1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)
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Item Biomanagement of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood - wilt fungus, Fusarium oxysporum disease complex in vegetable cowpea(Department of Nematology, College of Agriculture, Vellayani, 2021-12-07) Katakam Rupini Krishna; Nisha, M SThe study entitled „Biomanagement of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood - wilt fungus, Fusarium oxysporum disease complex in vegetable cowpea‟ was conducted at Department of Nematology, College of Agriculture, Vellayani, Thiruvananthapuram during 2019-2021. The objectives were to study the interaction between M. incognita and F. oxysporum and to evaluate the efficacy of biofumigation, biocontrol agents and organic amendments in the management of nematode - fungus disease complex in vegetable cowpea. An pot culture experiment was laid out in completely randomized design to study the interaction between M. incognita and F. oxysporum and their effect on nematode multiplication, disease incidence and growth parameters in vegetable cowpea. In Interaction study, the treatments were M. incognita alone, F. oxysporum alone, simultaneous inoculation of M. incognita and F. oxysporum, M. incognita + F. oxysporum one week after nematode inoculation, F. oxysporum + M. incognita one week after fungus inoculation and uninoculated control. M. incognita was inoculated @ one J2 g soil-1 and F. oxysporum mass multiplied in sand maize medium (20×107 cfu g-1 ) was mixed in soil @ 500 g in different intervals. The results unveiled that highest cohabitation of both the pathogens was observed when M. incognita was inoculated seven days prior to F. oxysporum inoculation with lowest shoot length (11.15 cm) and root length (9.26 cm). Meanwhile, lowest number of nodules 5 g root-1 (14.00) was recorded in plants treated with M. incognita alone. Highest reproduction factor of 1.67 was observed in M. incognita alone followed by M. incognita + F. oxysporum one week after nematode inoculation (1.14). Similar trend was observed in number of galls, egg masses and eggs per egg mass. Highest (100.00%) and early (23 days) disease incidence was recorded in plants inoculated with M. incognita + F. oxysporum one week after nematode inoculation 120 Field study was conducted to evaluate the efficacy of biofumigation using crop residues of cauliflower, bioagents (Pseudomonas fluorescens, Trichoderma viride, Purpureocillium lilacinun) and organic amendment (neem cake) in comparison to chemical (Fluopyram 400 SC). The experiment was laid out in CRD with eight treatments and three replications. Variety used was Vellayani Jyothika. All treatments showed statistically significant reduction in nematode population in comparison with control. Among the non chemical methods, P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 showed maximum reduction in nematode population in soil (88.68 per cent over control) and root (83.68 per cent over control). Lowest reproduction factor was recorded in chemical (0.14) followed by P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 (0.30), T. viride enriched FYM @ 20 g m -2 (0.69) and P. lilacinum enriched FYM @ 20 g m -2 (0.70). Similar trend was observed in the case of number of galls also. Effect of P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 found to be equally effective to P. lilacinum enriched FYM @ 20 g m -2 in reducing number of egg masses and eggs per egg mass giving 52.51 to 76.74 per cent reduction over control. Lowest disease incidence (27.76 %) was recorded in fluopyram 400 SC @ 250 g a.i. ha-1 , P.fluorescens@ 10 g kg seed-1 + neem cake @ 100 g m-2 and T. viride enriched FYM @ 20 g m-2 . Regarding biometric characters (shoot length, fresh and dry shoot weight, root length, fresh and dry root weight) and yield, effect of P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 was statistically on par with chemical fluopyram giving 56.81 to 76.90 per cent increase over control. Highest number of nodules (87.00 5 g root-1 ) was observed in P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 and it was significantly superior to all other treatments. From this study, it was concluded that highest interactive effect between nematode and fungus was recorded when M. incognita inoculated seven days prior to F. oxysporum inoculation.Application of P. fluorescens @ 10 g kg seed-1 + neem cake @ 100 g m-2 can be recommended for 121 management of M. incognita and F. oxysporum disease complex in organic cultivation of cowpea.Item Ecofriendly management of major fungal foliar diseases affecting yard long bean in polyhouse(Department of Plant Pathology, College of Agriculture, Vellayani, 2019) Deepthi Nair, S; Sajeena, AThe study entitled ‘Ecofriendly management of major fungal foliar diseases affecting yard long bean in polyhouse’ was conducted at College of Agriculture, Vellayani and Integrated Farming System Research Station (IFSRS), Karamana during 2017- 2019 with the objectives to determine the major fungal foliar diseases affecting yard long bean grown in polyhouse; and their management using natural resources and ecofriendly methods. A survey was conducted in 15 polyhouses located at different parts of Thiruvananthapuram district, where yard long bean was cultivated. NS 621 was the most common variety of yard long bean cultivated in polyhouses. Powdery mildew (Disease Incidence (DI) - 100% and Per Cent Disease Index (PDI) - 60.70) and Diaporthe leaf spot (DI - 80% and PDI - 45.77) were the major fungal foliar diseases of the crop observed in these polyhouses. Five varieties of yard long bean viz. Lola, Vellayani Jyothika, Gitika (KAU Varieties), VS 50 (KAU pre release culture) and NS 621 (Namdhari Seeds Private Limited) were screened in the polyhouse at IFSRS, Karamana in completely randomized design (CRD) with four replications, to assess the natural incidence and severity of different fungal foliar diseases. The most susceptible variety to natural incidence of powdery mildew (PDI - 50.89) and Diaporthe leaf spot (PDI - 58.66) diseases was NS 621, whereas VS 50 was tolerant to powdery mildew disease (PDI - 11.11). In vitro evaluation of organic preparations viz, egg-lemon juice extract (10%) and sunflower oil (25 ml) + baking soda (10 g) + bar soap (10 g) + water (5 l), botanicals viz. fermented weed (Setaria barbata) extract (10%) and nimbecidine (0.5%), and non-hazardous compounds viz. potassium silicate (1%) and sodium bicarbonate (0.5%) against Diaporthe tulliensis by poisoned food technique in potato dextrose agar (PDA) medium revealed that fermented extract of S. barbata (10%), sodium bicarbonate (0.5%) and a combination of egg-lemon juice extract (10%) and fermented extract of S. barbata (10%) resulted in cent per cent inhibition of the mycelial growth of the fungus, which were further used for in vivo evaluation. Fermented egg-lemon juice extract (10%), potassium silicate (1%) as well as Psuedomonas fluorescens (KAU isolate) had no inhibitory effect on the mycelial growth of the fungus. A trial was conducted to assess the efficacy of selected treatments for the management of powdery mildew and Diaporthe leaf spot diseases in NS 621 in the polyhouse of IFSRS, Karamana in CRD with eight treatments replicated thrice. The plants sprayed with tebuconazole 50% + trifloxystrobin 25% (WG) (0.04%) (positive control) at 20, 40 and 60 days after planting (DAP) resulted in maximum control of Diaporthe leaf spot (PDI - 4.89) and powdery mildew (PDI - 1.22) diseases. Among the treatments, the combined application of arbuscular mycorrhizal fungi (AMF) (KAU isolate) @ 5g plant-1 at the time of planting along with the foliar application of fermented extract of S. barbata (10%) at 20, 40 and 60 DAP resulted in significant control of Diaporthe leaf spot (PDI - 11.35), whereas the combined application of AMF @ 5g plant-1 at the time of planting along with the foliar application of sodium bicarbonate (0.5%) at 20, 40 and 60 DAP resulted in significant suppression of powdery mildew disease (PDI -11.59). Soil application of AMF alone and foliar application of P. fluorescens (2%) had least effect in reducing the severity of both the diseases. Thus, the present study revealed that powdery mildew and Diaporthe leaf spot were the most important diseases of yard long bean in polyhouses of Thiruvananthapuram district. Soil application of AMF @ 5g plant-1 at the time of planting and foliar spray of fermented extract of S. barbata (10%) or sodium bicarbonate (0.5%) at 20, 40 and 60 DAP were the most effective treatments against Diaporthe leaf spot and powdery mildew diseases respectively, which could be used as a green technology to produce safe-to-eat yard long bean.Item Soil and nutrient management for supperssion of fusarium wilt disease of yard long bean (vigna unguiculata subsp. sesquipedalis (L.) verdcourt)(Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani, 2018) Sooraj, R S; Biju JosephItem Standardisation of grafting in bitter gourd (Momordica charantia L.) and watermelon Citrullus lanatus (Thunb.)(Department of Olericulture, College of Horticulture, Vellanikkara, 2018) Akhila, A N; Sarah T George