ICRISAT Archival Report 2006 - The seedlings of success in the ...

Milestone 5A.5.1.2: Spatial and temporal virulence pattern of downy mildew pathogens assessed through virulence
nursery and on-farm survey results (RPT/RS/KNR/RB/CTH, 2009)
Virulence monitoring in pearl millet downy mildew: The downy mildew pathogen, Sclerospora graminicola,
evolves fast in response to selection pressure imposed by host resistance gene(s). Occurrence of new virulence and
virulence shift is monitored through on-farm surveys and multilocation virulence nursery.
On-farm downy mildew survey: Under the ICAR-ICRISAT partnership project, roving surveys were conducted in
Gujarat, Maharashtra and Rajasthan in collaboration with AICPMIP pathologists of the respective states during the
summer and rainy seasons. In Gujarat, during summer, a total of 70 pearl millet fields were surveyed in six talukas
of two districts (Mehasana and Banaskantha) where summer pearl millet is important. Of the 70 fields surveyed, 41
(58%) had DM incidence ranging from 1 to 93%. Of the three public sector hybrids observed, HHB 67 had 11%
incidence and the other two hybrids, GHB 557 and GHB 558 were DM-free. Of the 23 private sector hybrids, 11
(Bioseed, HY 555, M-50, Nandi 5, Nandi 52, PAC 982, Pioneer 86M34, Pioneer 86M52, Proagro 9444, Raasi 2246
and Ritu) were disease-free, six (Chandini 511, Nandi 35, Nirmal 1651, NK 1616, Paras Sarpanch and Proagro
9555) were resistant (1−10% incidence) and the remaining six (Ajay VBBH 334, Nandi 32, Paras Ganesh, Pioneer
7777, Rani, and Seedtek) were susceptible (30−61% incidence).
In Maharashtra, we surveyed a total of 99 pearl millet fields in 18 talukas of 7 districts, (Ahmadnagar, Aurangabad,
Beed, Dhule, Jalgaon, Jalna and Nashik) during the rainy season. There were 15 private sector hybrids (Amar
Ratna 6, Anuja 6, Hy. 555, MBH 163, MDBH 318, MLBH 308, MLBH 367, MLBH 504, MRB 204, MRB 212,
MRB 2210, Nirmal 1651, Pioneer 86M34, Proagro 9330 and Tulja) and all were disease free.
In Rajasthan, a total of 123 pearl millet fields in 20 talukas of 7 districts (Alwar, Dousa, Jaipur, Karouli, Sawai
Madhopur, Sikar and Tonk) were surveyed during the rainy season. Of the 123 fields surveyed 93 (76%) showed
DM incidence ranging from of 1−96%. Of the 24 private sector hybrids observed, 3 (JKBH 598, Kanchan and MRB
2210) were disease free, 4 (JKBH 26, Nirmal 1651, Proagro 9444 and Pioneer 86M52) were resistant (1−5%
incidence) and the remaining 17 were susceptible (Akash, Ankur 2226, Anmol, Arjun, Aswani, Bioseed 8510, Sri
Hari Krishna 1044, Kaveri 456, MLBH 75, MLBH 308, PAC 982, PG 5850, Pioneer 7688, Pioneer 86M32, Pioneer
86M34, Rani and RBH 36) were susceptible (37−96% incidence). One public sector hybrid, ICMH 356 found in just
2 fields was also disease free. Most of the seed companies supplied the metalaxyl-treated seeds to the farmers.
We believe that the absence of DM in several hybrids and high levels of resistance in some other hybrids may
require confirmation of their genetic resistance as most of the seed were treated with metalaxyl. In addition, lack of
disease in Maharashtra could be due to the initial dry spell of about 20 days after planting and the practice of
different cropping sequences, such as soybean-cotton-millet; wheat-cotton-millet, sorghum-cotton-millet; maizecotton-millet;
cotton-castor-millet and onion-cotton-millet that affect initial soil inoculum level. This needs further
investigation.
RP Thakur and Rajan Sharma
Output target 5A.6: At least two improved populations and experimental hybrids of pearl millet with high
forage yield potential developed (2009)
Activity 5A.6.1: Develop and evaluate improved open-pollinated varieties and hybrids for their forage yield
potential
Milestone 5A.6.1.1: Additional germplasm sources with high biomass yield identified (KNR/RB/HDU/MB, 2009)
Germplasm sources: Over the last few years, there has been an increased emphasis on developing hybrid parents or
varieties with high forage yield potential. This has necessitated exploiting germplasm accessions of diverse origin
with high biomass yield. Ten germplasm accessions visually selected for high forage yield during the 2005 rainy
season were planted for producing S 1 progenies. In addition, three of the most promising accessions were random
mated to develop an open-pollinated forage variety ICMV 06111. An experimental forage hybrid (ICMA 00999 ×
IP 17315) earlier identified as the most promising, and consistently giving 15−30% more dry forage yield over the
released forage hybrid Proagro 1, is now routinely used as a control in forage trials. In a preliminary yield trial
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