Photosynthate Partitioning in Asiatic Lilies Under Ammoniacal and Nitrate Sources of Nitrogen

Dry matter accumulation, photosynthate partitioning and chlorophyll retention by Asiatic lily cultivars “Serreda” and “Navona” were evaluated under two sources of nitrogen, urea as NH4 − and calcium nitrate as NO3 −, applied at the rate of 40 g m−2 (as N). The fertilizers were applied in 2, 3 and 4 equal splits at 30, 60 75 and 90 days after planting (DAP). Nitrogen in the form of calcium nitrate significantly improved relative growth rate (RGR), net assimilation rate (NAR), net chlorophyll content and leaf area throughout the growth period. Nitrogen application was advantageous as 3 and 4 split applications and significantly improved RGR, NAR and net chlorophyll content, thus helping export of photosynthates to bulbs as well as chlorophyll retention in the 105 DAP period. The results of the present study showed that the cultivar “Serreda” was having better growth than the cultivar “Navona” in terms of dry matter accumulation, chlorophyll retention, leaf area and photosynthetic partitioning. Nitrate was significantly superior in improving plant growth, leaf area, dry matter accumulation and net chlorophyll content. Application of 40 g N m−2 in three (S2) and four (S3) split applications significantly improved overall growth and yield.