Dažādu augu maisījumu ietekme uz smiltsērkšķu veģetatīvo dzinumu augšanu un ogu kvalitāti = The effect of different plant mixtures on the growth of vegetative shoots and berry quality of sea buckthorns

Until now green manure and high-quality grassland cultivation in interrows in the cultivation of berry and fruit trees in Latvian conditions have been used very little. The most popular and frequently used types of fertilization in sea buckthorn cultivation were either the use of mineral fertilizers or manure or cultivation without additional fertilization at all. The use of fertilizers is especially relevant in organic farms because the possibilities are limited. At the same time, it is known that Latvian sea buckthorn berries are a potential export product. Buyers need large quantities of uniform, high-quality large berries. The research took place from the spring of 2020 to February 2023 in seven farms in different parts of Latvia (Project 19-00-A01620-000066 “Using innovative methods for promotion of productivity and berry quality of sea buckthorn plantations”). The effect of different plants in interrows on sea buckthorn growth, yield and berry quality was evaluated. Four treatments were used in each farm: naturally growing grass as a control and three treatments of different perennial and annual plant mixtures in interrows. The applied plant mixtures differed among farms because of variability in soil granulometric composition, pH, and nutrient supply levels in farms. The following plant seed mixtures offered by Ltd “Latvijas Šķirnes Sēklas” (https://www.seklas.lv/) were used in the trials: S1 – annual plant seed mixture intended for deep soil cultivation; G5 – a perennial plant seed mixture intended for different types of soils; N2 – perennial plant seed mixture, intended for light mineral soils to fulfil greening requirements; P2 – seed mixture for high quality forage, intended for mowing, also suitable for poorer soils. In 2021 and 2022, annual growths and stem diameters were measured for sea buckthorn in autumn in each treatment, and the average weight of 100 berries was determined. Shoot growth was different among farms depending on the effect of the plant mixture. For the plant mixture G5, the biggest increase in growth was observed in a farm of Tukums region in 2022. The highest average berry weight was obtained in treatments with plant mixture N2 in several farms.