Sodicity is a major factor affects crop growth and productivity at global level. Out of 1.5 billion ha of cultivable land at global level, 23% are affected due to salinity and 37% by sodicity. Fourteen Big onion varieties were screened by employing germination test in an osmatic solution of Na2CO3 (Sodium bicarbonate).Simultaneously, all the varieties were allowed to germinate in distilled water (control).Three Replications of 20 seeds of each variety were counted and distributed over two layers of paper towel (21x21 cm) previously moistened with water equivalent to three times the dry weight of the paper and tied both ends with rubber band and kept in a plastic tray with different concentrations ( 0, 25mM, 50mM, 75mM, 100 M ) of Na2CO3. At the end of the 21st day, final germination percent, root length, shoot length, root dry weight, shoot weight, Relative water content and membrane stability index, were recorded in Na2CO3 solution as against the distilled water was calculated. The experiment was designed as a completely randomized design with two factors.  As a result a decline in all onion growth paramers, with increasing sodicity stress has been recorded. Significant differences were observed between the varieties and different Na2CO3 concentrations. Irrespective of Na2CO3 concentrations, Bhima Safed recorded significantly maximum stress tolerant index compared to other varieties and minimum stress tolerant index value recorded bhima red variety. Based on stress tolerant index, Bhima safed variety tolerant to sodicity stress and Bhima red variety sensitive to sodicity stress.

Iron (Fe) deficiency is a major nutritional disorder in crops growing in calcareous soils. Varagu crop are more susceptible to (Fe) deficiency in the early stage of growth and the deficiency is exhibited as chlorosis developing interveinally in the new leaves.  The objective of the present study was to see the impact of different levels iron on mitigation of chlorosis in varagu, Paspalum scrobiculatum under calcareous soil and to investigate the influence of soil and foliar application of iron on growth, physiological and improvement of yield potential of varagu under calcareous soil condition. The varagu variety CO3 taken for this study The treatments comprised T1, NPK (44:22:0 kg ha-1) + 12.5 t  FYM/ha,T2, NPK (44:22:30 kg ha-1) +12.5 t FYM/ha, T3, T1 + Soil application of FeSO4   (25 kg ha-1), T4, T2 + Soil application of FeSO4 (25 kg ha-1), T5, T1 + Soil application of FeSO4 (50 kg ha-1), T6, T2 + Soil application of FeSO4 (50 kg ha-1), T7, T3 + Foliar spray of 0.5% FeSO4, T8, T4 + Foliar spray of 0.5% FeSO4, T9,T5 + Foliar spray of 0.5% FeSO4, T10,  T6 + Foliar spray of 0.5% FeSO4. During experimentation, morphological characteristics, growth attributes, physiological and biochemical components and biomass traits determined the mitigation of iron chlorosis. The iron deficiency in varagu was effectively controlled by T10, soil treatment 50 kg ha-1 FeSO4 and foliar spray of 0.5% FeSO4 applied on the 30th and 50th days after sowing through maintaining highest growth parameter values, maximum catalase and peroxidase activity and maintaining more chlorophyll content.

Sodicity is a major factor affects crop growth and productivity at global level. In the cultivablel and at global level, 23% is affected by salinity and 37% land by sodicity. Two seed propagating aggregatum onion varieties (CO 5, CO 6) and two bulb propagating aggregatum onion varieties (Permbalurlocal, thuraiyurlocal) were screened by employing germination test in an osmatic solution of NaHCO3 (Sodium bicorbanate). Three Replications of 20 seeds of each variety were counted and distributed over two layers of paper towel (21x21 cm) previously moistened with water equivalent to three times the dry weight of the paper and tied both ends with rubber band and kept in a plastic tray with different concentrations (0, 10 mM, 20 mM, 30 mM, 40 mM, 50 mM) of NaHCO3 (sodium bicorbanate). Also another bulb propagated varieties, perambalur and thuraiyur local varieties bulb directly sown in beaker have 1.5 kg sand. Control beaker irrigated with only water and other beakers irrigated with different concentrations (25 mM, 50 mM, 75 mM and 100 mM) of sodium bicarbonate solution. Germination percentage was recorded 7 days after. At the end of the 21th day,in four aggregatumonion varieties where final germination per cent, root length, shootlength, vigourindex, stresstolerant index, relative water content and membrane stability index, were recorded in NaHCO3 solution as against the distilled water was calculated. The experiment was designed as a completely randomized design with two factors. As a result a decline in all onion growth paramers, with increasing sodicity stress has been recorded. Significant differences were observed betweenthe varieties and different NaHCO3 concentrations. Irrespective of NaHCO3 concentrations two seed propagating aggregatum onion varieties, CO 6 recorded significantly maximum stress tolerant indexcompare with CO 5 and two bulb propagating aggregatum onion varieties, Thuraiyur local variety recorded significantly maximum stress tolerant index compare with Perambalur local in all sodicity concentation. Based on stress tolerant index, CO 6 and thuraiyur local variety tolerant to sodicity stress and CO5, perambalurlocal variety susceptible to sodicity stress.

An experiment was made to standardize the radicle emergence test to predict the field emergence performance in ten different seed lots [L1 to L4: high vigour lots (> 90 % germination), L5 to L7: medium vigour lots (80-90 % germination) and L8 to L10: low vigour lots (< 80 % germination)] of rice cv. CO 51. The results showed that the significant differences are observed in physiological and biochemical parameters in different seed lots. The seed vigour was classified into three groups viz., high, medium and low vigour based on the relationship between mean germination time and field emergence. When the Mean Germination Time (MGT) was < 34 hours, the field emergence was > 85 per cent, which was considered as high vigour; when the MGT was 34-35 hours, the field emergence was 80-85 per cent, that was considered as medium vigour; when the MGT was > 35 hours, the field emergence was < 80 per cent, that was considered as low vigour. The radicle emergence test (2mm radicle length) was highly negatively correlated with mean germination time (-0.930**) followed by mean just germination time (-0.852**) and electrical conductivity of seed leachate (-0.827**) and it was positively correlated with field emergence (0.894**) followed by germination (0.878**) and dehydrogenase activity (0.864**). The R2 values between seed vigour parameters and radicle emergence test were significantly higher in 2mm length of radicle emergence when compared with 1mm length of radicle emergence. Finally, the study concluded that 36 hour MGT with the attainment of 2mm radicle emergence percentage could be used as a quick method to assess rice seed lots' quality by the seed analysts and seed industry.

Abstract:Seed grading is an important practice for better crop establishment and to improve efficiency of planting ratio in field and also useful in separation of quality seed in a seed lot. The influence of seed size on physiological and biochemical seed quality characters were evaluated in Tephrosia seeds using seeds retained on 5.5/64″, 6/64″ and 7/64″ sieves along with control. The estimations revealed that larger size seeds retained on 7/64" sieves recorded the maximum recovery (64 %), 100 seed weight (2.0 g), speed of germination (14.1) germination ( 86 %), root length (8.5 cm), shoot length (11.0 cm), dry matter production (15.92 mg seedlings -10 ), vigour index (1677) and protein (10.56 %) compared to BSS 5.5 / 64'', BSS 6 / 64'' and ungraded seeds.