First Report of 'Candidatus Phytoplasma citri' related strain (16SrII-C subgroup) associated with phyllody disease of cumin in India.

Cumin (Cuminum cyminum L.), is an important export-oriented seed spice crop for India. Cumin is popularly used for flavouring food, including soups, pickles and vegetables, and for herbal medicine. India is the largest producer, consumer and exporter of cumin seed with an annual production of 0.795 million tones over an area of 1.09 million hectares. During 2020-21, India exported about 0.299 million tons of cumin worth of Rs 33280 million (Anonymous, 2021). Recently, phytoplasma suspected symptoms were observed in cumin at Agricultural Research Station, Mandor, Jodhpur, Rajasthan, India from 2019. The symptoms related to phytoplasma infection were first recorded after 70-75 days of sowing in the month of January of the years 2019 to 2022. The major symptoms recorded were yellowing, phyllody, witches-broom, yellowing and deformed elongated seeds. Disease incidence was recorded as 0.25-1.0%, 0.5-1.5%, 0.5-2.5 % and 0.5-10.6% during the years 2019, 2020, 2021 and 2022, respectively using quadrate method. In 2022, among different genotypes assessed GC 4, MCU 73, MCU 105, and MCU 32 exhibited lower disease incidences ranging from 0.5% to 1.5%, while MCU 78 recorded the highest disease incidence at 10.6%. To detect the association of phytoplasma with symptomatic cumin samples, genomic DNA was extracted from four representative cumin genotypes (CuPP-MND-01 to CuPP-MND-04) and one asymptomatic cumin plant using the Qiagen DNeasy plant mini kit (Germany). The extracted DNA was amplified using nested PCR assays with universal phytoplasma detection primers for 16S rRNA gene (P1/P7 and R16F2n/R16R2) (Schneider et al., 1995; Gundersen and Lee, 1996) and secA gene specific primers (SecAfor1/SecArev3 followed by nested PCR primers SecAfor5/ SecArev2) (Hodgetts et al. 2008; Bekele et al. 2011). The amplicons of ∼1.25 kb with 16S rRNA gene and ∼600 bp with secA gene specific primers were amplified in all symptomatic cumin plant samples and positive control of brinjal little leaf. PCR amplified products from the four selected positive samples (CuPP-MND-01 to CuPP-MND-04) of 16S rRNA gene and secA gene, were sequenced from both ends. The 1,245 bp sequences were deposited in GenBank (OQ299007-10), which showed 100% sequence identity with each other and 99.4% identity with 'Candidatus Phytoplasma citri' reference strain (GenBank accession: U15442) (Rodrigues Jardim et al. 2023). The phylogenetic analysis and virtual RFLP analysis using 17 restriction enzymes of 16S rRNA gene sequences through iPhyclassifier allowed affiliating the cumin phytoplasma strains with 16SrII-C subgroup strain with a similarity coefficient of 1 to the reference pattern of 16Sr group II, subgroup C (GenBank accession: AJ293216) (Zhao et al. 2009). In addition, the phylogenetic analysis of the secA gene-based sequences (OQ305073-76) further confirmed the close association of 16SrII-C group phytoplasmas with phyllody and witches' broom disease of cumin. Earlier 16SrII-C subgroup phytoplasma has been reported from various crops and weeds in India (Rao et al. 2021). However, no phytoplasma association has been reported earlier with cumin in India and abroad. To the best of our knowledge, this is the first report on the association of 16SrII-C group phytoplasma causing phyllody, witches' broom in cumin genotypes. This report has economic and epidemiological implications and needs immediate attention to reduce export losses due to phytoplasma disease in cumin and to prevent the potential spread to other crops.

First Report of Candidatus Phytoplasma asteris (16SrI-B subgroup) associated with phyllody disease of fenugreek in the world.

Fenugreek (Trigonella foenum-graecum) is a leafy vegetable and spice crop, native to Indian subcontinent and Eastern Mediterranean region. Phytoplasma infection symptoms were observed in fenugreek at ICAR-National Bureau of Plant Genetic Resources Regional Station, Jodhpur and Agricultural Research Station Mandore Jodhpur, Rajasthan, India. The first appearance of phytoplasma suspected symptoms of little leaf was recorded after 50 days of sowing in the months of January 2022. The major symptoms recorded were virescence, phyllody, shoot proliferation, witches-broom, little leaf, yellowing and overall stunted growth in 146 germplasm accessions at NBPGR research farm, Jodhpur and one major commercially cultivated variety RMT 305 at Mandore Jodhpur. Ten samples from symptomatic and five samples from asymptomatic fenugreek plants were collected and processed for total DNA extraction using the Qiagen DNeasy plant mini kit (Germany). The extracted DNA was amplified using nested PCR assays with universal phytoplasma detection primers for 16S rRNA gene (P1/P7 and R16F2n/R16R2) and secA gene specific primers (SecAfor1/SecArev3 and SecAfor2/SecArev3) (Schneider et al. 1995; Gundersen and Lee 1996; Hodgetts et al. 2008). The amplicons of ∼1.25 kb with 16S rRNA and ∼480 bp with secA gene specific primers were amplified in all symptomatic fenugreek samples. In negative control (asymptomatic plants) no amplification was observed with either of gene specific primers in gel electrophoresis. PCR amplified products from the six selected positive samples (FPP-NBPGR-J-01 to FPP-NBPGR-J-04 and FPP-MND-01 to FPP-MND-02) of 16S rRNA and secA gene, were sequenced from both ends. Sequences were deposited in the NCBI GenBank with accession numbers ON756108-ON756113 for 16S rRNA gene sequences and ON745809 to ON745814 for secA gene sequences. BLAST analysis of 16S rRNA and secA sequences revealed 100% sequence identity among themselves and 99.95 to 100% sequence identity with the earlier reported phytoplasma strains of aster yellows group related phytoplasma strains (GenBank Acc. No. MN239504, MN080270) belonging to Ca. P. asteris (16SrI group). Further analyses of the 16S rRNA and secA gene-based phylogenetic tree and the iPhyClassifier-based virtual RFLP analysis of 16S rRNA gene study demonstrated that the phytoplasma associated with fenugreek phyllody belonged to 16Sr group I ('Ca. P. asteris') and subgroup B (GenBank accession AP006628), with similarity coefficient of 1.0. Earlier association of 16Sr-II-D subgroup (Ca. P. australasiae) with fenugreek as host was reported from Pakistan (Malik et al., 2020). To the best of our knowledge, this is the first report of a 'Ca. P. asteris', 16SrI-B subgroup related phytoplasma strain associated with fenugreek phyllody in the world. The 16SrI-B phytoplasma strain is a widely distributed strain associated with several agricultural and horticultural crops of India (Rao 2021). This is not only the first instance of fenugreek phyllody disease found in India, but also the first instance of fenugreek phyllody caused by 16SrI-B subgroup phytoplasma worldwide. This report has epidemiological significance and needs immediate attention, as fenugreek is one of the most common seed spice crop being grown all over India.

First Report of Candidatus Phytoplasma asteris (16SrI-B Subgroup) associated with phyllody disease of moth bean in world.

Moth bean (Vigna aconitifolia), a drought and heat-resistant legume from the Fabaceae family, is commonly cultivated in arid and semi-arid regions of the Indian subcontinent In September 2022, phyllody symptoms (Figure 1) were observed on 50-days-old moth bean plants at the ICAR-NBPGR research farm in Jodhpur, Rajasthan, India. The disease incidence ranged from 10 to 25%. To investigate the cause, ten symptomatic VacoJod (1-10) and ten asymptomatic VacoJod (11-20) Vigna aconitifolia plants were collected. Insect populations were also collected from the vicinity using the sweep-net method to examine the role of insect vectors. The leafhopper was identified based on morphological characterization as Empoasca sp. at the Division of Entomology, ICAR-IARI, New Delhi. DNA was extracted from midribs of all collected plants and the Empoasca sp., using Qiagen DNeasy Plant Mini Kit and Blood and Tissue kit, respectively. Nested polymerase chain reaction (Nested-PCR) with universal primers P1/P7 and R16F2n/R16R2 (Deng and Hiruki, 1991; Gundersen and Lee, 1996), and secA gene primers (secAfor1/secArev3 and secAfor2/secArev3) (Hodgetts et al., 2008) were employed to determine phytoplasma species association. Out of the 10 symptomatic plants and 10 leafhopper samples, 6 leafhopper samples and all symptomatic plants produced expected band sizes for the 16S rRNA (approximately 1.25 kb) and secA gene (480 bp). The PCR products were cloned, sequenced, and sequences (two each from moth bean and leafhopper) were submitted to NCBI GenBank with accession numbers OP941130, OP941132, OP941133 and OP941134 for 16S rRNA and OP958868, OP958869, OP958870, and OP958871 for secA gene sequences. Nucleotide BLAST analysis of 16S rRNA sequences revealed a minimum of 99.92% similarity with 'Primula acaulis' yellows phytoplasma (KJ494340) from Czech Republic. All 100% hits corresponded to 16SrI-B group phytoplasmas, for example rapeseed phyllody phytoplasma (CP055264) from Taiwan. Similarly, nucleotide BLAST analysis of secA sequences revealed a minimum of 99.15% sequence similarity with Paulownia witches'-broom phytoplasma (secA) (OP124308) from China. All 100% hits were of 16SrI-B group phytoplasmas, for example Ageratum conyzoides yellowing phytoplasma (MW401697, secA) from India. Phylogenetic analysis using MEGA11 (Tamura et al., 2021) clustered the moth bean and Empoasca sp. phytoplasma strains with 16SrI-B phytoplasma reference strains. iPhyClassifier tool classified the 16S rRNA gene sequences into 16Sr group I, subgroup B, with a similarity coefficient of 1.0 (Figure 2a, 2b). This marks the first report of the association of 'Ca. P. asteris' 16SrI-B related phytoplasma strain with moth bean plants globally. The 16SrI-B phytoplasma strain is prevalent in various crops in India (Singh et al., 2023). This report emphasizes the epidemiological studies and highlights the need for further research and preventive measures to manage the spread of this phytoplasma strain, which could impact crop production and food security in hot and dry regions.

Endophytic bacteria promote growth of the medicinal legume Clitoria ternatea L. by chemotactic activity.

Part of the native root nodule endophytic microflora referring to members of the genera Proteobacteria and Sphingobacteria were used to test their bioefficacy as seed biopriming. These were quantified for their plant growth promoting (PGP) attributes such as IAA production, P and K-solubilization and ACC deaminase production. Results showed that significantly highest IAA was produced by E. hormaechi RCT10. The highest P-solubilization was observed with S. maltophila RCT31 it was solubilizing all the substrate tri-calcium phosphate, di-calcium phosphate, and zinc phosphate. Significantly highest K-solubilization was observed with S. maltophila RCT31 followed by E. turicensis RCT5. However, the maximum zinc solubilization was reported with S. maltophila RCT31 followed by E. turicensis RCT5. The maximum ACC deaminase was quantified in the bacterium. Results revealed that the E. hormaechi RCT10 utilized seed leechates most effectively while root exudates were maximally utilized by S. maltophila RCT31. The pots experiment proves that S. maltophila RCT31 was the most effective bacterium and it was replication vis-à-vis field experiment. In particular, S. maltophila RCT31 holds strong potential to be possibly used as a bioformulation for the medicinal legume, as an economical and eco-friendly alternative to agrochemicals.

The potential of arbuscular mycorrhizal fungi in C cycling: a review.

Arbuscular mycorrhizal fungi (AMF) contribute predominantly to soil organic matter by creating a sink demand for plant C and distributing to below-ground hyphal biomass. The extra-radical hyphae along with glomalin-related soil protein significantly influence the soil carbon dynamics through their larger extent and turnover period need to discuss. The role of AMF is largely overlooked in terrestrial C cycling and climate change models despite their greater involvement in net primary productivity augmentation and further accumulation of this additional photosynthetic fixed C in the soil. However, this buffering mechanism against elevated CO2 condition to sequester extra C by AMF can be described only after considering their potential interaction with other microbes and associated mineral nutrients such as nitrogen cycling. In this article, we try to review the potential of AMF in C sequestration paving the way towards a better understanding of possible AMF mechanism by which C balance between biosphere and atmosphere can be moved forward in more positive direction.

Revisiting the plant growth-promoting rhizobacteria: lessons from the past and objectives for the future.

Plant beneficial rhizobacteria (PBR) is a group of naturally occurring rhizospheric microbes that enhance nutrient availability and induce biotic and abiotic stress tolerance through a wide array of mechanisms to enhance agricultural sustainability. Application of PBR has the potential to reduce worldwide requirement of agricultural chemicals and improve agro-ecological sustainability. The PBR exert their beneficial effects in three major ways; (1) fix atmospheric nitrogen and synthesize specific compounds to promote plant growth, (2) solubilize essential mineral nutrients in soils for plant uptake, and (3) produce antimicrobial substances and induce systemic resistance in host plants to protect them from biotic and abiotic stresses. Application of PBR as suitable inoculants appears to be a viable alternative technology to synthetic fertilizers and pesticides. Furthermore, PBR enhance nutrient and water use efficiency, influence dynamics of mineral recycling, and tolerance of plants to other environmental stresses by improving health of soils. This report provides comprehensive reviews and discusses beneficial effects of PBR on plant and soil health. Considering their multitude of functions to improve plant and soil health, we propose to call the plant growth-promoting bacteria (PGPR) as PBR.

Post-harvest processing and valorization of Kinnow mandarin (Citrus reticulate L.): A review.

Kinnow is a prevalent fruit crop of the mandarin group and belongs to the Rutaceae family. It is nutritionally rich in vitamin C, vitamin B, ß-carotene, calcium, phosphorous and other health beneficing compounds. The fruit is grown commercially for fresh consumption and since the processing techniques are less prominent, a plentiful amount of harvested fruit goes for waxing and grading operations. To reduce the post-harvest losses, appropriate processing techniques need to be followed as considerable fruit waste is generated while processing. The foremost fruit wastes viz. peel and seeds are rich source of bioactive compounds and can be utilized for the extraction of aromatic compounds, essential oils and low-methoxyl pectin. Overall utilization of kinnow and its components through various technological interventions will not only enhance the profitability of processing industries but also assist in reducing the pollution load on the environment. The prevailing bitterness in kinnow juice has constrained its processing, value-addition, popularity and acceptability. Limited work has been done on kinnow processing leaving scarce relevant literature published on the post-harvest management. Efforts made by researchers worldwide, regarding the post-harvest application of kinnow and its by-products for product development, value addition and waste utilization is presented and discussed in this paper. This compiled information is envisioned to encourage the cottage food processing units in order to improvise the overall benefits along with achieving complete utilization of kinnow.

Arbuscular mycorrhiza: a viable strategy for soil nutrient loss reduction.

Arbuscular mycorrhiza fungi's (AMF) role in plant nutrition and stress management is well known, but very few researches and studies have been conducted so far on the fungal ability to reduce different nutrient losses (runoff, leaching and volatilization) from the soil system. This important ecosystem service of AMF had been neglected largely. From the recent findings, it has been confirmed that mycorrhizal symbiosis has potential to check the losses of applied nutrients. The role of soil biota in nutrient cycling is indispensable and determines the nutrient availability to plants. Among these biota, AMF's association with plants is the most prevalent, but the exact mechanisms followed by AMF in nutrient cycling, transformation and reducing nutrient loss ability are still inconclusive. In this review, we will try to unlock this particular aspect of AMF which is important to achieve global food demand in a sustainable way.

Combinatorial approaches for controlling pericarp browning in Litchi (Litchi chinensis) fruit.

The availability of fruit like litchi has been limited by variability in yield, alternate bearing, seasonal differences and most commonly post harvest problems. The litchi fruit has a very short shelf-life during which red color turns brown which greatly affects the appeal to consumer although not the unique flavor. This review article focuses on the post harvest problems especially browning of litchi. The pericarp of litchi is also sensitive to desiccation and turns brown and brittle once moisture is reduced to half. A large number of approaches have been tried to solve this problem starting from hydro-cooling to gamma irradiation but single approach could not suffice for all. In modern era, the logical base of controlling browning is either to control the responsible enzyme or remove the undesirable product of enzyme catalyzed reaction. Thus enzyme technology with good postharvest practice can definitely solve this problem.

Conservation agricultural practices for minimizing ammonia volatilization and maximizing wheat productivity.

A large amount of ammonia volatilization from the agricultural system causes environmental problems and increases production costs. Conservation agriculture has emerged as an alternate and sustainable crop production system. Therefore, in the present study, ammonia losses from different agricultural practices were evaluated for the wheat crop under different tillage practices. The results of the present study showed that the cumulative emission of ammonia flux from the wheat field varied from 6.23 to 24.00 kg ha-1 (P ≤ 0.05) in conservation tillage (CA) and 7.03 to 26.58 kg ha-1 (P ≤ 0.05) in conventional tillage (CT) among different treatments. Application of basal 80% nitrogen resulted in the highest ammonia flux in conventional and conservation tillage practices. The ammonia volatilization followed the following trend: urea super granules with band placement > neem-coated urea with band placement > neem-coated urea with broadcast before irrigation > neem-coated urea with broadcast after irrigation > slow-release N fertilizer (urea stabilized with DCD and N(n-butyl)thiophosphoric triamide) with band placement. The conservation agricultural practices involving conservation tillage appear to be a sustainable approach for minimizing ammonia volatilization and improving wheat productivity.

Electrophysiological Study in Acute Spinal Cord Injury Patients: Its Correlation to Neurological Deficit and Subsequent Recovery Assessment by ASIA Score.

BACKGROUND: To investigate the relationship between neurological deficit and subsequent recovery as assessed by ASIA score and findings of electrodiagnostic study in acute spinal cord injury (SCI) patients. METHODS: Thirty-five patients with acute SCI presenting within 48 h of injury were clinically evaluated for the level, extent, and severity of SCI according to the ASIA standards in a tertiary-level care center. Electrodiagnostic studies of bilateral two motor (tibial and peroneal), one sensory (sural) nerves, and five muscles [iliopsoas, vastus medialis, tibialis anterior, gastrocnemius, and extensor hallucis longus (EHL)] were conducted and repeated at 3 months and 6 months. RESULTS: The neurological recovery was highly significant (p < 0.001) at 6 months. The difference in mean amplitude was statistically significant (p < 0.05) for all the nerves; mean conduction velocity significant for peroneal and sural nerves, and with no significant difference in mean latency. The differences in mean recruitment of motor unit potential (MUP) and mean peak-to-peak amplitude were highly significant (p < 0.001). Statistically significant kappa agreement between neurological recovery according to ASIA score and nerve conduction velocity was found for right tibial nerve (K = 0.324); electromyography finding of recruitment of MUP with right and left tibialis anterior (k = 0.400) and left EHL (k = 0.407); peak-to-peak amplitude with right tibialis anterior (k = 0.211), right gastrocnemius (k = 0.390), and right EHL (k = 0.211). CONCLUSIONS: There is a strong relationship between electrodiagnostic findings and ASIA scoring to predict neurological deficit and subsequent recovery after acute traumatic SCI. Serial neurologic evaluation by ASIA score and electrodiagnostic studies may help in designing customized rehabilitation programs for the patients according to the expected neurological recovery; and evaluating future research in the field of SCI with more scientific authenticity.

Agriculture, dairy and fishery farming practices and greenhouse gas emission footprint: a strategic appraisal for mitigation.

Rising global population would force farmers to amplify food production substantially in upcoming 3-4 decades. The easiest way to increase grain production is through expanding cropping area by clearing uncultivated land. This is attained by permitting deadly loss of carbon (C) stocks, jeopardizing ecosystem biodiversity and deteriorating environmental quality. We aim to propose key agronomical tactics, livestock management strategy and advance approaches for aquaculture to increase productivity and simultaneously reduce the environmental impacts of farming sector. For this, we considered three major sectors of farming, i.e. agriculture, fishery and dairy. We collected literatures stating approaches or technologies that could reduce GHG emission from these sectors. Thereafter, we synthesized strategies or options that are more feasible and accessible for inclusion in farm sector to reduce GHG emission. Having comprehensively reviewed several publications, we propose potential strategies to reduce GHG emission. Agronomic practices like crop diversification, reducing summer fallow, soil organic carbon sequestration, tillage and crop residue management and inclusion of N2-fixing pulses in crop rotations are some of those. Livestock management through changing animals' diets, optimal use of the gas produced from manures, frequent and complete manure removal from animal housing and aquaculture management strategies to improve fish health and improve feed conversion efficiency could reduce their GHG emission footprint too. Adapting of effective and economic practices GHG emission footprint reduction potential of farming sector could make farming sector a C neutral enterprise. To overcome the ecological, technological and institutional barriers, policy on trade, tax, grazing practice and GHG pricing should be implemented properly.

Nullifying phosphatidic acid effect and controlling phospholipase D associated browning in litchi pericarp through combinatorial application of hexanal and inositol.

The role of phospholipid modification initiated by phospholipase D (PLD) in enzymatic browning has been revoked through this study. Various alcohols and aldehydes were tried to read out their PLD controlling behaviour. Based on in-vitro results, reagents like hexanal and inositol were used to regulate PLD activity of litchi fruit stored at ambient temperature and their effects on fruit quality and physiological characteristics were also investigated. The results showed that combinatorial chemical treatment was successful in maintaining freshness of fruit through delayed physiological loss in weight and hence maintaining firmness. Combinatorial treated fruit had lower browning index than control by day 7. This novel treatment also maintained comparable levels of total phenolics and lowered the level of malondialdehyde. Evaluation of antioxidative enzymatic profile also confirmed the alleviation of oxidative stress of litchi fruit at ambient temperature. Thus, this strategy of enzyme regulation could play a vital role in overall quality maintenance of litchi fruit.

Evaluation of potassium solubilizing rhizobacteria (KSR): enhancing K-bioavailability and optimizing K-fertilization of maize plants under Indo-Gangetic Plains of India.

Imbalanced potassium (K) fertilization in agricultural fields has led to considerable negative impacts and remains to be the foremost challenge for maize production in India-Gangetic region. Plant growth-promoting rhizobacteria, particularly potassium solubilizing rhizobacteria (KSR), could serve as inoculants and a promising strategy for enhancement of plant absorption of K hence reducing dependency on chemical fertilizers. Maize seeds were microbiolized for 30 min with KSR suspensions. In the present study, the use of chemical fertilizers along with Agrobacterium tumefaciens strain OPVS10 showed pronounced beneficial effect on growth and yield attributes in maize. There was a significant difference among different parameters studied when varying doses of K and KSR strains were applied. Results showed that the combined application of KSR strain OPVS10 with 100% RDK (recommended dose of K) was most effective in modulating growth, physio-biochemical, and yield attributes in maize thus could be regarded as a promising alternative to mineral K-fertilization. Principal component analysis (PCA) revealed that 100-grain weight and grain yield were the most important properties to improve the sustainable growth of maize. Therefore, these KSR strains have different mechanisms for modulating various activities in maize plants. Results suggested that the synergistic application of KSR strain OPVS10 with 100% RDK can be used for optimized breeding, screening, and nutrient assimilation in maize crop. Hence, this eco-friendly approach may be one of the efficient methods for reducing dependency on chemicals, which pose adverse effects on human health directly and indirectly.

Does a rhizospheric microorganism enhance K⁺ availability in agricultural soils?

The potassium solubilizing microorganisms (KSMs) are a rhizospheric microorganism which solubilizes the insoluble potassium (K) to soluble forms of K for plant growth and yield. K-solubilization is carried out by a large number of saprophytic bacteria (Bacillus mucilaginosus, Bacillus edaphicus, Bacillus circulans, Acidothiobacillus ferrooxidans, Paenibacillus spp.) and fungal strains (Aspergillus spp. and Aspergillus terreus). Major amounts of K containing minerals (muscovite, orthoclase, biotite, feldspar, illite, mica) are present in the soil as a fixed form which is not directly taken up by the plant. Nowadays most of the farmers use injudicious application of chemical fertilizers for achieving maximum productivity. However, the KSMs are most important microorganisms for solubilizing of fixed form of K in soil system. The KSMs are an indigenous rhizospheric microorganism which shows effective interaction between soil and plant systems. The main mechanism of KSMs is acidolysis, chelation, exchange reactions, complexolysis and production of organic acid. According to literature, currently negligible use of potassium fertilizer as a chemical form has been recorded in agriculture for enhancing crop yield. Most of the farmers use only nitrogen and phosphorus and not use the K fertilizer due to unawareness so that the problem of K deficiency occurs in rhizospheric soils. The K fertilizer is also costly as compared to other chemical fertilizers. Therefore, the efficient KSMs should be applied for solubilization of a fixed form of K to an available form of K in the soils. This available K can be easily taken up by the plant for growth and development. Our aim of this review is to elaborate on the studies of indigenous K-solubilizing microbes to develop efficient microbial consortia for solubilization of K in soil which enhances the plant growth and yield of crops. This review highlights the future need for research on potassium (K) in agriculture.