Commercially available Trichoderma inoculums (bioderma) were collected from Ispahani Agro Tech. Bangladesh Ltd. The collected inoculums were mixed with vermi-compost @ 1:20 (w/w) and kept for 7 days for multiplication of Trichoderma into the mixture and it’s designated as Tricho-compost-1. Previously, collected and isolated virulent cultured of T. harzianum (TM7)by Plant Pathology Division, BARIwas initially formulated in substrates containing a mixture of rice bran, wheat bran and mustard oilcake. The formulated Trichoderma was mixed with vermi-compost @ 1:20 (w/w) and kept for 7 days for multiplication of Trichoderma into the mixture and it’s designated as Tricho-compost-2.

The field trials were conducted in the fields of Plant Pathology Division, BARI, Gazipur during 2017-18 and 2018-19 cropping years. There were 8 treatments viz. (i) Tricho-compost-1 @ 2 kg/pit (ii) Tricho-compost-2 @ 2 kg/pit (iii) Tricho-compost-1 @ 2 kg/pit + Furadan 5 G @ 20 g/pit (iv) Tricho-compost-2 @ 2 kg/pit + Furadan 5 G @ 20 g/pit, (v) Poultry refuse @ 5-6 kg/pit + Furadan 5 G @20 g/pit , (vi) Neem oil cake @ 500 g/pit + Furadan 5 G @ 20 g/pit (vii) Saw dust burning + Furadan 5 G @ 20 g/pit and (viii) Farmers practices. The field experiments were laid out in randomized complete block design (RCBD) with 4 replications. The unit pit size was 2 m x 2 m keeping 1m distance from pit to pit. Standard cultivation procedures recommended by BARI were followed to grow country beanwith little modification. The experimental land was prepared with proper tillage and fertilizers were added during final land preparation. Requisite amount of poultry refuse and neem oil cake were incorporation with the soil 3 weeks before seed sowing whereas Tricho-composts were added in the soils 5 days before seed sowing. After application, the organic materials were properly mixed with the soil and kept moist for proper decomposition. In case of saw dust burning, 6 cm thick layer of dry saw dust cover with pit soil and burned the soil properly. After burning the ash were mixed with the soil. Furadan 5G was added at the time of seed sowing. To ensure inocula of the nematode, chopped severely galled roots of tomato infected with Meliodogyne incognitawere mixed with the pit soils @100 gmpit^-1 before seed sowing. The country bean seeds variety BARI Shem-2 were sown in the pits and each pit received ten seeds. During crop season necessary weeding, irrigation and other intercultural operations were done as per recommendation of the crop. After 45-50 days seed sowing, 2 seedlings were kept in each pit and the rest of the seedlings from each pit was uprooted carefully without disturb the root system for data collection.

Data on different parameters viz. plant height, plant weight, root length, root weight and yield were recorded. Gall index was recorded following 0-10 scale 27. Data were analyzed statistically by using the MSTATC program. The treatment effects were compared by applying the least significant different (LSD) test at P=0.05 level.

In both the years, plant growth parameter viz. shoot length and shoot weight of country bean significantly enhanced by soil treatment with Tricho-composts, integration of Tricho-composts, poultry refuse (PR), neem oilcake (NOC) and saw dust burning (SDB) with Furadan 5G compared to farmers’ practices (Table 1). Average shoot length of country bean under farmers’ practices was 121.3 cm plant^-1 in the first year and 135.3 cm plant^-1 in the second year. Soil amendments with PR + Furadan 5G, NOC + Furadan 5G, SDB + Furadan 5G, Tricho-compost-2+Furadan 5G, Tricho-compost-1+Furadan 5G, Tricho-compost-2 and Tricho-compost-1 increased the parameter to 175.5-200.5 cm plant^-1 in the first year and 163.5-175.0 cm plant^-1 in the second year. In the first year, soil amendments with PR+ Furadan 5G and NOC+ Furadan 5G gave the higher shoot length followed by Tricho-compost-2+ Furadan 5G, Tricho-compost-1+ Furadan 5G, Tricho-compost-2, Tricho-compost-1 and SDB + Furadan 5G (Table 2). In the second year, all the treatment gave significantly similar effect in increasing shoot length compared to farmers’ practices (Table 1).

In first year, average shoots weight of country bean was 107.3 gplant^-1 in farmers’ practices. It increased to 152.2-174.6 g plant^-1 due to soil treatments with PR + Furadan 5G, NOC + Furadan 5G, Tricho-compost-2+Furadan 5G, Tricho-compost-1+Furadan 5G, Tricho-compost-2, SDB +Furadan 5G and Tricho-compost-1(Table 1). The highest shoot weight 174.6 g plant^-1 was achieved from soil treatments PR+Furadan 5G treatment, which was followed by soil amendments Tricho-compost-2+Furadan 5G, NOC+ Furadan 5G, Tricho-compost-1+Furadan 5G and Tricho-compost-2 where the shoot weight was 171.8, 170.7, 169.2 and 168.0 g plant^-1, respectively (Table 1). The least effective treatment to increase shoot weight was Tricho-compost-1, which was followed by SDB +Furadan 5G treatments. In second year, the lowest shoot weight of country bean was 112.3 g plant^-1 recorded in the farmers’ practices. In this year all the treatments were significantly similar effect in increasing shoot weight than farmers’ practices (Table 1).

Amendment of soil with PR+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2+ Furadan 5G, Tricho-compost-1+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2 and Tricho-compost-1 showed positive effects on root growth of country bean as compared to farmers’ practices (Table 2). In first year, the minimum root length of 15.00 cmplant^-1 was recorded under farmers’ practices. Soil amendment with Tricho-compost-2+ Furadan 5G gave the highest shoot length as 28.00 cmplant^-1 followed by PR+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-1+ Furadan 5G, Tricho-compost-2, SDB + Furadan 5G and Tricho-compost-1 where root length was 27.25, 26.10, 26.00, 23.25, 23.25 and 21.75 cmplant^-1, respectively (Table 2). More or less similar trend was also observed in the second year trial. In second year, the lowest plant weight of bottle gourd was 4.55 g plant^-1 recorded in the farmers’ practices. Soil amendment with PR+ Furadan 5G gave the highest shoot weight 6.06 g plant^-1 followed by soil treatment with Tricho-compost-2+Furadan 5G, Tricho-compost-1+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2 and Tricho-compost-1 where the shoot weight was 5.93, 5.88, 5.81, 5.81 and 5.70 g plant^-1, respectively but significant difference among treatments were not observed (Table 2). The least effective treatment was SDB +Furadan 5G where the root weight was 5.28 gplant^-1 (Table 2).

In both the years, the severity of root-knot disease of country bean was reduced significantly over farmers practices due to soil treatment with Tricho-composts, integration Tricho-compost, poultry refuse (PR), neem oilcake (NOC) and saw dust burning (SDB) with Furadan 5G (Table 3). In the first year, the maximum average gall index value of 5.18 was recorded in the farmers’ practices. It was reduced to 1.50 to 2.00 due to application of different treatments. All the treatment gave significantly similar effect in reduction of root knot disease severity compared to farmers’ practices (Table 3). Soil amendment with PR + Furadan 5G gave the highest reduction of root-knot nematode disease severity 70.04% compared to farmers’ practices followed by Tricho-compost-2+ Furadan 5G, Tricho-compost-1+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2, Tricho-compost-1 and SDB+ Furadan 5G where the reduction of root-knot nematode disease severity was 69.88%, 69.31%, 68.73%, 62.74%, 62.55% and 61.39%, respectively (Table 3).

In the second year, the highest gall index value of 3.63 was found in farmers’ practices plot and the values were reduced to 0.50 to 0.93 due to application of different treatments (Table 3). The reduction in disease severity was significant compared to farmers’ practices. The maximum reduction 86.23% compared to farmers’ practices was obtained from soil amendment with Tricho-compost-2+ Furadan 5G treatment followed by PR + Furadan 5G, Tricho-compost-1+ Furadan 5G, Tricho-compost-2, NOC+ Furadan 5G, Tricho-compost-1 and SDB+ Furadan 5G where the reduction of root-knot nematode disease severity was 85.40%, 85.40%, 84.85%, 84.02%, 82.09% and 74.38%, respectively than farmers’ practices (Table 3).

Soil amendments with PR+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2 + Furadan 5G, Tricho-compost-1+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2 and Tricho-compost-1 played significant role in increasing crop yield per hectare of country bean in both years (Table 4). In the first year, the lowest fruit yield of 11.63 tha^-1 was found under farmers’ practices. The yield was increased to 18.75 to 22.30 tha^-1 due to application of different treatments with Tricho-compost-2+ Furadan 5G, PR+ Furadan 5G, Tricho-compost-1+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2, Tricho-compost-1 and SDB+ Furadan 5G. Soil treatment with Tricho-compost-2+ Furadan 5G, PR+ Furadan 5G and Tricho-compost-1+ Furadan 5G gave higher yield of country bean with 22.30, 21.88 and 21.38 tha^-1, respectively followed by soil treatment with NOC+ Furadan 5G, Tricho-compost-2 and Tricho-compost-1 where yield was 20.88, 20.81 and 20.38 tha^-1, respectively but there was no significant difference among the treatments (Table). The least effective treatment in increasing the yield of contry bean was SDB+ Furadan 5G. The maximum yield increased was obtained with treatment of Tricho-compost-2+ Furadan 5G where fruit yield was 47.85% higher compared to farmers’ practices which followed by PR+ Furadan 5G, Tricho-compost-1+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-2, Tricho-compost-1 and SDB+ Furadan 5G where the yield was 46.85%, 45.60%, 44.30%, 44.11%, 42.93% and 37.97% higher yield than farmers’ practices, respectively. In the 2^nd year, average fruit yield was 11.50 tha^-1 under the farmers’ practices and the yield was increased 17.88 to 20.50 tha^-1 under treated plots (Table 4). The highest increase of yield 43.90% compared to farmers’ practices in PR+Furadan 5G treatment which was followed by Tricho-compost-2+ Furadan 5G, NOC+ Furadan 5G, Tricho-compost-1+ Furadan 5G, Tricho-compost-2 and SDB+ Furadan 5G where yield was increase 43.38%, 43.21%, 41.77%, 41.42% and 40.66%, respectively over farmers’ practices. The lowest increase 35.68% than farmers’ practices was achieved with Tricho-compost-1 treatment (Table 4). 

Root-knot nematodes (Meloidogyne spp.) are among the most economically damaging genera of plant parasitic nematodes on horticultural and field crops. Nematodes especially root knot nematodes management is complicated and difficult. Organic amendments and bio-control agents have been recognized in the management of plant parasitic nematodes and improvement of soil health. Due to their apparent environmental nontoxic benefits they have been considered in integrated nematode management with inorganic amendments. In general, combining different nematode management practices are a good option to prevent disease outbreaks and secure yield. The present study was designed to determine the potentiality of soil treatment with bio-products, Tricho-composts containing biological control agent T. harzianum or integration of Tricho-composts with chemical nematicide Furadan 5G or integration of organic amendment viz. poultry refuse and neem oilcake with Furadan 5G as well as saw dust burning with Furadan 5G in the suppression of root-knot nematodes and increasing plant growth as well as yield of country bean in the field. Our results demonstrated that integrated soil amending with Tricho-composts with Furadan 5G, poultry refuse with Furadan 5G and neem oil cake with Furadan 5G drastically suppressed gall index valued caused by root-knot nematode M. incognita and increasing plant growth parameters such as shoot length, shoot weight, root length and root weight as well as yield of country bean compared to farmers’ practices. Soil amendment with only Tricho-composts and saw dust burning with Furadan 5G also reduced gall index values and improved plant growth to some extend but its efficacy was not as good as the integration of Tricho-composts with Furadan 5G, poultry refuse with Furadan 5G and neem oil cake with Furadan 5G .

These results are in agreement with that of Dahlin et al. 28 who reported that the combination of a chemical treatment to down regulates the M. incognita population followed by the application of a fungal antagonist is more successful to control these nematodes compared to each treatment alone. Biocontrol agent combinations have also shown varied results. For example, Rao 29 showed that combining P. chlamydosporia and P. fluorescens improved nematode control. Combining neem cake amendments with P. penetrans gave encouraging results 30. Sundaram and Hangaraj 31 also reported a reduction of the population of M. incognita, when T. harzianum were applied as a seed treatment. The fungal bioagent T. harzianum showed their bioefficacy against M. incognita in respect of reducing their reproduction rate as compared to the untreated control 32333435. Similarly, Lal and Rana 36 who recorded the lowest number of galls, egg masses and final nematode population of M. incognita in okra plants treated with T. harzainum. Many other researchers also confirmed previous findings, on the use of isolates of Trichoderma spp. for the management of root-knot nematodes in vegetable crops 212232. In the present study soil amendments with organic soil amendments and nematicide gave the encouraging finding for the management root knot nematode and increasing yield of country bean. Many previous reviews have focused on the use of organic amendments to control plant-parasitic nematodes 16179. Soil amendment with poultry refuse or integration of poultry refuse with nematicde Furadan 5G has also been reported to be effective against root-knot nematode of tomato 37, brinjal 38, potato 39, bottle gourd 40 and jute 41 which supported the results obtained from this study.Beneficial effects of organic wastes, poultry manure on nematode control and crop growth were also observed by other researchers 421643444546474849. Oil cakes are usually considered good for controlling nematodes. Akhtar and Malik 16 repeatedly tested neem (Azadirachtaindica) oil cake, and found that it is particularly efficient against root-knot nematodes even at low dosages (1 to 2 t/ha). Several studies reported that oil cake applications reduced the Meloidogyne spp. population increasing plant growth and yield of different crops 5051.