CROP PROTECTION PLANT PATHOLOGY

Transcription

1 F - 1 CROP PROTECTION PLANT PATHOLOGY Research Findings: Path.1 Epidemiological studies on cotton diseases Path.1 (a): Observations on the occurrence of various diseases (all centers except Pune and CICR, Sirsa) North Zone Cotton leaf curl disease (CLCuD), Bacterial Blight (BB), Fungal Foliar leaf spots (FFLS) were the diseases observed in different districts of Punjab by Faridkot center. The PDI of CLCuD varied from 0.1 to 89.2%. 40 to 77% ; 37 % to 65 % on varieties/hybrids like RST-9, RS 921, F 846, F 505, F 1378, F 1861, F 2383, F 2228, RCH 650 Bt, Bioseed 6488 BGII, Bioseed 6588 BGII and RCH 773 BGII in different villages & research farm of Faridkot, Fazilka and Muktsar districts/ area (Table-1). Bacterial blight was found in 0.1 to 2.9% in Faridkot and traces to 2.1% in Fazilka and traces to 2% in Muktsar on hybrids like Bioseed 6488 BGII, Bioseed 6588 BGII and various entries of coordinated trials in different cotton growing areas. The fungal foliar leaf spots caused by Alternaria, Myrothecium and Cercospora, ranged from 0.3 to 2.6%, traces to 2.4% and traces to 2.1% disease intensity on RST-9, RS 921, F 846, RCH 650 BG II and RCH 773 BG II and different entries of coordinated trials at research farm. The incidence was also observed in the different districts of Punjab i.e. Bathinda, Mukstar and Mansa by Bhatinda center. Incidence of bacterial blight, fungal foliar leaf spot and root rot was noticed in traces and reported in Bathinda district only. The data (Table-2) revealed that the PDI of CLCuD varied from , and respectively in different villages of district Bathinda, Mansa and Muktsar. Highest PDI was recorded in US Agriseeds US 21BG II as in Village Jodhpur of district Bathinda. Out of four tehsils surveyed in Sriganganagar district of Rajasthan, Sriganganagar tehsil, was found to be severely invaded by leaf curl virus showing average disease intensity of 31.1 per cent. In Srikaranpur and Padampur tehsils the average disease intensity was 5.2 and 2.7 per cent, respectively whereas incidence was not observed in Suratgarh tehsil. In adjoining cotton belt of Hanumangarh district, the average disease intensity was 6.1 per cent (Table-3). The survey in Haryana was undertaken to record the occurrence of different diseases in major cotton growing districts (Sirsa, Hisar, Fatehabad, Jind and Bhiwani) as well as in the nontraditional areas of Haryana (Kaithal, Rohtak, Mahendergarh and Rewari) from July to September, At farmer s field highest per cent disease index (PDI) of 58.3 (Ankur 3028 BG II), 50.0 (Bio 6588BGII), 46.6 (RCH 602 BG II) and 43.3 (RCH 650 BG II) were observed in villages Siswal, Danoda, Dhingsara and Darba Kalan of districts Hisar, Jind, Fatehabad and Sirsa respectively. In Bhiwani district disease appeared in the month of September up to 21.7 PDI. Whereas, Mahendergarh, Rewari and Palwal districts were free from CLCuD. At CCS HAU research farm PDI of CLCuD was observed from 4.8 to 66.6 in different cultivars. Bio 100 showed resistant reaction against CLCuD with the lowest PDI of 4.8. Among the fungal foliar diseases, Myrothecium leaf spot (MLS) PDI

2 F - 2 varied from 0.0 to 25.0%. Other diseases viz. Alternaria leaf spot (ALS), root rot (RR) and Bacterial leaf blight (BLB) did not appear at farmer s field on all locations surveyed in Haryana (Table-4). Central Zone Alternaria leaf blight was the major disease observed during the year on research farm at Rahuri in Maharashtra. The disease intensity irrespective of variety/hybrids ranged from 4.25 to per cent (Table-5) and it reduced from October onwards. The other foliar diseases viz., Myrothecium, Cercospora, grey mildew and bacterial blight were observed in traces during crop growth. The incidence of Tobacco streak virus was very low i.e. only upto 3% which was mainly observed as localized infection on upper leaves of the plants. The sowing of Bt cotton under irrigated areas was done from 15 th May onwards, but the water stress conditions resulted in high incidence of the physiological disorder - para wilt. Due to low rainfall, the sowing of rainfed cotton (Bt/non-Bt) was also delayed up to first fortnight of July (28 th MW) in most part of Maharashtra. Alternaria blight was the major disease observed and the disease intensity ranged between 2.15 to per cent irrespective of variety/hybrids and locations. The other foliar diseases were observed in traces. In the current year very low rainfall than the average was received in most of the areas of Maharashtra during Kharif season, which resulted in the drought conditions and low productivity of seed cotton. The normal sowing of cotton was also delayed up to 20 th July on farmer s field. The Alternaria was found wide spread disease followed by bacterial blight and grey mildew on G. hirsutum and G. arboreum cotton in the areas surveyed around Nanded, Maharashtra. The intensity of Alternaria varied from 6.50 to PDI, while the intensity of bacterial blight ranged from 2.50 to PDI; grey mildew intensity varied from 0.00 to 3.00 PDI. The incidence of para wilt varied from 0.00 to 3.00 PDI, during this year (Table-6). During seedling stage crop was free from diseases at farmers and research field at Akola, Maharashtra. The bacterial blight was observed in flowering stage varied from 1.01 to 4.08 and 0.33 to 2.56 per cent disease intensity on farmers and research field. Maximum disease intensity was observed at boll development stage 5.41 and 5.54 per cent in varieties/bt hybrids at farmers and research field respectively. The grey mildew intensity was not observed on farmer field and research farm. The Myrothecium leaf spot was observed at flowering stage within range of 0.81 to 2.02 and 0.72 to 1.72 per cent on farmers and research field respectively. Alternaria leaf spot was not observed during crop season. (Table-7) Myrothecium leaf blight of cotton was first observed in II week of August in Khandwa. In the month of September the disease incidence increased up to 18.8%. Bacterial blight was observed in 2 nd week of July. The incidence increased up to 15.2 %. Grey mildew was first observed in second last week of September. The disease incidence increased up to 12.7 %.On the farmer s fields where cotton sown in early summer Bacterial Leaf Blight and Myrothecium leaf blight was observed in 3 rd week of July. The incidence of New Wilt in Bt hybrids has not been observed in Research Farm and farmer field in vicinity of Khandwa. On Research farm at Surat, Gujarat, periodic observations recorded on G. Cot. Hy. 12 revealed that bacterial blight appeared during the 2 nd week of July (2.0 %) and then gradually developed and reached at its peak (23.5 % PDI) during the 3 rd week of September and then

3 F - 3 declined, but prevailed up to 1 st week of December (Table 8). Observations were also recorded on other cultivars. The susceptible cultivars viz., LRA 5166 showed bacterial blight intensity to the tune of 2.5 to 23.0 per cent PDI moreover, non Bt cotton was more susceptible to the bacterial blight disease. During DAS (vegetative stage of the crop), the BLB was more pronounced on lower leaves. Roving survey was conducted in Surat, Bharuch and Narmada districts on farmers field. The BLB incidence was found in the range of 0.0 to 5.5 %, 0.0 to 5.5 % and 0.0 to 24.0 % PDI in Surat, Bharuch and Narmada districts, respectively on cultivars fields in majority growing approved BG II hybrids. Moreover, Alternaria leaf spot was observed in the range of 0.0 to 13.5 % in Nandod taluka of Narmada district (Kuta Amba village). Whereas, in other two districts viz., Surat and Bharuch, it was in the tune of 0.0 to 4.5 % and 0.0 to 2.5 % PDI. The disease incidence was also recorded in the HDPS experiment under TMC MM 1 project at Surat which revealed that all the four genotypes were found Moderately resistant to BLB disease with the Grade 2 and Alternaria leaf spot diseases was not observed. (Table-8a) Survey on the occurrence of various cotton diseases was carried out on farmers field and cotton research station JAU Junagadh, Gujarat. Total of 29 locations covering 7 districts namely, Junagadh, Amreli, Surendranagar, Jamnagar, Rajkot, Gir Somnath and Porbander were intensively surveyed. Bacterial blight was recorded during flowering stage while Alternaria leaf spot recorded in almost all locations during boll formation (Table-9). The alternaria leaf spot (ALS) recorded in Junagadh district in different varieties ranging from 8.0 to 17.0, and bacterial leaf blight (BLB) 1.0 to 3.0 per cent disease intensity (PDI). In Amreli district, ALS disease was found in the ranging from 11.0 to 19.0 and BLB 1.0 to 2.0 per cent. In Surendranagar district ALS disease noted to the ranging of 14.0 to 15.0 and BLB 0.0 to 1.0. In Jamnagar district ALS disease noted in range of 0.0 to 17.0 and BLB 0.0 to2.0 per cent. Disease condition in Rajkot district, ALS was noted in range of 13.0 to 19.0 and BLB 0.0 to 1.0 PDI. In Gir Somnath, ALS and BLB disease recorded in the ranging of 7.0 to 11.0 and 0.0 per cent, respectively. In Porbander district ALS and BLB disease incidence recorded in the range of 9.0 to 18.0 and 0.0 to 1.5 PDI, receptively. At cotton research station, Junagadh varieties G. Cot.hy-6 and G. Cot hy-18 recorded ALS 16.0 and 17.0; BLB 4.0 and 3.0 percent respectively. During the season Grey Mildew was not observed in all locations, while root rot and wilt were observed negligible in some locations. South Zone Survey results from Dharwad, Karnataka indicated the predominance of Alternaria blight (05-30%) in early stages of the crop growth followed by Grey mildew (05-30%) and Bacterial blight (10-25%). Rust appeared after 90 DAS (20-40%). (Table-10). The results of incidence of Cotton foliar diseases as influenced by technology for Organic cotton production (G. arboreum) indicates that, the treatment no.8 (RDF through inorganic fertilizers i.e. 60:30:30NPKkg/ha)has least incidence of Alternaria blight and rust with higher yield (Table 10 a). Alternaria leaf spot, bacterial blight, grey mildew and rust were recorded during the surveys conducted from September to December 2015, in cotton growing districts of Andhra Pradesh viz., Guntur, Praksam, Anathapur, Kurnool, Kadapa and Krishna (Table11 ). Intensity of bacterial blight, Alternaria leaf spot, grey mildew and rust diseases in various hybrids and varieties of cotton trials conducted at RARS, Lam was also recorded. During August and September traces of Bacterial blight was recorded in Jadoo BG II in Brahmanapalle village, Guntur district during November 2015 (8.5 PDI) and Virupapuram village, Kurnool district during December 2015 (18.0

4 F - 4 PDI). Traces of root rot were observed in Jadoo BG II during September 2015 at Ravela village and in RCH 659 BG II at Kesanupalli village, Guntur district during October Traces of Boll rot was recorded during September 2015 in Bhakthi BG II at Krishnapuram village, Krishna district. Cercospora leaf spot was (11.2 PDI) observed in Jadoo BG II during October 2015 at Tallacheruvu village, Krishna district. Alternaria leaf spot, grey mildew and rust diseases were recorded to the tune of 0 to 21.3%, 0 to 18% and 0 to 16.3% in farmers fields surveyed during September to December. Low to moderate intensity of Alternaria leaf spot and rust were observed at Regional Agricultural Research Station, Lam, and Guntur while grey mildew recorded moderate to severe intensity. Survey was conducted to assess the severity of cotton diseases from regions viz., Dharapuram, Tirupur, Erode, Anthiyur, Thondamuthur, Ariyalur and Coimbatore of Tamil Nadu. The incidence of diseases viz., root rot, wilt, Alternaria leaf blight, Rust, grey mildew, bacterial blight and TSV were assessed in the above mentioned cotton growing regions. Survey results indicated that the foliar diseases viz., rust, BLB and grey mildew was not found to occur till harvest in surveyed areas except Coimbatore where the incidence of the diseases was observed. The incidence of Alternaria leaf blight ranged from 2.0 to 8.0 PDI. The maximum incidence was observed in Coimbatore district. Survey for the occurrence of root rot indicated that the incidence varied from 5.0 to 18.0%. The maximum incidence of root rot was observed to an extent of 18.0% in Coimbatore district. The incidence of both wilt and root rot was found to be higher in diploid cotton. The severity was more when the disease was found to occur along with the stem weevil incidence. Survey for the occurrence of viral diseases revealed that Tobacco Streak Virus was found to be observed in all cotton growing tracts surveyed in Tamil Nadu. Incidence of TSV varied from 2.0 to 11.0%. The maximum TSV infection of 11.0% was recorded in Coimbatore district (Table-12). 1(b): Disease progress in relation to weather factors (all centers) NORTH ZONE: Cotton leaf curl viral disease (CLCuD) was observed on susceptible variety RS 921 in 26th meteorological week (25-01 July) at Faridkot. Observations on the appearance and progress of CLCuD were taken at weekly interval starting from 25 th upto 44 th meteorological week. It was found that CLCuD % increased upto 42 nd meteorological week (87.2). The bacterial blight started late in the season in 30 th meteorological week with 0.1 % DI. The fungal foliar leaf spots (caused by Alternaria, Myrothecium, and Cercospora) ranged from 0.1to 2.8; 0.1 to 2.6 and 0.3 to 2.6 disease index from 30 th to 42 nd meteorological week (Table-13). Co-efficient of correlation [r] for CLCuD %, Percent CLCuD increase was positively significant with white fly population, relative humidity and min temperature and rainfall. Co-efficient of correlation [r] of per cent disease index (PDI) of bacterial blight (BB) was positively correlated with wind direction, bss and negatively co related with rainfall, maximum and minimum temperature. Similar type of Correlation of per cent disease index (PDI) of Myrothecium leaf spot (MLS), Alternaria leaf spot (ALS) and Cercospora leaf spot (CLS) was observed in all the three fungal disease. Leaf curl first appeared on 26th June after 43 rd day of sowing during 26 th St. Week and the incidence at the end of this week was only 0.47 per cent at Sriganganagar. However in subsequent standard week s leaf curl incidence in crop showed fast progressive increase reaching maximum level of per cent on 29th Aug. during 35 th Standard Week. Data presented in (Table-14)

5 F - 5 indicate that disease remained slow up to 27 th Std. Week (2 July 8 July) with disease severity of 9.80 per cent. In subsequent 28 th to 30 th std. week disease increased about three fold reaching to the level of per cent. Fast progress of disease was observed up to 31 th Std. Week (30 July 05 th Aug) and the leaf curl incidence reached to per cent. Thereafter progress of disease was slow between 32 rd (06 th Aug 12 th Aug.) to 35 th (27 th Aug 02 th Sept) standard week. During this period progress of disease was between to per cent only. The overall precipitation from June to August (vegetative phase) during this year was mm. The maximum average monthly temperature during this period of June to August remained between and o C and Relative humidity between 55.3 and 76.2 per cent (Table14a). CLCuD appeared on 9 th June, 2015 in the 23 rd standard meteorological week after 17 days of sowing and disease incidence increased up to 100 % in 27 th week ( to ) at Hisar. During this period the average maximum and minimum temperature were 38.1 and 25.1 o C, whereas, morning and evening relative humidity ranged from 73.5 to 48.2 per cent with 7.5 bright sun hours having whitefly population 47.2 per three leaves. However, 1.0 PDI was observed in 23 rd standard meteorological week, which increased up to 55.9 in 31 st standard meteorological week (Table-15). The per cent leaf curl disease data of cotton (2005 to 2015) were correlated with the meteorological parameters. The maximum temperature (-0.58), min. temperature (-0.48), wind speed (-0.66), evaporation (-0.65), actual vapour pressure at morning (-0.29) & evening (-0.25), evening relative humidity (-0.01), and rainfall (-0.06) showed negative correlation with disease development, whereas, morning relative humidity (0.43), sunshine hours (0.19) and cumulative rainfall (0.68) showed positive correlation. The optimum temperature for the disease development was noted to be between 33 to 37 C, RH m 77 to 90 percent, evaporation 2.9 to 7.1 mm, wind speed 1.9 to 5.3 km per hours, bright sunshine hours 4.3 to 8.2 hrs. The wind speed showed a highly significant negative correlation with disease development which may be favorable for white fly migration. There was an exponential relationship between disease development and cumulative rainfall (sigmoid growth curve) i.e. the rate of disease development was initially slow till the accumulation of 100 mm rainfall and thereafter, disease development increased sharply. The sunshine hours showed a linear relationship with disease indicating that the clear days favored its development. Stepwise multiple linear regression process was carried out to identify best suited model using above weather variables. The leaf curl virus disease initiated in 24 th met week (11-17 June) and the incidence reached 100% by 34 th week (20-26 August) at Sirsa. An increasing trend of whitefly incidence from 1.75 per 3 leaves upto 70 whiteflies per 3 leaves was observed during the season. The maximum temperature ranged from 31.8 to C whereas minimum temperature was between25.5 to C. Relative humidity morning and evening ranged between and % respectively. The rainfall received during this period was mm. (Table-16). CENTRAL ZONE: The first incidence of Alternaria blight was noticed on 20 th July (29 MW) on research farm at Rahuri. The average maximum and minimum temperature during 28 th MW was C and C, respectively and average morning and evening humidity was 67.9 and 41.3 per cent, respectively with 0.0 and 17.4 mm rainfall in 28 th and 29 th MW, respectively. The intensity of Alternaria blight increased at slower rate from 2.9 per cent in 29 th MW to 20.7 per cent in 38 th MW.

6 F - 6 The average maximum and minimum temperature during 37 th MW was C and C, and average morning and evening humidity was 78.9 and 58.1 per cent, respectively. As per the correlation there was significant positive correlation of rainfall (at 1 %) with Alternaria blight development. Also, the minimum temperature had significant negative correlation ( 1 & 5 %) with the Alternaria blight development. The other weather parameters i.e. morning and evening humidity, sunshine hours and rainy days had positive and maximum temperature negative correlation with PDI of Alternaria blight in cotton (Table17 and 17a). Bacterial blight was initiated during first week of September 2015 (36 MW), when the maximum and minimum temperature was C and C along with relative humidity between the range of 87 and 57 percent at Akola. Later gradually increased and maximum per cent disease intensity i.e. 8.6% was observed during (41 MW). Maximum and minimum temperature was C and C with relative humidity range of percent. Later decreasing trend was observed (Table-18). In LRA-5166 as well as Bunny Bt, similar trend was observed. Myrothecium leaf spot diseases was initiated during first week of September 2015 (36 MW), during this year and maximum disease intensity i.e. 2.08% was observed during (37 MW). Maximum and minimum temperature was C along with relative humidity between the range of 88 and 54 per cent in LAR 5166 and Bunny Bt respectively. Grew mildew was not observed on LRA 5166, Bunny Bt and AKA-8 throughout the season. The data presented in Table-18a indicated that the correlation between rainfall, minimum temperature and relative humidity morning and evening showed negative and non-significant at both the level of significance with disease whereas maximum temperature and sunshine hours has showed positive and significant correlation with bacterial blight disease at both levels of significance. On susceptible cultivar JK-4 bacterial blight was first observed in traces on 25 th Standard Meteorological Weeks (SMW) at Khandwa. The disease intensity gradually increases upto35 th SMW and then decreased up to 43 th SMW. From the last week of August disease increases and in 35th SMW incidence was maximum, the grade was 3.0 in 0-4 scale. Myrothecium leaf disease was also first noted in 25th SMW and increased up to 35 th SMW. The incidence of Grey Mildew was first noted in 39 th SMW and increased up to 43 th SMW, the grade was 2.0. (Table-19). Bacterial blight disease (BLB) progress was recorded with its first appearance and subsequently at weekly interval till it prevailed on G. Cot. Hy.12 on Research farm at Surat. The result presented in Table, indicated that the disease first appeared in 2 nd week of July (2.0 %) i.e. in 28 th Met. week. The incidence of bacterial blight disease (BLB) was noticed from 28 to 49 th standard week with the maximum disease intensity in third week of September (23.5 %) i.e. in 39 th Met. week. Non significant correlation with all the parameters (Morning & Evening humidity, Max temperature, Rainy days and Rainfall) was found for the disease development (Table-20). The first occurrence of Alternaria Leaf Spot was observed during third week of September (39 th SMW) at Junagarh. Highest percent disease incidence of was recorded during second week of November (46 th SMW). The first occurrence of BLB was recorded during second week of August i.e. 32 nd meteorological standard week. Maximum (9.40 %) BLB incidence was recorded during first week of December (49 th SMW) and there after it declined. The grey mildew disease remain absent during the season (Table-21). The data presented in Table reveled that Alternaria leaf spot disease found non significant with maximum temperature, rainfall and rainy days. The minimum temp and relative humidity (%) at morning and evening were recorded significant and

7 F - 7 negative correlation at 1 per cent level. The maximum temperature, rainfall and rainy days found negative correlation at 5 per cent level. Bacterial leaf blight disease correlation coefficient studies recorded non significant with maximum temperature, rainfall and rainy days. The minimum temperature and relative humidity morning and evening found negative correlation at 1 per cent level. While maximum temperature, rainfall and rainy days found negative correlation at 5% level. The Grey mildew disease was not observed during the season (Table21a). SOUTH ZONE: Maximum Alternaria blight incidence(pdi) of 32.2,28.7,32.9 & 34.4 was noted in 46 th met week at Dharwad farm in Abadhita, Jayadhar, Bunny Bt and RCH 2 Bt. Bacterial blight was noted upto 11.9, 7.2 and 8.0 in Abadhita, Bunny Bt and RCH 2 Bt respectively. In case of Grey mildew a maximum of 12.7, 26.8, 4.4 & 7.3 PDI was noted. Whereas rust incidence was 23.0, 13.9, 30.5 & 20.8 respectively in above referred varieties/hybrids at 46 th met week. (Table-22 and 22a).With respect to Alternaria blight, bacterial blight, grey mildew and rust diseases significant positive correlation was observed between the maximum temperature and the genotypes. Significant negative correlation or no correlation was observed between minimum temperature and genotypes in general. No correlation was observed between RH Morning and RH Evening in four genotypes with respect to four diseases. Significant positive correlation was noticed between total rainfall and rust in all the genotypes and no correlation was noticed between rainy days and the genotypes with respect to all the four diseases (Table-22b). The data recorded at Guntur showed that Alternaria leaf spot appeared in 36 th standard week during September 2015 when the mean maximum temperature was C; mean minimum temperature was C; mean relative humidity of 88%; mean rainfall was 93.8mm; rainy days were 4.86; sun shine hours were 5.83; wind speed 4.86kmph and evaporation was Alternaria leaf spot attained a maximum PDI of 30.0 on Jadoo BG II during 48 th standard week i.e., last week of November, during which the mean maximum temperature was C; mean minimum temperature was C; mean relative humidity of 98.3%; shine hours were 4.7; wind speed 4kmph and evaporation was 6.7 RCH 2 BG II and Bunny BG II recorded 21 and 20 PDI, respectively, during the same period (Table-23).Grey mildew disease appeared in 44 th standard week during November 2015 on Jadoo BG II when mean maximum temperature was C; mean minimum temperature was C; mean relative humidity of 92%; sunshine hours were 6.3, wind speed 4.7kmph and evaporation was 9.7. The disease progressed and reached PDI of 52.5 on Jadoo BG II during 51 st week of 2015 during which the mean maximum temperature was C; mean minimum temperature was C; mean relative humidity was 97.5%; sunshine hours were 3.38, wind speed 3.88kmph and evaporation was 3.0. Disease intensity was negatively correlated with maximum, minimum temperatures, RH II, Rainfall, rainy days, wind speed, evaporation; positively correlated with RH I and sun shine hours Significant correlation was recorded with temperature, RH I, number of rainy days, wind speed and evaporation. Multiple linear regression analysis revealed that minimum temperature and rainfall significantly influenced the disease intensity. In Bunny BG II grey mildew appeared later in 48 th SMW during which the mean maximum temperature was C; mean minimum temperature was C; mean RH of 98.3%; shine hours were 4.7; wind speed 4kmph and evaporation was 6.7. The disease progressed and reached PDI of 34.0 during 51 st week of 2015 during which the mean maximum temperature was C; mean minimum temperature was C; mean RH was 97.5%; sunshine hours were 3.38, wind speed 3.88 kmph and evaporation was 3.0 (Table 1b.1). Positive correlation was recorded with maximum

8 F - 8 temperature, SSH and wind speed, while it was significant for max temperature. Minimum temperature, RH and evaporation showed negative and non significant correlation. Multiple linear regression analysis revealed that temperature and RH II significantly influenced the disease intensity. Rust disease appeared in 49 th standard meteorological week during December 2015 when mean maximum temperature was C and mean minimum temperature was C, and mean RH of 99.4%. The disease progressed and reached PDI of 45 on RCH 2 BG II during 4 th week of 2015 during which the mean maximum temperature was C; mean minimum temperature was C and mean RH was 96%. Jadoo BG II and Bunny BG II recorded 41% and 35% during the same week. Disease intensity was negatively correlated with maximum temperature, RH II and evaporation which were significant while minimum temperature and RH I were non-significant. Sunshine hours and wind speed were positively correlated and non significant. Multiple linear regression analysis revealed that maximum temperature and RH II significantly influenced the disease intensity while evaporation also showed partial influence on disease intensity. Disease intensity was negatively correlated with temperature, rainfall, sunshine hours and wind speed; positively correlated with RH and evaporation during kharif Significant correlation was recorded with temperature; RH I and RF. Multiple linear regression analysis revealed that temperature, RH II and wind speed significantly influenced the disease intensity (Table-23a). Studies on the impact of weather factors on the intensity of foliar and soil borne diseases starting from 35 th and 40 th meteorological week at TNAU, Coimbatore revealed that foliar diseases such as Alternaria leaf blight was found to be associated with varieties MCU13 and hybrids viz, RCHBGII and TCH32. However, comparison between different meteorological weeks indicated that, the incidence of foliar diseases was found to be initiated during 35 th meteorological week (September, 2015). The maximum incidence of Alternaria leaf blight (8.0PDI) was observed in the hybrids viz, RCHBGII, TCH32 and variety. The maximum incidence of Alternaria leaf blight was observed during peak boll bursting stage. The incidence of TSV was found to be associated up to 9.0% in RGHBGII and TCH32 followed by 7.0% in the variety MCU13. Similarly, assessment of root rot revealed that the maximum incidence of 15.0% was observed during 45 th meteorological week in the variety MCU13 and disease incidence was not observed in hybrids. However, in general the incidence of TSV and leaf spot were found to be more in the hybrid than the variety (Table-24). 1(c): Studies on the variability of Alternaria leaf spot (all centers) Nanded center has reported Alternaria dianthi in isolations from their samples. At Junagarh center samples were collected from seven different location and pure cultures were obtained (Table-25). At Dharwad center, Among the Six isolates of Alternaria isolated from the different infected samples during , four isolates (from Kalghatagi, Murgod, Hebballi farm, and Gadag) resemble to Alternaria macrospora with respect to length of conidia, beak length and number of septa. The other two isolates differed from Alternaria macrospora with respect to the conidial characters (Table-26). During the survey for cotton diseases at Guntur, Alternaria leaf spot samples were collected from 16 locations in farmers fields and experimental plots at RARS, Lam and observed for the presence of Alternaria (Table-27). Based on the spore structure the species was identified as Alternaria macrospora. The fungus was cultured and the isolate was sent to TNAU, Coimbatore for molecular analysis. At TNAU, Coimbatore, 25 isolates of Alternaria were obtained and their symptoms and culture characteristics were documented. (Table-28).

9 F - 9 1(d): Survey and Epidemiology of TSV (Guntur, Nandyal, TNAU Coimbatore, Akola, Nanded & Rahuri) The occurrence of Tobacco streak virus (TSV) was observed from first fortnight of July on most of the Bt cotton hybrids sown on farmers field around Rahuri, Maharashtra. However, the incidence of the disease was only up to five per cent during the season. Moreover, the virus was observed to infect only the upper leaves and symptoms were confined to leaves only. Systemic infection of the virus was rarely noticed. As against, incidence of the disease during was up to 40%. Environmental conditions during the current year may be the reason for low incidence of the disease (Table-29). Nanded center, Maharashtra surveyed six districts ie Aurangabad (Fulambri); Parbhani (Selu); Hingoli (Kalamanuri); Latur (Ahemadpur); Jalna (Ambad) of Marathwada region for TSV incidence and confirmation for TSV but not a single infected plant was observed. During the surveys conducted in Cotton growing districts by Guntur center, Tobacco Streak Virus disease was recorded from September to December 2015 on Cotton. The incidence on different hybrids varied from 0% to 12% (Table-30). TSV disease incidence was negligible on cotton varieties and hybrids in experimental plots of Regional Agricultural Research Station, Lam during September 2015 January Progress of TSV disease incidence (%) was in the range of 0.8% to 13.0% in Bt Cotton hybrids (Table-30a). The incidence was more during September when the crop was at 5 to 6 weeks old and thrips counts were in the range of 0.0 to 2 per three leaves. The symptoms were restricted to few leaves and/or branches. The incidence of TSV disease was less from second fortnight of October onwards and thrips were not found. Direct Antigen Coated Enzyme Linked Immunosorbent Assay of cotton leaves showing different symptoms confirmed the presence of TSV. Analysis of common weeds in cotton plots revealed the presence of TSV in Cyperus rotundus, Cleome viscose and Panicum species (Table- 30b). Survey for the occurrence of viral diseases by TNAU, Coimbatore revealed that Tobacco streak virus disease incidence was observed in all cotton growing tracts surveyed in Tamil Nadu. Incidence of TSV varied from 1.0 to 11.0%. The incidence was maximum (11.0%) in the Coimbatore. The minimum incidence of 1.0 and 2.0% of TSV was noticed in the Dindigul, Palladam, Anthiyur and Dharmapuri. TSV disease incidence was more in rainy season when compared to other seasons (Table-31).

10 F - 10 Path 2 (a): Screening of breeding lines for diseases reaction (all centers): Table Path 2(b): Confirmation and maintenance of disease resistant lines (all centers) The results (Table-72) showed that out of 24 entries tested under field conditions at Faridkot against cotton leaf curl disease (CLCuD), two entries viz., Su-Flum and Bihani-251 gave moderately resistant reaction and one entry namely, MR 68 moderately susceptible reaction and four entries F 2164, H 1471, SSGR105 and CSH-2931 gave susceptible reaction to (CLCuD) and all other entries gave highly susceptible reaction. Against bacterial blight five entries viz., Su-Flum, Bihani-251, F 2501, RS 2765 and MR 68 gave resistant reaction and all other entries gave moderately resistant reaction and RST 9 gave moderately susceptible reaction. Against fungal foliar leaf spot (FFLS) caused by Myrothecium, Alternaria and Cercospora, one entry viz Bihani-251 gave resistant reaction and RST 9 gave moderately susceptible reaction. All other entries were found in moderately resistant group. In National trial (Br 02) entries namely RS 2670, L1008 and SCS 1001 were found highly resistant against CLCuD during crop seasons. Above entries were sown further during , and crop seasons for confirmation of resistance against CLCuD. But all the entries were found susceptible to CLCuD under unprotected natural conditions. Hence no resistant entry was available for confirmation of resistance against CLCuD at CCS HAU, Hisar centre. Twenty one breeding lines from Central Zone and National trials showing resistant during , were sown in earthen pots during and screened against Alternaria blight disease under in vivo conditions by artificial inoculation of fresh culture of A. macrospora at Rahuri. The susceptible check LRA-5166 was also sown for comparison. The reaction of breeding lines is given in Table.Twelve lines showed resistant reaction against ALB CCH 12-2; GTHV 04/13; GJHV 497; CNH 5; L 1008; GSB 45; ARBB 1302; ZC (Suvin); TCB 37; ARBD 27; DSC 1401; RAHC 1011(Table-73). For Bacterial Blight it was observed that during and , among 12 genotypes tested, 3 genotypes showed resistance to bacterial blight i.e. (NDLH-1943, P-2151, ADB- 542) whereas remaining genotypes were categorized as moderately resistant i.e. (BHV 180, AKH 10-1, BS 30, AKH 8828, BGDS-1063, SCH-1062, BS 79, BGHV 180, SCS - 793).( Table-73a) At Nanded, twenty four breeding lines screened during against important diseases viz., Alternaria Leaf spot, Bacterial blight, Grey mildew, TSV, Wilt and para wilt. From each line five plants were randomly selected and artificially sprayed by culture of Bacterial blight, and Alternaria leaf blight. None of the line was found disease free and resistant to cotton diseases. At Akola, it was observed that during and , among 12 genotypes tested, 3 genotypes were resistant to bacterial blight i.e. (NDLH-1943, P-2151, ADB- 542) whereas remaining genotypes were categorized as moderately resistant i.e. (BHV 180, AKH 10-1, BS 30, AKH 8828, BGDS-1063, SCH-1062, BS 79, BGHV 180, SCS - 793). (Table-74) The entries found disease free and resistant during previous year were tested this year under natural field and artificial condition against the different diseases at Surat. Infester row of susceptible check LRA 5166 was grown alternating every two rows of the test entries. Artificial inoculation was made twice by preparing the spore suspension of BLB. Total 2 entries were screened through artificial inoculation, from these entries viz., GSHH 2729 and GSHV 162 was

11 F - 11 observed disease free under the artificial reaction. Alternaria leaf spot disease was not observed (Table-75). Seventeen breeding lines were evaluated against Alternaria leaf spot, bacterial leaf blight and grey mildew diseases under field condition during kharif-2015 at Junagadh. Two entries recorded susceptible, 15 moderately susceptible reactions against Alternaria leaf spot disease. In case of bacterial leaf blight disease, the sixteen entries found resistance and one entry found moderately resistance. The grey mildew disease was not observed during the Kharif-2015(Table- 76). Five varieties viz., ARBB 1401, DB 1402, CCB 36, ARBB 1402 and DB 1302 along with two susceptible checks RCH 2 BG II (for bacterial blight and rust) and Jadoo BG II (for Alternaria leaf spot and grey mildew) were evaluated for second consecutive year at Guntur. Two checks RCH 2 BG II (for bacterial blight and rust) and Jadoo BG II (for Alternaria leaf spot and grey mildew) after every four rows of randomized entries and also as border. Natural disease pressure was supplemented with artificial inoculations with grey mildew spore suspensions. The test entries showed resistant reaction to grey mildew disease and moderately resistant reaction to Alternaria leaf spot while the respective check entries showed susceptible reaction (Table-77). The genotype SVA-1118 exhibited resistance to Alternaria blight, Bacterial blight, Grey mildew and Rust at Dharwad. The genotypes DB-14, DB-40 and SCS-1206 showed resistant reaction against Alternaria blight, Bacterial blight and Grey mildew but found susceptible against Rust (Table-78). At Coimbatore, Seventeen entries from Br03a, Br04a and Br06a zonal trials of were screened against foliar diseases under natural conditions. The entries viz., ZC (Suraj), TSH04/115, Local Check, GJHV-516, CCH13-2, BGDS1063, DSC-1302 and DSC-1301 were free from Myrothecium leaf spot, root rot, grey mildew and BLB (Table-79). Path 2(c): Monitoring of breakdown of resistance against CLCuD in cotton(centers-hisar, Sriganaganagar & Bhatinda). A total of eight cultures (three CLCuD susceptible and three resistant G hirsutum varieties along with one susceptible and tolerant Bt hybrid) were screened against CLCuD at three locations to monitor break down of resistance due to appearance of new recombinant strains at 3 locations. The cumulative reaction results revealed that all the four susceptible cultures showed HS reaction whereas the three resistant cultures also showed HS reaction. The tolerant Bt hybrid showed susceptible reaction (Table-80). Path 3 (a1): Validation of seed dressing chemicals against seed and soil borne diseases of cotton (Centers - Junagarh, Dharwad, Guntur & Coimbatore). Based on pooled results of three years ( ), the minimum seedling mortality was observed when seed was treated with Carboxin 37.5%+ Thiram 37.5%DS at 4.5 g /kg followed by Thiram 75 WP at 4g/kg and Carboxin 75 % at 3g/kg. In case of Alternaria blight also the minimum PDI was observed when seed was treated with Carboxin 37.5%+ Thiram 37.5%DS at 4.5 g /kg but this was followed by Carboxin 37.5%+ Thiram 37.5%DS at 3.5 g /kg and Carboxin at 3g/kg. Bacterial

12 F - 12 blight was best controlled by Thiram75WS at 4g/kg followed by Thiram75WS at 3g/kg & Carboxin 75 % at 2g/kg. Root was observed minimum in case of seed treatment of Carboxin 37.5%+ Thiram 37.5%DS at 4.5 g /kg followed by Thiram 75 WP at 4g/kg & Carboxin 37.5%+ Thiram 37.5%DS at 3.5 g /kg. Maximum seed cotton yield also was noted in Carboxin 37.5%+ Thiram 37.5%DS at 4.5 g /kg treatment (10.79 q/ha) followed by Carboxin 37.5%+ Thiram 37.5%DS at 3.5 g /kg & Thiram 75 WP at 4g/kg. Maximum benefit cost ratio was noted in treatment Carboxin 37.5%+ Thiram 37.5%DS at 4.5 g /kg at Dharwad and Coimbatore (Table-81). Path 3 (a3): Evaluation of TrichoCASH (Trichoderma harzianum) CICR-G 1% WP for cotton root diseases at CICR Sirsa and Pune The trichocash (Trichoderma harzianum) CICR-G 1% WP (seed 5 & 10 g/kg seed alone and with 0.5% & 1.0%) evaluation alone and in combination with thiram seed treatment(@3g/kg seed) was done against root rot disease of cotton caused by Rhizoctonia sps at CICR, regional station Sirsa under sick field conditions. Non significant results were obtained during the season. However, numerically lowest seedling mortality was noted in trichocash seed + seed followed by trichocash seed. In case of root rot observations, lowest incidence was noted in commercial Trichoderma formulation seed seed followed by trichocash seed (Table-82) At Pune center, 10g/kg seed + 3g/kg showed maximum 45.26% disease control of cotton wilt, followed by Tricho 5g/kg seed + 3g/kg (43.33%) disease control (Table-83). Path 3 (c): Developing IDM modules for the management of cotton diseases (Centres- Dharwad, Akola, Junagarh) The maximum bacterial blight disease intensity 8.3 per cent was recorded on Bunny Bt in the Control plot (untreated plot) at Akola. All six different modules were found effective in managing the bacterial blight disease of cotton over untreated plot, where neither seed treatment nor any fungicide/ bioagent sprays were given (Table-84). However, the seed treatments of bioagent with chemical sprays were found more effective in minimizing the BLB disease in Bt hybrid (module 5).The significantly maximum seed cotton yield (13.5 q/ha) compared to control was recorded in the treatment of Bunny Bt + module 3 which was at par with treatment Bunny Bt + module 5 (13.03 q/ha) and Bunny Bt + module 2. Whereas, the minimum seed cotton yield 8.4 q/ha was recorded in untreated plot. The results on yield contributing parameters revealed that there was not much difference in seed germination (92.8 to 97.9 %), days to flowering (38 to 42 days) and root length (37.2 to 41.2 cm) due to different treatments. There was not much variation in plant height in Bt hybrid with different module, however plant height of Bunny Bt was (64.1 to 71.1 cm) whereas, the highest plant height 71.1 cm was recorded in the treatment of soil application of Pseudomonas fluorescens (PF Kg/ha Foliar spray with P. fluorescens (module 3), which was followed by Seed Treatment of Pseudomonas fluorescens PF g/kg of seed; Soil Application of Trichoderma 2.5 Kg /ha TV-TNAU1 FS with Propiconazol 0.1% for foliar diseases and COC (0.3%) + Streptocycline (0.01%) for BLB or Carbendazim 0.1% for grey mildew on need basis (module 5).

13 F - 13 At Junagadh center, out of the total seven Modules including the control, Module-6 (8.8%) followed by Module-5 (9.2%) and Module-1(9.8%) recorded significantly minimum Alternaria leaf spot as compared to the Module-7 i.e. Control (16.4%) in RCH-2 BG-II hybrid, while all the remaining Modules found statistical at par with the Module -7 i.e. control for Alternaria leaf spot. For bacterial leaf blight, all the Modules except Module- 4 recorded significantly minimum bacterial leaf blight in RCH-2 BG-II hybrid as compared to the control. Out of total Modules used in field condition the minimum bacterial leaf blight was recorded in Module-6 (1.8%), followed by Module- 5 (1.97%), Module-3 (2.2%), Module-2 (2.3%) and Module-1 (2.5%) as compared to the control i.e. (3.99%). Considering mortality per cent, the minimum mortality per cent (2.9%) was recorded in Module-6 and it was at par with rest of Modules except control. The highest seed cotton yield was recorded in Module-6 (18.3 Q/ha), followed by Module-5 (17.5Q/ha) and Module-2 (17.1 Q/ha). The seed cotton yield was found statistically significant in Module-6 and it was at par with Module- 5 and Module-2 (Table85). The highest mean germination percentage was recorded in Module-6 (99.3%) and the lowest mean germination percentage was recorded in control (93.0%). The same results were also found for plant height in RCH-2 BG-II hybrid at Junagadh centre (Table-85a). At Dharwad, least per cent of seedling mortality was found in T6 (Pseudomonas fluorescens 10g/kg of seed Soil application of Trichoderma 2.5 kg/ha (TV-TNAU) in 250 kg of Compost or FYM foliar spray with 1ml/lit followed by 1.5g/lit for Fungal diseases or COC 0.3% + Streptocycline 0.01% for BLB). With respect to per cent disease index, T6 recorded lower incidence with higher yields. Though higher yield was recorded in T6 it was found to be on par with T4 (Table-86). Path 3 (e): Innovative interventions for the management of CLCuD(Centers-Hisar, Faridkot, Sriganganagar, CICR, Sirsa and Bhatinda). The experiment conducted at different locations to study the efficacy of ecological interventions i.e., Butter 5%, Cow Neem oil@1%, Mustard oil@3%, Calcium nitrate@0.5%, Cow urine + Calcium nitrate, Cow urine + Butter milk, Butter milk + Calcium nitrate, Lachesis30@1ml/l, Digitalis@1ml/l, Apis mallifera30@1ml/l, Bryonia30@1ml/l, Natrum Polo@0.1%, and control was studied during The minimum CLCuD PDI was noted in Polo followed by cow neem oil and cow urine + calcium nitrate combination. (Table 87). Maximum seed cotton yield was also observed in polo spray followed by cow urine +calcium nitrate treatment (Table 87a).As per the reduction in white fly population during the peak population period at all the locations, in case of Sirsa maximum reduction was obtained under Polo (36.75%) followed by cow urine (15.98%), neem oil and mustard oil. In Hisar Polo, Buttermilk (12.28%), Naturum mure (12.84%) and Bryonia (11.30%) comparatively reduced the population of whitefly. In Sriganganagar, Neem oil (50.41%) followed by polo (47%) gave the maximum reduction however in all the treatments a good reduction in whitefly population ( %) was recorded. (Tables 87 b,c &d)

14 F - 14 Path 4(e): Crop loss estimation due to CLCuD and distribution pattern of CLCuD in North zone. Experiment-1: To work out relationship between disease index and yield reduction due to cotton leaf curl virus disease (Centers-Hisar, Faridkot & Sriganganagar). The percent seed cotton yield reduction ranged from , and respectively in Bt cotton hybrids(bioseed 6588 BG II, RCH 650 BG II, Ankur 3028 BG II & MRC 7017 BG II) tested at Hisar, Faridkot and Sriganganagar locations respectively (Table-88).In case of grade wise seed cotton yield reduction (%) and in Bioseed 6588 ; and 6.3 to 67.5 in RCH 650 ; and 12.0 to 64.5 in Ankur 3028 ; and in MRC 7017 respectively at Hisar and Faridkot was observed (Table-88a). Experiment-2: Study on distribution pattern of cotton leaf curl virus disease on local popular Bt hybrid at farmer s field (Centers: Hisar, Faridkot & Sriganganagar). The district wise pooled CLCuD PDI data of Punjab showed that per cent disease index varied from Rajasthan s Sriganganagar district showed a per cent disease index of The district wise pooled CLCuD PDI data of Haryana showed that per cent disease index varied from No CLCuD was observed at farmer s field in Bhiwani (Siwani & Loharu blocks), Rewari, Mahendergarh, Palwal and Jhajjar districts (Tables-89). Experiment-3:CLCuD progress and yield estimations (CICR Sirsa center). In order to study CLCuD progress and yield estimations, an experiment with two resistant and two susceptible Bt hybrids was conducted at Sirsa in half an acre area. The disease progress (%incidence) in resistant hybrid Yuva and Bunty from 50DAS to 140 DAS was and respectively. Whereas it was and in susceptible hybrids Ankur Jai Bt and Ankur 3028 respectively (Table 90).The PDI in above referred hybrids from 80 DAS to 140 DAS ranged from ; ; and , respectively. Seed cotton yield in Yuva, Bunty, Ankur Jai BT and Ankur 3028 was 6.9, 9.2, 8.3 and 9.2 q/ha, respectively (Table 90a). Path 7: Fusarium wilt of cotton (Pune centre) Total 169 genotypes received from the Project Coordinator, (Cotton Improvement) & Head CICR Coimbatore, Principal Scientist and I/C Oilseed Research Station Jalgaon, Cotton Breeder, were tested for Seedling Resistance (SRT) in glass house. All the entries showed susceptible reaction against Fusarium wilt. Sixteen Intra hirsutum and 12 G. hirsutum x barbadense hybrids received from Cotton Breeder, MPKV, Rahuri were found free from Fusarium infection at seedlings stage. The root rot infection ranged from % in different entries was noticed in genotypes tested during The lowest Rhizoctoina root rot was observed in the entry RHB (14.81) followed by Phule 328 (15.38) under pot sick soil condition. The incidence of Tobacco Streak Virus was recorded 0.00to 2.86 % in G. hirsutum. The entries RHH-0917, RHH-0707, RHH-1007, RHH-1015, RHH-1112 and RHH-1025 remain free from infection. In G. barbadense 0.00 to 2.33%TSV was recorded. The entries RHB-0708, RHB-0707, RHB-0922, RHB-0711 and RHB-1123 were free from TSV infection.

15 F - 15 Path 1(a): Observations on the occurrence of various diseases (in farmer s field and research farms) NORTH ZONE Table 1: Observations on the occurrence of various diseases in farmer s field and research farms (Faridkot) District Faridkot Fazilka Muktsar Locations CLCuD BB FFLS (PDI) (DI) (DI) Variety/Hybrid Acerage F F Traces F F 1054 R.S. Faridkot F F F F Different entries of Co-ordinated and State trials Sindwan Jan Bioseed 6488 Bt, 6acre Romana 57 Traces 2-Jan Bioseed 6488 Bt 1acre Bioseed 6588Bt 1acre Kaliana Jan JK 1947 Bt 3 acre Jan Bioseed 6588 Bt 3acre Chahal 47 Nil RCH 650 Bt 2 acre 49 Traces Traces RCH 773 Bt 2 acre Saddiq Bioseed 6488 Bt 5 acre Kotkapura Bioseed 6588 Bt 7 acre F F F 505 CRS Abohar F F F F 1054 Zandwala khatta Bioseed 6488 Bt 5 acre 70 Traces 0.1 Bioseed 6588 Bt 5 acre Khuiya Bioseed 6488 Bt Khera Traces Bioseed 6588Bt - Alamgarh Bioseed 6588 Bt 2 acre Bioseed 6488 Bt 2acre Kamalwara 45 Traces Traces Bioseed 6588 Bt 3 acre 49 Traces Traces Bioseed 6488 Bt 3 acre Gobindgarh Jan Bioseed 6488 Bt 5 acre 65 2-Jan Traces Bioseed 6588Bt 5acre Kundal 60 2-Jan Traces Bioseed 6588Bt 4 acre Bioseed 6488 Bt 10 acre Jan Mallan Traces Bioseed 6588 Bt 2acre 47 Traces Traces RCH 773 Bt 2acre 37 Traces RCH 650 Bt 2 acre 44 Traces 2-Jan RCH 773 Bt 7 acre Baang 40 Traces 2-Jan RCH 653 Bt 2 acre 55 Traces Traces JK 109 Bt 2 acre Kothe Dashmesh nagar 40 2-Jan 2-Jan RCH 773 Bt 4 acre Muktsar 52 2-Jan Traces Ankur 3028 Bt 5 acre 46 2-Jan Traces Ankur 3244Bt 5 acre Maha Bhaddar 40 2-Jan 2-Jan RCH 651Bt 2.5 acre Kotbhai 44 2-Jan Traces Bioseed 6588 Bt 2 acre