4.1. Screening of Brassica Germplasm and Breeding Materials

4. Plant Pathology

Disease Scenario During 2015-16, moderate to the severe incidence of Alternaria blight was recorded at FZB, DOL, and PNT. However, low to the medium incidence of Alternaria blight was recorded from HSR, MOR, and KNG. White rust appeared in moderate to severe form at FZB, KNG, HSR and MOR. A Severe incident of downy mildew was observed at the cotyledonary stage at FZB. Powdery mildew severity was low to moderate at most of the locations. Moderate to the severe incidence of Sclerotinia stem rot was observed at HSR, MOR, and DOL. After first Irrigation, mild to moderate incidence of bacterial rot (BR) was recorded at few places in Haryana, FZB, and PNT. Date of sowing of different trials is given below:

Trials Centre 4.1 4.2 4.3 4.4 4.5 4.6 4.9 KNG Nov. 09 Nov. 09 -- Nov. 09 ------PNT Oct. 19 Oct. 19 Oct. 19 Oct. 19 Oct. 23 Oct. 19 Oct. 19 HSR Nov. 09 Nov. 09 Nov. 09 Nov. 09 Nov. 09 Nov. 09 Nov. 09 LDH Oct. 28 Oct. 28 Oct. 28 -- Oct. 28 Oct. 28 -- SGN Nov. 09 Nov. 09 ------NDH Nov. 04 Nov. 04 ------Oct. 24 (4.1a) KPR Nov. 11 Nov. 11 Nov. 11 -- Oct. 24 Nov. 07 Nov. 11 (4.1b) FZB Nov. 21 Nov. 20 Nov. 20 -- -- Nov. 22 -- MOR Nov. 10 Nov. 10 Nov. 10 Nov. 10 -- Nov. 10 Nov. 09 SKN Nov. 26 Nov. 26 ------Nov. 26 Nov. 26 JAG Nov. 27 Nov. 26 ------Dec. 05 Nov. 27 DOL Dec. 02 Dec. 02 Dec. 02 -- Dec. 04 Dec. 04 Dec. 05 BER Nov. 26 Nov. 26 ------Nov. 26 Nov. 26 SHL Nov. 23 -- Nov. 23 -- Nov. 23 Nov. 23 -- BPR Nov. 04 ------4.1. Screening of Brassica germplasm and breeding materials Natural conditions: BER, DOL, KPR, PNT, MOR, NAV, JAG, LDH, SGN, KNG, SKN, NDH, BPR and SHL. Artificial conditions: AB: KPR, DOL, PNT, LDH, FZB and SHL WR: PNT, MOR, HSR and LDH DM: PNT PM: SKN SR: DOL, LDH, HSR, and BPR. 57 strains including 6 checks were sown in single 3-m row in randomized completely block design (RCBD) with 2 replications. Susceptible checks were used after every two test rows. Repeated inoculation was done after collecting inoculum from naturally infected plants for AB to facilitate the secondary spread. For screening against WR and DM, the oosporic material of local isolate was added with seed after grinding hypertrophied plant material collected from the previous year’s crop as per standard procedure. Observations on Alternaria blight on leaves (ABL), WR, DM, PM, SR and BR were recorded at 75 and/or 90-100 days after sowing (DAS). A number of staghead and Alternaria pod blight (ABP) incidence were recorded 15 days before harvest. The results are given in Table 4.1.1-5. PP-1 WR: Under natural and artificial conditions RLC-3, RLC-4, PDZ-1, PDZ-3, PDZ-4, DRMR- 1-5 and DRMRIJ 13-38 of B. juncea were found resistant to WR at four locations whereas, DRMR-2-11, PDZ-2, and EJ 8-118 were found resistant at three locations. Entries of B. rapa var. toria escaped WR infection at most of the locations. DM: DRMR 2-11 and DRMRIJ 13-38 of B. juncea and TH-1102, JT 90-1 and TS-46 of B. rapa var. toria showed resistance to DM at PNT. 4.2. Uniform Disease Nursery for major diseases Locations : BER, DOL, FZB, KPR, PNT, MOR, NAV, JAG, HSR, KNG, SKN, LDH, SHL, NDH and SGN. 34 strains, including 4 checks, were sown in a single 3-m row with two replications in RCBD. Susceptible checks were sown after every two test rows. Artificial inoculation of Alternaria brassicae (AB), Albugo candida (WR) and Sclerotinia sclerotium (SR) was done following standard procedure to record their reaction. Observations on DM, PM and BR was also recorded under natural infection conditions (Tables 4.2.1-3). WR: DRMRMJA-35, RMWR 09-5-1, ABS(3)-21, DRMR-2019 and PRD 2013-2 of B. juncea; DRMR-316, DRMR-312, and DRMR-100 of B. carinata showed resistance to WR. DRMRMJA-35 of B. juncea was found resistant to WR during 2012-13 2013-14 and 2014- 15 also. PM: PRD 2013-3 of B. juncea; DRMR-316 and DRMR-100 of B. carinata showed resistance to PM. 4.3 National Disease Nursery (NDN) for Alternaria blight Locations: PNT, DOL, MOR, HSR, LDH, KPR, FZB and SHL. 33 strains, including 3 checks i.e. Rohini (susceptible) and PHR-2 and EC 399301 (tolerant), were sown in paired rows of 3 m length. Observations on AB was recorded on leaves 75, 90/100 DAS at siliquae formation stage and 15 days before harvesting under artificial inoculation conditions. Reaction to WR, DM, SR, PM and BR was also recorded under natural conditions (Table 4.3.1-2). DRMRAB-713, DRMRAB-753, DRMRAB-233, ABS (3)-21 and RMWR 09-05 of B. juncea showed a resistant reaction to WR. 4.4 National Disease Nursery (NDN) for white rust Locations: PNT, MOR, KNG, HSR, KPR, and BPR. 30 genotypes, including 2 checks, were sown in paired-row of 3 m length between susceptible check. Observation for WR on leaves and staghead formation was recorded at 75, 90 / 100 DAS under artificial inoculation conditions. Reaction to AB, SR, DM and PM was also recorded under natural conditions (Table 4.4.1). Fourteen strains of B. juncea showed either immune or resistant reaction to WR at one or more than one locations. Some of the promising strains sowing resistance to WR are DRMRIJ 12-28, DRMRIJ 12-40, DRMRIJ 12-44, DRMRIJ 12-26, DRMRIJ 12-14, DRMRIJ 12-39, DRMRIJ 12-48 and DRMRMJA-35 (3 locations); DRMRIJ 12-41, DRMR-2035, DRMRIJ 12-06, DRMR-1219 and RMWR 09-05 (2 locations). DRMRIJ 12-28, DRMRIJ 12-40, DRMRIJ 12-

PP-2 44, DRMRIJ 12-26, DRMRIJ 12-14, DRMRIJ 12-39, DRMRIJ 12-48, DRMRMJA-35, DRMRIJ 12-41 and DRMRIJ 12-06 were found resistant to WR during 2014-15 also. 4.5 National Disease Nursery (NDN) for Sclerotinia rot Locations: DOL, PNT, NAV, HSR, LDH, and SHL. 10 strains including 02 checks were sown in paired rows of 3 m length between susceptible check (Rohini). Stem inoculation was done to ensure SR infection. Sclerotinia rot was recorded prior to harvest. In addition, reaction to AB, WR, DM and PM was also recorded (Table 4.5.1-2). DRMR-261 of B. carinata showed a resistant reaction to white rust. 4.6 Screening of IVT entries of Brassica against different diseases Locations: DOL, KPR, PNT, FZB, HSR, LDH, MOR, NAV, JAG, SGN, SKN, BER and SHL. 109 strains including 6 checks were sown in single 3m row in RCBD with 2 replications. Susceptible check(s) were used after every 2 test rows. Susceptible variety ‘Varuna’ was used as filler. Observations on Alternaria blight on leaves, WR, DM, PM, SR and BR were recorded at 75 and/or 90-100 DAS. A number of staghead and Alternaria pod blight incidence was recorded 15 days before harvesting. The entries showing resistance/ tolerance to AB, WR, DM, PM and SR under natural condition have been listed in Table 4.6.1-3). WR: Twelve entries of B. juncea were found resistant to WR at one or more than one locations. PDZ-5, PDZ-6, PRE 2012-1 and RLC-5 were found resistant at two locations and RMM 09-10, RRN-871, DRMRIJ 15-66, DRMRIJ 15-85, RLJEB-52, RH-1209, PRD 2013-2 and 5IJ-1110 were found resistant at one location. Almost all the entries of B. rapa var. toria and B. rapa var yellow sarson escaped WR infection. 4.7 Standardization of differential hosts for identification of races in A. candida The reaction of 11 rapeseed-mustard genotypes was recorded against 3 isolates of Albugo candida (PNT, HSR, NDH) at PNT. Genotype Varuna, Pusa bold and RH-30 gave a susceptible reaction in the scale 3-7. The most variable reaction was observed on EC- 399313. (Table.4.7.1). 4.8 Epidemiology of Alternaria blight, white rust, powdery and downy mildew Location: PNT. Experiments on the epidemiology of foliar diseases of rapeseed-mustard were laid out with cv. ‘Varuna’ and ‘Kranti’ at PNT. The experiment was sown on ten different dates at the weekly interval (Oct 1, 08, 15, 22, 29; Nov 05, 12, 19, 26 and Dec 03) without adopting any protection measures against pest and diseases (Table 4.8.1-6). Downy mildew disease first appeared 10 DAS on Nov 19 sown crop whereas, on Oct 8 and Oct 15 sown crop the disease appeared very late 40 DAS on both the cultivars. The disease progressed maximum up to 50 DAS. The white rust disease first appeared 50 DAS on Nov 26 and Dec 03 sown crop and continued up to 120 DAS. The disease appeared quite late on Nov 05 sown crop (80 DAS) on both the cultivars.

PP-3 As far Alternaria blight disease is a concern, the disease was first noticed 40 DAS on leaves on Nov 19 sown crop of both the cultivars. On Oct 01 and Oct 08 sown crop, the disease appeared very late i.e. 70 DAS. The disease continued to progress up to 110 DAS on leaves on both the cultivars. The Alternaria blight on pods first appeared 80 DAS on late (Nov 19, Nov 26 and Dec 03) sown crop. On early (Oct 01, Oct 08) sown a crop, the symptoms on pod appeared late after 120 days of sowing. The disease on pods continued to progress up to 140 DAS. Powdery mildew disease appeared late in the season i.e. 110 DAS first on Oct 22 sown crop of both the varieties and continued to progress up to 140 DAS. The maximum seed yield was observed of Oct 01 sown crop followed by Oct 08 and Oct 15 sown crop of both the cultivars. The maximum reduction in seed yield was observed on Dec 03 sown crop followed by Nov 26 and Nov 19 sown crop. 4.9 Evaluation of fungicides against major diseases of rapeseed-mustard Locations: MOR, NAV, KPR, SGN, DOL, HSR, SKN, JAG, and BER. Fungicidal spray in different combinations significantly reduced the severity of AB,

WR, DM, PM and SR over control and increased the seed yield.(Table 4.9.1-2). T9 (single spray of mancozeb 0.2% followed by single spray of propiconazole 25 EC @ 0.05%) was found most effective in controlling the ABL and ABP followed by T 8 (single spray of mancozeb 0.2% followed by single spray of difenoconazole 25 EC @ 0.05%) and T 7 (single spray of mancozeb 0.2% followed by single spray of hexaconazole 25 EC @

0.05%). For the management of white rust, again T 9 (single spray of mancozeb 0.2% followed by single spray of propiconazole 25 EC @ 0.05%) was found most effective followed by T6 (single spray of mancozeb 0.2% followed by single spray of metalaxyl 8%+ mancozeb 64% @ 0.2%) and T 7. T9 was also found most effective in controlling

Sclerotinia rot followed by T 3 (single spray of hexaconazole 25 EC @ 0.05%) and T 7. T6 (single spray of mancozeb 0.2% followed by a single spray of metalaxyl 8%+ mancozeb 64% @ 0.2%) was found most effective in controlling the downy mildew disease followed by T8 and T7. For the management of powdery mildew disease T 1 (single spray of mancozeb @ 0.2%) was found most effective followed by T 7 and T8. 4.10 Yield losses due to Sclerotinia rot disease Locations: BPR and HSR The experiment was conducted in RBD with plot size 3x5 meter and 4 replications. An area specifically recommended varieties were used in the experiment along with recommended management plot. After 90-100 days of sowing, 20 plants from each replication showing disease symptoms in different rating scale were tagged for yield assessment. At BPR four varieties viz., NRCDR-2, RH-406, DRMRIJ-31, and RH-749 were used in the experiment. As the disease rating increased, the yield loss also increased in all the four varieties. The maximum yield loss was recorded on DRMRIJ-31 variety followed by DRCDR-2. The least yield loss was recorded with RH-749. Similar was the case at HSR also. The yield loss increased with increasing severity of disease and approached 100% at 5 rating scale in all the three varieties used. Among the varieties, RH-8812 was found better as compared to others.

PP-4 Survey of farmer’s field for disease outbreak KNG: The appearance of white rust and Alternaria blight on leaves was observed in the 2nd fortnight of December in the mustard cultivar RCC-4 sown on November 5, 2015, at the farmer’s field near Kangra. The rains and other weather parameters during November and the 1st fortnight of December were favorable for the outbreak of diseases. However, almost dry weather and lower relative humidity in January did not favor the progress of diseases, especially white rust. Weather conditions during February to the 1st fortnight of March favored the development of Alternaria blight on leaves and pods. Up to 55% and 32% severity of Alternaria blight disease and white rust on leaves was observed at the time of maximum disease appearance. 40% severity of Alternaria blight on pods and 1.3 % staghead infection was also recorded in the mustard crop at the farmer’s field about two weeks before the harvest. HSR: Survey was conducted in different districts of Haryana for the presence and severity of diseases in Indian mustard during the month of February- March 2016. In Hisar and Bhiwani districts, white rust severity ranged between 0-30%. However, up to 50%, white rust severity was also observed near Loharu in Bhiwani district. Alternaria blight disease severity ranged between 10-25% at these locations. In Fatehabad district, 12 villages were surveyed and the white rust severity ranged between 5-40%, while Alternaria blight severity ranged between 0-30%. The incidence of bacterial stalk rot and downy mildew was noticed at few locations in these districts just after first irrigation. Out of six locations surveyed in Sirsa district, white rust intensity ranged between 5-30%, while Alternaria blight severity ranged between 15-25%. Due to rains at maturity of the crop, the incidence of Sclerotinia rot was observed throughout the state ranging between 5-15%. However, up to 30% incidence of Sclerotinia rot was also observed at some of the locations in all the districts. Powdery mildew disease appeared in moderate to severe form under late sown conditions. NAV: During entire crop season of 2015-16, the appearance of fog was almost nil which may be the main reason for low incidences of diseases in the mustard fields. The rainfall was also in very low and scattered during the main growing season (December to February) of the crop, Due to this reasons also the incidence of different mustard diseases was very low. NDH: During 2015-16, low to the medium incidence of Alternaria blight on the leaf was observed at IARI, New Delhi. White rust appeared in moderate form. KPR: Alternaria blight first appeared at the farmer’s field in the first week of December and severe infection was recorded during the 4th week of February to 1 st week of March. Severe infection of Alternaria blight and white rust was observed at Sarsaul, Saini, Fatehpur, Allahabad and Raibarelly districts. No staghead formation was seen at University farm as well as at Farmers field. Powdery mildew was seen at the farmer’s field in the mustard intercropped with Wheat. Sclerotinia rot was not recorded at the farmer’s field during the 2015-16 season. FZB: Downy mildew appeared on B. juncea and B. rapa cultivars at a cotyledonary stage in the Ist week of November in October 3 rd week sown crops and became severe in the 4th week of November. The disease progressed up to 2 nd and 3rd leaves and also caused

PP-5 seedling mortality at some places in Varanasi, Ghazipur, Sultanpur, Jaunpur, Ambedkar Nagar districts. Severity was recorded up to 89.33%. In late sown crops infection varied from mild to moderate form. Alternaria blight disease appeared in the 3rd week of December in early sown crops of yellow sarson and progressed slowly up to February 2016. Average maximum disease severity was recorded more than 69% in a normally sown crop of India mustard and more than 80% in B. rapa in late sown crops. White rust appeared in the 3rd week of January on normally sown crops. Maximum disease severity was recorded up to 80% at some farmer’s fields in Mirzapur, Varanasi, Ghazipur, Sultanpur, Jaunpur, Ambedkar Nagar districts on late sown crop. The general reaction of the disease was mild to moderate. Staghead development due to white rust and downy mildew complex was in mild form. Powdery mildew appeared in 1 st week of March and progressed slowly and became severe causing more than 90% disease severity in late sown crop. Normal sown crop escaped the disease incidence. S clerotinia stem rot was observed on timely sown crops in Indian mustard at some farmers fields in the 4 th week of January. The general disease reaction was mild type at different locations. Bacterial rot disease appeared in the 3rd week of November on early sown crops. General disease reaction was mild type at different locations. PNT: The weather conditions during 2015-16 was highly favorable for Alternaria blight disease. Downy mildew disease appeared on B. juncea and B. rapa cultivars at the cotyledonary stage on October 30, 2015. White rust and Alternaria blight appeared on leaves on December 7, 2015. The white rust and Alternaria blight were severe in the month of January and February. The disease pressure of Alternaria blight was very high during the year due to highly conducive conditions. However, the disease pressure of white rust, downy mildew and Sclerotinia rot was quite low in the Tarai area of Uttarakhand. Staghead development due to WR+DM was also low. The Sclerotinia stem rot appeared during the 1 st week of January 2016 and was severe during the month of February. Powdery mildew disease was observed in the 1 st week of March and assumed severe form during the 2nd week of March. Bacterial blight and viral diseases were also observed during the 2nd week of November at few places. No outbreaks of other diseases were observed. MOR: The weather condition was not much favorable for mustard disease during 2015-16 because of low rainfall during the cropping season. The WR, AB, and DM diseases appeared in the last week of November. The severity of theses disease was very low, particularly on early sown crop. In late sown crop, the severity of white rust disease was 0-51%; Alternaria blights 16-52%, and downy mildew 0-36%. Sclerotinia stem rot incidence was higher (15-40%) in late sown crop as compared to early sown crop (5- 15%). Low to medium (0-35%) staghead formation was observed in late sown crop. About 50% severity of powdery mildew was recorded on late sown long duration varieties. SKN: During 2015-16, powdery mildew was observed in moderate form. In normally sown mustard, powdery mildew severity was observed 25-30% and white rust severity was observed only 5-10%. DOL: Alternaria blight disease appeared in moderate (45%) to severe (80%) format many places on farmers filed in Muzaffarpur and Samastipur districts. The severity of white

PP-6 rust disease was very low (10-15%) whereas low-moderate incidence of Sclerotinia rot was reported at these locations