Influencia de la radiación solar en la producción de semilla-tubérculo de papa bajo cultivo sin suelo

The aim of this research was to determinate the effect of four-radiation levels (100, 70, 50 and 0 %) provided by plastic mesh (30, 50 and 60 % shade, and a control without mesh) on tuber biomass accumulation in exposed greenhouse plants. Giant variety tubers 15 to 17 mm in diameter were grown in perlite. Seventy-five days after emergence plants under 100 and 70 % radiation had a higher number of tubers tuber (25 a 35 %) and total and tuber biomass (50 %), net photosynthesis, absolute growth rate, net assimilation rate and net economic rate than those grown under 50 and 40 % radiation. The harvest index was 0.71 at 100 % vs. 0.51 at 40 % radiation. This general behavior was observed in samples 40, 50, 60 and 70 days after emergence. Lower radiation affects photosynthetic efficiency of potato plants, decreasing tuber and total biomass, as well as the efficiency indexes of the growth analysis.