EFFECT OF FOLIAR APPLICATION OF AMINOACIDS ON PLANT YIELD AND SOME PHYSIOLOGICAL PARAMETERS IN BEAN PLANTS IRRIGATED WITH SEAWATER

With increasing demand for irrigation water, alternative sources are being sought. Seawater (saline water) was previously considered unusable for irrigation. However, this water can be used successfully to grow crops under certain conditions. Plants growing in saline stress face three main problems: High salt concentrations in the soil solution (that is, high osmotic pressure and correspondingly, low soil water potential ‘‘drought stress’’), high concentrations of potentially toxic ions (such as Na+ and Cl-), and nutrient imbalance as a result of depressed uptake, impaired internal distribution and shoot transport of minerals. Foliar spraying treatment of plants with naturally occurring compounds in plant cells is an easy technique and an alternative approach used to overcome salinity problems.

Plants are continuously exposed to biotic and abioticstresses. Salt stress is one of the most severe abiotic stresses limiting plant productivity. If excessive amounts of salt enter the plant, eventually rise to toxic levels in the older transpiring leaves, causing premature senescence, and reduces the photosynthetic leaf area of the plant to a level that cannot sustain growth. Salt stress that leads to both the decrease of the substrate osmotic potential and ion-special toxicity affects almost every aspect of the physiology and biochemistry of plants. Salinity reduces stomatal conductance greatly and consequently reduces photosynthetic rate. However, the inhibition of photosynthetic rate imposed by stomatal closure may promote an imbalance between photochemical activity at photosystem II (PSII) and electron requirement for photosynthesis, leading to excess excitation and subsequent photoinhibitory damage of PSII reaction centers. Differences in the accumulation patterns of Na+ and K+ were found under salinity stress.

Result 

Data in Table 2 clearly show that, growth parameters (shoot length, leaf number per plant, shoot fresh and dry weights) were reduced gradually and significantly with increasing salinity levels in faba bean plant in the two seasons SI and SII. Amino acid treatments caused stimulatory effects on such parameters under both saline and non-saline (control) conditions. Amino acid treatments alleviated the inhibitory effect of salt stress on the above mentioned parameters. Table 2 also shows an increased stimulation response of amino acid with increasing concentration in both seasons.

Reference

ABDELHAMID, M., SH SADAK, M. and SCHMIDHALTER, U., 2014. EFFECT OF FOLIAR APPLICATION OF AMINOACIDS ON PLANT YIELD AND PHYSIOLOGICAL PARAMETERS IN BEAN PLANTS IRRIGATED WITH SEAWATER. Acta Biológica Colombiana, 20(1), pp.140-152.