Spring frosts can cause very significant losses on fruit farms. The most common method of active protection against frost is sprinkling. The aim of this study was to assess the effectiveness of a sprinkling system used to protect apple trees against the effects of a spring frost. The experiment was conducted on the Mączewscy Fruit Farm. The orchard in which the observations were made is equipped with a system of sprinklers. When the temperature readings showed values close to zero, the sprinkler system was activated. Due to a limited water supply, one row of sprinklers had not been activated, and thus some of the trees were not sprayed at all. The assessment of fruit yield carried out in the autumn of 2015 demonstrated high effectiveness of the sprinkling used to protect apple trees against the spring frost. The frost had damaged most of the flowers of the unprotected trees, which resulted in a decrease in yield of as much as 85 - 93%. ...
The objective of the study was to examine the influence of supplemental lighting with sodium light and LED on leaf gas exchange and growth of tomato transplants. During cultivation period (September - October) the transplants received supplemental artificial lighting provided by standard high-pressure sodium lamps (HPS) or high-power solid-state lighting modules with red, blue and far-red LEDs. Quantum irradiance in both combinations was maintained at the same level. The third group of plants (control combination) was grown under the natural light (without supplemental lighting). The following measurements were taken: leaf gas exchange (net photosynthesis and transpiration rate) and selected morphological parameters (fresh weight of plant organs, leaf surface area, plant height). The results showed that supplemental illumination using LED or HPS light sources affected growth and physiological responses of tomato plants. The higher rates of leaf gas exchange were found in the plants supplementary lighted (compared to the control ones). Supplemental lighting also resulted in enhanced plant growth, however no significant differences were found between the plants lighted with HPS or LED. The obtained results showed that HPS lamps can be replaced by LEDs in greenhouse lighting systems for tomato transplant production during periods with insufficient natural light. ...
In the past few years, Poland has been growing into a leader in the cultivation of highbush blueberry in Europe and now occupies a very high 3rd place in world production, just behind the USA and Canada. The leading position on the European market, the growing demand for the fruit and the possibility of entering new markets present to Polish producers new opportunities and increase the number of new plantings. In the cultivation of blueberry, irrigation is a factor determining the size and quality of the crop, as the blueberry plant, due to its shallow root system, requires adequate moisture and permeability in the topsoil, generally throughout the entire growing period. The results obtained in several studies confirm the high effectiveness of blueberry irrigation, particularly on plantations at their full fruiting potential. The rise in yield achieved through the use of irrigation averaged 95%, corresponding to 4.51 t∙ha-1. The average irrigation efficiency coefficient was a 41.37 kg rise in fruit yield per 1 mm (10 m3) of water used for irrigation. ...
