Several introduced high-yielding varieties of grain sorghum were screened for natural infestation of shootfly Atherigona yorki Deeming, and stem borers, Sesamia cretica Led. and Chilo partellus (Swinhoe), at different sowing dates in 1980–1 and 1981–2 sowing seasons in People's Democratic Republic of Yemen (PDR Yemen).
The recently introduced high-yielding variety Dwarf White Milo (DWM) was found to be more prone to infestation by shootfly and stem borers than the local variety ‘Baini’ although it gave higher yield. All varieties tested gave higher yields when sown in March, August, September than when sown in April, May, October or November; 26 August and 16 September sowings gave the highest yields. B815, W823 and 8454 gave higher yields than the recently recommended high-yielding variety DWM, in response to lower infestation with the shootfly and stem borers; B815 and 8454 gave higher yields when sown on 26 August than when sown on 16 September. On the contrary, W823 gave higher yield when sown on 16 September than when sown on 26 August. This information could be used in formulating insect pest management programmes for sorghum pests in PDR Yemen.