Leaf Yield Research Articles

Recycling of Mulberry Stalk as Biochar and its Effect on Uptake of Nutrients by Mulberry

A field experiment was conducted in the mulberry crop to know the effect of soil application of mulberry stalk biochar on nutrients uptake by mulberry at farmer’s field at Sidlaghatta (Tq), Chikkabalapura District. A randomized block design was employed with eight treatments and three replications. A randomized block design was employed with eight treatments replicated thrice. Results revealed that, Combined soil application of biochar @ 10 t ha-1 and FYM @ 10 t ha-1 (T8) recorded higher leaf yield per hectare (13.07 t ha-1) and it was on par with T7 (12.61 t ha-1) which received soil application of biochar @ 7.5 t ha-1 and FYM @ 10 t ha-1. The lowest leaf yield of 10.45 t ha-1 was recorded in control which was devoid of biochar. Among different treatments, significantly higher uptake of primary nutrients (Nitrogen, phosphorus and potassium of 90.68, 9.07 and 47.10 kg ha-1, respectively) secondary nutrients (calcium, magnesium and sulphur of 44.48, 17.26 and 9.75 kg ha-1, respectively) and micronutrients (iron, manganese, zinc, copper and boron of 748.20, 153.22, 139.34, 60.92 and 54.25 g ha-1, respectively) by mulberry were recorded in the treatment (T8) which received soil application of biochar @ 10 t ha-1 + FYM @ 10 t ha-1 and followed by T7 which received biochar @ 7.5 t ha-1 + FYM @ 10 t ha-1 and found superior over other treatments. The control with no biochar application recorded lower nutrients uptake by mulberry crop. The findings revealed that utilization of mulberry stalk as a biochar has positive effect on nutrient uptake by mulberry crop and it could partly replace chemical fertilizers and promote organic farming in a circular economy concept.

Water-Use Characteristics of Wheat–Maize Rotation System as Affected by Nitrogen Application Rate in North China Plain

Reducing the nitrogen (N) application rate and improving water-use efficiency (WUE) are extremely important for sustainable agricultural development in wheat–maize rotation systems in the North China Plain (NCP). We conducted a three-year experiment to investigate the effects of the N application rate on the water-use characteristics of wheat–maize rotation systems in the NCP. The experiment consisted of four N application rates: 250, 167, 84, and 0 kg hm−2, denoted by N3, N2, N1, and N0, respectively. The results showed the following: For the 0–60 cm soil layer, N deficiency could lead to reduced soil water use (SWU) in wheat seasons, but in maize seasons, N deficiency showed no significant effects on SWU in the 0–60 cm layer. For the 60–140 cm soil layer, N deficiency could lead to reduced SWU in wheat seasons, but in maize seasons, the effects of N deficiency on SWU in the 60–140 cm layer varied with the SWC in the 0–60 cm layer. Throughout the three-year experiment, the evapotranspiration (ET), leaf area index (LAI), yield, and WUE of plants receiving low N treatments decreased with the growing season due to the negative effects of low N treatment (N1 and N0) on the soil. The LAI, total ET, grain yield, and WUE were all positively correlated with each other for both wheat and maize. Considering grain yield and WUE, a single-season N application rate of 167 kg hm−2 (N2 treatment) in the NCP could meet the growth needs of the wheat–maize rotation system.

Coconut Rugose Spiraling Whitefly <i>Aleurodicus Rugioperculatus</i> Martin Nutrient Depletion and Yield Loss

The study was conducted to find out the yield limiting nutrients in coconut palms a result of infestation of invasive rugose spiraling whitefly Aleurodicus rugioperculatus Martin through understanding the relationship between the leaf nutrient status and yield. The nitrogen levels were negatively and highly significantly correlated with yield loss (%) in Godavari Ganga hybrid (r = - 0.997**) and East Coast Tall (ECT) palms (r = - 0.999**). The phosphorus (P), potassium (K), calcium (Ca), boron (B) and magnesium (Mg) were found to be ideal in the leaflets of hybrid and ECT palms, with optimum critical levels of P, K, Mg, B ranging from 0.12, 0.80, 0.25, 0.30% and 10 mg/ kg. It can be concluded that the impact of A. rugioperculatus incidence was noticed on nitrogen content of coconut leaflets and reflected in the form of nut yield reduction in Godavari Ganga hybrid and ECT coconut palms at Kalavalapalli plantations.

Effect of Mulberry Stalk Biochar on Soil Nutrients Status and Productivity of Mulberry (Morus alba L.)

Biochar as an organic amendment improves soil attributes, with a potentially significant effect on soil fertility. The main objective of this study was to quantify the effect of biochar addition on nutrients status in mulberry cultivated soil. A field experiment was conducted in the mulberry crop to know the effect of soil application of mulberry stalk biochar on nutrients build up in soil at farmer’s field at Sidlaghatta (TQ), Chikkaballapura District during 2020-2021 (rabi2020, summer and kharif-2021). A randomized block design was employed with eight treatments replicated thrice T1: Control (NPK375:140:140 kg ha-1 alone) T2: POP (FYM (25 t ha-1) + NPK 375:140:140 kg ha-1) T3: Soil application of biochar @ 5 t ha-1T4: Soil application of biochar @ 7.5 t ha-1 T5: Soil application of biochar @ 10 t ha-1T6: Soil application of biochar @ 5 t ha-1 + FYM @ 10 t ha-1T7: Soil application of biochar @7.5 t ha-1 + FYM @ 10 t ha-1T8: Soil application of biochar @ 10 t ha-1 + FYM @ 10 t ha-1NPK is common for all the treatments. Combined soil application of biochar @ 10 t ha-1 and FYM @ 10 t ha-1 (T8) increased the leaf yield (13.07 t ha-1) by 21 % over control (10.45 t ha-1 Significantly higher soil primary, secondary and micronutrients were recorded in T8 (soil application of biochar @ 10 t ha-1 + FYM @ 10 t ha-1) followed by treatment T7 which received soil application of biochar @ 7.5 t ha-1 + FYM @ 10 t ha-1. The lower soil primary, secondary and micronutrients were recorded in T1 which is devoid of biochar. The findings revealed that utilization of mulberry stalk as a biochar has positive effect on the improvement of nutrient status and it could partly replace chemical fertilizers and promote organic farming in a circular economy concept.

Method for Monitoring Wheat Growth Status and Estimating Yield Based on UAV Multispectral Remote Sensing

An efficient and accurate estimation of wheat growth and yield is important for wheat assessment and field management. To improve the accuracy and stability of wheat growth and yield estimation, an estimation method based on a genetic algorithm-improved support vector regression (GA-SVR) algorithm was proposed in this study. The correlation analysis between vegetation indices calculated from spectral data and wheat growth phenotypes and yields was performed to obtain the optimal combination of vegetation indices with high correlation and good estimation performance. At the same time, the optimal model for wheat growth monitoring was screened and constructed in experiments with 12 wheat varieties and 3 gradient nitrogen fertilizer application levels. Then, the yield estimation model was established and its applicability was verified under different nitrogen fertilizer application levels. The results showed that the constructed models for the leaf area index, plant height, and yield estimation performed well, with coefficients of determination of 0.82, 0.71, and 0.70, and root mean square errors of 0.09, 2.7, and 68.5, respectively. This study provided an effective UAV remote sensing technique for monitoring wheat growth status and estimating yield. This study provides an effective unmanned aerial remote sensing technique for monitoring wheat growth and estimating yield, and provides technical support for wheat yield assessment and field management.

Assessing Impact of Manual Topping and Suckericide Application at Different Stages on FCV Tobacco Quality and Yield

Tobacco (Nicotiana tabacum L.) topping is one of the essential practice to obtain good quality and adequate yield. The suckericide (Flumetralin as a best herbicide and plant growth regulator). For the purpose to compare topping as manual and herbicide application the experiment was conducted on flue cured Virginia (FCV) tobacco at Tobacco Research Station, Khan Ghari, Mardan during 2021-2022. The experiment was conducted in RCB design with three replications and five treatments (Control, Manual de-suckering, 1000, 1200, 1500 ml of Flumetralin ha-1). Treatments were applied at three stages (button stage, early flowering stage and late flowering stage). The data revealed that topping timing and maximum dose (1500 ml ha-1) of (Flumetralin) resulted maximum (896 cm-2) leaf area, less number (14) of sucker plant-1, lower (132 g) green weight and dry weight (20.30 g) of sucker plot-1, more cured weight (5.08 kg) of leaves plot-1 and maximum yield (3038) kg ha-1, lower nicotine contents (2.26) and less sugar contents (16.24) at button stage. Moreover, Flumetralin application on at button stage resulted less sucker growth and enhanced leaf yield. I suggest that the tobacco K399 with the application of suckericide and growth regulator (Flumetralin) have the potential to incorporate in further breeding program for low content of nicotine, reduced sugar content and high yield.

Consecutive Pruning Enhances Leaf Flavonoids, Leaf Yield, and Cutting Rooting in Ginkgo biloba

Ginkgo biloba L. is a valuable medicinal plant known for its high content of flavonoids and terpenoids in the leaves of young trees. Pruning can increase leaf yield in ginkgo plantations; however, it is unclear how the intensity of pruning affects leaf yield and quality. In addition, G. biloba exhibits low cutting rooting rates, which limits its efficiency in asexual propagation. In our study, we compared consecutive pruning with varying levels of intensity, including top pruning, light pruning, and heavy pruning, to evaluate the effects of pruning on leaf yield and cutting rooting. The results showed that these three pruning methods all contributed to an increase in the number of new branches, the leaf weight, and the flavonoid content in five-year-old trees. Among them, the effect of light pruning was the best, with a 150% increase in branch number, a 130% increase in leaf weight, and a 40.6% increase in flavonoid content. The secondary pruning further increased leaf area by 22.3%, indicating that secondary pruning further enhanced the rejuvenation of plants and increased leaf yield. At the transcriptional level, pruning can significantly change the expression of genes related to bud sprouting, resulting in a particularly significant increase in SHR expression in the buds. Pruning also promoted the expression of important genes related to flavonoid synthesis, including chalcone synthase (CHS), flavonoid 3′-hydroxylase (F3′H), flavonol synthase (FLS), and dihydroflavonol reductase (DFR). Furthermore, we demonstrated a significant increase in the rooting rate of these second-pruned branch cuttings and screened the optimal hormone ratio for rooting, which is 1.5 μM MeJA + 400 mg/L NAA + 100 mg/L Uniconazole-P. These results suggest that secondary pruning can effectively rejuvenate plants to promote cutting rooting in G. biloba. This method can not only be used to improve the yield and quality of ginkgo leaves, but also for cutting propagation.

Inbreeding Depression and Genetic Diversity of S1 Lines Corn Plants Under Drought Stress Conditionson Dry Land

Selfing was carried out on the F2 population of corn plants and the S1 line was produced. Selfing is carried out to form pure lines in order to create hybrids. The aim of the research was to determine the magnitude of inbreeding depression, genetic diversity and heritability of leaf angle trait, yield and harvest age of the S1 line of corn plants under drought stress conditions in dry land. The experiment was carried out from March to June 2023 in Gumantar village, North Lombok district. The design used was a randomized block design, two replications. The number of treatments was 31, namely 30 S1 lines and an F2 population. Plantings are given heavy stress. Observed variables include flowering, growth, harvest age, yield components and yield. The level of inbreeding depression is based on the F2 population and is expressed as a percent. Genetic diversity is calculated based on the results of analysis of variance at a significance level of 5 percent. The results showed that inbreeding depression in leaf angle and harvest age of the S1 lines were relatively low; while the yield is classified as high. Broad categories of genetic diversity were obtained in the yield; while the leaf angle and harvest age are relatively narrow. Broad sense heritability was relatively high in the yield; while the leaf angle is classified as medium and the harvest age is relatively low. The selection of S1 lines should be based on yield, namely lines that have the same yield as the F2 population.

Impact of diverse tillage and nitrogen management on growth and yield of conservation agriculture-based wheat (Triticum aestivum)

A study was carried out during the winter (rabi) seasons of 2020–21 and 2021–22 at ICAR-Indian Agricultural Research Institute, New Delhi to assess the effects of diverse tillage and nitrogen management scenarios on growth, development, and yield of a conservation agriculture (CA)-based wheat (Triticum aestivum L.) crop grown in sequence with maize (Zea mays L.). Experiment was conducted in split plot design (SPD) comprised of 3 different tillage practices in main plots [Conventional tillage + residue (CT); Zero tillage + residue (ZT); and Permanent beds + residue (PB)] and 5 nitrogen (N) options in sub plots [Control (zero nitrogen); Recommended dose of N-RDN @150 kg N/ha (50 kg N/ha Basal + 2-equal splits at 37 days after sowing (DAS) and 84 DAS); Green Seeker (GS) based application of N @148 kg N/ha (GS); Urea super granules applied as basal @75 kg N/ha + GS based N application (USG); and Slow release fertilizer as 100% basal application @150 kg N/ha (SRF)] with 3-replications. The findings revealed that in both the seasons, both tillage and nitrogen management approaches significantly affected wheat growth, yield characteristics, and overall yield, whereas the time to anthesis and physiological maturity, and test weight remained unaffected. Within the spectrum of tillage practices, leaf area index (LAI) and yield attributes exhibited the trend PB>ZT>CT. PB recorded the highest grain yield (5159 kg/ha), followed by ZT (4916 kg/ha) and the lowest grain yield was observed with CT (4578 kg/ha). The wheat grain yields were 12.7% and 7.4% higher in PB and ZT, respectively, over to CT. Among nitrogen management options, the grain yield exhibited the pattern USG>N150>SRF>GS>N0. This study emphasizes that adopting conservation agriculture (CA) practices, particularly CA-based permanent beds using urea super granules (USG) for nitrogen management can improve wheat growth and yield.

KASP genotyping reveals disease resistance and yield enhancement in swarna introgression lines

Deployment of marker-assisted selection (MAS) in the molecular breeding programmes has transformed the crop breeding over the last decade, bringing speed and precision to the breeding programmes. The experiment was conducted during rainy (kharif) seasons of 2019, 2020, and 2021 at ICAR-Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana for validation of the Kompetitive Allele Specific PCR (KASP) SNP markers for routine marker- assisted selection through genotyping and phenotyping of a set of breeding lines segregating for grain number, yield and resistance to bacterial blight and blast diseases. Initially, 150 introgression lines of Swarna possessing bacterial leaf blight (Xa21), blast (Pi54) and yield enhancing gene (Gn1a) at ICF4 generation were genotyped using trait specific KASP markers, and a set of 22 plants was identified to be homozygous for all the three genes, 68 plants were found positive for two genes possessing either Xa21 + Gn1a and Pi54 + Gn1a, rest were having different single gene. Simultaneously, plants which were triple gene positives were also subjected for stringent phenotypic screening for the targeted stresses, viz. bacterial blight and blast disease resistance and further evaluated for grain number and other key agronomic traits. All the three-gene positive plants exhibited high level of resistance to bacterial blight and blast diseases in comparison with positive checks and displayed higher grain number and yield than the recurrent parent, Swarna. The efficiency of SNP marker system provided by Intertek is accurate, cost effective and accurate with phenotype.

KASP genotyping reveals disease resistance and yield enhancement in swarna introgression lines

Deployment of marker-assisted selection (MAS) in the molecular breeding programmes has transformed the crop breeding over the last decade, bringing speed and precision to the breeding programmes. The experiment was conducted during rainy (kharif) seasons of 2019, 2020, and 2021 at ICAR-Indian Institute of Rice Research, Rajendranagar, Hyderabad, Telangana for validation of the Kompetitive Allele Specific PCR (KASP) SNP markers for routine marker- assisted selection through genotyping and phenotyping of a set of breeding lines segregating for grain number, yield and resistance to bacterial blight and blast diseases. Initially, 150 introgression lines of Swarna possessing bacterial leaf blight (Xa21), blast (Pi54) and yield enhancing gene (Gn1a) at ICF4 generation were genotyped using trait specific KASP markers, and a set of 22 plants was identified to be homozygous for all the three genes, 68 plants were found positive for two genes possessing either Xa21 + Gn1a and Pi54 + Gn1a, rest were having different single gene. Simultaneously, plants which were triple gene positives were also subjected for stringent phenotypic screening for the targeted stresses, viz. bacterial blight and blast disease resistance and further evaluated for grain number and other key agronomic traits. All the three-gene positive plants exhibited high level of resistance to bacterial blight and blast diseases in comparison with positive checks and displayed higher grain number and yield than the recurrent parent, Swarna. The efficiency of SNP marker system provided by Intertek is accurate, cost effective and accurate with phenotype.

Chlorophyll content and leaf area correlated with corn (Zea mays) yield components in F<sub>1</sub> hybrids

Chlorophyll content and leaf area are important biochemical and biophysical regulators of water, energy and carbon exchange during photosynthesis. The present study was carried out during 2020 (autumn) and 2021 (spring) at the agronomy experimental station, College of Agricultural Engineering Science, Salahaddin University, Erbil, Iraq to identify the relationship of chlorophyll and leaf area with yield and yield-related characteristics among 8 introduced corn (Zea mays L.) F1 hybrids. Results demonstrated that the 8 hybrids were significantly different from each other for the number of kernels/row, number of leaves/ear, chlorophyll content and leaf area. Hybrid-by-year interaction was significant for ear yield, ear length, ear diameter, number of rows/ear, number of kernels/row and number of leaves/ear. No relationships phenotypically and genetically were found among chlorophyll with yield and yield-related traits in both the years. However, phenotypic and genotypic correlations were significant between leaf area and yield contributing traits in autumn 2020. Short vectors or obtuse angles by biplot analysis showed the same direction for correlation analysis. In conclusion, more information in future plant breeding programmes at phenotypic and DNA levels are required to represent the relationship between chlorophyll content with yield and yield-related traits. However, different correlations between leaf areas in the two growing years might be owing to the fluctuated local environmental factors during the plant growth period and/or no adaptation of new hybrids to the local environments.

Influences of tobacco straw return with lime on microbial community structure of tobacco-planting soil and tobacco leaf quality.

Soil amendment is an important strategy for improving soil quality and crop yield. From 2014 to 2019, we conducted a study to investigate the effects of tobacco straw return with lime on soil nutrients, soil microbial community structure, tobacco leaf yield, and quality in southern Anhui, China. A field experiment was conducted with four treatments: straw removed (CK), straw return (St), straw return with dolomite (St+D), and straw return with lime (St+L). Results showed that after 5 years of application, the St+L significantly increased the soil pH by 16.9%, and the contents of soil alkaline nitrogen (N) and available potassium (K) by 17.2% and 23.0%, respectively, compared with the CK. Moreover, the St+L significantly increased tobacco leaf yield (24.0%) and the appearance (9.1%) and sensory (5.9%) quality of flue-cured tobacco leaves. The addition of soil conditioners (straw, dolomite, and lime) increased both the total reads and effective sequences of soil microorganisms. Bacterial diversity was more sensitive to changes in the external environment compared to soil fungi. The application of soil amendments (lime and straw) promoted the growth of beneficial microorganisms in the soil. Additionally, bacterial species had greater competition and limited availability of resources for survival compared to fungi. The results showed that soil microorganisms were significantly influenced by the presence of AK, AN, and pH contents. These findings can provide an effective method for improving the quality of flue-cured tobacco leaves and guiding the amelioration of acidic soil in regions where tobacco-rice rotation is practiced.

Optimum Transplanting Date for Rape Forage and Grain Yields in the Ridge Culture Place Planting System on the Yangtze River Delta

The ridge culture place planting system (RCPPS) is a promising technique for planting rapeseed that can promote the growth of rapeseed by late rice stubble, which has been widely adopted in the Yangtze River delta. To determine the optimum planting date for rape (Brassica napus L.) forage and grain yield in an intensive rice–rape rotation system, a field experiment was conducted with five transplantation dates (from 20 October to 30 November at 10 day intervals) in RCPPS. The forage/grain yield, nutrition, and growth parameters were analyzed. At podding, rape biomass yield was highest, and no significant differences were found among treatments. It was around 12.0% crude protein, 11.4% ether extract, 38.8% neutral detergent fiber, and 34.9% acid detergent fiber. In the treatments of 20 and 30 November, crude protein content increased and acid detergent fiber content decreased significantly. Compared with 20 October, the grain yield of rape transplanted in November decreased significantly by 17.2% to 22.5%. The grain yield was significantly correlated with the number of secondary branches, pods, and seeds. At the final flowering stage, rape transplanted in November had noticeably reduced leaf growth, rhizome width, and yield than 20 and 30 October. Overall, for multiple uses of rapeseed in the Yangtze River delta belt with RCPPS, it is optimal to plant in mid to late November for forage use with higher nutritional value, being coordinated with the previous rice crop, whereas late October is the appropriate planting time to obtain a higher grain yield.

Reduced Root Cortical Tissue with an Increased Root Xylem Investment Is Associated with High Wheat Yields in Central China.

Trait-based approaches are increasingly used to understand crop yield improvement, although they have not been widely applied to anatomical traits. Little is known about the relationships between root and leaf anatomy and yield in wheat. We selected 20 genotypes that have been widely planted in Luoyang, in the major wheat-producing area of China, to explore these relationships. A field study was performed to measure the yields and yield components of the genotypes. Root and leaf samples were collected at anthesis to measure the anatomical traits relevant to carbon allocation and water transport. Yield was negatively correlated with cross-sectional root cortex area, indicating that reduced root cortical tissue and therefore reduced carbon investment have contributed to yield improvement in this region. Yield was positively correlated with root xylem area, suggesting that a higher water transport capacity has also contributed to increased yields in this study. The area of the leaf veins did not significantly correlate with yield, showing that the high-yield genotypes did not have larger veins, but they may have had a conservative water use strategy, with tight regulation of water loss from the leaves. This study demonstrates that breeding for higher yields in this region has changed wheat's anatomical traits, reducing the roots' cortical tissue and increasing the roots' xylem investment.

Preliminary Exploration of Physiology and Genetic Basis Underlying High Yield in Indica–Japonica Hybrid Rice

The utilization of heterosis is of great significance in improving rice yield. To explore the physiological and genetic basis for high yield in indica–japonica hybrid rice, Zheyou18 (z18) and Yongyou12 (y12) were used as materials and compared with indica hybrid rice, Zheyou12 (z12); japonica hybrid rice, Liangyoupeijiu (LYPJ); and the conventional lines zhe04B (04B) and zhehui818 (h818) under seedling growth vigor, functional leaf morphology, chlorophyll content, yield component, panicle trait, and InDel heterosis analysis. Z18 and y12 showed the largest increase in plant height 6 d and 9 d after germination; the root dry weight of z18 was 31.2% and 42.0% higher than its parents on the 12th d. The length of functional leaves ranked in the middle, while the width was the largest, resulting in z18 and y12 having the largest leaf area. Yield components showed that z18 and y12 had the highest number of primary branches, spikelets, and grains, and grain yield, which was 58.1 g in z18, increased by 29.8% and 8.7%, respectively, in comparison with h818 and LYPJ. The InDel genetic distance was significantly positively correlated with single spike weight, with r reaching 0.771, making it the only consistent and most correlated among the seven traits. Therefore, we speculated that as the InDel genetic distance expands, heterosis mainly manifests in the increase in single spike weight. This study comprehensively explored the physiological mechanism of yield improvement in indica–japonica-hybrid rice and used InDel genetic distances to study the genetic basis of heterosis, which will be helpful for future rice yield improvement.

Evaluation of Mulberry Germplasm for Growth and Yield Parameters during Different Seasons

Evaluation of mulberry germplasm for growth and yield parameters was carried out during the rainy and winter seasons of 2019-2020 in the Department of Sericulture, University of Agricultural Sciences, GKVK, Bengaluru-65. The experimental material for the present study comprised of Seventy-one mulberry accessions and two check varieties M5 and V1. Among Seventy-one mulberry accessions evaluated the leaf yield of different genotypes differed significantly among different seasons. Among the elite mulberry genotypes, no single genotype was superior in respect of all the traits in different seasons. However, during rainy and winter season MI-232 and MI-143 recorded highest leaf yield.

The Effects of Transplanting Date on Management of Tobacco Insect Pests. Min review

The main review purpose this paper provides updated information on the effect of different transplanting dates on the infestation of tobacco insect pets were carried out at different location by different Scholars. The results revealed that different trials conducted in different agro ecological zone indicated that damage was higher and green leaves yield decrease were in late transplanted tobacco. While, the damage was gradually decrease and green leaves yield increase in early transplanted tobacco. Numerous species of insect pests of tobacco affect the crop in the field, in the greenhouse, and in storage. The effect tobacco insect pests reduced green leaf yield, quality and damage roots, leaves, buds parts of plants and others transmit several important tobacco disease pathogens. As management systems for flue-cured tobacco (Nicotiana tabacum L.) used different transplanting date were compared to evaluate their influence on insect pests’ damage, leaves yield and quality of flue-cured tobacco. The results indicated that early transplanted significantly increase leaf yield, growth parameters and decrease insect pest damage incidence. The study indicated that transplanted has pronounced positive effect on management of tobacco insect pests and growth of tobacco.

Optimized Nitrogen Application Rate Significantly Increases Total Economic Value and Quality of Flue-Cured Tobacco due to the Improvement of Superior Tobacco Yield

Summary With the improvement of irrigation and transportation infrastructures, single tobacco cultivation has been converted into tobacco–vegetable double cultivation in Yunnan Province. High residual nitrogen (N) levels in soil before tobacco transplanting induced by the excessive N input during the vegetable cultivation season resulted in a reduction of economic income and the quality of flue-cured tobacco. Therefore, the objective of this paper is to describe the optimization of N management and to provide a better understanding of the mechanism of optimal N application rate on the economic benefit and quality of tobacco. A field experiment with six N application rates (0, 45, 60, 75, 90, and 105 kg N ha−1) was carried out with a randomized block design in 2021 and 2022 in Yunnan Province. The economic value and yield, intrinsic chemical and processing quality, leaf growth rate and agronomic characters were determined. Compared with the currently recommended 105 kg N ha−1 rate, 75 kg N ha−1 significantly increased the total economic value and superior tobacco yields, improved the integrated grade of chemical compounds and resulted in leaf midrib proportions in an appropriate range. The total economic value positively correlated with the superior tobacco leaf yields (R2 = 0.91, p < 0.001), while not with medium and inferior leaf yield. The daily leaf growth rate in prosperous growth stage significantly correlated with the yield of superior tobacco and reached its maximum at a N rate of 75 kg N ha−1. The sum of N application rate and soil residual N before transplanting correlated with the total economic value (R2 = 0.66, p < 0.05) and superior leaf yield (R2 = 0.64, p < 0.05), respectively. Based on the amount of soil residual N before transplanting, the optimal N application rate was 66 kg N ha−1 which was 39 kg N ha−1 lower than the currently recommended N rate (105 kg N ha−1). Our results highlighted that the technical consultants and farmers should adjust the N application rate appropriately according to the residual N amount before transplanting and optimize the water and fertilizer management especially in the prosperous growth stage. An optimized N rate is not only of economic benefit and the improvement of quality of tobacco cultivation, but also environment friendly.

Genetic diversity, population structure and marker-trait associations in Indian kale (Brassica oleracea L. gp. acephala) using cross-species microsatellite markers

Kale is known for its exceptional nourishing and functional benefits to human body. However, it is an understudied species from genomic as well as agronomic aspects. It is important to characterize niche kale germplasms around the world to systematically conserve and utilize its genetic variability, especially for commercial traits in the interest of growers, consumers and industry. With this view, genomic and phenotypic characterizations of 62 Kashmiri kale accessions including popular landraces were done to estimate and partition genetic diversity, understand trait relationships, develop population structure and divulge marker-trait associations of economic significance. Sixty-six cross species microsatellite (SSR) markers within Brassica genus amplified 269 alleles in the germplasm. Their polymorphic information content (PIC) ranged from 0.00078 to 0.953 with an average of 0.407. The population structure analysis and neighbour joining tree clustering categorized the germplasm into three sub-populations. AMOVA revealed more within-population variance (67.73 %) than among-populations (32.27 %) variance. The principal component analysis (PCA) involving 24 agronomical traits revealed seven PCs (PC1 to PC7) having Eigen values more than 1, which explained a cumulative variation of 69.21 %. Association mapping with respect to these 24 agronomical traits using mixed linear model and general linear model revealed six overlapping significant marker-trait relationships with five being significant at probability value of 0.001/0.0001. The highly significant associations of two SSRs with economically important traits (siliqua length and seed weight) significantly correlated/related with leaf yield and seed yield were revealed for their possible utilization in marker assisted breeding for higher leaf and seed yields.