is a more effective technique for enhancing plant productivity and seed yield quality than using different laser lights in sequence, by which means synergistic relations are produced. A two-year, single-factor field experiment was performed in order to test selected combinations of light stimulation of soybean seeds, the effectiveness of which would be expressed as increased plant yield and improved quality parameters. Pre-sowing light stimulation of soybean seeds was shown to significantly influence the morphological traits of the plants. It significantly increased pod number, pod weight, seed number, and seed weight compared to the control. Coherent laser light stimulation of soybean seeds with a helium–neon laser and with an argon laser increased soybean yields by 30% on average compared to the control. The ratio of the yield from the main shoot to the yield from the lateral branches in this treatment was 40:60, indicating that pre-sowing stimulation of seeds had a significant and positive effect by increasing the yield of the lateral branches relative to the control. Stimulation of seeds (3 × 3 s) with a helium–neon laser significantly increased protein content in soybean seeds, on average by 11% compared to the control. A longer duration of pre-sowing stimulation of seeds (3 × 9 s) resulted in a significant increase in crude fat content in the seeds by an average of 5% compared to the control. The use of physical light stimulation on soybean seeds is a promising solution for increasing soybean yields.

Estimation of avoidable yield losses in Indian mustard (Brassica juncea L.) due to mustard aphid, Lipaphis erysimi (Kaltenbach) in Rewari district, Haryana, India

The Indian mustard (Brassica juncea L.) is a significant oilseed crop in India. The sap-sucking pest, mustard aphid (Lipaphis erysimi) emerged as a major threat to this crop, which can harshly reduce yield. The research experiment was carried out during the Rabi seasons, 2019-20 and 2020-21 at Rewari, Haryana to comprehend the influence of L. erysimi infestation on different yield parameters of B. juncea in the field. The two cultivars of B. juncea namely, RH 725 and RB 50 were raised in a paired plot design with two different sets viz., protected and unprotected and thirteen replications each set were kept. The protected set was sprayed with insecticide Dimethoate 30 EC @ 625 ml ha-1 one time only, whereas unprotected set was kept free from insecticidal application for natural infestation of the pest. The present investigation revealed that under unprotected conditions, the yield parameters viz., weight of 100 siliquae, 100 siliquae husk, 10 main apical shoots (10 cm) and 1000 seeds, as well as seed yield, were significantly (P<0.01) affected by the L. erysimi infestation, while parameter, seed germination percentage influenced non-significantly (P>0.01). The maximum seed yield losses were registered in genotype RH 725 (26.25 %) when compared with RB 50 (25.92 %). All other yield parameters exhibited the same pattern except for three parameters i.e. weight of 100 siliquae, 100 siliquae husk and 10 main apical shoots (10 cm). In conclusion, this research highlights the colossal yield losses inflicted by L. erysimi infestation in B. juncea in unprotected conditions and the utility of insecticidal application in the enhancement of crop yield by management of this insect pest in protected conditions.

Contribution of tillers to maize yield stability at low plant density

AbstractOne of the main challenges of using low plant densities in restrictive and variable environments is to maximize the use of resources in better‐than‐expected years. In this context, tillering could be an alternative to increase reproductive and vegetative plasticity. The objectives of this study were to (a) characterize the correlation between environmental conditions, tiller traits, crop grain yield, and grain yield advantages due to tillers; (b) determine the grain yield response to tillering (i.e., grain yield difference between tillered and nontillered crops) for a wide range of environments; and (c) to evaluate the effect of tiller presence on grain yield of the main shoot, considering its effect on the apical and subapical ears. Tillered and nontillered crops were evaluated under rainfed conditions during two seasons (2018–2019 and 2019–2020). These experiments were carried out at 11 sites in the southern Argentinean Pampas, varying sowing date (22 Oct. to 5 Dec.), plant density (2–3 plants m−2), genotype (AX7784 and AX7761), and soil depth. Grain yield (3.2–11.9 Mg ha−1) was correlated with tillers productivity, mainly explained by postflowering precipitations. The contribution of tillers to grain yield was more proportional than their consequent yield depression at the main shoot. Tillers either increased (3 sites) or maintained (8 sites) grain yield, and their contribution increased as the environment improved without any detrimental effect in the most restrictive environments. Tillering has the potential for increasing resource (radiation, water, nitrogen) use efficiency under low plant density strategies adopted for restrictive environments.

Detection of Candidate Loci and Genes Related to Phosphorus Efficiency at Maturity through a Genome-Wide Association Study in Soybean

Phosphorus (P) deficiency is one of the major factors limiting soybean production, and approximately 90% of P absorbed by plants occurs during the reproductive stage. Thus, it is important to understand the genetic mechanism underlying soybean low-P tolerance, especially in the mature period. Here, we evaluated six P-efficiency-related traits at maturity of 219 soybean accessions, namely, plant height (PH), node number of the main shoot (NN), branch number of the main shoot (BN), pod number per plant (PN), 100-seed weight (100SW), and seed yield per plant (SY), under normal-phosphorus (NP) and low-phosphorus (LP) conditions across two environments. Then, a genome-wide association study (GWAS) in conjunction with a high-density NJAU 355 K SoySNP array was performed. As a result, 27 P-efficiency-related single nucleotide polymorphisms (SNPs) were identified. Furthermore, two repeated SNPs, AX-93897192 and AX-93897200, located on chromosome 19 that were associated with both PH and NN were considered as stable SNPs associated with P deficiency, and the candidate gene GmABCG39 was identified. This work will be helpful in breeding high-P-efficiency soybean varieties.

Adaptive potential and productivity of two Salix viminalis L. clonal varieties grown in North Central Bulgaria

Salix viminalis L. is a broadly cultivated willow species that has been intensively used for breeding purposes, particularly in selection of clones and hybrids for biomass production. The present study aimed to explore and compare growth and adaptability of two basket willow (Salix viminalis L.) clonal varieties - rubra and purpurea - at the specific edaphic and climate conditions and cultivation practice presented in an experimental plantation in North Central Bulgaria. The influence of spacing, genotype, root age and rotation on their productivity were also investigated and allometric relationships for non-destructive estimation of woody plant biomass were suggested. The trial plantation was established in the spring of 2018 as 4 sectors of a Nelder wheel plot with 15 nearly-square spacings, ranging from 0.25 to 9.80 m2 (40000–1020 plants per hectare). The two varieties were arranged in 4 four-spoke sectors (2 sectors per clone). Data collection took place from 2018 to 2020 and comprised 1- and 2-year rotations. The study showed that Salix viminalis var. rubra was more susceptible to desiccation-causing adverse climatic changes, poorly adapted to the specific conditions of the study site and gradually died out during the second and the third year. Salix viminalis var. purpurea exhibited steady survival rate (97 - 77%) and annual biomass productivity varying from 3 to 17 Mg/ha/year across the densities, sectors and years. During the first year of growth purpurea variety had a significantly higher plant weight and sprout number than rubra variety. Growing space affected positively the number of shoots and tree dendromass, and sprouting was reinforced by coppicing that doubled the shoot number during the subsequent rotation. This was reflected in the development of the stump-level allometric models that were differentiated according to rotation. The stump-level allometric model of higher predictive power was based on the main shoot length and shoot number. An exponential relationship to the breast-height shoot diameter was also suggested for biomass estimation of each sprout separately.

Wheat yield potential can be maximized by increasing red to far-red light conditions at critical developmental stages.

Sensing of neighbours via the Red to Far-Red light ratio (R:FR) may exert a cap to yield potential in wheat. The effects of an increased R:FR inside the canopy were studied in dense wheat mini canopies grown in controlled environments by lowering FR. To distinguish between effects exerted by light sensing and assimilate supply, the treatments were complemented with elevated CO2 , applied between different developmental timepoints to specifically impact tillering, spike growth, floret fertility and grain filling, in different combinations. The yield response to high R:FR was strongly dependent on the developmental stage in all three cultivars and pivoted between positive if applied after the start of stem elongation, and negative or null if applied before. Yield gains of up to 70% and 120% were observed, respectively, in two cultivars, associated with a higher number of tiller spikes and grains per spike in the main shoot. The response to the combination of high R:FR and elevated CO2 or CO2 alone were cultivar dependent. Taken together, our results suggest that R:FR exerts a significant control on yield potential in wheat and achieving a high R:FR from stem elongation to maturity is a promising lever towards a significant increase in grain yield.

Apical dominance control by TAR-YUC-mediated auxin biosynthesis is a deep homology of land plants

A key aim in biology is to identify which genetic changes contributed to the evolution of form through time. Apical dominance, the inhibitory effect exerted by shoot apices on the initiation or outgrowth of distant lateral buds, is a major regulatory mechanism of plant form.1 Nearly a century of studies in the sporophyte of flowering plants have established the phytohormone auxin as a front-runner in the search for key factors controlling apical dominance,2,3 identifying critical roles for long-range polar auxin transport and local auxin biosynthesis in modulating shoot branching.4-10 A capacity for lateral branching evolved by convergence in the gametophytic shoot of mosses and primed its diversification;11 however, polar auxin transport is relatively unimportant in this developmental process,12 the contribution of auxin biosynthesis genes has not been assessed, and more generally, the extent of conservation in apical dominance regulation within the land plants remains largely unknown. To fill this knowledge gap, we sought to identify genetic determinants of apical dominance in the moss Physcomitrium patens. Here, we show that leafy shoot apex decapitation releases apical dominance through massive and rapid transcriptional reprogramming of auxin-responsive genes and altering auxin biosynthesis gene activity. We pinpoint a subset of P.patens TRYPTOPHAN AMINO-TRANSFERASE (TAR) and YUCCA FLAVIN MONOOXYGENASE-LIKE (YUC) auxin biosynthesis genes expressed in the main and lateral shoot apices and show that they are essential for coordinating branch initiation and outgrowth. Our results demonstrate that local auxin biosynthesis acts as a pivotal regulator of apical dominance in moss and constitutes a shared mechanism underpinning shoot architecture control in land plants.

How Strigolactone Shapes Shoot Architecture.

Despite its central role in the control of plant architecture, strigolactone has been recognized as a phytohormone only 15 years ago. Together with auxin, it regulates shoot branching in response to genetically encoded programs, as well as environmental cues. A central determinant of shoot architecture is apical dominance, i.e., the tendency of the main shoot apex to inhibit the outgrowth of axillary buds. Hence, the execution of apical dominance requires long-distance communication between the shoot apex and all axillary meristems. While the role of strigolactone and auxin in apical dominance appears to be conserved among flowering plants, the mechanisms involved in bud activation may be more divergent, and include not only hormonal pathways but also sugar signaling. Here, we discuss how spatial aspects of SL biosynthesis, transport, and sensing may relate to apical dominance, and we consider the mechanisms acting locally in axillary buds during dormancy and bud activation.

Effect of temperature stress on Brassica rapa genotypes during germination and reproductive growth

The effect of temperature stress on the reproductive development and yield of five Brassica rapa was studied in a controlled growth chamber. The seeds of five Brassica genotypes namely BARI Sarisha-6, Tori 7, Kallayania, BARI Sarisha-9 and BINA Sarisha-4 were grown under day/night temperatures at 22/170C until early flowering or early siliqua development stage. The high temperature stress i.e., 28 /170C or 35/170C, both at early flowering stage and early siliqua formation stage were imposed for 7d and then allowed to recover at 22/170C for normal growth. Shoot dry matter accumulation varied with temperature and genotype. The highest shoot dry matter was recorded by Kallayania followed by BARI Sarisha-9. The optimum day temperature for seed yield of the main shoot showed closer to 280C. The largest seeds were produced in the 22/170C, the size, however, remained similar with 28/170C temperature stress. During this temperature regime, the highest seed yield was observed with BARI Sarisha-6 while BARI Sarisha-9 produced the lowest seed yield. Severe temperature stress (35/170C) reduced seeds per siliqua and 1000 seed weight in all genotypes. Maximum pollen viability and germination were recorded at 200C by Kallayania followed by Tori 7 at 250C. However, the temperature above 300C reduced pollen viability and germination for all the genotypes. In another set of treatments, the high temperatures exposure (28/230C) for 5d reduced oil content and increased protein concentrations. Plant exposed to 25/200C temperature stress showed significant changes in oleic, linoleic, and linolenic acids. The levels of saturated fatty acids were similar across the five genotypes in the control treatment, but palmitic acid and stearic acids increased with the temperature. Bangladesh J. Agri. 2019-2021, 44-46: 19-29

Effect of chicken manure and pruning on kyuri cucumber plant

Japanese or kyuri cucumber was more longer, softer and suitable for salads than local cucumber. Cultivation techniques for increasing the production of cucumbers can be done by manipulating growth by the pruning and application of manure especially chicken manure which is more complete than other manures. The study was conducted at Deli Serdang regency in polybag from January until April 2021. The result showed that the application of chicken manure has a significant on fruit weight per plant and root weight at a dose of 600 g/polybag. Pruning the main stem shoots has a real effect on the weight of the fruit. There is an interaction between chicken manure and pruning on fruit weight per plant. The best interaction was in combination of treatment with pruning and manure 600 g/polybag. So, cultivation of cucumbers in polybags is recommended using chicken manure 600 g/polybag and pruning on the main stem shoots.

Morphometry of shoots and flowers of Utricularia minor at a large site in the Czech Republic

In 2021, a large population of Utricularia minor was found in a revitalized former sandpit with strongly acidic and dystrophic water in the Czech Republic. The plants in the population were robust, highly branched, flowered prolifically, and set seeds. The mean length of main shoots of robust U. minor plants was 72 cm (range 54-90 cm). Each plant had a total of 7-17 branches. Inflorescences with at least one ripening fertile capsule were 11-33 cm long and bore 6-11 flowers or capsules at different ages. However, only two ripe fertile capsules (mean 1.21) formed at maximum in one inflorescence.

Genetic Variability Analysis of M4-M5 Mutants of Indian Mustard (Brassica juncea L.)

Indian mustard [Brassica juncea (L.) Czern. & Coss.] is an important oilseed crop grown in India under diverse agro-ecological conditions in the temperate and subtropical regions during Rabi season. It fits well in the rainfed cropping system with low production cost and high potential to increase edible oil. Farmers in Assam grow rapeseed toria (Brassica rapa) due to its short duration but end up with low yield. Development of short-duration superior Indian mustard varieties is required to increase the average yield of rapeseed-mustard in Assam. Some Indian mustard genotypes were developed by induction of mutations at Assam Agricultural University, Jorhat. In the present study, 143 M4 lines from the parent variety NRCHB-101 of Indian mustard developed through mutation breeding using gamma rays, were evaluated during Rabi 2020-21 followed by 116 M5 selected lines during the Rabi 2021-22 to assess to genetic variability and interrelationships between yield component traits. Significant variation due to genotypes for the characters observed. Moderate genetic variation was observed for seed yield plant-1, number of primary and secondary branches plant-1. Moderate heritability coupled with high genetic advance was observed for number of siliquae in main shoot, number of primary branches, and number of secondary branches. The mutant lines JMM-NRCHB101-37, JMM-NRCHB101-57, JMM-NRCHB101-107 were found to be promising exhibiting superior performance for most of the yield attributing characters. The mutant line JMM-NRCHB101-86 and JMM-NRCHB101-95 also showed potentiality for early maturity with a high yield which could be exploited for the development of early maturing mustard varieties.

Depositing capacity of winter wheat stem segments under natural drought during grain filling in Ukrainian forest steppe conditions

Drought is a major abiotic factor adversely affecting wheat productivity. Water deficit reduces significantly photosynthesis and hence the remobilization of stored assimilate reserves from the stem becomes important sources for grain filling. We assessed the ability of different stem internodes and leaf sheaths to deposit and remobilize reserve assimilates as well as their role in grain yield formation in 6 winter wheat varieties under drought conditions during the period of grain filling. The dry weight and content of water-soluble carbohydrates in the dry matter of stem internodes and leaf sheaths of the main shoot was determined at anthesis, the beginning of milk ripeness and full grain ripeness. The total amount of water-soluble carbohydrates in stem segments was calculated as the product of their specific content in the dry matter of the stem segment and its mass. The amount of remobilized dry matter and water-soluble carbohydrates for each segment was estimated as the difference between the appropriate values at anthesis or milk ripeness and full ripeness. The maximum accumulation of water-soluble carbohydrates in the stem was reached at early milk ripeness. The most productive varieties Kyivska 17 and Horodnytsia had the largest amount of remobilized water-soluble carbohydrates in all internodes. Depositing capacity of the second and third (counting from the top) internodes was higher compared to others and has a significant effect on the grain productivity of wheat varieties studied. Despite significant variability and strong genotype x year interaction of the relationships between depositing capacity traits of different stem segments and grain productivity, mainly tight correlations were found for dry matter and total water-soluble carbohydrates accumulation and remobilization in second and third internodes with yield and grain weight per spike. The obtained data suggests that the remobilization of deposited water-soluble carbohydrates is an important factor contributing to the filling of winter wheat grain in arid conditions and more detailed studies of relationships of depositing capacity of individual stem segments with yield can be useful for development of breeding tools for further genetic yield improvement.

Entomocomplex of onions in the Right-Bank Forest-Steppe of Ukraine

Goal. To monitor the phytosanitary condition of onion crops in the Right-Bank Forest-Steppe of Ukraine and to establish the species composition of dominant pests.
 Methods. The research was carried out in accordance with the generally accepted methodological recommendations in entomology.
 Results. As a result of long-term monitoring of onion crops, 12 species of phytophages from the ranks of Coleoptera — 46.2%, Lepidoptera — 23.1%, Diptera — 15.4%, Thysanoptera — 10.4%, Orthoptera — 5.0% and others. In the phase of leaf development (main shoot) (ВВСН 1—19) the most harmful are soil-dwelling pests: larvae of Agriotes sputator L. and Agriotes lineatus L.; larvae of the Melolontha melolontha L., the Melolontha hippocastani F), the Amphimallon solstitialis L.; Scotia segetum Schiff. and Gryllotalpa gryllotalpa L. In the phase of the beginning of thickening of the base of the leaves — bulb formation (ВВСН 41—43) phytophages dominate: onion fly (Delia antique Mg.), onion trips (Trips tabaci Lind.), Ceuthorrhynchus jakovlevi Schulzer.
 Conclusions. It was studied that with the number of soil pests 1.5—2.8 specimens/m2, plant damage is 24.6—28.3%, which is the reason for the liquefaction of crop density. It has been established that significant damage to onion crops is caused by the onion fly (Delia antique Mg.), the period of harmfulness of which lasts throughout the growing season. During the years of research, the flight of the phytophagous adult took place in the third decade of April — first decade of May, at the sum of active CAT temperatures (> 5°C) = 104—131°С. Mass flight of the pest was observed in the II—III decades of May, at an average daily air temperature of 12.8—17.4°C.

Genetic Variability and Trait Association in Indian Mustard [Brassica juncea (L.) Czern and Coss

Background: Twenty-four released varieties of Indian Mustard were evaluated during rabi 2015-16 and 2016-17 under irrigated environment to study character association for seed yield and its component traits. Methods: Analysis of variance on thirteen quantitative characters was carried out and pooled over the years. Path analysis was carried out using correlation coefficients to know the yield contributing traits. Result: Significant differences were noticed for all the traits among the genotypes. The genotypic and phenotypic variation is higher for seed yield/plant, 1000 seed weight, secondary branches/plant and total siliquae/plant. Heritability estimate were very high for 1000 seed weight, siliqua length, plant height, seeds/siliqua, total siliquae/plant and days to maturity. Genetic advance as percent of mean were high for seed yield/plant, 1000 seed weight, secondary branches/plant and total siliquae/plant. The correlation of seed yield/plant shows significant positive association with days to maturity, primary branches/plant, secondary branches/plant, total siliquae/plant, siliqua length, seeds/siliqua, 1000 seed weight and length of main shoot. From correlation coefficients and path analysis it appeared that length of main shoot, 1000 seed weight, number of secondary branches/plant and days to maturity were most important yield components having highly positive direct and indirect effects.