Two pots experiments were carried out at Experimental Station of Agricultural Botany Department, Faculty of
Agriculture, Moshtohor during 2020 and 2021 seasons on squash plant cv. Eskandarani. Seeds of squash were
soaked and foliar spray with calcium at 250 & 500mg/l, nano calcium at 50 & 100mg/l, phosphorus at 250 & 500
mg/l, nano phosphorus at 50&100 mg/l and distilled water (control) to evaluate the effect of treatments on
vegetative growth, photosynthetic pigments, anatomical characteristics (out-doors pot experiment) of squash plants
(Cucurbita pepo L.) grown under natural cold stress conditions. Foliar application of squash plants with the
previous treatments gave the highest values of vegetative growth of roots (size, length, diameter, fresh and dry
weights), stems (length, diameter, fresh and dry weights) and leaves (number, total leaves area, fresh and dry
weights), photosynthetic pigments compared with the control especially, nano phosphorus at 50 mg/l followed by
nano calcium at 100 mg/l. For the anatomical characteristics, results revealed that different anatomical
characteristics of squash roots and stems were improved positively. Also, the most traits of squash anatomical
features were increased with different applied treatments. Generally using nanoparticles can be applied to increase
squash growth and productivity under cold stress conditions