Mature leaves of kale and collard, and Brussels sprouts were heated by moist air at 40, 45, 50, or 55ºC for durations of 0, 30, 60, or 90 minutes. Heating of kale at 45 ºC for 30 minutes was effective in maintaining better postharvest quality, delaying yellowing, and reducing losses of sugars and organic acids during subsequent storage at 15 ºC. Exposure of collard at 40 ºC for 60 minutes also delayed yellowing and maintained turgidity of the leaves. Other treatments were either less beneficial, not effective, or caused injury.
Symptoms occur in cabbage and Brussels sprouts. As the heads approach maturity, inner leaves become necrotic along their margin. Margins of one or more leaves turn brown beginning at the leaf pores. The area affected may be a narrow band or involve up to half of the leaf. Symptoms occur at one time and are not progressive. There is no external evidence that the heads are affected by tipburn.
The Guide is divided into three sections. The first section provides cultural information and management practices for a number of important vegetable crop groups. For each family, key pests and disease problems are described. Cultural methods and management practices that will help control each problem are listed, as well as materials that may be recommended for use.
Vegetable seeds can be saved to sow new crops in the future, but not all seeds are suitable for saving. Varieties suitable for seed saving include local varieties that have been grown in one region for a very long time, self-pollinating crops (for example, beans and peas), and open-pollinated varieties of some cross-pollinating crops (for example, pepper, cucumber and carrot).