Application of beneficial bacterial strain B125 (Enterobacter sp.) and strain PZ9 (Bacillus sp.) in lettuce transplants production significantly enhanced seed germination and plant biomass. The best effect was obtained when the mixture of B125 and PZ9 was used. Combined application of these bacteria significantly increased transplants biomass, which was about 45% higher than that in the control. However, after planting these transplants in organic field, generally, there were no differences in yield and nutrient content in plants treated and not treated with the bacteria, except for nitrogen and vitamin C. The lettuce grown from transplants treated with bacterial mixture B125 + PZ9 contained significantly higher nitrogen than plants from other treatments. Opposite to nitrogen, bacterial applications decreased the amount of vitamin C. The growth and organic lettuce composition was affected by planting time. The yield was higher in spring, but the concentration of nutrients in these plants was lower than that in plants harvested in autumn. Climatic and light conditions in the late season were the reasons for increased dry matter content, minerals, phenolic compounds, and vitamin C, as well as high concentration of nitrates.

The use of inducers of systemic acquired resistance (SAR) is widely described in the literature. Such substances have important advantages over plant protection products (PPPs) and, thus, are often indicated as their alternatives. The main risk indicated in the context of the widespread use of SAR inducers is that of yield reduction that may result from the excessive metabolic imbalance of the treated plant. The general aim of the study presented was to check the effect of using a new active substance, namely N-methoxy-N-methylbenzo(1.2.3)thiadiazole-7-carboxamide (BTHWA), on tulips cultivated in greenhouse conditions. The plant response to BTHWA treatment was also analyzed in terms of the extent to which the growth–immunity phenomena would occur. Surprisingly, the application of BTHWA provided not only efficient protection against fusariosis but also resulted in the stimulation of the growth and development of tomato plants. The results proved very interesting as they stand in contrast to other results on SAR induction. The method of BTHWA application used in this study resulted in SAR induction at a level sufficient to provide effective protection and, at the same time, did not cause disruption to plant metabolism that would result in yield reduction.

No abstract

SummaryThe investigations were conducted at the Research Institute of Horticulture in Skierniewice in 2012−2014. The aim of the research was to evaluate the effect of pre-harvest protection with products: Amistar 250 SC (reference product), Silvit and Huwa-San TR 50 on control of soft root rot and quality and storage potential of celeriac roots. Celeriac plants were protected during the growing season and the last spraying was performed 7 days before harvest. After 7 months of storage characteristic symptoms of soft rot were observed and then evaluation of percentage of infected roots and percentage of marketable and unmarketable roots and decrease of weight were conducted. In the both seasons of investigations the product Silvit showed the best efficacy against soft rot during long storage in comparison to the reference product. There was the highest percentage of marketable roots too. In contrast the influence of Huwa-San TR 50 on soft rot gave inconsistent results. In the first year of investigation its effectiveness was higher than in the control, but next year its effectiveness was significantly lower.Key words: celeriac; soft rot; storage potential StreszczenieCelem badań prowadzonych w Instytucie Ogrodnictwa w latach 2012−2014 było określenie wpływu przedzbiorczej ochrony selera korzeniowego z zastosowaniem środków: Amistar 250 SC (środek referencyjny), Silvit i Huwa-San TR 50 na ograniczenie miękkiej zgnilizny oraz jakości i trwałości przechowalniczej korzeni spichrzowych w okresie długotrwałego przechowania. Selery były chronione przez cały okres wegetacji, przy czym ostatni zabieg wykonano 7 dni przed zbiorem. Po 7 miesiącach przechowania przeprowadzono ocenę porażenia korzeni przez sprawców miękkiej zgnilizny oraz określano procentowy udział korzeni handlowych i poniesione straty. W obydwu latach badań, najwyższą skutecznością ochrony korzeni spichrzowych selera przed miękką zgnilizną w czasie długotrwałego przechowywania oraz najwyższy plon handlowy w porównaniu do kombinacji kontrolnej wykazał środek Silvit. Natomiast wpływ dezyfektantu Huwa-San TR 50 na ograniczenie miękkiej zgnilizny zobrazowały rozbieżne wyniki. W pierwszym roku badań jego efektywność była wyższa niż w kontroli, natomiast w następnym, jego skuteczność była znacznie niższa.Słowa kluczowe: seler; miękka zgnilizna; trwałość przechowalnicza Instytut Ogrodnictwa Konstytucji 3 Maja 1/3,

Possibilities of integrated protection against Alternaria leaf spot (Alternaria spp.) of Chinese cabbage using three different groups of plant protection products Możliwości integrowanej ochrony kapusty pekińskiej przed czernią krzyżowych (Alternaria spp.) z zastosowaniem trzech różnych grup preparatów Agnieszka Włodarek*, Jan Sobolewski, Józef Robak SummaryThe aim of the field experiments carried out in 2011-2013 was to evaluate the usefulness of fungicides, natural products and a growth stimulator used in integrated protection against Alternaria leaf spot of Chinese cabbage (Alternaria spp.). The following products were evaluated: two fungicides -Amistar 250 SC and Signum 33 WG, the natural products -Timorex Gold 24 EC and a strawberry extract and a growth stimulator Huwa-San TR 50. The examined products showed high effectiveness in protection of Chinese cabbage against Alternaria leaf spot.