He said that normal maximum and minimum temperatures for the week were 18.2 degree C and 3.8 degree C, respectively, that is below the normal value of 19.0 degree C and 5.0 degree C, respectively. He said that these conditions might result in the incidence of frost which will adversely affect sensitive vegetable crops, especially potato, tomato, peas, etc. These conditions can also impact horticultural and ornamental crops.

Dr Jagtar Singh Bal, senior horticulturist, said that plants like papaya, guava, banana and kinnow and young plants of mango and litchi were sensitive to low temperature. The delicate small plants should be protected against cold by erecting thatch enclosures with exposure towards the eastern side. The nursery plants may be protected through polythene covers. Dr Bal said that steps like providing light irrigation in the evening and creation of smoke-screen by burning fallen leaves in small stacks can be helpful in protecting the plants from frost.

Dr DS Cheema, Head, Department of Vegetable Crops, said that most of the field-grown winter vegetables needed protection against frost. He said that capsicum, cucumber, tomato etc, growing under low tunnel would require cover as a protection measure against cold. He, however, said that proper ventilation needed to be ensured in case the temperature rose. These crops growing in open would require protection against frost by raising sarkanda thatch. He urged the farmers to not to go for early sowing of cucurbits in polythene bags and should do so only in the third week of January. Dr Cheema said that light irrigation to the crops such as capsicum, cucumber, tomato, brinjal, etc., grown in the net-house, would be required for protection against frost damage.

Discussing the prevailing weather in relation to ornamentals, Dr Ramesh Kumar, Head, Department of Landscaping and Floriculture, said that potted plants of ornamental foliage, palms and dieffenbachia, etc were sensitive to cold weather. He said that the foliage ornamentals and young seedlings of annuals needed to be protected against the occurrence of frost.

He urged flower growers to irrigate their fields as per requirement. The tall growing plants like Dahlia required support and the potted plants needed to be shifted to warm and sunny places and farm-yard manure may be applied in thin layers to deciduous woody ornamentals in the properly prepared basins, he said.