Effects of nitrogen and foliar application of boron on yield and some physiological characteristics in karela (Momordica charantia L.)

In order to study the effect of different amounts of nitrogen fertilizer and foliar application of boron on some physiological traits in karela plants (Momordica charantia L.), a factorial experiment in a randomized complete block design with three replications was conducted at the Sharood University of Technology in 2013. The treatments consisted of three levels of nitrogen fertilizer: 75, 150 and 225 kg N.ha-1 (urea source) as the first factor and four foliar applications of boron including: 0, 1, 2 and 3 g per liter of boric acid as the second factor. The traits measured in this study included the length and diameter of fruit, fruit yield, chlorophyll "a","b", and carotenoids, the conent of sugar nitrate and nitrate reductase enzyme activity. The results showed that, nitrogen fertilizer except diameter of fruit had significant on all of attribute traits. Foliar application of boron in this study had significant effect on fruit yield, the content of chlorophyll "b" (P