Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Drought english


Published on

Published in: Technology
  • Be the first to comment

  • Be the first to like this

Drought english

  1. 1. scw..ing1-3 Tolerance -- - 4 a iirouiht --u-- ---- e -yI I 1 11 Sugarcane Breeding lnstltuto (Indian Council of Agricultural Resemh) -I ~ t o r e - 6 4 l a n, ;~ I
  2. 2. ugarcane (Saccharurn spp.) is an important crop globally not only for sugar production, but also increasingly as a bioenergy crop due to its phenomenal dry matter production capacity. Drought is one of the mostimportant environmental stress limiting sugarcane production worldwide. Dueto the erratic nature of rainfall, sugarcane growers rely heavily on irrigation tomeet production goals. However, water for irrigation is a limited and continuousresource and its effective management is critical, not only in reducing wastefulusage, but also in reducing production costs and sustaining productivity. In viewof the sugar requirement of 27 million tonnes by the year 2020 and scope forfurther increase in area under sugarcane cultivation being limited the evolutionof drought resistant varieties has become a major research priority. Hence, eachyear advanced breeders materials are being evaluated in field condition with theobjective of identifyingresistant genotypes to drought.Critical phenological phase for water demand In sugarcane, four distinct growth stages have been characterized,namely: germination, tillering, grand growth and maturity. The tillering phase isknown as the formative phase and has been identified as the critical waterdemand period, mainly because during this phase maximum number of shootsare formed. In most of the sugarcane growing areas, the crop experiencesmoisture stress during the formative phase, affecting germination and tillering.As a result stalk population and stalk growth are reduced, resulting in 30-50%yield loss. Varieties response to water deficit stress during this growth stagecould therefore be useful in identlfyrng drought tolerant genotypes.Screening methodology fBt drought tolcmce: in field Field experiments were conducted in split plot design with control andmoisture stress treatment as main plot and genotypes as sub plot (in replicated .id) to evaluate the elite breeders materials (lVT/AVT genotypes) for drought osed from 60 to 150 days of crop age olding irrigation in treatment plots (Fig.1). The lusion of border rows and a gap of 3 m treatment blocks (to minimize seepage effect). Soil
  3. 3. Rating for drought tolerance The harvest index proposed by Donald was used as one of the criteria toassess the potential yield and stability in different environments. The relativeperformance of the genotypes in terms of cane yield and sugar yield wasassessed by plotting the cane yield under drought treatment against yield undernormal condition. Similarly, for sugar yield also relative performance wasworked out. The graph was constructed in such a way that the plot area of thegraph was divided into four quadrants by dividing the X axis at the point of meancane yield under normal condition and Y axis at the point of mean cane yieldunder drought condition. Genotypeswith better cane and sugar yield in normalas well as drought treatment falling in quadrant- I were considered as toleranttypes; genotypes falling in quadrant I1 & 111 were considered as moderatelytolerant, while genotypes falling in N quadrant were considered as susceptibletypes.Sugarcane genotypes tolerant to drought Varieties CoC 671, Co 8208, Co 85007, Co 85004, Co 86032, Co 85019and Co 87263 are suitable for water limited condition. AVT clones screenedduring 2004 (Co 99004- Damodar) and 2006 (Co 2001-13 (Sulabh) and Co2001-15 (Mangal) were recently released for peninsular zone (Fig. 2). Newpromising drought tolerant genotypes also have been identified (Table 1). Table 1. Drought tolerant aenatvws VSI
  4. 4. Drought tolcmt wlctles