Effect of NaCl Salinity on Various Parameters of Seed Germination of Cashew Nut (Anacardium occidentale L.)

Abstract

Cashew (Anacardium occidentale L.) is an economically important fruit crop. About 50 years ago, the tree species was introduced in the hilly areas of Bangladesh. But, its potentiality to grow in the southern saline prone coastal plains had never been explored. Assessment of salt stress tolerance is a vital observation to introduce any new crop in the salt-affected areas. Thus, an experiment was conducted under laboratory and shade house conditions to observe the effect of salinity on different germination parameters of cashew nut. Cashew seed nuts were subjected to five concentrations of NaCl solutions, viz., 0 (control), 5, 10, 15 and 20 ppt. The experiment was laid out in completely randomized design (CRD) with five replications. The germination parameters such as germination initiation time, last day of germination, germination duration, germination (%), mean germination time, mean germination ratio, uncertainty of germination process, synchronization index, germination index, coefficient of velocity of germination, time to 50% germination were studied. Results of the experiment revealed that most of the parameters were negatively influenced with the increase in NaCl salinity; germination (%) was higher in 0 ppt (91 ± 4%), followed by 5, 10, 15 ppt, and no seed germination was observed in 20 ppt salinity. Germination initiation time, germination duration, germination (%), mean germination ratio, uncertainty, germination index, coefficient of velocity of germination of cashew nut varied significantly with the increasing salinity. Germination (%), mean germination ratio, uncertainty, germination index, coefficient of velocity of germination of cashew nut had a significant negative correlation with NaCl salinity, whereas mean germination time and time to 50% germination had a positive significant correlation with NaCl salinity. In this study, only one genotype had been used, and in the future, studies with other genotypes are suggested for further extension of knowledge in this regard.