Investigation of plant hydraulic characteristics (water transport pathway through aquaporins/apoplast and root hydraulic conductivity) can be done on plants grown in hydroponics system. The advantage of the hydroponic system is that we have complete access to the root without interference of soil particles, and then a number of plant treatment can easily be applied to the root system. The hydroponic system has to be established with proper aeration (oil free compressor) facility.
To raise the crop for hydroponic system seeds should be treated with fungicide (to avoid fungal contamination) and sowing is done into sand saturated with nutrient solution. Rhizobium inoculum (Strain No: IC 2002) should be added to ensure proper root nodulation in legume crops. Around a week later seedlings are attached to the perforated thermocol sheet and laid over a plastic tub with hydroponic solution (cereals) or alternatively seedlings can be directly transfer to 250ml Erlenmeyer conical flask (legumes) containing nutrient solution (modified Hoagland’s solution). In the case of cereal crops seedlings from plastic tubs are transferred to 300ml Erlenmeyer conical flask containing nutrient solution optimally after 4th leaf stage. Seedlings should be transferred into the flasks carefully through the hole of a rubber stopper that fits tightly to the flask aperture and the hypocotyle is fixed with cotton to avoid the seedling from slipping through. Ideally, the glass flasks should be painted in two layers; first black to ensure darkness in the rooting medium and prevent the algae growth followed by a second layer of white paint to reflect the excess of sun rays and avoid over-heating of roots. Aeration needs to be continuously supplied to roots to avoid water-logging symptoms. Water needs to be refilled daily to compensate the losses of nutrient solution from the flasks through transpiration and the whole solution should be changed every few days.
The composition of the modified Hoagland’s solution for the legume crops (chickpea, groundnut, pigeon pea) is: MgSO4 (1mM), K2SO4 (0.92mM), CaCl2.2H2O (0.75mM), KH2PO4 (0.25mM), Fe-EDTA (0.04mM), Urea (5mM) and micronutrients [H3BO3 (2.4µM), MnSO4 (0.9µM), ZnSO4 (0.6µM), CuSO4 (0.62µM), Na2MoO4 (0.6µM)]. The composition of the solution for the cereal crops (pearl millet, sorghum, maize) is: MgSO4 (2.05mM), K2SO4 (1.25mM), CaCl2.2H2O (3.3mM), KH2PO4 (0.5mM), Fe-EDTA (0.04mM), Urea (5mM) and micronutrients [H3BO3 (4µM), MnSO4 (6.6µM), ZnSO4 (1.55µM), CuSO4 (1.55µM), CoSO4(0.12 µM) and Na2MoO4 (0.12µM)]. The pH of the nutrient solution has to be maintained between 6.0 and 6.2 (in the case of legumes, hydroponic solution can be buffered with a pinch of Ca2CO3 every time the nutrient solution is changed, in order to maintain pH at a neutral level).
For us gems means GEMS, or G*E*M*S (genotype by environment by management by society) interactions, i.e. the fact that crop yields results from complex biophysical interactions while acceptance depends on farmer/consumer preferences. This complexity becomes an opportunity when it is cracked into components that can be analysed, understood, predicted, and then used to prioritise research investments to maximise return. This is what we do, and this is when GEMS become gems!
For us gems means GEMS, or G*E*M*S (genotype by environment by management by society) interactions, i.e. the fact that crop yields results from complex biophysical interactions while acceptance depends on farmer/consumer preferences. This complexity becomes an opportunity when it is cracked into components that can be analyzed, understood, predicted, and then used to prioritize research investments to maximise return. This is what we do, and this is when GEMS become gems!
A crop performs in different ways in different sites, years and agronomic managements. These are called genotype-by-environment-by management(G*E*M) interactions, and they are a main challenge for breeders and agronomists. There is one more layer of interaction, even more complex: the society (S). Farmers and consumers have different desires, needs, expectations, and a cultivar that fits one may not fit the other (G*E*M*S interactions). The puzzle is complex and challenging but if its components are understood, specific interventions can be undertaken.For instance, breeding for a particular genotype (G, with particular physiological characteristics), for a particular environment (E, with a particular kind of drought pattern that requires a specific adaptive trait), in a particular management practice (M, for instance a sowing density, or a N fertilizer treatment), and targeted to particular farmer/consumer (S, for instance a genotype that produces a lot of rich stover for cattle ranchers) is the need of the hour.