A pot culture experiment was conducted during Kharif season in the year 2021- 2022 at Green polyhouse, Department of Nematology, College of Agriculture, Odisha University of Agriculture and Technology, Bhubaneswar, Odisha in order to study effect of different inoculum level of M. incognita on chlorophyll content of pigeon pea. The experiment was laid out in Completely randomized design (CRD) with 5 treatments i.e T1 (500 J2/plant), T2(1000J2 / Plant), T3(1500J2/plant), T4(2000J2/plant), T5(Control)and 4 varieties were UPAS-120(R), IPA-15-1 (MR), IPA 14-7(S), CO-6(HS). To find out the effect of increase in inoculum level of nematode on chlorophyll content of pigeon pea leaves showed that highest reduction in chlorophyll in treatment T4 then T3, T2 and then T1 over control T5. The results have demonstrated that nematode infestation leads to highest decreased by 41.75% total chlorophyll content (a+b) in UPAS -120(R)) in the leaves and highest decrease found in case of high inoculum level inoculation of nematodes in the pigeon pea plant.

Chickpea (Cicer arientinum L.) is one of the most dominant pulse crops in India, which contributes 38 percent of the area and 50 percent production of pulses compare to the total pulse production of India. Chickpea contains protein-2.1%, carbohydrates-61.5%, and fat-4.5% and more iron, calcium and niacin content. The main constrain of chickpea production due to parasitic nematodes (Meloidogyne incognita) is about 14% of total global production in annual yield loss. Pseudomonas fluorescens is a bacterial bio-agent that can help in nematode suppression in chickpea plants. This experiment was conducted to experience the differences, if any, in manganese content concerning chickpea inoculated with M. incognita with a combination of Pseudomonas fluorescens as a bioagent, where different treatments of nematode, bacteria, and chemicals are used sustaining the enhancement of disease resistance in chickpea cultivars RSG 974, GG 5, GNG 2144. The total manganese content of chickpea variety GNG 2144 was found highest in treatment, where only bacteria (P. fluorescens) was inoculated, i.e., 6.44 mg/100g of a root, followed by GG 5, i.e., 5.63 mg/100g of root and RSG 974 was, i.e., 4.14 mg/100g of root respectively. Application of Pseudomonas fluorescence combined or alone gradually increased the manganese concentration in roots of chickpea plants i.e., RSG 974 (4.14 mg/100g), GG 5(5.63 mg/100g), GNG 2144 (6.44 mg/100g) compared to the health check.

Four tomato cultivars viz. Banki Local (R), Kashi Aman (MR), Utkala Dipti (S) and Utkala Kumari (HS) were inoculated with Glomus fasciculatum (Gf) and Meloidogyne incognita (Mi) and studied the effects on the changes of macronutrients and crude protein contents of shoots and roots. The percentage of shoot N, P, K and crude protein contents were decreased in all the treatments except Gf alone inoculated plant in all varieties and the maximum decrease was seen in Mi alone inoculated plant over untreated control. These were increased in roots of all treatments over untreated control and maximum in Gf alone inoculated plant. Among varieties, Utkala Kumari recorded the maximum percentage increase and decrease of N, P, and K content in root and shoot while minimum was recorded with Banki Local. T1 shows maximum decrease in shoot N, P, K and crude protein content over untreated check. T2 shows maximum root accumulation of macronutrients followed by T4 where Mi inoculated 7 days after Gf inoculation to tomato plants.

This study was conducted in the Department of Nematology, College of Agriculture, OUAT. The experiment was designed using completely randomized completely randomized design (CRD) with different combinations of root knot nematode (Meloidogyne incognita) and leguminosarum strain of rhizobium in the three field pea germplasms, which are resistant, moderately resistant and susceptible against the root knot nematode infection. Different combination of interaction between root knot nematode and rhizobium affect the nutrient content likely nitrogen, phosphorus and potassium uptake of the roots of field pea germplasms. Different combination of interaction between root knot nematode and rhizobium shows the decreased trend of nutrient uptake than that of only rhizobium treated plants

Strong and healthy saplings are a prerequisite to establish a successful forest. Therefore, an attempt has been made to develop the best package for nutrient supplementation to raise healthy Acacia mangium saplings, especially in acidic soil. The seeds were sown in pots, receiving different combinations of Arbuscularmycorrhizal (AM), Rhizobium inoculation with application of lime, and mustard oil cake (MOC). The highest spore count and infection percentage (3220 kg−1 soil and 69) were recorded in the AM + MOC + R treated pot, whereas the lowest (2553 kg−1 soil and 37) were recorded in the AM + L treated pot. Nitrogen concentration and uptake in the sapling were higher in the Rhizobium-inoculated treatments than the uninoculated ones. The sulfur concentration and uptake were higher in the MOC-supplemented treatment. Similarly, the P, K, Ca, and Mg concentrations and uptakes were higher in the limed treatments than the unlimed ones. The micronutrient concentration and uptake were higher in the unlimed treatments compared to the lime practice. The concentration of N in Rhizobium-treated pots, P and K in lime-treated pots, and S in MOC-treated pots were increased, whereas the soil pH decreased in all treatments except in the integrated package (AM + MOC + R + L) after 120 days. The Ca and Mg were reduced in all treatments, whereas micronutrients were reduced in all packages except the control. Under different nutrient management practices, plant height and stem girth continuously increased by 9.5 to 12 cm and 3 to 4 times, respectively. The production of robust saplings required integrated application of lime, MOC, AM, and Rhizobium in an acid soil that facilitated better root growth with availability of adequate nutrients for saplings.

The significant constraints in Chickpea (Cicer arietinum L.) production hampers a bit more than 14% global yield loss due to plant-parasitic nematodes. Root-knot nematode (Meloidogyne sp.) is an endoparasite and a significant species affecting the chickpea plant. So, the chemical basis of management is more cost-effective, and pest resurgence building is enhanced in the pathogen. So, ecological-based nematode management is requisite, which also is got hampered due to breeding for resistance against such plant-parasitic nematodes. This was the primary reason to conduct this experiment to enhance resistance in the chickpea plants based on Zinc uptake by using bioagent, Pseudomonas fluorescens alone or in combination. where Different treatments including nematode, bacterium, and chemicals were used sustaining the enhancement of disease resistance in chickpea cultivars, RSG 974, GG 5, GNG 2144. Zinc content of chickpea variety GNG 2144 was found the highest in treatment, when only bacterium (P. fluorescens) was inoculated, i.e., 3.14 mg/100g of root followed by GG 5, i.e., 2.79 mg/100g of root and RSG 974 was, i.e., 2.35 mg/100g of root respectively in a descending order. Application of P. fluorescence combined or alone gradually increased the Zn concentration in roots of chickpea plants compared to healthy check followed by chemical treated plants.

The study was aimed to control nematodes in ginger crop in a sustainable way through inoculation of bio-agent, Trichoderma viride. The outcome of our research revealed that Trichoderma viride alone (T2) was the most effective treatment among all. This bio-agent has lowered the root-knot nematode populations by suppressing the disease intensity and responsible for enhancement of plant growth, increases the availability of nutrients to host plant. Meloidogyne incognita alone (T1) infected rhizomes resulted in highest reduction of calcium content amounting 2.26 and 2.43 mg/100g dry weight whereas maximum content was recorded in Trichoderma viride alone (T2) inoculated rhizomes as 2.84 and 3.08 mg 100g-1 dry weight in suravi and suprabha over control (T7) respectively. Trichoderma viride inoculated 15 days prior to Meloidogyne incognita (TV→MI) was found to be most efficient one among all combined treatments. Susceptibility towards nematode induced more nutrient deposition in rhizomes of ginger crop due to poor translocation process through xylem.

India is the world's largest producer and consumer of a wide variety of pulses which is dominated by tropical and subtropical crops. The carbohydrates provided by pulses are released slowly as compared to cereals and so have a high value for maintaining optimal blood sugar levels and restoring energy over a long period of time after the meals. The cowpea (Vigna unguiculata L.walp.) belongs to family Leguminaceae with subfamily Papilionaceae. Cowpea is called as vegetable meat due to high amount of protein with better biological value on duty weight basis. Cowpea is a leguminous crop and can fix atmospheric ‘N’ with the help of rhizobium bacteria. Deficiency of N, P and K are among major constraints on higher crop productivity in tropical regions. Hence for optimum yield, crop need to be fertilized properly. Among the various pests, M. incognita poses a potential threat to the cultivation of pulse crops by infecting upon severe yield losses [8, 9, 10]. Physiological and biochemical activities of the host plant are drastically affected on nematode infection [2]. Leaf pigment composition is sensitive to plant stress and nematode infection causes either a loss of photosynthetic pigments (e.g. chlorophylls) or higher levels of photoprotective pigments, such as zeaxanthin or β-carotene [4]. Various forms of abiotic and biotic stresses damage plant leaf tissue and the chloroplasts [7]. The chlorophyll released from damaged chloroplasts has to be degraded rapidly to avoid cellular damage owing to its high reactivity [11]. Failure to degrade the chlorophyll may cause an accumulation of reactive oxygen species (ROS) that can easily damage the cellular organelles [5, 13]. That is why chlorophyll must be degraded rapidly following pathogen attack [6]. In our experiments, more chlorophyll a was degraded than chlorophyll b. This may have happened because chlorophyll a was degraded before chlorophyll b. This is in agreement with suggestions that the chlorophyll catabolic pathway, and specifically the enzyme chlorophyllase, is involved in modulating the plant defense response by affecting damage-derived photodynamic free chlorophyll levels, leading to a rise in ROS [6]. The production of cowpea crops unfortunately suffers from several constraints of which pest and disease are the most important once. Among pests, phytoparasitic nematodes have been recognized as one of the major constraint in pulse production. The extent of losses due to nematodes in cowpea crops is yet to be estimated properly but in cowpea production is estimated to cause annual yield losses of nearly 15% worldwide. In India average loss caused by rootknot nematode on pulses may be 14.6% which could go as high as 50-80% in some crops. In another study estimated 28.60 per cent losses due to root-knot nematode, M. incognita in cowpea. Abstract Plants adapt themselves to overcome adverse environmental conditions, and this involves a cellular activities. Physiological experiments or metabolic profiling can quantify this response. Among several diseases of cowpea, root-knot nematode infection caused by Meloidogyne incognita causes severe damage to the plant and hence, the oil production. In the present study, we identified M. incognita morphologically and physiologically changes in cowpea. M. incognita was artificially inoculated at different levels of second stage juveniles (J2) to examine the effect on cowpea plant growth parameters. Chlorophyll content in M. incognita was also evaluated in response to infection. The results have demonstrated that nematode infestation leads to highest decreased by 97.44%, 74.33% and 93.42% chlorophyll content ‘a’, ‘b’ and chlorophyll (a+b) in Gomati in the leaves of the cowpea plants.

Seventeen bitter gourd genotypes/ seeds were collected and screened under greenhouse condition for both susceptibility and biochemical reactions to root-knot nematode (RKN) Meloidogyne incognita. Only one variety was resistant with 7-10 number of galls per plants while others were moderately resistant to highly susceptible with > 10 numbers of galls per plants. In order to understand the basis of nematode resistance six varieties namely Sundargarh local-1, Amatalla Beejghar Karala long green, Ankur hybrid (Moderately resistant) and Nakhara local, Indojapane hybrid, Rajsunakhala local-1 (Highly susceptible) were sown in earthen pots in the greenhouse maintaining four replications in Completely Randomized Design. This experiment was terminated at 45 days after sowing of seeds or 30 days after inoculation of nematodes. The Nitrogen content (%) in shoot was significantly lower by 11.92-69.34 in the resistant varieties as compared to that of susceptible variety but increased by 5.94% in root system of resistant variety in contrast to susceptible one (37.07%). The crude protein of the infected shoot decreased in the similar trend like nitrogen content of the infected shoot. The infected plants had decreased percent of phosphorus content in shoots of highly susceptible and moderately resistant varieties except Sundargarh local-1 with increased percent of phosphorus content in roots. Significant increase of potassium content of both susceptible and resistant infected plants which increase was more pronounced in both shoots and roots of resistant varieties as compared to the susceptible varieties. In shoot and root the micronutrients were observed decrease percentage in Zinc by 19.00-21.76 and 9.53-23.93, Iron by 3.11-4.1 and 14.35-33.85, Copper by 5.91-48.04 and 15.10-25.08 respectively, except Manganese by 4.10-18.5 in shoot and an increase trend of percentage of 6.35 to a decrease trend of 41.02percent in infected plants over control in varieties of bitter gourd.

Biochemical changes in different ridge gourd cultivars inoculated with Meloidogyne incognita were investigated. All the parameters showed higher activity during post infection period, both at shoots and roots level. Cultivar Priya had significant higher activity of phenylalanine ammonia lyase (PAL) than rest of the cultivars in infected shoots. However, it had only significant higher PAL expression in infected roots of Harsha cultivar of ridge gourd. All the cultivars showed non-significant changes in infected shoots for tyrosine ammonia lyase (TAL) contents. In infected roots, culture BSS 1009 showed significant increase in TAL than cultivars Harsha and Aarti, however Priya only had significant higher expression of TAL than culture Harsha. For peroxidase contains, all the cultivars displayed significant variation at infected shoots and roots level. Highest increase in peroxidase was noticed in resistant than susceptible cultivars in infected shoots of different ridge gourd cultivars. In general, with few exceptions resistant cultivars had higher catalase activity both in infected shoots and roots of different ridge gourd cultivars.

Macronutrient changes in Ridge gourd varieties inoculated with root-knot nematode, Meloidogyne incognita were investigated. Observations were recorded on macronutrient modifications relating to various parameters like nitrogen, crude protein, phosphorus and potassium content during post infection periods. The variation in nitrogen, crude protein, phosphorus and potassium content in five cultivars i.e. Priya, BSS-1009, Aneeta, Aarti and Harsha were studied 30 days after inoculation. Reduced percentage of nitrogen, crude protein and phosphorus contents were observed in inoculated shoot samples than the healthy counterparts, whereas it increased in root samples. However, an increase in amount of potassium contents was observed in the diseased tissues.

Twenty five tomato varieties were screened to study their reactions to root-knot nematode (Meloidogyne incognita) and the nematode reproduction in the nematode induced pot culture experiment. At 30 days after nematode inoculation, whole plants were uprooted, washed and ranked for root galling on the basis of root-knot index (1-5 scales). All the tomato varieties had shown varying degree of responses. Out of 25 varieties screened, only two varieties were resistant with least gall number (4-6 galls/plant), one variety was moderately resistant (25 galls/plant), nine varieties were susceptible (32-66 galls/plant) and eleven were highly susceptible (105-132 galls/pant). Due to infection of root-knot nematode, the maximum average shoot length of tomato varieties was 60.43 cm in variety Banki local. The decrease in shoot length was more pronounced with 23.43 cm in Utkala kumari variety, which was statistically different from other varieties. The decrease possibly due to improper uptake and transport of elements, nutrients and water resulted from nematode infection. The decrease in shoot weight (8.53 g) and dry root weight (0.40 g) of the tomato varieties, Utkala kumari and Utkala dipti was significantly different from the rest varieties possible reason for reduction of shoot weight and root weight in infected plant may be due to improper supply of nutrients resulting from nematode infection for which it is compensated to some extent in resistant varieties.

Mineral nutrient changes in 5 Ridge gourd varieties inoculated with root-knot nematode, Meloidogyne incognita were investigated. Five ridge gourd varieties, namely Priya, BSS-1009, Aneeta, Aarti and Harsha were inoculated with root-knot nematode and studied their effects on the changes of mineral nutrients contents of shoots and roots. The contents of Ca, Mg, Fe, Zn, Cu and Mn varied greatly among the varieties in both shoot and root. Some changes in mineral nutrients were observed due to the inoculation of root-knot nematode. The percentage of Ca, Mg, Fe, Zn, Cu and Mn were found lower in inoculated shoot and root samples than the healthy counterpart in most cases. The lowest Ca content was found in Priya in both shoot and root but Mg content was minimum in Aarti variety.

Present study was conducted to assess the yield loss caused by root knot nematode Meloidogyne incognita in ride gourd. Study was conducted in naturally infected plot, which was divided into two parts i.e., untreated and treated one and each plot again subdivided in 10 sub plots with size 3m x 2m size, as replication. All the treated plots were treat by Carbofuran (Furadon 3G) @ 2 kg a.i/ha before the sowing of ridge gourd seeds and it was followed by light irrigation. The experiment was ceased 100 days after sowing and the observations were recorded in both treated and untreated plots on plant growth parameters as well as on the nematode population development. Result of present study revealed that preventable yield losses due to root-knot nematode in ridge gourd was up to 74.52 percent under field conditions with application of Furadon 3G at 2 kg a.i./ha. Furthermore, there was maximum reduction in reproduction factor which was found highest decrease in replication 2 (72.72%) and least in replication 10 (26.49%).

Biochemical changes in Ridge gourd varieties inoculated with root-knot nematode, Meloidogyne incognita were investigated. Observations were recorded on biochemical modifications relating to various parameters like chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll, total sugar and starch and total protein content during post infection periods. The variation in chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll, total protein, total sugar and starch content in five cultivars, i.e. Priya, BSS-1009, Aneeta, Aarti and Harsha were studied 30 days after inoculation. Reduced percentage of chlorophyll ‘a’, chlorophyll ‘b’, total chlorophyll contents were observed in inoculated samples than the healthy counterparts. However, an increase in amount of total sugar, starch and total protein contents was observed in the diseased tissues.

The variation in total proline content in six greengram cultivars i.e., 24 ML-233 (R), 7 GGG 10-14 (R), 17 IPM 9901-6 (R), 8 GM 04-02 (R), 28 PM 10-12(S) and 29 PUSA 0672 (S) were studied 45 days after inoculation of Meloidogyne incognita.The total proline content in the shoots of both healthy and resistant cultivars was higher compared to the susceptible cultivars.However, in the inoculated plants the total proline content in four resistant variety varied from 100 mg/g to 150 mg/g as compared to two susceptible variety (90 mg/g to 140 mg/g) .An increasing trend was also observed in the proline contents in the shoots of inoculated susceptible and resistant cultivars.

Biochemical changes in black gram varieties inoculated with root-knot nematode, Meloidogyne incognita were investigated. Observations were recorded in the biochemical modifications relating to various parameters like total chlorophyll , total sugar contents, protein, and proline content during post infection periods. The variation in total chlorophyll, total protein, proline and total sugar content in six cultivars i.e PU 09-36(S), MU-44(S) ,VBG 11-031(R) ,VBG 11-016(R) ,KUG- 715 (R)and NUL- 205(R) were studied 45 days after inoculation . Reduced percentage of total chlorophyll contents were observed in inoculated samples than the healthy counterparts. However, an increase in amount of total protein ,proline and total sugar contents was observed in the diseased tissues.

A study was undertaken with rice-bean (Vigna umbellata) varieties to compare the effects of root-knot nematode infection on the chlorophyll “a”, “b” and “total contents of both susceptible and resistant varieties under infected and uninoculated control condition. Infection by the nematode caused decrease in chlorophyll content as 84.18, 2.93, 15.27 and 30.79% in the varieties BBSR-19-2-1, BRB-26-1, BRB-25-1 and BRB-7-1 respectively. Similarly chlorophyll ‘b’ content was also reduced as 0.92%, 0.23%, 14.62% and 53.75% in the varieties BBSR-19-2-1, BRB-26-1, BRB-25-1 and BRB-7-1 respectively. Due to infection of the nematode total chlorophyll content of rice bean varieties was reduced as 10.39, 2.92, 15.16 and 38.75% in the varieties BBSR-19-2-1, BRB-26-1, BRB-25-1 and BRB-7-1 respectively. However, the decrease was non-significant in resistant varieties as compared to susceptible varieties. Decrease in chlorophyll content may possibly due to the alteration of host nutrition and physiology by nematode infection.