SATrends Issue 51                                                                                                                  Febuary 2005

  • New Pearl Millet Hybrid Resists Downy Mildew
  • Hens on a Diet
  • Crops and Livestock in a Changing Landscape
  • Forging Ahead with Forage Pearl Millet
  • 1. New Pearl Millet Hybrid Resists Downy Mildew
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    Farmers growing pearl millet in the Haryana and Rajasthan states of India need not fear the downy mildew (DM) disease any longer. Collaborative research between ICRISAT and the Haryana Agricultural University (HAU) has resulted in a new hybrid, HHB 67-2, which is resistant to DM (caused by fungus Sclerospora graminicola). It is the first ever product of marker-assisted breeding in pearl millet to be released for cultivation in India.   By rapidly adopting the improved hybrid, farmers in Haryana and Rajasthan can avoid grain losses approximating Rs 28.8 crores, in the first year of a major DM outbreak. In years of severe DM attack, up to 30% of the pearl millet harvest can be lost (income losses are estimated from an average grain yield of 800 kg per ha, and a minimum selling price of Rs 3 per kg).

     

     Haryana farmers and HHB 67-2.

    With the Haryana State Varietal Release Committee approving the release of HHB 67-2 on 14 January 2005, the seeds may reach the farmers this rainy season. The new hybrid is an improved version of the popular pearl millet hybrid HHB 67.

    According to Dr William Dar, Director General of ICRISAT, this breakthrough is a result of ICRISAT’s cutting edge scientific research and effective .The new hybrid brings additional benefits to the farmers.

    HHB 67, grown on at least 400,0partnerships00 hectares in Haryana and Rajasthan, was released in 1990 by the HAU. It is very popular since it matures very quickly – within 65 days – thereby escaping the end-of-season drought and providing an opportunity for double cropping. Unfortunately, there has been no alternative available in its maturity group. In recent years, HHB 67 was starting to succumb to DM. To develop the new hybrid, the parental lines were improved for DM resistance through marker-assisted, as well as conventional backcross, breeding programs at ICRISAT-Patancheru in southern India.

    The gene for DM resistance was added to the male parent, H 77/833-2, using ICRISAT elite parent ICMP 451, and to the female parent, 843A/B, from ICRISAT line ICML 22. The All India Coordinated Pearl Millet Improvement Project tested the new hybrid at various locations over the past three rainy seasons.

    ICRISAT has produced Breeder Seed of the parental lines of HHB 67-2 that can be used to multiply the hybrid.

    For more information contact c.hash@cgiar.org
    2. Hens on a Diet
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    Looking for inexpensive eggs without reducing quality? The project titled Exploring marketing opportunities through a research industry and users coalition: sorghum poultry feed (funded by the UK Department for International Development, R8267), studied the chemical composition and nutritive value of improved sorghum cultivars and the performance of layer birds fed with sorghum-based poultry feed. The sorghum cultivars used were CSV15, CSH16, PSV 16 and S35 known for high grain yields, low tannin content and resistance to grain molds.

    Feeding trials were conducted on White Leghorn chickens at Acharya NG Ranga Agricultural University (ANGRAU). Feeding trial (n=504) from 1 day old to 18 weeks comprised 6 dietary groups (7 replicates per group). Sorghum replaced maize at 0, 50,100%. Feed was prepared in mash and pellet forms. At this stage the experiment was disturbed due to mortality across all the trials in the experiment station. During this period all the birds were given control diet. Trials resumed after six weeks. Layer feeding trial (n=256) from 24 weeks to 44 weeks age comprised 8 dietary groups (4 replicates per group). Sorghum replaced maize at 0, 50,100%. The latter diet contained 3% Stylosanthes leaf meal as a source of pigments in place of de-oiled rice bran. Body weight and feed intake was recorded, and feed conversion ratio (FCR) was calculated for ages 8 and 18 weeks. From 24-week egg production, mortality, feed intake, egg weight and egg quality parameters (2 eggs per replicate on 3 consequent days) were recorded.Egg quality parameters include albumin index, yolk index, Haugh unit score, shell thickness and yolk color score (Roche fan color scale).FCR per 12 eggs, FCR per kg egg mass, feed cost during growth and egg laying period was also calculated.

    There was no significant difference between the sorghum and control diets with respect to body weight, feed intake and FCR until Week-8. The birds also achieved standard body weight both on sorghum and control diets at Week-18. However, feeding sorghum diets to growing birds up to the 18th week saved feed cost per bird by Rs 3.04 and Rs 1.39 in mash and pellet form, respectively. From Week-24 onwards, the inclusion of sorghum at different levels resulted in similar egg production and FCR as against the control.

    Layer birds fed with sorghum-based diets

    Feed cost per production of egg was cheaper with sorghum-based diets for both mash and pellet feeds. Sorghum could replace maize in layer diets without affecting layer performance and egg quality (except for the yolk color). Sorghum-based diets supplemented with Stylosanthes leaf meal not only improved the egg yolk color but also lowered the feed cost.

    For more information please contact
     b.reddy@cgiar.org
    p.parthasarathy@cgiar.org


    admalarsreddy@rediffmail.com

    3. Crops and Livestock in a Changing Landscape
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    Worldwide, population densities are increasing, and so is the pressure on natural resources. Zimbabwe is no exception. A recent ICRISAT study showed that human populations in one region had nearly doubled during the last 20 years, with major consequences for both farmers and researchers.

    Scientists used satellite data to study changes in land use in the semi-arid Tsholotsho district over the past two decades. Landsat images for Oct 1984, April 1992, and May 2002 were obtained and reclassified using standard raster-based GIS software. The important landscape features were identified – fields on red sandy soils, fields on clay soils, good rangeland, and degraded through continuous heavy grazing.

    More households… more livestock and more crop fields to feed these households... more degradation. The total area under crops in Tsholotsho almost doubled in 18 years, largely at the cost of rangeland. Livestock populations have more than doubled since 1984, and are probably a major cause of degradation. Fenceline contrasts – sharp, visible differences between good and degraded rangeland on opposite sides of a fence – were already developing in 1992 and were clearly identifiable by 2002. An estimated 46 km2 of rangeland have been lost to crop fields in 18 years. Even more significant is the loss in rangeland quality: over half the good quality rangeland in 1984 is in poor condition today! This will seriously affect livestock production, especially during drought years.

    Satellite images clearly show degradation and land
    use patterns in Zimbabwe’s drought-prone Tsholotsho district


    Of course farmers have made efforts to arrest the decline, eg, collecting and storing crop residues for livestock feed, in an attempt to reduce overgrazing and prevent rangeland from deteriorating. But is the quantity (and quality) of crop residues produced on fields enough to make up for the rangeland lost to establish these fields? Often, and especially during dry years, this is not possible. That’s where research comes in. Two key issues are improved use of crop residues, and development and promotion of new crops and varieties to meet feed/fodder requirements during the dry season.

    ICRISAT is a major partner in a newly established Regional Program for Crop-Livestock Systems Development, which aims to promote greater efficiency in crop-livestock systems in semi-arid regions through improved feed utilization. It is only through such a systems perspective – crops, livestock, rural welfare as a whole – that we can progress towards our ultimate goal of alleviating poverty in the semi-arid tropics.

    For more information contact a.vanrooyen@cgiar.org

    4. Forging Ahead with Forage Pearl Millet
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    Pearl millet (Pennisetum glaucum (L) R. Br.) is grown primarily for grain production in the semi-arid tropical regions of Asia and Africa. It is also valued for its stover for use as fodder  The fodder quality of the stover, however, is poor when compared to green forage.  Higher forage yield potential and crude protein content, greater water-use efficiency and drought and heat tolerance, and much fewer disease and insect pest problems make pearl millet a more valuable forage crop than other warm-season cereals.

    Based on multi-location performance of several varieties in the Initial and Advanced All India Coordinated Forage Trials conducted under rainfed conditions, pearl millet had 11-22% higher green forage yield and 21-31% higher dry forage yield than sorghum and maize. The trials also showed pearl millet dry forage having 8-9% crude protein (45-50% more than sorghum and maize).

    Pearl millet is much better adapted to acidic soils than other warm-season cereals. A partnership study with the International Center for Biosaline Agriculture showed that pearl millet is better adapted to saline soils as well, demonstrating its adaptability to stress environments with a wider range of pH values. Used as a summer season forage crop in rotation with wheat, pearl millet can utilize the residual nitrogen and reduce nitrate pollution of the water resources.In such crop rotation, it also reduces nematode problems in wheat.

    ICRISAT has recently incorporated genetic improvement of forage yield and quality in its pearl millet research agenda. Population progenies with high biomass yield are initially being used to develop open-pollinated varieties, but will also be more extensively tested for their hybrid yield potential.

    High-yielding experimental forage hybrid

    Preliminary results with experimental forage hybrids, based on male-sterile lines initially developed for breeding dual-purpose hybrids, have shown some of these having up to 5.0 t ha-1 dry forage yield (19% more than a released forage pearl millet hybrid Proagro No1 and 8% more than a commercial sorghum-sudan hybrid GK 908) at 50-day harvest, and 18.6 t ha-1 dry forage yield (144% more than Proagro No.1 and 41% more than GK 908) at 90-day harvest. The availability of an alternative A5 cytoplasmic-genic male-sterility (CMS) system, on which about 90% of the breeding lines work as maintainers, increases the prospects of genetic diversification of A-lines five-fold compared to the currently commercially A1 CMS system. The use of this new CMS system in breeding A-lines would substantially enhance the prospects of breeding high-yielding forage hybrids of pearl millet.

    For more information contact k.rai@cgiar.org