The response of blackgram (Vigna mungo L. Hepper) to two levels of elevated carbon dioxide (550 and 700 ppm) in terms of growth and yield was investigated and compared with ambient CO 2 level (365 ppm) using open-top chambers. The growth parameters viz., length and weight of root and shoot, root:shoot ratio, leaf area and weight significantly increased at 700 ppm CO 2 when compared with 550 ppm. The percentage increase in total biomass at 700 and 550 ppm CO 2 was 65.4% and 39%, respectively compared to the ambient (chamber) control. The increase in total seed yield at 700 ppm (129%) was due to an increase in number of pods per plant and 100 seed weight, whereas at 550 ppm (88.7%) it was due to an increased number of pods/plant and seeds/pod. The results indicate variable responsive effects at different levels of CO 2 emphasizing the pertinence of research on elevated CO 2 in various agroecological inhabitations all over the world. The indication of higher responses for root and leaf at initial growth stages at the higher elevated level of CO 2 (700 ppm), which leads to better root establishment, achieving early photosynthetic efficiency and also better biomass production, and its improved partitioning can be reckoned as a positive aspect of increasing concentrations of CO 2 in atmosphere. The harvest index increased significantly to 35.7 and 38.4% at 550 and 700 ppm, respectively; it is a very important phenomenon in pulses for breaking the yield barrier.

Growth and yield responses of castor bean (Ricinus communis L.) to two elevated CO 2 levels (550 and 700 ppm) were evaluated up to the maturity of first order spikes in open top chambers (OTCs). The growth characteristics -root and shoot lengths, root volume, root:shoot ratios, leaf area, dry weights of different plant parts, leaf area duration and crop growth rate increased with 550 and 700 ppm of CO 2 levels compared with ambient control. The spike length, pod and seed yield of first order spikes increased under enhanced CO 2 levels over ambient control. Elevated CO 2 levels significantly increased the total biomass and yield of castor bean, however enhanced CO 2 levels per se did not changed the content and quality of the castor oil. A positive response of castor bean to increased CO 2 concentrations is a good indication for its future existence in potentially changed climatic conditions.

An attempt was made to understand the interactive effect of the elevated CO 2 and moisture stress on germination and initial growth responses of blackgarm (Vigna mungo L. Hepper). Four open top chambers (OTCs) were used for different conditions: irrigated with ambient CO 2 (365 ppm), irrigated with elevated CO 2 (600 ppm), moisture stress with ambient CO 2 and moisture stress with elevated CO 2 . The percentage of germination, germination speed, emergence index, and vigor index were measured on the 5 th and 6 th day after sowing (DAS). Plants were harvested at different time intervals, i.e. on 7, 14, 21 and 28 DAS; leaf area and dry weights of the seedlings were recorded. It was observed that moisture stress in general reduced the germination in all the conditions and affected seedling growth of blackgram. Germination percentage, emergence index, germination speed and vigor index were increased with elevated CO 2 under both irrigated and moisture stress conditions. Plants grown with elevated CO 2 were taller and attained a greater leaf area along with more biomass than ambient CO 2 levels under irrigated and moisture stress conditions at all time intervals. The increase in the germination, larger leaf area and dry matter of root, shoot and leaf proved that CO 2 enrichment of the atmosphere will be beneficial for the crops for better establishment and greater productivity.

The present study was conducted at Banana Research Station, Kannara, Kerala Agricultural University Thrissur, Kerala, India during 2017-2018. Evaluation was conducted by raising the crop under different manurial combinations. Banana yield and fruit quality characters were found to be influenced by the different treatments. Analysis was conducted for the biochemical constituents of mature and ripe Nendran banana fruits. Maximum starch (99.61 mg), protein (5.53 mg), crude fibre (3.95%) and tannin content (0.81 g) in mature fruits were obtained in Treatment-8 (FYM @ 29 kg, lime @ 0.5 kg and wood ash @ 4 kg plant-1 as basal dose+fertigation with extract of 14 kg FYM till one month after bunch emergence, once in four days+in situ green manuring). This treatment also recorded lowest titrable acidity (0.38%), highest β-carotene content (595.67 µg) in ripe banana fruits. Maximum TSS content (26.23 obrix) was obtained in Treatment-6 in which fertilizers applied as modified package of practices (POP) recommendation of KAU as per soil test). Maximum yield (160.88 kg plot-1) and fruit quality parameters; maximum total sugars (17.55%) and reducing sugars (11.38%), sugars/acid ratio (45.07) of ripe banana fruits were obtained in Treatment-3 where 15 kg FYM and 0.5 kg lime as basal+Poultry manure @ 14 kg plant-1+ash @ 4 kg plant-1 applied in two splits i.e. one as basal and one 3 MAP+in situ green manuring practised. It was evident from the study that application of organic manures improved fruit quality characters in Nendran banana.

Background: Chlorophyll is a green molecule found in plant cells that aids photosynthesis. It absorbs sunlight and converts the energy into carbohydrates using CO2 and water as a starting point. Chlorophyll ‘a’ and chlorophyll ‘b’ are the two forms of chlorophyll found in plants and each serves as a photoreceptor in photosynthesis, assuming higher electron transport, thus improving photochemical capacity. Methods: The present study was conducted at Banana Research Station, Kannara, Kerala Agricultural University, Thrissur, Kerala during 2017-2018 to elucidate the response of banana Musa (AAB) ‘Nendran’ in terms of growth, yield and quality to nutrient sources.Variation in leaf parameters, phyllochron and chlorophyll content in leaf tissue of banana raised with different nutrient sources was analysed. The amount of chlorophyll present in the leaves, is an indication of photosynthetic efficiency. Result: Highest Leaf Area Index (2.34) were recorded in T4 (integrated use of organic manures with biofertilzers practised). Highest amount of chlorophyll ‘a’ (1.20 mg), chlorophyll ‘b’ (1.62 mg), total chlorophyll (2.82 mg) and lowest phyllochron (7.33) were obtained in T8 (Fertigation with organic sources FYM @29 kg, lime @0.5 kg and wood ash @4 kg as basal; fertigation once in four days with 14 kg FYM till one month after bunch emergence+ in situ green manuring) which was followed T3 (POP recommendation of KAU with organic manures FYM @15kg + lime @0.5 kg as basal + Poultry manure @ 14 kg/plant + Wood ash @4kg/plant applied in two splits i.e. one as basal and one 3 MAP + in situ green manuring) at 150 days after planting. The results indicated that the manuring Nendran banana with organic manures had advantage over chemical fertilizers in term of chlorophyll production and increase in photosynthetic efficiency.