Today, cucumber is one of the most popular vegetables in many countries and of greatest economic importance in Spain. It is the third most important crop in Almería, reaching an area of approximately 5.600 hectares in the last season. (David E Meca – Cajamar Experimental Station).
To achieve maximum productivity and ensure plant well-being, a temperature of 20 to 28°C and a humidity level of 50 to 80% must be maintained. Solar radiation is another determining factor in cultivation.
In the warmer months, this radiation is usually very high, increasing the temperature and, in turn, the level of stress suffered by plants due to the intense heat, combined with variations in humidity after modifying overlapping irrigation strategies to alleviate summer stress.
Generally, the main physiopathies in cucumber cultivation that are caused by these extreme environmental conditions result in significant damage to the commercial appearance of the fruit.
High temperatures above 40°C stunt plant growth. Similarly, relative humidity levels that are too low can cause symptoms in the fruit, and humidity levels below 40% can cause plant death.
In the cucumber plantations of Almería, it is observed very frequently a withering Transient, saddened plants as a result of very low relative humidity, resulting in symptoms such as yellowing, wilted, and curled leaves. Often, even the terminal buds are burned. This problem occurs primarily because plants are unable to counteract the amount of water they transpires. That is, evapotranspiration is greater than the amount of water absorbed.
Wilt in cucumber
Water deficit in cucumber
Regarding irrigation, cucumber is a vegetable with high water requirements and is very sensitive to irregular water supplies. water deficit especially during the flowering and early fruit development stages, it results in fruit abortions, the main symptoms of which are loss of consistency, dehydration of the skin, curvature or hooked fruit.
In turn, stress due to excess water causes chlorosis in young plants, root asphyxiation, as well as flower abortion and decreased fruit production and quality.
The lack of thermal and humidity corking, with significant differences between day and night, favors the appearance of another physiopathology known as "lizard skin," in the form of microcracking.
Lizard skin on cucumber
In view of the negative effects produced by extreme environmental conditions in areas with the highest cucumber production, Cultifort proposes a strategy based on biostimulants, specifically on the precise action of, BVC 2021, which will help the plant avoid stressful situations by maintaining a correct water balance, preventing flower abortion, while promoting fruit set and fattening.
To maintain water balance, plants develop an osmotic adjustment mechanism at the cellular level as a resistance response. This consists of a decrease in water potential in plant tissues, allowing water to enter and, therefore, preventing a decrease in turgor or photosynthetic productivity.
Cucumber is one of the crops most sensitive to these adverse conditions; it lacks the ability to maintain osmotic regulation on its own. This makes it difficult for the plant to adapt to environmental changes characteristic of the area, resulting in the aborting of cucumber flowers during development and/or physiological disorders caused by these conditions.
The seaweed included in BVC 2021 They perform two important functions: osmoregulation and phytoregulation (growth regulation). They contain osmotically active substances (polysaccharides, alginate, mannitol, glycerol, sorbitol, proline, and betaine) that improve the efficiency of water use within cells, allowing them to maintain cell wall turgor and properly develop their physiological activity. They also have a potent antioxidant effect, helping to eliminate free radicals under conditions of environmental stress.
Related to the phytoregulatory effect is the ability of the algae extract to induce the synthesis of growth-regulating compounds (or phytoregulators) in crops, in this case, cytokinins. These promote cell division in non-meristematic tissues and organ formation, delay senescence, and the development of lateral buds. They also participate in maintaining adequate water levels in the plant (cell turgor), thus reducing water stress.