Effect of elevated CO2 and temperature on crop growth and yield attributes of bell pepper (Capsicum annuum L.)

Investigations were carried out during 2014 and 2015 to study the effect of elevated CO2 and temperature on growth and yield contributing parameters of bell pepper (Capsicum annuum L.) under open top chamber (OTC) at research farm of Department of Environmental Science, Dr Y.S. Parmar UHF, Nauni, Solan, Himachal Pradesh with four treatments [T1(eCO2): OTC with elevated CO2 550±10 ppm; T2(eT & eCO2): elevated temperature by 1°C and elevated CO2 550±10 ppm; T3(aT & aCO2): ambient temperature and CO2 and T4: natural condition] and each treatment had two varieties (California Wonder and Solan Bharpur) of bell pepper which were replicated thrice. Results revealed that bell pepper recorded maximum plant height, leaf area, yield attributes under eCO2 which were significantly higher than all other treatments. However, the harvest duration and days to first harvest was lowest under eCO2. Higherfruit size as well as fruit weight was recorded with eCO2 followed by eT and eCO2, aT and aCO2 and open natural condition. But maximum number of fruits and highest fruit yield was obtained with natural condition which was significantly superior over eCO2 as well as over eT and eCO2 because increase in temperature negated fruit set due to less pollen viability under eCO2 and eT & eCO2 as compared to open. In open natural conditions due to higher pollen viability and more fruit setting as compared to higher CO2 andtemperature conditions, it resulted more yield. Solan Bharpur recorded higher total fruit yield (800.2 g plant-1) than California Wonder (399.1 g plant-1). Elevated CO2 has positive effect on plant growth and yield attributes in both cultivars of bell pepper. However, under interactive effect of elevated CO2 and elevated temperature, rising temperature negated the positive effects of elevated CO2 on crop production.

Effect of elevated CO2 and temperature on growth and yield contributing parameters of pea (Pisum sativum L.) crop

An experiment was conducted during 2014 and 2015 at Solan, Himachal Pradesh to study the effect of elevated CO2 (eCO2) and temperature (eT) on growth and yield contributing parameters of pea (Pisum sativum L.) crop under four conditions of CO2 and temperature in open top chambers and open natural condition. The study revealed that pea plants performed better under eCO2, with slight changes in development and yield attributing traits, depending on the cultivars. However, the beneficial direct impactof elevated CO2 (eCO2) on crop yield can counteract by elevated temperature (eT). Pooled data for two years indicated that growth and yield attributing traits like plant height, days to first harvest of pods, harvest duration, fresh weight and biomass, number of pods per plant, pod length, pod girth, pod yield were improved under eCO2. However, responses of these attributes were negated with eT. Pea cultivars PB-89 performed well under eCO2 and eT conditions as compared to Azad P-1.

Effect of elevated CO2 and temperature on growth and yield of winter rice under Jorhat condition

A pot experiment was conducted during kharif, 2018 inside CO2 Temperature Gradient Tunnels (CTGT) to assess the effect of elevated CO2 and temperature [T0: ambient temperature & ambient CO2, T1: elevated temperature (ambient +1°C) & elevated CO2 (ambient+25% of ambient) and T2: elevated temperature (ambient +2°C) & elevated CO2 (ambient + 50% of ambient)] under three different transplanting dates (D1: 25th June, D2: 10th July and D3: 25th July) on growth and yield of rice in Jorhat district of Assam. The result showed that occurrence of different phenological stages was earlier under elevated CO2-Temperature conditions resulting in reduction of crop duration by about 8-15 days. On the other hand,days to tiller initiation increased whereas days to panicle initiation, flowering and physiological maturity reduced with delay in transplanting. Yield attributing parameters were improved under elevated CO2-Temperature condition. With respect to dates of transplanting, D2 recorded higher number of panicles hill-1 (17.9) and higher filled grains panicle-1 (156.6). Higher grain yield (55.9g hill-1) was found under T2 which was at par with T1 and it was significant higher over the ambient. Grain yield was significantly reduced when transplanting was delayed after 10th July. The results revealed that the growth and yield of rice was found to be better under elevated CO2-temperature levels when transplanted on 10th July.

Elevated CO2 and Temperature Resetting the Expression of Resistance, Pest Incidence, Geographical Distribution and Physiology in Insect-pests of Grain Legumes: A Review

The most important factor that affects the crop production in terms of nutritional content of foliar plants is the global climate change. Herbivore’s growth, development, survival and geographical distribution all are determined by elevated CO2 and temperature. The interactions between herbivores and plants have changed due to increasing level of CO2 and temperature. The effect of high CO2 and temperature on grain legume plant which change in to plant physiology (e.g., nutritional content, foliage biomass) and how it change in herbivory metabolism rate and food consumption rate. Plant injury is determined by two factors viz. resistance and tolerance and both are influenced by greater CO2 and temperature. Legumes are an important source of food and feed in the form of proteins and also improve the soil environment. The repercussions of the abiotic factors mentioned above needs discussion among the scientific community. We may able to limit the negative repercussions of stated factors in future breeding projects by harnessing the practical favourable impacts and by including such influences of elevated CO2 and temperature on pulses productivity. The extensive research is necessary to overcome the negative effects of high CO2 and temperature on insect-plant interaction.

Study of physiological responses of Allium sativum to elevated CO2 and temperature

Aim: The present investigation was undertaken to study the response of some garlic varieties of Allium sativum under different ambient and elevated CO2 and temperature conditions in order to investigate the physiological responses under changing climatic condition. Methodology: A two factorial CRD experiment was conducted for two years with four varieties of Allium sativum (Ekfutia Assam, Assam Local, Bhima Omkar and Bhima Purple) under four atmospheric regimes [T1= Ambient CO2 and temperature; T2= Carbon dioxide Temperature Gradient Tunnel-I (400 ppm CO2 + 2oC higher than ambient); T3 = Carbon dioxide Temperature Gradient Tunnel-II (550 ppm CO2 + 4oC higher than ambient); T4 = Carbon dioxide Temperature Gradient Tunnel-III (700 ppm CO2 + 6oC higher than ambient)]. Major changes in physiological parameters of the varieties were recorded in Carbon dioxide Temperature Gradient Tunnel-II as compared to ambient condition. The rate of photosynthesis was measured on fully expanded youngest leaves of each sample plant using a portable Infrared Gas Analyzer. Results: The mean photosynthetic rate of all four varieties grown over two years was 13.43% higher in Carbon dioxide Temperature Gradient Tunnel-II over varieties grown for two consecutive years under Ambient CO2 and temperature. However, high CO2 concentration and temperature stress significantly reduced the stomatal conductance approximately by 27.48%. Interpretation: The results of this study gives a comprehensive analysis of garlic varieties under four different climatic conditions of CO2 and temperature and revealed that Ekfutia Assam and Assam Local and garlic varieties Bhima Omkar and Bhima Purple were promising varieties as they responded significantly to elevated CO2 and temperature regimes. This may provide some critical inputs for optimizing the strategies in future farming and farming opportunities of this commercially and medicinally important crop under changing climatic conditions.

Elevated CO2 and temperature effect on growth and physiology of Chenopodium album L.

A study was conducted in open top chambers (OTCs) to understand the effect of elevated temperature (ambient+2±0.5oC) and elevated CO2 (550±50 ppm) individually and in combination on Chenopodium album. Impact of the climate variables was studied in terms of selected plant attributes, viz., leaf area, RGR etc. Study showed that elevated temperature as well as elevated CO2 individually and in combination had significant positive effect on growth and development, rate of photosynthesis, and water use efficiency of the Chenopodium album. Rate of transpiration and stomatal conductance increased marginally in plants grown at elevated temperature, but a marked decrease was evident at elevated CO2 individually and in combination with elevated temperature as compared that in plants grown in ambient conditions in the Chenopodium album. No significant changes were observed in relative water content and relative stress injury under any of the Chenopodium album. Treatments changes were evident with respect to the activity of antioxidant enzymes and nitrate reductase and peptide banding pattern using SDS-PAGE. This research was conducted to examine the joint effects of increased temperature and elevated CO2 level onChenopodium album (C3 weed). Results from this experiment suggested that rising (CO2) could alter physiochemical response for growth and development of Chenopodium album and it is well defined competitors with different crops in current changing climate conditions.

Response of soybean genotypes to iron limiting stress in calcareous vertisol under ambient and elevated CO2 and temperature conditions

Aim: To compare the relative performance of two contrasting genotypes of soybean to iron limiting conditions under ambient and elevated CO2 and temperature conditions. Methodology: A pot culture experiment was performed using calcareous vertisol soil. The environmental factors viz. CO2 and temperature were combined and applied as a single factor with two levels: a-[CO2+T] (400±10 µmol mol-1, day/night temperature 30oC/22oC) and e-[CO2+T] (610±10 µmol mol-1, day/night temperature 34oC/26oC). Soybean genotype that differed in iron use efficiency was used as another factor and two contrasting genotypes were used as two levels viz. iron efficient and responsive (FeER) and iron inefficient and responsive (FeIR). Results: The higher partial pressure of CO2 under elevated carbon dioxide and temperature condition (Pco2 = 61.8 Pa) dissolved the native CaCO3 from calcareous vertisol soil and thereby resulted in higher HCO3- ion concentration. The antagonistic interaction between Fe2+ with HCO3- ion resulted in greater iron stress. As compared to ambient condition, seed yield was significantly reduced under more stressed e-[CO2+T] condition and resulted in ~1.4 and ~1.9 times drop in FeER and FeIR genotypes, respectively. Iron efficient and responsive (FeER) genotype recorded an impressive performance, as compared to the iron inefficient and responsive (FeIR) genotype, in counteracting iron deficiency stress, both under ambient and elevated conditions. Interpretation: The intra-specific variability between soybean genotypes and their response to elevated CO2 and temperature can be exploited to remediate the emerging iron deficiency stress in soybean plants and suggest ways to structure the future breeding programmes to adapt to the climate change. Key words: Calcareous vertisol, Chlorosis, Climate change, CO2, Soybean