Optimization of crop geometry for improved growth and yield of cabbage varieties under sub-humid conditions

Introduction

Cabbage is a globally significant cole crop, valued for its nutritional density and economic importance in smallholder and commercial farming systems. In sub-humid regions, characterized by moderate rainfall and specific humidity regimes, cabbage production offers a viable source of income and food security. However, yield potential is often sub-optimal due to non-site-specific and non-varietal agronomic practices, particularly plant spacing. Crop geometry, defined by inter-and intra-row spacing, is a fundamental management lever that dictates plant population, canopy development, and resource capture (light, water, nutrients). An overly dense population induces competition, leading to smaller heads, reduced airflow (increasing disease risk), and lower quality. Conversely, overly wide spacing wastes valuable land, reduces total yield per hectare, and can encourage excessive lateral growth at the expense of head formation (Bracy et. al 1993) [2] . While the impact of spacing on cabbage growth is documented, the critical interaction between specific varietal architecture and geometry under sub-humid conditions remains underexplored. Varieties differ markedly in plant frame, leaf orientation, and head size. A 'onesize-fits-all' spacing recommendation fails to account for these genetic differences. This study, therefore, hypothesizes that optimizing crop geometry based on varietal growth habit will significantly improve growth, yield, and yield-contributing parameters of cabbage under subhumid conditions. The objective was to identify the physical and engineering property of cabbage crop.

Materials and Methods

Experimental site and conditions

The experiment was conducted at Raipur, Chhattisgarh, located in a sub-humid climatic zone. The study area, Raipur, is situated within the Chhattisgarh plains, a sub-humid climatic region classified as a primary rice-growing zone.

This region experiences a mean annual precipitation of 1370 mm, with approximately 85% of the total rainfall concentrated from mid-June through the end of September. Seasonal temperatures exhibit significant variation, with summer maxima peaking at 44.3 °C and winter minima dropping to 12.5 °C. Relative humidity remains elevated from June to October, followed by a steady decline to its lowest annual levels during the peak winter month of January (https://igkv.ac.in).

Observations recorded

The study entailed a comprehensive characterization of selected physical and engineering properties across three distinct cabbage cultivars. The investigated varieties included the hybrids T-621 and NS-183, alongside the open-pollinated standard Golden Acre. Concurrently, critical engineering parameters were measured using standardized instrumental analysis. This systematic recording generated a comparative dataset of the cabbage variety.

Physical property

The various physical properties such as plant height, plant diameter, plant weight, head height, head diameter, head weight, moisture content, stem diameter (0 cm, 1 cm, and 2 cm from bottom of cabbage head), length of stem for the different Varity T 621, NS 183 and golden acre were measured in the farmer field of Raipur district Chhattisgarh.

Plant height

Plant height was measured using a standard measuring tape. For every plant, three individual measurements were taken from the soil surface to the apical meristem (topmost growing point). This triplicate approach ensured accuracy and consistency in the data collection process. The average of these three readings was then computed for each specimen. This resulting mean height served as the definitive measurement for all study-related analysis and comparisons.

Plant diameter

Plant diameter was measured using a standard measuring tape. For each plant, three separate horizontal measurements were taken across the widest span of the outer canopy. This triplicate procedure ensured precision and minimized observational error. The mean of these three values was calculated for every individual plant. This average diameter was then used as the representative data point for subsequent analysis in the study.

Plant weight

Plant weight was measured using a calibrated electronic balance. For each harvested plant, three separate weight measurements were recorded to ensure accuracy and account for any minor variability. This triplicate weighing procedure was implemented to enhance data reliability. The mean of these three readings was subsequently calculated for every individual sample. This average fresh weight was then adopted as the definitive value for all further yield analysis and comparative assessment within the research.

Head height

Head height was measured using a flexible measuring tape for overall dimensions and a Vernier caliper for precise, localized depth. Three separate vertical measurements were taken from the base of the head at the stem junction to the apex. This triplicate approach minimized measurement error and ensured consistency. The mean of these three recordings was calculated to establish a representative value for each head. The final averaged measurement, utilizing both tools for comprehensive accuracy, was used for all subsequent morphological analysis.

Head diameter

Head diameter was measured using a flexible measuring tape for the maximum outer width and a Vernier caliper for precise core diameter. Three perpendicular measurements were taken across the widest portion of each head to account for asymmetry. This triplicate method ensured measurement accuracy and consistency. The mean of these three values was calculated to establish a representative diameter for every individual head. The resulting average was then used for comparative analysis of head size and morphology in the study.

Head weight

Head weight was determined using a calibrated digital weighing balance. Each harvested cabbage head was weighed three times consecutively to account for any minor instrumental fluctuation. This triplicate measurement protocol was followed to ensure precision and repeatability of the data. The mean of the three recorded weights was computed for every individual head. This average value served as the final fresh weight datum for all yield and performance evaluations in the study.

Stem diameter

The stem's thickness was measured at three specific points using vernier calipers: right at the bottom of the cabbage head (0 cm), then 1 cm below it, and again at 2 cm below the base. To make sure every reading was as accurate as possible, each of these three spots was measured three separate times. This careful, repeated approach helped account for any natural variation or slight human error. The three readings taken at each height were then averaged together, giving one reliable thickness value for the 0 cm, 1 cm, and 2 cm points. These final averaged measurements were used to understand the stem's shape and structure in the study.

Stem length

The stem length was determined by measuring the vertical distance from the point of head attachment to the base of the stem using a flexible measuring tape. For precise validation at specific nodes, a Vernier caliper was used to measure localized stem sections. Each measurement was recorded three times to ensure reliability and to average out any minor inconsistencies. The mean of these triplicate observations provided the definitive stem length value. This combined methodological approach ensured both gross dimensional accuracy and localized precision for the study's.

Moisture content

The moisture content of cabbage stem was determined using the standard gravimetric oven-dry method. Fresh stem samples were precisely weighed and placed in a forced-air oven at 105°C until a constant dry weight was achieved. The dried samples were cooled in a desiccator to prevent moisture reabsorption before final weighing. The moisture content was calculated as the percentage of mass lost relative to the original fresh weight. This procedure was performed in triplicate to ensure analytical accuracy and reliable results.

Where, W i = Initial weight of sample, g W f = Final weight of sample, g

Engineering properties

The two engineering properties such as coefficient of friction angle of cabbage and cutting force of the different Varity T 621, NS 183 and golden acre were measured in the lab of SV CAET & RS, FAE, IGKV Raipur, Chhattisgarh

Coefficient of friction angle of cabbage

The coefficient of static friction for cabbage crops is effectively determined using the inclined plane method. In this procedure, a cabbage is placed on a slowly tilting plane and the angle at which sustained sliding initiates is recorded as the angle of friction. To ensure accuracy and account for the vegetable's natural surface variability, this measurement is repeated three times for each individual cabbage, rotating it between trials. The average of these three angles for each cabbage is calculated, and the final coefficient of friction is derived from the tangent of this average angle. This protocol yields a reliable and reproducible value essential for designing post-harvest handling equipment (Sahu et.al 2020).

Cutting force

The required cutting force for the cabbage harvester mechanism was quantified using a texture analyzer fitted with a Warner-Bratzler knife blade. Measurements were taken at stem positions 0, 1, and 2 cm below the head to target the less fibrous zone. Each clamped stem was cleanly severed at a controlled speed of 10 mm/s to record the peak force. This data directly informs the power specification for the harvester's cutting unit design (Kushwaha et al. 1983; Dixit and Rawat, 2022; Liu et al. 2025) [10,5,12] .

Result and Discussion

The study analyzed the physical and engineering properties of three cabbage varieties T 621, Golden Acre, and NS 183 at farmer's field of Raipur district Chhattisgarh and engineering properties were tested at the lab of SV CAET&RS, FAE, IGKV, Raipur Chhattisgarh. The mean head diameter of the T 162 cabbage variety, calculated from the average of three replications per sample, was 118.8 mm. The observed values spanned from 87.33 mm to 146.00 mm. Statistical analysis revealed a standard deviation of 18.97 and a coefficient of variation of 15.97%, pointing to a fair degree of dispersion in head size among the tested samples of this variety. An analysis of triplicate sample averages for head diameter revealed that the Golden Acre cabbage variety achieved a mean of 127.53 mm, with avg. values of three replication of each sample clustering between 109.00 mm and 137.67 mm. This limited spread is corroborated by a low standard deviation of 7.80 and a coefficient of variation of merely 6.12%, demonstrating remarkable consistency in head size for this cultivar. Statistical evaluation of the NS 183 variety, using averages derived from three replications per sample, determined the mean cabbage head diameter to be 159.43 mm. Measurements across samples displayed a broad spectrum from 150.00 mm to 226.00 mm. This distribution is characterized by a standard deviation of 17.88 and a moderate coefficient of variation of 11.23%, reflecting a predictable yet notable variation in head diameter for this variety.

Plant height

Plant weight

Head diameter

Head weight

The cabbage head weight of T 162 variety, calculated as the average of three replications for each sample, showed considerable variation among the observations. The mean head weight was 625.63 g, indicating a moderate-sized head under the given experimental conditions. The minimum and maximum head weights recorded were 497.00 g and 930.67 g, respectively, reflecting a wide range in head development. The standard deviation (136.33 g) indicated noticeable variability around the mean, while the coefficient of variation (21.79%) suggested moderate variability in head weight among the samples, which may be attributed to differences in microclimatic conditions, plant vigor, or soil fertility within the experimental farmer field. The cabbage head weight of the Golden Acre variety, calculated as the average of three replications for each sample, exhibited substantial variation among the observations. The mean head weight was 1245.95 g, indicating comparatively heavier heads under the experimental conditions. The minimum and maximum head weights recorded were 849.33 g and 1720.67 g, respectively, showing a wide range in head size. The standard deviation (282.22 g) reflected considerable dispersion of values around the mean, while the coefficient of variation (22.65%) indicated moderate variability in head weight among the samples, which may be attributed to differences in plant growth, nutrient availability, and field conditions during the cropping period. The cabbage head weight of the NS 183 variety, calculated as the average of three replications for each sample, showed relatively uniform performance. The mean head weight was 1234.95 g, with values ranging from 1040.67 g to 1480.67 g. The standard deviation (129.32 g) indicated low dispersion around the mean. A coefficient of variation of 10.47% reflected good uniformity and stability in head weight among the samples. The stem diameter of cabbage measured at 0 cm below the lower leaf of the cabbage head for the T 162 variety, calculated as the average of three replications for each sample, showed moderate variation. The mean stem diameter was 24.95 mm, with a minimum of 17.67 mm and a maximum of 31.00 mm. The standard deviation (4.22 mm) indicated reasonable dispersion around the mean. The coefficient of variation (16.94%) suggested moderate uniformity in stem thickness among the samples. For stem diameter measured immediately below the cabbage head, the Golden Acre variety showed an average of 26.21 mm based on triplicate sampling. The results varied from 21.00 mm to 32.33 mm across the tested samples. This variation is quantified by a standard deviation of 3.57 and a coefficient of variation of 13.62%, indicating a moderate level of uniformity in stem thickness for this cultivar. The NS 183 variety exhibited a mean stem diameter, measured directly beneath the cabbage head, of 23.54 mm based on averaged triplicate samples. The recorded values fell within a narrow range from 20.33 mm to 25.60 mm. This limited dispersion is reflected in a low standard deviation of 1.48 and a coefficient of variation of 6.29%, signifying a high degree of uniformity in this structural trait for the variety.

Stem diameter at 1 cm from bottom leaf of cabbage head

For the T 162 variety, the stem diameter measured 1 cm below the cabbage head averaged 23.28 mm, derived from triplicate sample means. The measurements varied from 17.67 mm to 29.00 mm. This variability is reflected in a standard deviation of 3.75 and a coefficient of variation of 16.11%, indicating a moderate to high degree of dispersion in stem thickness at this specific position for the cultivar. For the Golden Acre variety, the stem diameter measured 1 cm below the cabbage head averaged 25.13 mm based on triplicate sample means. The values ranged from 20.00 mm to 31.33 mm. These results show a standard deviation of 3.53 and a coefficient of variation of 14.03%, representing a moderate level of variability for this specific stem characteristic in the cultivar. Measured at 1 cm below the cabbage head, the NS 183 variety displayed a stem diameter averaging 22.54 mm when calculated from triplicate sample means. Observations were confined to a narrow span of 19.33 mm to 24.33 mm. This minimal spread is evidenced by a low standard deviation of 1.38 and a coefficient of variation of 6.13%, underscoring the pronounced uniformity in this structural feature for the variety.

Stem diameter at 2 cm from bottom leaf of cabbage head

Analysis of the T 162 variety at a point 2 cm below the cabbage head revealed an average stem diameter of 21.5 mm, determined from triplicate sample averages. The data exhibited a range from 15.33 mm to 29.00 mm. With a standard deviation of 3.43 and a coefficient of variation calculated at 15.98%, these results demonstrate a significant degree of variation in stem thickness for this cultivar at the specified measurement point. When measured at a point 2 cm below the cabbage head, the Golden Acre variety yielded an average stem diameter of 24.13 mm from the mean of triplicate samples. The data spanned from 18.33 mm to 30.33 mm. This distribution is reflected in a standard deviation of 3.69 and a coefficient of variation of 15.28%, which corresponds to a moderate level of variability for the cultivar at this specific stem position. At a measurement depth of 2 cm below the cabbage head, the NS 183 variety maintained an average stem diameter of 21.28 mm, as derived from triplicate sample averages. The results clustered within interval of 18.33 mm to 23.33 mm. This consistency is further demonstrated by a low standard deviation of 1.42 and a coefficient of variation of 6.67%, indicating highly uniform stem dimensions for the variety at this stem section. The moisture content of the T 162 cabbage variety averaged 88.14%, based on the mean of triplicate sample analyses. The values were confined to a narrow range of 82.76% to 93.28%. This high consistency is reflected in a low standard deviation of 2.59 and an exceptionally low coefficient of variation of 2.94%, demonstrating remarkable uniformity in water content across the tested samples of this cultivar. The Golden Acre cabbage variety exhibited a mean moisture content of 85.24%, derived from triplicate sample averages. The minimum recorded value was 80.70%, while the maximum reached 88.25%. This notably narrow range between the min and max values is further evidenced by a low standard deviation of 2.19 and a very low coefficient of variation of 2.57%, collectively confirming exceptional uniformity in moisture retention for this cultivar. The NS 183 cabbage variety displayed an average moisture content of 86.32%, calculated from triplicate sample means. The minimum observed value was 82.48%, and the maximum was 88.45%. This extremely tight distribution is supported by a standard deviation of 1.62 and the lowest coefficient of variation in the study at 1.88%, denoting outstanding homogeneity in water content for this specific genotype. The coefficient of friction angle for the T 162 cabbage variety averaged 23.54°, determined from the mean of triplicate sample measurements. The values ranged narrowly from 20.33° to 25.60°. This low dispersion is indicated by a standard deviation of 1.48 and a coefficient of variation of 6.29%, reflecting highly consistent frictional properties for this cultivar. For the Golden Acre variety, the coefficient of friction angle averaged 25.38° as calculated from triplicate sample means. The results fell within a confined range of 22.67° to 28.33°. This minimal variation is supported by a low standard deviation of 1.65 and a coefficient of variation of 6.51%, indicating very uniform frictional characteristics for this cabbage cultivar. The NS 183 cabbage variety exhibited a mean coefficient of friction angle of 25.57° derived from triplicate sample averages. Measurements demonstrated a tight range from 25.57° to 28.60°. This high level of consistency is further evidenced by a low standard deviation of 1.62 and a coefficient of variation of 6.32%, reflecting uniform frictional properties in the cultivar's surface characteristics.

Stem length

Cutting force

Conclusion

The study's findings on varietal physical properties directly inform the optimization of crop geometry for improved cabbage performance in sub-humid climates. The tall but variable stature of T 621 suggests a need for wider spacing to mitigate light competition, while the compact uniformity of Golden Acre allows for higher density planting. NS 183 combination of height and consistent head size indicates it would best utilize an intermediate spacing configuration to maximize yield per unit area. Planting arrangements to these specific architectural traits can optimize light interception, airflow, and resource use. Consequently, implementing variety-specific crop geometries is a key strategy

References

1. Anonymous. District statistical booklet 2024. Raipur (Chhattisgarh): Department of Agricultural Meteorology, Indira Gandhi Krishi Vishwavidyalaya; 2023. Available from: https://igkv.ac.in
2. Bracy RP, Parish RL, Bergeron PE, Moser EB, Constantin RJ. Planting cabbage to a stand with precision seeding. HortScience. 1993;28(3):179-181.
3. Cervenski J, Danojevic D, Medic-pop S, Savic A. Late cabbage planting density. Selekcija I Semenarstvo. 2018;24. DOI:10.5937/selsem1802026C.
4. Champa WAH, Palipane KB, Weerakkody WAP, Fernando MD. Maturity indices for harvesting of cabbage (Brassica oleracea L.) variety green coronet. Trop Agric Res. 2007;19:254-264.
5. Dixit J, Rawat NJ. Development and evaluation of selfpropelled cabbage/cauliflower harvester. J Agric Sci. 2022;4(1):56-63.
6. Haque FA, Islam N, Islam MN, Ullah A, Sarkar MD. Growth, yield and profitability of cabbage (Brassica oleracea L.) as influenced by applied nitrogen and plant spacing. Agriculturists. 2015;13(1):35-45.
7. Jain R, Meena ML, Dangayach GS, Bhardwaj AK. Risk factors for musculoskeletal disorders in manual harvesting farmers of Rajasthan. Ind Health. 2018;56:241-248.
8. Johnson GE, Buzby KM, Semmens KJ, Waterland NL. Comparison of two harvest methods for lettuce production in an aquaponic system. J Agric Sci. 2017;9(1):64-74.
9. Khatiwada PP. Plant spacing: A key husbandry practice for rainy season cabbage production. Nepal Agric Res J. 2001;45:48-5.
10. Kushwaha RL, Vaishnav AS, Zoerb GC. Shear strength of wheat straw. Can Agric Eng. 1983;25(2):163-166.
11. Liu Z, Wan E, Mao H, Zuo Z, Peng H, Zhao M, et al. Design and testing of an electric side-mounted cabbage harvester. Multidiscip Digit Publ Inst. 2024;14(1741):1-20.
12. Liu S, Yang X, Zhang Z, Xu J, Zhao P, Tian S, et al. Design and simulation of Chinese cabbage harvester. MDPI. 2025;831(15):1-22.
13. Moniruzzaman M. Effect of plant spacings on the performance of hybrid cabbage (Brassica oleracea var capitata) varieties. Bangladesh J Agric Res. 2011;36(3):495506.
14. Manasa S, Lakshmi LM, Sadarunnisa S, Rajasekharam T. Response of red cabbage (Brassica oleracea L. var. capitata f. rubra) to different levels of plant and row spacing. Int J Curr Microbiol Appl Sci. 2017;6(11):1684-1689.
15. Meena A, Meena ML, Yadav S, Shaili, Kumari M, Kumar L, et al. Growth and yield of cabbage (Brassica oleracea L. var. capitata) as influenced by applied different varieties and plant spacing. Int J Adv Biochem Res. 2025;9(2):328-331.
16. Panday T, Singh V. Physical properties of cabbage for mechanical harvesting. Int J Creat Res Thoughts. 2019:23202382.
17. Paranhos LG, Barrett CE, Zotarelli L, Darnell R, Migliaccio K, Borisova T. Planting date and in-row plant spacing effects on growth and yield of cabbage under plastic mulch. Sci Hortic. 2016;202:49-56.
18. Sahu M, Victor VM, Verma A, Agrawal S. Study on physical and frictional properties of Farm Yard Manure (FYM) to develop mechanized application and handling unit of FYM. Pharma Innov J. 2020;9(1):101-107.
19. Sharan G, Rawale K. Physical characteristics of some vegetables grown in Ahmedabad region. Ahmedabad: Indian Institute of Management Ahmedabad, Research and Publication Department; 2003. Report No.: WP2003-12-01.
20. White JM, Forbes RB. Effect of spacing and fertilizer rates on cabbage yield and head weight. Proc Fla State Hort Soc. 1976;89:118-120.
21. Tegar A, Banafar KNS, Gauraha AK, Chandrakar MR. An analysis of growth in area, production and productivity of major vegetables in Bilaspur district of Chhattisgarh state, India. Plant Arch. 2016;16(2):797-800.