Joanna Golian

In studies conducted in 2018–2020 on transplant kale, methods of weed control, including mechanical weeding, flame weeding, mechanical weeding combined with flame weeding, and herbicide use, were tested. Chemical control was based on the...

Observations of weed infestation were carried out in onion and carrot crops from 1995 to 2024 in the Skierniewice region. Weed infestation was assessed on unsprayed fields based on weed numbers determined between 29 and 78 days after sowing. Based on species composition and weed abundance, the weed community structure was determined using the Shannon-Wiener species diversity index (H), Simpson's dominance index (SI), Pearson correlation coefficients (r) and Multiple regression. Weed populations in onion and carrot exhibited substantial year-to-year variability and no long-term trends. The most abundant species in onion and carrot were Capsella bursa-pastoris, Thlaspi arvense, Chenopodium album, and Galinsoga parviflora. In onion, an increasing tendency in the number of Galinsoga parviflora Capsella bursa-pastoris, Thlaspi arvense, and Echinochloa crus-galli was observed, while the number of Chenopodium album plants showed a tendency to decrease. In carrot, an upward trend in the populations of Capsella bursa-pastoris and Chenopodium album was observed, although annual fluctuations remained substantial. The climatic effects on weed communities were weak and inconsistent across crops, explaining only a small weed variation and indicating that long-term weed dynamics are shaped primarily by non-climatic factors.

The studies were conducted in 2020–2022 in Skierniewice, in the greenhouse and in the open. The observations were carried out on carrot (Daucus carota L.), parsley (Petroselinum sativum (Mill) Fuss.), and celeriac (Apium graveolens L. var. rapaceum (Mill)). The seeds of tested vegetable crops were sown in a greenhouse, and before sowing, Phelipanche ramosa seeds were mixed with the top layer of the substrate for half of the pots. The number and height of P. ramosa inflorescence shoots, the number of capsules with seeds in one pot, and the height of vegetable plant’s inflorescence shoots were determined in experiments. It was found that tested vegetable cropsfrom Apiaceae family can be the host plants for P. ramosa. Celeriac appeared to be a better host than carrot and parsley. Inflorescence shoots of carrot and celeriac parasitised with P. ramosa were lower than shoots growingwithout the parasite, but shoots of parsley were higher. The study aimed to determine the possibility of P. ramosa parasitizing vegetable crops from Apiaceae family, under Polish conditions, and its influence on the plant’s morphological features.

In the pot experiments conducted in the greenhouse and in the open, in the years 2009-2010, 2013-2014, and 2019-2020 in Skierniewice in Poland was found that Phelipanche ramosa L. Pomel (branched broomrape) can parasite on the roots of Galinsoga parviflora Cav. (gallant soldier) and was also confirmed its ability to parasite some vegetable crops such as Chinese cabbage (Brassica rapa L. subsp. pekinensis (Lour.) Hanelt.) and the crops from Apiaceae family: carrot (Daucus carota L. subsp. sativus (Hoff.)), celeriac (Apium graveolens L. var. rapaceum (Mill)) and parsley (Petroselinum sativum (Mill) Fuss.). G. parviflora is a segetal weed that commonly infests crops in many countries, including Poland. It was found that Chinese cabbage is a better host for P. ramosa than G. parviflora but the possibility of parasitizing G. parviflora by P. ramosa is new information and it may be a new way to spread this parasite into new areas.

The studies were conducted from 2012 to 2015 at the National Institute of Horticultural Research in Skierniewice, Poland. The aim of the research was to determine the yield of Chinese cabbage, its storage ability and nutritional value, depending on weed management methods used during cultivation. In the field experiments the following methods were compared: mechanical treatments, mechanical treatments + growth stimulators, soil mulching with black polypropylene, black polyethylene and biodegradable foil and hand weeding. After harvest the Chinese cabbage was stored at 0-2°C for 125-126 days depending on the year and after storage marketable and rotten heads were sorted. The percent of yellowed, rotten leaves in the total mass of the stored heads was also determined, as well as the natural weight loss. The chemical composition of Chinese cabbage was analyzed after harvest and after storage. The analyses included: dry matter, total sugars, vitamin C and soluble phenol content. After harvest the highest yield of Chinese cabbage grown in black polyethylene mulch was obtained. After storage the highest yield of marketable heads from cabbage mechanically weeded with additional application of biostimulator AlfaMax during cultivation was obtained. Chemical analyses showed that after harvest the highest dry matter, total sugars and vitamin C content were found in Chinese cabbage mechanically weeded and soluble phenols were the highest in non-weeded Chinese cabbage. After storage the highest content of dry matter was recorded in non-weeded Chinese cabbage, while total sugars were the highest in cabbage mulched with black polyethylene and biodegradable foil. Vitamin C was the highest in mechanically weeded and soluble phenols were the highest in hand-weeded cabbage.

A trial assessing the suitability of multifunctional living mulch to maintain the soil and reduce weed infestation was carried out in an organic apple orchard in the years of 2019-2020. Perennial plants (Alchemilla vulgaris, Fragaria vesca, Mentha piperita) and annual crops (Tropaeolum majus and Cucurbita maxima) were grown in the in the rows of the apple trees. The weeds number and soil weeds coverage in tree rows were assessed. Regardless of the living mulch species utilized, the soil resulted to be mostly covered by perennial weed species such as: Equisetum arvense and Taraxacum officinale and annual species such as: Lamium purpureum, Stellaria media, Galinsoga parviflora, Capsella bursa-pastoris and Poa annua, which were the most common species also for the natural cover used as control. However, all living mulch species limited weed infestation and M. piperita, F. vesca and T. majus most strongly limited weeds growth. It is concluded that living mulch species can be a feasible practice to manage the soil on the tree rows in organic orchards.

The establishment of living mulches in organic orchards could potentially improve the orchard biodiversity and, when specific plant species are selected, provide additional eco-services and functions, including adequate weed management. This study was conducted in an organically managed apple orchard in Skierniewice (Poland) to assess the effect of two selected living mulching species: Alchemilla vulgaris and Mentha piperita. They were assessed on weed control, weed biodiversity, tree nutritional status, root dry weight density (RDWD), and other root morphological traits compared to a natural soil cover (control). Overall, both living mulches produced 42.5% more dry biomass, increased weed species number (+29%), and increased soil coverage (+33%) compared to control mowed plots. The apple leaf chlorophyll index and nutrient content were higher in the presence of both living mulches than in the control. In addition, apple trees had 30–46% higher root dry weight densities, even though other root morphological traits were not affected by the treatments. The results suggested that the tree row can be managed with living mulches of herbs; these species have the potential to provide an additional income to the farmer, as well as beneficial effects for the orchard biodiversity, without impairing the tree root development and nutrient status.

In the years 2012–2014, at The National Institute of Horticultural Research in Skierniewice, research was carried out on determining the impact of various methods of weeding on leek yield, its storage stability and nutritional value after harvest and storage. In the field experiments the following methods were compared: mechanical treatments, mechanical treatments + growth stimulator, soil mulching with polypropylene and black foil and hand weeding. After harvest the leek were storage at the temperature 0°C for 124–150 days depending on the year and after the storage it was sorted as: marketable leeks and plants with diseases symptoms and rotten plants, and also leek’s natural weight loss was determined. After harvest and after storage, the content of dry matter, total sugars and soluble phenols in leeks was determined. The highest marketable yield immediately after harvest was obtained from plants mulched with black materials. After storage, the most marketable leeks were obtained from the control and hand weeded during cultivation. Chemical composition of leek was analysed after harvest and after the storage period. After harvest the highest yield from leek grown in black mulch were obtained and after the storage from control and hand weeding. Chemical analyses showed that the highest dry matter and total sugars contents were found in leek weeded by hand, and after storage mulched with black and polypropylene foil. After harvest, the highest content of soluble phenols was recorded in leek weeded mechanically and treated additionally with a growth stimulator, and after the storage – in mechanically weeded leeks.

The studies carried out in the years of 2014–2017 at the Institute of Horticulture in Skierniewice were aimed to compare the biological effectiveness of foliar applied herbicides: oxyfluorfen, prosulfocarb, bromoxynil, pyridate and their mixtures, as well as assessment of suitability of these substances for weeds control in sowed onion. Herbicides were applied with the split application method, in three treatments, every 5–8 days from 1‒2 true leaves stage of onion or in two treatments from 2–3 leaves of onion. The studies assessed the effect of herbicides and their mixtures on the degree of weed damage, secondary weed infestation, selectivity, as well as onion growth, development and yield. The results showed that the greatest reduction of weeds and the highest yield, with slight, transient phytotoxicity symptoms, were obtained after 3 times spraying with oxyfluorofen in a mixture with bromoxynil. The weakest weed control and the lowest onion yield were obtained after applying oxyfluorfen in two treatments, in a mixture with pyridate.