Shepherd pecan cultivar has shown promise for growers looking for an early ripening and hardy tree. Besides the regular production of and good nut quality, Shepherd is noted for its resistance to pecan scab. However, Shepherd seems to be susceptible to another disease--vein spot.
At right is a photo of the foliage of a Shepherd tree growing at Missouri's Horticulture and Agroforestry Research Center near New Franklin. Vein spot appears on the foliage as elongated black spots on leaf rachii and along the midribs of leaflets. With the dry summer we've had this year, I was surprised to see even this low level of disease on the foliage.
Vein spot is usually not a problem in pecan orchards that receive scab sprays. Left untreated, a serious infection of vein spot can cause premature defoliation and cause increased alternate bearing. Resistance to pecan scab is a good thing but scab is not the only disease we need to consider when evaluating cultivars.