Two & a Bud

Impact of rehabilitating the tea growing soil prior to replanting with special emphasis on the soil physico-chemical properties, growth and yield of tea

J. Dutta — 2026-07-13

Following the removal of old tea bushes, a rehabilitation crop is often planted for around two years. In Northeast India, this crop is primarily Guatemala grass. The main goal of this is to shatter the monoculture that has been created by years of tea cultivation. In addition to contributing organic matter, Guatemala rehabilitation grass is believed to address some negative consequences of monoculture because it is eriodically lopped during growth and then cut and put into the soil after two years. On the other hand, it has occasionally been asserted that the rehabilitation phase might be skipped if organic materials could be introduced externally. This long-term study was conducted at the Borbheta Tea Estate between 2012 and 2021 to assess the effects of various alternative methods of soil rehabilitation compared to grass rehabilitation for one or two years on the development and yield of tea as well as certain soil attributes.The findings of this study showed that a two-year rehabilitation using Guatemala grass greatly increased the development of young tea plants by 12-23% and increased tea yield by 15-16%. During the two- year rehabilitation, soil aggregation increased (3.6%) and soil compaction decreased. Under the two years of rehabilitation, the status of organic carbon, soil available phosphorus and potassium improved considerably to the extent of 3.5-10.0, 4.5-15.0, and 2.1-7.7%, respectively. The pH of the soil was not much affected, but it was still maintained within the desired range for tea cultivation. It was concluded that, in order to restore the soil after old tea is removed and before new tea is planted, two years of soil rehabilitation under Guatemala grass is essential. This is not a substitute, but a requirement to improve the physico-chemical properties, growth and yield of tea.

Keywords: Guatemala, tea soil, physico-chemical properties, rehabilitation

Phytosterols profile of tea seed oil

P.K. Patel — 2026-07-13

This research work compares the phytosterol profiles of four bi-clonal tea seed stock oils i.e. TS 462, TS 464, TS 491, and TS 506. The phytosterols estimated by GC-FID exhibited that 24-methylene cycloartan-3-ol is the most abundant sterol in tea seed oil, accounting for 31% of the total phytosterols. The majority of the sterol differences were statistically significant (p< 0.05). TS 506 exhibited the highest amount of 24- methylene cycloartan-3-ol (476.03.7 mg kg-1) followed by TS 491 (475.97 mg kg-1). β-sitosterol, cycloartenol, canophyllol, lanosterol and campesterol were present with contents of 371.03 ± 0.26, 291.38 ± 0.12, 120.44 ± 0.13, 89.12 ± 0.19 and 69.05 ± 0.24 mg kg-1 respectively. Tea seed oils may also be effective n preventing cardiovascular diseases and delaying aging.

Keywords: Phytosterols, GC FID, tea seed oil

Enhancing tea soil health by utilizing the indigenous natural resources: A comprehensive review

H. Malakar — 2026-07-14

The soil sustains plants, serves as the physical determinant of root development and spread, and acts as the primary reservoir for plant-accessible water and nutrients. It governs nutrient availability through bio-physiochemical processes, which depend on soil and plant characteristics. The primary difficulty of soil management in tea gardens is to maintain soil health while ensuring nutrient availability within a pH range of 4.5 to 5.5. The amendment of soil with organic matter can enhance soil health through the application of biosolids, manure, compost, vermicompost, biochar, and biofertilizers. The use of various organic inputs in soil clearly has the capacity to enhance organic carbon levels and, consequently, augment nutrient availability in tea-cultivating soil. Biochar derived from tea pruning litter has demonstrated efficacy as a superior soil conditioner, enhancing the physicochemical and microbiological characteristics of tea-cultivating soil. Nutrient cycles are mediated by microbes, with distinct groups isolated from local soil responsible for transforming each nutrient from its bound form to a plant-available form. Consequently, indigenous natural resources in tea gardens could be efficiently and prudently employed to enhance soil health, augment tea yield, and perhaps diminish chemical fertiliser usage in tea growing.

Keywords: Biochar, Biofertilizer, Soil health, Tea, Vermicompost

Rapid Quality Evaluation and Market Valuation of CTC Black Tea Using Near-Infrared Spectroscopy

A.K. Hazarika — 2026-07-13

The market success of Crush–Tear–Curl (CTC) black tea depends largely on rapid and reliable methods of quality evaluation. Despite advances in tea processing, the assessment of CTC black tea quality is still dominated by time-intensive chemical testing and sometimes subjective tasting, underscoring the need for rapid, objective alternatives. This study shows that Near Infrared (NIR) spectroscopy can provide fast, non-destructive, and objective predictions of tea liquor, infusion, overall quality, and theaflavins (TF). Using CARS–PLSR and Random Forest models, strong prediction performance was achieved (RPD > 3.0). Random Forest gave the most accurate liquor assessment, while CARS–PLSR excelled for infusion and TF. These findings suggest that portable NIR devices, when combined with robust modelling, could support faster and more objective grading in tea factories, auction centres, and quality-control laboratories. Rather than replacing traditional sensory and chemical evaluations, this approach offers a practical supplement that may improve efficiency, transparency, and consistency across the tea value chain.
Keywords: NIR, Theaflavin, liquor-infusion-quality (LIQ), PLSR, RF, CARS

Distribution of catechin profile and caffeine content in different parts of tea shoots

Podma Pollov Sarmah — 2026-07-13

The leaves of the tea plant (Camellia sinensis L.) are one of the major sources containing the highest amounts of polyphenolic substances, mainly catechins, which include (+)-catechin (+C), (-)-epigallocatechin (EGC), (-)-epicatechin (EC), (-)-epigallocatechin gallate (EGCG), and (-)-epicatechin gallate (ECG), along with caffeine. These catechins and caffeine are mostly responsible for the quality of made tea. However, the contents of these components drastically vary in different parts of tea plants. In this study, the distribution of these components has been determined in various parts of tea shoots such as the bud, first leaf, second leaf, first and second internodes of cultivar TV25. The content of EGCG and ECG was found to be highest in the bud, whereas +C and EC content was observed to be highest in the first internode. The caffeine contents also followed the same trend as EGCG, with the highest amount in the first leaf. This study will help in understanding the distribution of the catechin profile and caffeine content in various parts of tea shoots, which in turn will help produce better quality tea.

Native tea rhizospheric Streptomyces costaricanus WZ162 against Ustulina zonata causing Charcoal stump rot disease in Tea ( Camellia sinensis)

Mausomi Madhab — 2026-07-14

The rhizosphere microbiology of plantation crops is less explored for the antagonistic actinomycetes, which
are agriculturally important soil microbial communities. This study deals with the population dynamics
of actinomycetes present in the rhizosphere of tea bushes in three different zones of the Brahmaputra
valley. A total of 17 actinomycetes strains were isolated from rehabilitated, non-rehabilitated and virgin
soils of selected tea gardens, out of which eleven Actinomycetes strain showed antagonistic potentiality
when screened for its antagonism against Ustulina zonata, a relevant fungal pathogen responsible for
causing charcoal root rot of tea. Among the eleven potential actinomycetes strains two of the strains MM/
PH/AC-02 and MM/PH/AC-09 identified as Streptomyces spp. showed more than 45 percent inhibition
under study in in vitro condition. Among the two, MM/PH/ AC-09, identified as Streptomyces costaricanus,
was found to control the tea pathogen as well as promote the growth of tea bushes under nursery trials.
The results of this study facilitate the exploitation of this potentially antagonistic Streptomyces sp from
the rhizosphere of tea and other plantation crops with diverse disease control efficiency.
Keywords: Antagonistic, Rehabilitation, Non-Rehabilitation, Virgin, Streptomyces costaricanus Ustulina zonata.

Performance of Indaziflam 1.65% w/w + Glyphosate isopropyl ammonium 44.63% w/w SC(Ready mix)against weed complex in Tea plantations of Assam

Rajashri Saikia — 2026-07-14

A field experiment was conducted at Jorhat, Assam to evaluate the efficacy of Indaziflam 1.65% w/w + Glyphosate isopropyl ammonium 44.63% w/w SC (marketed as Alion Plus) on weed control in tea plantation. The dominant weed florae present in the experimental plots were Axonopuscompressus (Sw.) Beauv.,Paspalum conjugatumBerg., Murdanniamalabarica(L.) Brueck, Pteridium aquilinum Kuhn. and Gleichenia linearis (Burm.f.) Clarke., Borreria hispida (L.) K. Schum., Ageratum conyzoides Linn., Eupatorium odoratum Linn. and Erechthitesvalerianaefolia DC. The experiment was laid out in a randomized block design, with five replications and four treatments. The treatments comprisedAlion plus @ 2.5 L/ha(T₁), Glyphosate 41 % SL @ 2.5 L/ha(T₂), Manual weeding(T₃) at 0 and 30 days after application (DAA) of treatments and Untreated control(T₄).The fluids used for T₁ and T₂ were 500 L/ha and 400 L/ha respectively. Results revealed that among the treatments, T₁ recorded the lowest weed density (0.71 No./m²), lowest weed dry weight (0.71 g/m²) and highest weed control efficiency (100%),which was statistically at par with T₃and significantly over T₄upto 75 DAA,irrespective of weed species. However, T₁ and T₂ were not statistically identical acrossall the observations and weed species. This treatment(T₁) effectively controlled all the weeds upto 75 DAA, with no regrowth observed except in Murdanniamalabarica(L.) Brueck. Considering the requirement of higher number of mandays in manual weeding andoverall performance of T₁, Alion Plus @ 2.5 L/ha is a good option to control a broad spectrum of weeds in tea plantations.
Key words: Camellia sinensis (L) O. Kuntze,Alion Plus, weed dry weight, weed control efficiency

Risk assessment of Flupyradifurone in tea - A note for the stakeholders of tea

R. Pal — 2026-07-14