Hi Sir, 

Higher light intensity would lead to higher carbohydrate production and hence tuber yield (Solanum potato by Bodlaender'5 and by Posthumus (unpublished results) for radish (Raphanus sativus L. var. radicula) under phytotron conditions. According that reference greatest tuberization in radishes occurred in red light. This may therefore be a photo-morphogenetic rather than a photosynthetic effects. In Solanum potato, illumination of the stolon' tips inhibits tuberization by converting these into leafy

shoots. An instance of a negative influence of light on tuberization is the complete inhibition of tuber initiation in sweet potato that occurs by exposure of the root system to Iighf'J . The high light intensity in the tropics compared with that in temperate climates, should generate sufficient potential photosynthetic energy to produce abundant crop yields, through the process of tuberization.

Hi! 

When we talk about the effect of light on quality of quality potato there are many things that we also need to consider. Light intensity or duration of exposure (photoperiod), potato genotype,  the agro-ecology, cultural practices, time of planting etc. Different genotypes could behave deferentially under similar light intensity and duration but due to temperature. In the tropics, for example, the same potato variety could have high dry matter content if grown in relatively cooler area (high altitude) than somewhat warm (less altitude), without significant difference in both light intensity and duration. The major factor here is temperature that enhance vegetative growth and high rate of respiration at the expense of tuber formation and dry matter accumulation. In such cases you may need to maintain soil moisture throughout the growing season water to reduce the its temperature, especially if your potato tubers are for industrial processing like chip making (that needs potatoes with high dry matter or starch content). Although it is difficult to produce potatoes in tropical lowlands (hot and short days), it is possible to grow some varieties by providing frequent irrigation. However, the tubers are watery and may not fit for processing and have short shelf life. The interaction of light intensity, photoperiod, genotypes and cultural practice need to be considered. please look..(http://akademiai.com/doi/abs/10.1556/ABiol.52.2001.1.13; https://link.springer.com/article/10.1007/BF02358164 ).

Potato grows generally in hill stations, where low temperature prevails.  The requirement of optimal light intensity may be determined invitro.  To determine the quality of light, different spectra  of light like, blue, red,yellow either independently or collectively tried on productivity of tubers.  The light can be photomorphogenetic  besides triggering photosynthesis

 bakrajo

Light also has negative effect on potato tubers.It cause producing some materials such as Solanine which is a posionous material if it is used as human food.