positively regulates vulval development positive regulation of vulval development up-regulation of vulval development activation of vulval development up regulation of vulval development Any process that activates or increases the frequency, rate or extent of development of the vulva. Vulval development is the process whose specific outcome is the progression of the egg-laying organ of female and hermaphrodite nematodes over time, from its formation to the mature structure. In nematodes, the vulva is formed from ventral epidermal cells during larval stages to give rise to a fully formed vulva in the adult. biological_process upregulation of vulval development GO:0040026 stimulation of vulval development regulation of vulval development positive regulation of developmental process biological regulation