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Geetha P.,ICAR Sugarcane Breeding Institute | Velayutham A.,Tamil Nadu Agricultural University
Indian Journal of Agricultural Research | Year: 2016

An investigation was carried out to fine tune nutrient management techniques for improving the yield of rice fallow blackgram at the Wetlands of Tamil Nadu Agricultural University, Coimbatore in a split plot design. Three fertilizer application practices viz. recommended dose of fertilizer to preceding rice crop, recommended dose of fertilizer (last split through DAP based on N equivalent) to the preceding rice crop and basal application of fertilizer to blackgram of N and P2O5 @ 12.5:25 kg ha-1 (10 days prior to harvest of rice crop) formed the main plot treatments and foliar sprays viz., control, 1% urea, 2% DAP, 1% KCl and 2% DAP + 1% KCl twice at flowering and pod filling stages of crop growth constituted the subplot treatments. The treatments were replicated thrice. The results revealed that basal application of N and P2O5 fertilizers @ 12.5:25 kg ha-1 (10 days prior to harvest of rice crop) to blackgram favoured the nutrient uptake. Similarly the NPK uptake at harvest (64.64, 6.75 and 46.51 kg ha-1) and yield (1037 kg ha-1) were significantly influenced when foliar spray of 2% DAP + 1% KCl was given at flowering and pod filling stages of crop growth. Interaction between basal application of fertilizer N and P2O5 @ 12.5:25 kg ha-1 just before the harvesting of preceding rice crop along with foliar spray of 2% DAP + 1% KCl twice at flowering and pod filling stages was significant for NPK uptake, yield attributes and yield.

Viswanathan R.,ICAR Sugarcane Breeding Institute
Sugar Tech | Year: 2016

Vegetative propagation in sugarcane favours accumulation of pathogens inside the canes and carryover of pathogenic inoculum through planting materials. Except foliar diseases, disease-infected setts serve as a primary source for disease spread for most of the diseases in the crop. In case of fungal diseases, planting infected setts leads to disease builds up in plant crop and probably death of the affected clump. However, in case of non-fungal diseases continuous accumulation of pathogens systemically leads to loss of vigour in sugarcane varieties referred to as ‘varietal degeneration’ and this results in loss of yield potential in elite commercial varieties. Past decades witnessed many such instances of degeneration in popular sugarcane varieties and their replacement with new varieties. With the development of precise molecular diagnostic tools, the associated pathogens were precisely identified. Under Indian conditions, it was found that combined or separate infections of viruses causing mosaic and yellow leaf (YL), phytoplasmas causing grassy shoot and leaf yellows and bacterium causing ratoon stunting disease are associated with varietal degeneration. The degeneration was rapid and severe when all these pathogens infect sugarcane together as compared to their separate infections. However, among all these diseases, YL contributes more towards degeneration of sugarcane varieties. The disease occurrence to epidemic levels in different states is a serious concern for sugar industry and due to that longevity of the affected varieties in the field is threatened. Meristem-tip culture combined with molecular diagnosis was found effective eliminate the pathogens efficiently from the cane. Developing disease-free nurseries is imperative to sustain productivity of sugarcane and to realize yield potential of popular sugarcane varieties in India. © 2015, Society for Sugar Research & Promotion.

In India, red rot caused by Colletotrichum falcatum exhibits enormous variation in pathogenicity on sugarcane. The new cultivars released for commercial cultivation succumb to new pathotypes of the pathogen after some years in disease endemic regions. Due to the variability in C. falcatum, screening for red rot resistance in sugarcane progenies is being taken up with designated pathotype(s) separately for each agroclimatic regions in the country. The predominant C. falcatum pathotype of tropical India Cf671 (CF06) isolated from the then ruling cultivar CoC 671 is being used in tropical regions for disease screening. However, recently the pathotype has exhibited a reduced virulence on new cultivars and that has resulted in inconsistencies in disease reaction between artificial testing and field reaction under natural conditions. Hence, a detailed study was conducted during the past seven seasons on its pathogenicity on a set of 32 cultivars varying in red rot resistance in comparison with a new pathotype Cf94012 isolated from the cultivar Co 94012. The resistant cultivars such as BO 91, CoS 8436 and Co 98010 exhibited resistance reaction to both the pathotypes. However, other resistant cultivars such as Co 94008, Co 99006, Co 2001-15, Co 0238 and CoV 92102 showed a shift in their reaction to the new pathotype Cf94012 as moderately susceptible (MS) or susceptible (S) from resistant (R)/moderately resistant (MR) reactions in case of Cf671. Further, disease reaction on eight cultivars with MS behaviour and 11 susceptible cultivars clearly revealed a higher virulence of Cf94012 as compared to Cf671. Overall, the pathogenic behaviour of the two pathotypes during seven seasons revealed a higher virulence of Cf94012 as compared to Cf671 on resistant, moderately susceptible and susceptible cultivars. Although the pathotype Cf671 remained virulent on its host cultivar CoC 671, it could not exhibit such virulence on the cultivars developed in the recent years. Further, the study revealed that once a popular cultivar is removed from cultivation as in the case of CoC 671, the pathotype adapted to it no longer maintains its virulence, whereas the recently originated pathotype exhibits a higher virulence on the new cultivars of the host. This study also suggests adaptation of C. falcatum to the host cultivars. © 2016 Society for Sugar Research & Promotion

Prasad I.,Indian Central Soil Salinity Research Institute | Kulshreshtha N.,ICAR Sugarcane Breeding Institute | Chinchmalatpure A.R.,Indian Central Soil Salinity Research Institute | Sharma D.K.,Indian Central Soil Salinity Research Institute
Cereal Research Communications | Year: 2016

Soil salinity is one of the major environmental constraints in increasing agricultural crop production, especially wheat production in India. Screening of diverse germplasm in representative growing conditions is prerequisite for exploring traits with stable expression imparting salinity tolerance. A study was undertaken during 2011-2012 for characterizing wheat germplasm in three environments representing growing conditions of crop in Northern parts of India, estimating inter-relationship among traits and evaluating stability of trait conferring salinity tolerance. Significant value of mean square for observed trait across the environments signified presence of large variability in genotypes. Significant yield reduction was recorded in almost all genotypes in saline environment compared to non-saline condition. Ratio of potassium and sodium ion in leaf tissue (KNA); a key salt tolerance traits was found to be significantly correlated with biomass, SPAD value and plant height. Due to the presence of significant genotype × environment interaction (G × E) for KNA, additive main effect and multiplicative interaction (AMMI) model was utilized to study stability of KNA among genotypes and environments. IPCA1 and IPCA2 were found to be significant and explained more than 99 per cent of variation due to G × E. KRICHAUFF was having maximum trait value with specific adaptation while DUCULA 4 and KRL 19 were having general adaptability. AMMI2 biplot revealed high stability of Kharchia 65 and KRL 99 across environments. E1 (timely sown, non-saline soil) recorded maximum site mean while E2 (timely sown, sodic soil) was having minimum interaction with genotypes (AMMI1 = 1.383). Thus, our studies suggest that AMMI model is also useful for estimating adaptability of traits other than yield utilized for breeding salt tolerant wheat varieties. © 2016 Akadémiai Kiadó, Budapest.

Murali P.,ICAR Sugarcane Breeding Institute | Puthira Prathap D.,ICAR Sugarcane Breeding Institute
Sugar Tech | Year: 2016

Inefficiency in sugarcane production is one of the major factors hindering the exploitation of full potential of the improved technologies. The present study had estimated the technical efficiency of sugarcane farms in three different agro-climatic regions of Tamil Nadu, a constituent state of India, which has the highest cane productivity. The study was conducted on the basis of survey data collected from a random sample of 198 farm households during 2011–2013. A stochastic frontier production function was applied to ascertain the technical efficiency of individual farms and Garrett’s ranking technique was used for constraint analysis. The mean technical efficiency of sugarcane production was found to be 88, 80, 78 and 82 % in Western, Cauvery Delta, North-East Zones and pooled data as a whole, respectively. In the Cauvery Delta and North-Eastern Zones, the technical efficiency has indicated that sugarcane yield could be improved up to 20 and 23 % respectively, through better crop management practices. Our analysis also revealed that if the constraints such as non-availability of farm labourers, high wage rate, water scarcity, high price cost of fertilisers and low cane price are overcome, the technical efficiency of sugarcane farms is likely to be increased. Finally, the paper suggests suitable measures to improve the overall efficiency of the sugarcane farms to sustain sugarcane productivity. © 2016 Society for Sugar Research & Promotion

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