Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
May 24 and 25 was a period of cloudy conditions with high winds, peak gusts over 30 mph, wind speeds about double the average (near 12 average mph at Georgetown) and lows in the 40s across the peninsula. This was followed by clear skies and higher air temperatures. At the same time, planting of warm season transplants has continued. This combination has resulted in extensive wind damage and sun scorch in transplants. Some symptoms are marginal leaf burn, leaf bleaching, leaf desiccation, leaf dropping, stem browning, and in some cases, plant losses. Symptoms are most severe on newly transplanted crops or transplants that have not yet rooted in well. Because soils were moist from recent rains, we did not see the sandblasting that often is an issue on our light soils with high winds.
Growers with damage should evaluate plants for the extent of damage and need for replanting. Wilted, snapped, broken, or severely “wind burnt” or scorched plants may need to be replaced. Growers should also consider applying protectant fungicides/bactericides to reduce infections by opportunistic disease organisms on damaged tissues.
Wind damage can be reduced or eliminated by the use of rye windbreaks between rows or low tunnels over crops. Windbreaks require significant advance planning, planting the previous fall. Rye is very versatile in that it can be planted later than other small grains and still provide spring protection. Sun scorch can be avoided by having properly hardened off plants and avoiding moving plants from crowded growing areas where they are shading each other to outside growing areas without appropriate transitioning.