Farmer's Weekly (South Africa)
Water stress in lettuce
As a fast-growing crop with shallow roots, lettuce is susceptible to stress, which often shows up as angular midribs on the outer leaves, rather like elbows. These may not be severe enough to downgrade the crop, but they are a warning. In a spell of more severe weather, the damage may be worse.
There are many varieties of lettuce, with new ones being added from time to time. When trialling a new variety, plant it in a small area and examine it closely for adaptability to the climate and conditions in your area. How you grow the lettuce also matters; one farmer may have great success with a particular variety while another farmer in the same area may end up with a failed crop. The way the crop is irrigated and cared for can make all the difference.
WITH DRIP IRRIGATION, A WELL- WETTED SOIL SURFACE INDICATES OVER- WATERING
With South Africa’s changeable weather, it is best to select a variety that can cope with as broad a range of conditions as possible. In some countries with a more reliable weather pattern, farmers tend to use a number of varieties over the season to maximise the yield potential of each, changing the varieties as frequently as once a month.
Even in South Africa, a certain amount of variation is possible. For example, you could start with one variety in spring, continue through summer with a second variety, and go into winter with a third.
Start off small with a new variety. If it is successful,
Ensure that the soil moisture level remains high enough for the plants at all times.
If it falls rather low and a hot snap suddenly occurs, the plants can suffer stress, reducing crop quality.
Irrigate the crop in the cool of the day where possible, and never allow it to wilt. Some varieties can take a surprising amount of heat if well-watered.
Keep a garden trowel in hand when walking the land, and use it to dig into the soil and check the moisture level. The crop will become a duller, darker colour just before it wilts. If this happens, some damage has already been done to the plants.
However, overdoing irrigation can leach nitrogen beyond the shallow root system, so it is wise to check the soil moisture
Not so. Talk to anybody from FMS and you will immediately realise that they work within a culture that values their role in the sector in which they ply their trade.
RECOGNITION BY THE SECTOR
The company’s contribution to the fresh produce sector was recognised a couple of years ago by the Institute of Market Agents of South Africa, which presented them with the prestigious Shiny Red Apple Award for their services to markets.
It is not within the scope of this column to list all the services supplied by FMS, but they have shown a loyalty to fresh produce markets that is commendable.
• Michael Cordes is an agricultural journalist, consultant, trainer and former farmer. Email him at farmersweekly@caxton.co.za. Subject line: Market floor.