Vegetables

Last week Gordon Johnson had an article talking about cold damage to peas and there also has been some cold damage and weather induced damage to vegetables in high tunnels and greenhouses.

This heat wave we have had this past week will have repercussions over the next few weeks as the flowers of several crops including cucurbits, peppers and especially tomato will not pollinate or fertilize properly to develop into fruit. Daytime highs of 90o F and above and nighttime lows only getting down to 70o F in much of the midAtlantic for the last week will cause blossom drop and fruit abortion in tomatoes.

An odd cold/frost event occurred in a potato field just this past weekend (May 9 and 10). On Saturday morning the grower noticed dark brown necrotic areas appearing on some of their potato plants (fig. 1). Up-close some of the leaves with the necrotic areas appeared to have white fuzz on the underside of the leaf (fig. 2), which could indicate late blight.

Physiological Tomato Fruit Disorders

This has been a very wet period for most of us in the mid-Atlantic. Some fields have received repeated downpours of rain and have standing water while others have not gotten as much. But in almost all of the tomato fields I have found rain check (fig 1).

I know it may seem odd to see an article about sunscald or sunburn on leaves with the week of rain we just had, but leaves came in over the last week as the rain started and the damage had been done days before this. It is also possible that there will be a greater chance for sunscald in the coming days as growers try to get their transplants out.

I know this seems very obvious to most growers as we have sunscald every year in our vegetable plantings. This year just seems to be especially bad as I have gotten several calls from growers about a strange problem in their peppers that looks like sunscald, but couldn’t be. The reason given that it could not be sunscald is because the plants have thick foliage and the fruit seem well covered.

Tomato plants were transplanted on 7 May 2012 into black (grower standard), white or reflective plastic mulch.

An odd problem was seen in tomato plants being grown for harvest in a greenhouse that showed blister- or callus-like growths usually along veins that first appeared on the underside of older leaves (fig. 1). Leaves also showed unusual curling and other odd distortions on the top side of the leaf (fig. 2).

Over the last few weeks I have been sent pictures of and have seen dark spots on the foliage of strawberry plants (figs. 1 and 2).