Pointed gourd 2019.pptx

Pointed gourd

1. Pointed gourd is an important summer, cucurbitaceous vegetable crop in West Bengal. It gives harvest up to eight months. Local cultivars are grown in the state. So far 14 cultivars have been recorded based on morphology of fruits. 2. The crop is damaged by five insects and a mite. 3. In the present study, seven diseases of pointed gourd have been recorded from West Bengal. These are Downy mildew ( Pseudoperonospora cubensis ), Stem and fruit rot ( Phytophthora cinnamomi ), Stem rot ( Sclerotium rolfsii ), Anthracnose ( Colletotrichum capsid ), Fruit rot ( Pythium aphanidermatum ), Net blight ( Rhizoctonia solani ), Root knot ( Meloidogyne incognita). Symptoms of individual disease and characters of its pathogen were noted. 4. Out of seven diseases, Downy mildew, Stem and fruit rot and Root knot were considered to be major diseases. Net blight of pointed gourd, caused by very small sclerotia forming Rhizoctonia solani has been recorded first time in India. 5. Stem and fruit rot disease, in addition to rotting of fruits and vines, produced leaf blight, leaf spot, marginal blight symptoms. Oozing of sticky material from the point of infection in humid condition was one of the characteristic symptoms of the disease. In humid condition, white mycelial growth of the causal fungus with abundant sporangia was found on the infected tissues. Pointed gourd

2. Pointed gourd The causal pathogen of Stem and fruit rot of pointed gourd was identified as Phytophthora cinamomi based on sympoidially branched sporangiophore and internal sporangial proliferation. 7. A selective medium (Maize meal 17g + Vancomycin ( Vancocin ) 200mg + Pimaricin ( Elmycin ) lOOmg + Carbendazim ( Bavistin ) 25mg + Agar agar 20g + Distilled water 1000m!) was developed for isolation of Phytophthora cinnamomi . 8. In field conditions, the causal fungus infected pointed gourd and ridge gourd fruits but it invaded ridge gourd, bitter gourd, snake gourd, ivy gourd cucumber, tomato, capsicum, brinjal fruits on artificial inoculation 9 . Phytophthora cinnamomi and Pythium aphanidermatum could survive in field soil up to the next cropping season. Submerged condition (due to flood) of soil for 10-15 days did not eliminate the fungi from soil· Soil solarization immediately after destruction of the crop, eliminated Phytophthora cinnamomi and Pythium aphanidermatum from infested field soil.

3. Pointed gourd Favourable conditions for disease development and severity: i ) Heavy shower after a hot dry spell, continuous rainy days, stagnation of water in the field, poor sanitary condition (leaving diseased fruits and vines in or around the field), coverage of crop canopy with tender vines during the period of continuous rainy days were identified as favourable conditions for disease severity. ii ) Crop grown in soil bed and ratoon crop suffered more compared to crop raised on support or scaffold ( macha ) and newly planted crop respectively. iii)Male plants suffered less from Stem and fruit rot disease compared to female plants. 11. None of the cultivated varieties is resistant to Stem and fruit rot disease. 12. A new method of bioassay of fungicides against Phytophthora cinnamomi and Pythium aphanidermatum was standardized. Small pieces of infected fruit tissue were put in aqueous solution/suspension of fungicide in petridish . Extent of mycelial growth, sporangia formation and sporangial germination were recorded and compared to those in control (water). This method of bioassay can be followed, in case of, Phytophthora species infecting brinjal , guava and betelvine .

4. In vitro bioassay of chemicals against Phytophthora cinnamomi : i )Based on the fungitoxic property, out of 35 fungicides, 13 fungicides ( Blitox , Kocide 101, EmcopB , Cuman L , Thiram , Indofil M45, Foltaf , Hinosan , Contaf , Tilt, Folecure , Krilaxyl MZ, Curzate ) were selected as best perfoming fungicides in vitro. But the effect was more pronounced in respect to sporangia fonnation and sporangial germination. ii) Five antifungal antibiotics, tested did not show pronounced effect. None of the antibacterial antibiotics prevented mycelial growth. There was no sporangia formation in five antibiotics out, of eight antibiotics, at 100 ppm . iii) Among the other chemicals, Carina ( Profenphos ), Copper sulphate , Resochin ( Chloroquin phosphate) showed inhibitory property against this pathogen. 14. Blitox , Kocide 101, Foltaf , Contaf , Krilaxyl MZ showed cidal effect ; Thiram , Indofil M45, Tilt showed static effect against Phytophthora cinnamomi when colonized fruit tissue was treated with 0.1 % individual fungicide. Pointed gourd

5. In vitro bioassay of chemicals against Pythium aphanidermatum : Considering the effect of 14 fungicides on mycelial growth, sporangia formation and gennination of Pythium aphaidermatum , eight fungicides [ Emcop B(Shield), Indofil M45, FoItaf , Hinosan , KitaziI1, Contaf , Tilt, Krilaxyl MZ]were found to be good inhibitor. But the effect was more pronounced in respect to sporangia fonnation and sporangial germination. Resochin ( Chloroquin phosphate) ihhibited sporangia fonnation at a very low concentration. 16. From three years' field trial, copper oxychloride and a combination product of metalaxyl + mancozeb are selected as good fungicides for controlling Stem and fruit rot and Downy mildew of pointed gourd. Spaying of fungicides is needed for control of Downy mildew at early stage of plant growth. Performance of the combination product is better than copper oxychloride in this respect. Stem and fruit rot diseases can be kept under control with alternate spaying of the above two fungicides. Fungicide is to be sprayed at sunset on the date of harvest. Spraying of fungicides may be omitted if fair weather prevails. 17. Use of biocontrol agents Thichoderma harzianum & Pseudomonas fluorescens in preventing Stem and fruit rot disease was not successful. 18. An easy technique has been developed for isolation of Pythium aphanidermatum from soil. Pointed gourd

6. 1 . Practice of growing pointed as ratoon crop should be avoided. 2. Pointed gourd should not be grown in the same field for consecutive years. 3. If possible the crop may be raised on scaffold. 4. Planting material must be dipped in solution of 0.4% copper oxychloride or 0.3% combination product of metalaxyl + mancozeb formulation for 15-20 minutes. 5. Soil drenching (once) with O.l % carbendazim +0.2% mancozeb or 0.4% copper oxychloride formulation when vine starts elongating from the planting material. 6. Two or four spraying of 0.4% copper oxychloride , 0.3% metalaxyl + mancozeb formulation is to be given alternately on appearance of Downy mildew (during December-February). 7. Diseased/damaged fruit and vines must be removed from the field and should not be kept in and around the field. 8. Water stagnation in the field must be avoided. 9. Considering the possibility of rain, alternate spaying of 0.4% copper oxychloride , 0.3% metalaxyl + mancozeb formulation needs to be followed. Fungicide is to be sprayed at sunset on the date of harvest. Spraying of fungicides may be omitted if fair weather prevails. Recommendation for management of Stem and fruit rot disease of Pointed gourd

7. Damage Symptoms Symptoms appear as pale green areas on the upper surface of the leaves. Soon the infected areas change into yellow spots surrounded by leaf veins.  During moist weather the lower surface of leaves is covered with grayish-black layer of fungus.  In heavy infestation fruit yield and maturation is reduced.  Control Measures Cultural Destruction of plant debris of previous crop from field.   Biological Mixture of  Trichoderma   viridae  25 gm with 500 gm organic manure should be applied per pit during planting.   Chemical Spraying with  Mancozeb  75 % WP  @ 2.5 gm/lit or  Dinocap  48 % EC  @ 1 ml/lit or Metalaxyl  8 % +  Mancozeb  64 %  @ 2.5 gm/lit or  Propiconazole  25 % EC  @ 1 ml/lit of water. Downy Mildew of Pointed Gourd Pseudoperonospora   cubensis

8. ROOT KNOT OF POINTED GOURD A field experiment was conducted with eight treatments comprising of farm yard manure (@ 20t/ha), vermicompost (@ 2t/ha), Trichoderma viride (@ 10g/pit), Paecilomyces lilacinus (@ 10g/pit), neem cake (@ 500 kg/ha), vine dipping in monocrotophos (at 1000 ppm for 6 hours ), carbofuran 3G (@ 1 kg a.i ./ha) and untreated control in different combinations at Bidhan Chandra Krishi Viswavidyalaya , Nadia, West Bengal. Experimental results revealed that VD ( vine dipping) + Trichoderma viride at 10 g/pit (in two split doses) was superior to all the treatments and this was followed by VD + vermicompost at 2t/ha, vine dipping (VD) with monocrotophos 36SL at 1000 ppm for 6h + decomposed organic matter @ 20t/ha. Adoption of vine dipping in monocrotophos 36SL at 1000 ppm followed by soil inoculation of T. viride at 10g / pit once at planting and second dose at 40 days after planting reduced root galling caused by M. incognita and gave fruit yield almost double of the untreated plots. Oil cakes incorporated into the soil at the rate of 250 kg/ha significantly suppressed the incidence of the root-knot nematode, Meloidogyne incognita , in pointed gourd ( Trichosanthes dioica ). Neem cakes was more effective than mahuva or mustard cake in reducing root galling and in protecting fruit yield and compared favourably with carbofuran applied two kg ai /ha. Botanicals: Madar ( Calotropis procera ) and neem ( Azadirachta indica )  leaves application proved to be more effective in improving plant growth characters and reducing root-knot index and final nematode population. Among the doses tested, higher dose of 1.5 % (w/w) was more effective than lower ones.

9. Mosaic Mosaic  (A group of virus strains)  It is readily transmitted by aphids.   Damage Symptoms Plants are severely stunted; foliage is covered in distinctive yellow mosaic. Leaves of plant curl downwards and leaf size is smaller than normal. Flowers on infected plants may be deformed with green petals;  Fruits become distorted and are small in size. Fruit is often  discoloured .   Control Measures Cultural Planting of resistant varieties.  Chemical Spraying with  Buprofezin  25 % SC  @ 1 ml/ litre  or  Spinosad  45 % SC  @ 1 ml/5 litre  of water is recommended.

10. Powdery Mildew  ( Sphaerotheca   fuliginea ) Damage  Symptoms Symptoms first appear as pale,  chlorotic  spots on leaves that soon turn powdery-white in appearance (fungal spores) and spread to petioles and stems. It starts on the crown and lower leaves, mainly on the under-leaf shaded surface.  Young plants may turn yellow, stunted, and may die.  Severely infected leaves become brown, brittle and die.  Exposed fruits may suffer sun-scald.   Control Measures Cultural Planting of resistant varieties.  Maintaing  of proper spacing, balanced nitrogen amendments, weed control.  Chemical Spraying with  Carbendazim  50 % WP  @ 1 gm/lit or  Tridemorph  80 % EC  @ 0.5 ml/lit or  Myclobutanil  10 % WP  @ 0.5 gm/lit of water at the initiation of disease.

11. Insect and non-insect pests of Pointed gourd Pointed gourd ( Trichosanthes dioica Roxb .) was found to be infested by seven insect and non-insect pests viz. (1) Epilachna dodecastigma ( Wied .), (2) Aulacophora foveicollis (Lucas), (3) Diaphania indica (Saunders), (4) Bactrocera cucurbitae ( Coquillett ), (5) Bemisia tabaci ( Gennandius ), (5) Tetranychus urticae (Koch) and (6) Meloidogyne incognita ( Kofoid and White). Peak incidences of mite in last week of April to first fortnight of May, of leaf roller in third week of January, first to second week of March, first to second week of April, first fortnight of May, first week of June, second week of July, of fruit fly usually, in third week of May to first week of June and that of epilachna beetle in March, first fortnight of April, May, third week of July were obtained. Maximum temperature, morning and evening RH% and bright sun shine hour (BSS) had significant association on the mite population. Max temp., min temp., morning RH%, evening RH%, rainfall, soil temperature and BSS had significant association with leaf roller population. Max temp., min temp., morning RH% and soil temperature had significant association with fruit fly population. Max temp., morning RH%, evening RH%, rainfall and BSS had significant association with epilachna population.

12. Insect pests of Pointed gourd Treatments carbosulfan 25EC + neem granule + NSKE 5% or carbofuran 3G + propergite 7.5% contained consistently lowest level of fruit fly, leaf roller and epilachna infestation. carbosulfan 25EC + vermicompost + Paecilomyces lilacinus (PL + dicofol 18.5 EC followed by propergite 7.5% Or carbosulfan 25EC + PL + dicofol took much better care for root knot nematodes and mites infestation in pointed gourd. Considering incremental cost benefit ratio (ICBR), adoption of carbosulfan 25EC + azadirachtin 1% was found to be the most economical.