V K Dua

Forecasting impact of climate change on potato productivity in West Bengal and adaptation strategies

The WOFOST crop growth simulation model was used to study the impact of climate change on potentialpotato productivity in West Bengal and also to devise management strategy to minimize the impact of climatechange through selection of suitable variety and shifting the date of planting. The study was carried out at 13locations in West Bengal. The simulation was done for baseline scenario and future climate scenario of 2020and 2055 for three potato cultivars, viz., Kufri Badshah (long duration), Kufri Jyoti (medium duration) and Kufri Pukhraj (short duration), for A1FI high emission scenario of temperature and CO2. Simulation revealed that although the increase in temperature is likely to reduce the yield by 8.8 to 10.1% in 2020 and 23.7 to 28.8% in2055, a corresponding increase in CO2 may increase the yields by 4.5 to 4.7% in 2020 and 19.2 to 20.5% in 2055. However, under the combined effect of CO2 and temperature, the highest decline of 6.1% in productivity of KufriPukhraj is expected followed by 5.9% in Kufri Jyoti and 5.1% Kufri Badshah in 2020, with corresponding figuresof 12.0, 10.5 and 8.8% in 2055. Results further revealed that the negative effect of climate change on potatoproductivity can be counter-balanced to some extent through change in date of planting and/or selection ofsuitable varieties, as it may bring down the reduction in yield from 5.7 to 1.5% in 2020 and 9.7 to 7.1% in 2055.

Application of QUEFTS Model for Site-Specific Nutrient Management of NPK in Sweet Potato (Ipomoea batatas L. Lam)

ABSTRACT Sweet potato productivity in India is either stagnated or lowering down over the past many years. The main reasons for low yield are conventional blanket recommendation of fertilizers, lower nutrient-use efficiency and imbalance in the use of fertilizers. Recommendation of major nutrients, nitrogen, phosphorus, and potassium (NPK), based on quantitative approaches will augment sweet potato production per unit area by increasing the nutrient-use efficiency. The present study calibrated the Quantitative Evaluation of Fertility of Tropical Soils (QUEFTS) model for the estimation of NPK requirements and fertilizers recommendations for different target yields of sweet potato. The QUEFTS basically works on the principle of NPK nutrient interactions and climate-adjusted yield potential of a region. Published data sets from several field experiments related to NPK carried out till date were collected to reflect the environment variability. The results of the present study showed that to produce one ton tuber, 16:6:18 kg N, P, and K, respectively, would be needed with the internal efficiencies of 61:167:57 kg tubers kg−1 NPK removed. The maximum accumulation and dilution (kg tuber kg−1 nutrient removed) of N (40, 80), P (96, 272), and K (30, 85) were also derived as standard parameters in QUEFTS for optimum fertilizer recommendation in tropical and subtropical regions of India. The observed yields of sweet potato with different amounts of nutrients were in agreement with the values predicted by the model. Therefore, it is utmost important to have the results of the study validated in major growing environments of India for fertilizer recommendation in sweet potato.

Site-specific nutrient requirements of NPK for potato (Solanum tuberosum L.) in Western Indo-gangetic plains of India based on QUEFTS

Abstract Potato productivity in India is static due to unbalanced use of nutrients and intensive cropping system. Nutrient use efficiency and yield can be increased by application of nutrients based on quantitative approaches. We calibrated the quantitative evaluation of fertility of tropical soils (QUEFTS) model for the estimation of NPK requirements for different targeted yields of potato. Published data sets were used to calibrate the model. The results of the study showed that to produce one ton of potato tubers, 18, 4, and 24 kg N, P, and K, respectively, would be needed with internal efficiencies of 55, 285, and 42 kg tuber dry yield/kg N, P, and K removed. The observed yields of potato with different amount of nutrients were in agreement with the values predicted by the model. Therefore, the QUEFTS model based NPK fertilizer recommendations can be adopted for site-specific nutrient management of potato.

Response of potato to elevated CO2 under short days: Growth, physiological parameters and tuber yield

An experiment was conducted at ICAR-Central Potato Research Station, Jalandhar during 2014–15 to studythe effect of elevated CO2 concentration (600 ppm) on the physiological parameters, growth and yield of potatounder short day conditions. Effects on plant growth and yield was positive with increased stem height (7.5%), stem numbers (18.9%), leaf area (19.4% at 70 DAP), photosynthesis (21% at 40 DAP) and total biomass product(14%). Tuber yield increased by 28% under CO2 enrichment. Although harvest index did not change, specificleaf area (−2.6%) and stomatal conductance (−19%) decreased under CO2 enrichment. The increase in biomass and tuber yield may be due to enhanced leaf area coupled with increased rate of photosynthesis.

Genomics Approaches for Improving Nitrogen Use Efficiency in Potato

Increasing global food production to feed rapidly growing populations where cultivable land area is limited is a serious challenge. Moreover, increasing production costs, with high fertilizer input costs, particularly using nitrogen (N), and degrading soil health are the major concerns when enhancing the sustainable agricultural food production. Potato, being the major non-cereal food crop globally, is a heavy N fertilizer feeder crop. In the past several agricultural best management practices have been discussed regarding N management in potato crop production through the intervention of agronomy and soil science. However, unlike the advances in other model plants and cereals, the application of molecular genomics tools is lacking in potato, hence it is not possible to enhance plant genetic potential with better nitrogen use efficiency (NUE). Better N-use efficient plants can be grown with less fertilizer input and also on poor soil. This chapter highlights the application of novel genomics tools to improve NUE in potato through the discovery of novel genes and markers for applications in molecular breeding methods and gene manipulation (transgenic) techniques.

Performance of Phosphobacteria on Phosphorus Economy and Net Return in Different Potato Growing Region of India

Field experiments were conducted at eleven centers of All India Coordinated Research Project on Potato located in different agro-climatic zones to investigate the role of phosphobacteria in P economy in potato crop during 2005–06 and 2006–07. Six treatments consisting of combinations of different levels of P as well as phosphobacteria (PSB) used in the study showed significant effect on yield of potato. At Kalyani, Chhindwara, Kota, Patna, Hassan and Ooty, recommended dose of NK + 75% P + PSB was statistically at par with recommended dose of NPK in term of total yield. At Bhubaneshwar, Dholi, Hisar, Deesa and Modipuram, 75% of fertilizer P + PSB either had no significant effect on potato tuber yield or reduced the yield marginally in two years of experimentations. Net returns with recommended NPK or 75% P + PSB showed the best results at most of the centers. The per cent saving of fertilizer P, calculated using quadratic model, was maximum for Hassan (43%). In general, use of PSB saved around 20 to 25% P, depending upon agro-ecological situations and soil conditions. However, at Bhubaneshwar, Kota and Dholi the saving being very meager was not economical. The results clearly indicate the role of PSB in saving fertilizer P across different agro-climatic zones, However, it also came out very clearly that effectiveness of the PSB depends on agro-ecological situations and soil conditions.