Kaempferia galanga L., a rhizomatous plant species, is highly valued for its medicinal and culinary properties. Studying the effects of planting dates and spacing is crucial for optimizing the cultivation of K. galanga, as it can help farmers and cultivators maximize yields, improve resource allocation, and promote sustainable agricultural practices. This study investigated the impact of planting date and spacing on the growth and yield of K. galanga. The experiment was conducted over three consecutive years, with three planting dates (April 15, April 30, and May 15) and four spacing treatments (20 cm x 20 cm, 30 cm x 30 cm, 40 cm x 40 cm, and 50 cm x 50 cm). The results showed that planting date and spacing significantly affected canopy diameter, yield per plant, rhizome yield per hectare, and oil yield per hectare. The optimal planting window for maximizing yield and oil production was April 15-30, with a spacing of 20 cm x 20 cm. Wider spacing resulted in higher yield per plant, while closer spacing led to higher rhizome yields per hectare.

The concept of color has consistently played a significant role in developing various human societies globally. It impacts all aspects of our lives, including the clothes we wear. As a result, the synthetic textile colouring industry has grown significantly. On the contrary, there has been a resurgence in the attention towards natural dyes due to the environmental apprehensions of synthetic dyes and their harmful health effects, as natural dyes are perceived to be more sustainable. Weeds are plants that are out of place and undesirable in a particular environment. Converting these plants into valorized products will be an efficient way of managing them. Many weeds have been identified as potential sources of natural plant pigments like anthocyanins, betalains, carotenoids, and other natural pigments. Using weed plants for dye extraction not only provides an alternative dye source but also helps to reduce weed plant invasion. A variety of natural colours can be extracted from weeds. Furthermore, several invasive species, including wire weed, siam weed, common purslane, etc., can be used to extract different hues and tints.

With the increasing demand for stevia as a natural sweetener among health-conscious diabetics, a field trial was conducted in 2022 and 2023 at the Agronomy farm, College of Agriculture, Vellanikkara, to evaluate the impact of integrated nutrient management (INM) on growth rates and nutrient uptake of stevia (Stevia rebaudiana Bertoni). The experiment followed a factorial randomized block design (FRBD) with two factors: manure (no manure, vermicompost at 2.5 t ha-¹, and farmyard manure at 5 t ha-¹) and NPK levels (20:10:10, 40:20:20, and 60:30:30 kg ha-¹). The highest crop growth rate (CGR) was observed with FYM @ 5 t ha-¹ and 60:30:30 NPK kg ha-¹, particularly at the 30-45 DAP stage. Relative growth rate (RGR) was significantly influenced only during the first growth period, with the highest RGR observed under FYM @ 5 t ha-¹ and 60:30:30 NPK kg ha-¹. Pooled mean nitrogen and phosphorus uptake was highest with FYM @ 5 t ha-¹, and higher potassium uptake was with FYM @ 5 t ha-¹ and vermicompost @ 2.5 t ha-¹ among manures The highest NPK uptake was obtained with 60:30:30 NPK kg ha⁻¹ among NPK levels. In conclusion, the combined application of FYM @ 5 t ha-¹ and NPK @ 60:30:30 kg ha-¹ resulted in better growth performance and nutrient absorption by stevia.

Heavy metals can be extracted from the earth using hyperaccumulator plants. These plants can grow in soil with high concentrations of metals and concentrate trace elements in their biomass. Agromining is a branch of phytoremediation that aims to remove toxic metals from polluted ecosystems. The plants can be used to produce valuable metals such as Ni and Zn. The potential of agromining can be enhanced by improving biomass yield through agronomic practices. The phenological stage of the crop at harvest influences metal concentration in the tissues. Inoculation with microorganisms especially Arthrobacter sp. strain LA44 improved the metal yield in Alyssum murale. Observed high Ni yield in Phyllanthus rufuschaneyi and Rinorea bengalensis by the application of major nutrients. Agromining is still at an early stage of development. Even then, it created a new era in the recovery of metals from natural resources. Hyperaccumulator plants changed their recognition from a botanical curiosity to tangible socio-economic and environmental applications. However, rigorous and dedicated research is required for its wide utilization and to improve quantitative and qualitative performance.

A field experiment was conducted to understand the effect of organic manures on the crop growth rate (CGR), relative growth rate (RGR), and nutrient uptake of stevia (Stevia rebaudiana Bertoni) from April to August of 2022 and 2023 at the Agronomy farm, Department of Agronomy, College of Agriculture, Vellanikkara, Thrissur. The experiment was laid out in randomized block design (RBD) with 7 treatments replicated thrice which consisted of different levels of organic manures viz., three levels of farmyard manure (FYM@ 5, 10, 15 t ha­-1), three levels of vermicompost (VC@ 2.5, 5, 7.5 kg ha-1) and a control. The organic manure treatments significantly affected crop growth rate (CGR) and relative growth rate (RGR) in all the growth periods. The two-year pooled mean of CGR of stevia was significantly superior in FYM@15 t ha-1 over control in all the three growth periods i.e., at 0-30 DAP, 30-45 DAP and 45 DAP to harvest. Whereas, the two-year mean of RGR of stevia was found statistically higher in FYM@15 t ha-1 over control in the first two growth periods only. The organic manure treatments had a significant influence on the plant nutrient (NPK) uptake as well in both the years. The two-year pooled mean data regarding plant uptake of nitrogen and phosphorous was found significantly higher in FYM@15 t ha-1 over control whereas statistically higher pooled mean potassium uptake by stevia was found in VC@7.5 kg ha-1 over control. Overall, the higher levels of organic manure, especially FYM, significantly improve growth and nutrient uptake in stevia.

Pseudarthria viscida (L.) Wight & Arnott is an important, high-volume, traded, threatened medicinal plant native to South and Southeast Asia. Simple Sequence Repeats (SSR) markers were used to determine the genetic relatedness and diversity of 20 accessions of P. viscida collected from different parts of Kerala. Ten primer pairs used were found to be highly polymorphic, showing 100 percentage polymorphism and an average Polymorphic Information Content (PIC) of 0.986, indicating high genetic variation among the accessions. A total of 126 alleles with an average of 12.6 alleles per locus were detected. The cluster analysis based on Jaccard's similarity coefficient using an unweighted pair group method using arithmetic averages grouped the accessions into 4 clusters. The average genetic similarity coefficient of 0.09 indicates relatively high genetic diversity among the accessions. Principal Coordinates Analysis (PCoA) showed the presence of genetic diversity. The three principal coordinates explained 29.55% of the total variation. P. viscida populations have become vulnerable in their natural habitat, and immediate conservation measures are required. SSR markers could be used in future research on the genetic diversity of P. viscida.

Turmeric (Curcuma longa L.) is a significant crop that has historically been used worldwide as a medicinal plant, spice, food colouring agent, and a significant ingredient in cosmetic industries. After harvesting rhizomes, leaves are considered waste material. This research study aims to extract and chemically characterise the essential oil from the leaves waste of turmeric with an evaluation of different insecticidal, antioxidant, and phytotoxic activities. Subsequently, the contact toxicity, fumigant toxicity, and repellent activity were evaluated against two key stored grain insect species. The gas chromatography-mass spectrometry (GC-MS) characterisation revealed that & alpha;-phellandrene (28.95%), 2-carene (16.51%), eucalyptol (10.54%) and terpinolene (10.24%) were the major chemical constituents. The study's findings on the insecticidal effects of essential oils extracted from turmeric leaves revealed noteworthy repellent, contact (at 24 h, LC50 = 6.51 mg/cm2 for Tribolium castaneum and LC50 = 4.74 mg/cm2 for Rhyzopertha dominica) and fumigant toxicities (at 24 h, LC50 = 2.57 mg/L air for T. castaneum and LC50 = 2.83 mg/L air for R. dominica), against two key stored grain insects. In addition, turmeric leaf essential oil showed notable antioxidant activity (IC50 = 10.04 & PLUSMN; 0.03 & mu;g/mL for DPPH assay; IC50 = 14.12 & PLUSMN; 0.21 & mu;g/mL for ABTS assay. Furthermore, a phytotoxicity study was carried out on stored paddy seeds and no toxic effects were found on germination rate and seedling growth. So, it might be expected that the essential oils extracted from the turmeric leaf waste could be valorised and demonstrate their potential as safe botanical insecticides against stored-product insects, with noble antioxidant properties.

Phytosphere management studies for Desmodium gangeticum (L.) DC., an essential herbal remedy used in the Ayurvedic, Siddha, and Unani medical systems, were carried out at AICRP on MAP and B, College of Agriculture, Kerala Agricultural University. Treatments for standardizing shade requirements were 25% shade, 50% shade, 75% shade, and completely open growing conditions. The organic manuring treatments included basal application of FYM @ 10 t/ha, FYM @15 t/ha, vermicompost (to supply N equivalent to FYM 10 t/ha), vermicompost (to supply N equivalent to FYM 15 t/ha), coir pith compost (to supply N equivalent to FYM 10 t/ha), coir pith compost (to supply N equivalent to FYM 15 t/ha) and absolute control. Under 75% shade, the highest root production of 7589 kg/ha was observed. The lowest root yield was produced in the open condition (49% lower than the treatment with the highest yield). According to the findings, D. gangeticum could be used as a component in agroforestry systems with a high shade intensity. The root yields were comparable under 50 and 25% shaded conditions. The basal application of farm yard manure at 10 or 15 t/ha produced the highest root yield and total alkaloid content among organic manures. After two years of the experiment, the soil nutrient status revealed a decrease in the amounts of available nitrogen, phosphorus and potassium compared to the starting level. The absolute control showed the most significant nutrient depletion, emphasizing the importance of providing crops with manures or fertilizers.

A field study was carried out from May to November 2020, to assess the effect of growing conditions and planting date on herbage yield and quality of stevia (Stevia rebaudiana Bertoni) . The design of the experiment was split plot with two main plots (open and 50 per cent shade) and four sub plots (May 15 th , June 15 th , July 15 th , and August 15 th ). Higher plant height was observed under 50 per cent shaded conditions. Leaf weight, herbage yield, and steviol glycoside contents were higher under open growing conditions . The herbage yield was higher in the treatment combination of planting in May under open conditions (7800 kg ha -1 ) and was on par with the August planting (7212 kg ha -1 ) under open conditions. Lower herbage yield was recorded in June planting (3872 kg ha -1 ) under 50 per cent shade and was on par with the July planting (4077 kg ha -1 ) under 50 per cent shade . Under open conditions, the crop planted in May recorded the highest total steviol glycoside content (9.05 percent). A strong positive correlation was observed between growth parameters of stevia with maximum and minimum temperatures, whereas the correlation with rainfall was negative.

A field experiment was carried out to standardize spacing and pinching time to enhance the yield and quality of stevia (Stevia rebaudiana Bertoni) at the Department of Agronomy, College of Agriculture, Thrissur, Kerala, from September 2021 to May 2022. The design of the experiment was factorial RBD and replicated thrice. The experiment comprised three levels of spacing (15 cm × 10 cm, 20 cm × 10 cm, and 15 cm × 15 cm) and four pinching intervals (pinching at 20 days after planting (DAP), pinching at 30 DAP, pinching at flower bud initiation and no pinching) in all possible combinations. The plants grown with closer spacing (15 cm × 10 cm) were the tallest at all growth stages. The pinching of the apical bud caused a reduction in plant height and increased the number of branches. Pinched plants recorded higher fresh and dry leaf weights than plants left non-pinched. More leaves were registered under the wider (15 cm × 15 cm) spacing than narrower spacings. Pinching favored the formation of more lateral buds, producing a more significant number of branches and, finally, more leaves per plant. High-density planting of stevia yielded the highest aboveground fresh mass (10925 kg ha-1), whereas lower plant densities yielded the lowest aboveground fresh mass (7330 kg ha-1). The stevia planted at a spacing of 15 cm × 10 cm and pinched at flower bud initiation (11980 kg ha-1) produced higher herbage.

Citrus peel is a major fruit waste generated during the processing of citrus fruits. We extracted and chemically characterised essential oil from four different species of citrus peel waste and evaluated its insecticidal, antioxidant and phytotoxic activities. GC-MS/MS characterisation revealed D-limonene as the major constituent of citrus peel waste essential oil. The essential oils from the four citrus peel wastes showed significant contact, fumigant and repellent activities against two key stored grain pests Tribolium castaneum (Herbst) and Callosobruchus chinensis (L.). DPPH, ABTS, and FRAP assays revealed the antioxidant potential of the citrus peel waste essential oil. The essential oil did not affect the germination of wheat seeds and revealed the safety of essential oil to germinating seeds. Hence, the essential oil extracted from citrus peel waste can be valorised and utilised as a botanical insecticide against T. castaneum and C. chinensis.

Agronomic management exhibits great influence on growth and yield of crops by modifying physical, chemical and biological properties of soil and plants. Field experiment was conducted during June to December, 2018 to assess the effect of agronomic management viz. light intensity, application of manuring and weed management on soil microclimatic variations and its effects on root yield of Sida hemp (Sida alnifolia L.). The treatments included two levels of light intensity (open and 50 per cent shade), two levels of manuring (no manure and FYM@10 t ha-1), and four weed management practices (black polythene mulching, organic mulching with paddy straw @ 5 t ha-1, hand weeding at 1,3,5 MAP (Month after planting) and no weeding). Higher soil temperature at 10 cm depth was observed in open condition and under black polythene mulching throughout the growing period. Higher soil moisture content at 15 cm depth was recorded under shade and black polythene mulching. Black polythene mulching resulted in increase in soil temperature and soil moisture content by almost two percent as compared to bare soil in open condition. The highest root yield of 14.66 t ha-1 was noticed in plots with black polythene mulching with FYM under open condition. Soil temperature and light intensity showed positive correlation with root yield.

Several plants express the allelopathic phenomenon through release of allelochemicals. Plants rich in allelochemicals can be used for controlling weeds in organic crop production. Current study was aimed at screening of Andrographis paniculata (Burm.f.) Nees (bitter weed), Plectranthus amboinicus (Lour) Spreng (Indian borage) and Tagetes minuta L.(Southern cone marigold) for allelopathic potential against upland weeds.This study was conducted from February to May 2021 in the Department of Agronomy, College of Agriculture, Vellanikkara, Kerala Agricultural University, Thrissur. The methanol extracts of Tagetes minuta and Andrographis paniculate at 25-30% concentration as pre-emergence application exhibited allelopathic effect on broad-leavedweeds.

A study was conducted during two consecutive kharif seasons of 2019 and 2020 to standardize the shade requirement and method of harvesting for obtaining high essential oil and eugenol contents in tulsi. Experiments were laid out in split plot design with two main plots and four sub plot treatments. Growing of tulsi under 50 per cent shade and harvesting at 20 - 30 cm height from ground level at 75 and 135 days after transplanting (DAT) can be recommended for higher essential oil production. For open growing condition, harvesting at 20 - 30 cm height at 90 and 150 DAT can be recommended for higher eugenol content.

Two separate field experiments, one under 50 % shade and another under open condition was conducted at Kerala Agricultural University, Thrissur during 2019-20 and 2020-21 to find out the effect of harvesting time and height of harvest on tulsi (Ocimum tenuiflorum L.). Present investigations were formulated in randomized block design (RBD) having four treatments and five replications. Treatments included, harvesting at 20 cm height above ground level at 75 and 135 DAT (T1), harvesting at 30 cm height above ground level at 75 and 135 DAT (T2), harvesting at 20 cm height above ground level at 90 and 150 DAT (T3) and harvesting at 30 cm height above ground level at 90 and 150 DAT (T4). Irrespective of growing conditions, harvesting at 20 cm height above ground at 75 and 135 DAT (T1) and harvesting at 30 cm height above ground at 75 and 135 DAT (T2) produced significantly higher biomass yield, essential oil yield and total chlorophyll. Among growing conditions, tulsi plants grown under 50 % shade was superior to open condition with respect to fresh biomass yield and oil yield, proving feasibility of growing tulsi as an intercrop.

Abstract An experiment was conducted in the laboratory to evaluate the effect of herbicides on beneficial and pathogenic microorganisms. Eighteen treatments included six herbicides at three different doses viz., cyhalofop-butyl (80, 160 and 240 ppm), cyhalofop-butyl + penoxsulam (150, 300 and 450 ppm), bispyribac-sodium (25, 50 and 75 ppm), fenoxaprop-p-ethyl (60, 12 and 180 ppm), carfentrazone-ethyl (20, 40 and 60 ppm) and chlorimuron-ethyl + metsulfuron-methyl (4, 8 and 12 ppm) evaluated on beneficial microbial bioagents (Trichoderma viride and Pseudomonas fluorescens) and pathogenic microorganisms (Rhizoctonia solani, Pyricularia oryzae and Xanthomonas oryzae pv. oryzae). Results revealed that bispyribac-sodium and cyhalofop-butyl + penoxsulam had greatest inhibitory effect on pathogenic microorganisms Rhizoctonia solani (47.76 and 54.40%) and Pyricularia oryzae (49.07 and 61.12%), but showed no effect on Xanthomonasoryzaepv. oryzae, and were less harmful to biocontrol agents Trichoderma viride and Pseudomonas fluorescens at recommended doses, which were effective in control of broad spectrum of weed flora in rice ecosystem.