Increasing temperatures within our region place both open and protected agriculture under threat. My greenhouse is located approximately two thousand feet above sea level in the parish of Manchester, central Jamaica, where I was born and grew up. I have noticed a considerable change in at least two (2) aspects of climate, temperature and rainfall. The ideal range of temperature for our greenhouses is 72 – 76°C and a fall of 10 – 15°C during the night will not have adverse effects on production. Temperatures above 85°C are not recommended, but we have recorded 90°C. What are some of the impacts of exposing plants to too high temperatures? Plant functions are restrained and plant growth is reduced Pollination will not occur efficiently if the relative humidity is not within the vicinity of 70% and temperatures exceed the 70 – 82°F range. Plants are unable to efficiently use fertiliser feeds Physiological damage to fruit such as sunburns and sunscald on tomatoes and sweet peppers and tip burn in lettuce are quite common and increases as greenhouses warm up Workers are less comfortable in hot greenhouses making them less efficient in carrying out routine tasks. Consequently greenhouse farmers have to find ways to keep greenhouses at acceptable temperatures as the earth warms. These will be discussed in the next newsletter.
