Weed control is an important cultivation treatment in the cultivation of maize, while the time of conducting it, limited by the plant developmental stage, determines the yield height and financial outcome. However, the use of chemical plant protection products on ecological farms is not allowed, therefore, the level of obtained yields and economic effects of this species cultivation is largely affected by mechanical regulation of weed infestation. The aim of the study was economic evaluation of maize cultivated for green matter depending on the method of cultivation and dose of a fertilizer in a form of composted manure. Research material were results of the field experiment carried out in the years 2009-2011 at the Experimental Station of the Institute of Soil Science and Plant Cultivation, National Research Institute (IUNG-PIB) in Grabowo (Masovian Voivodeship). Primary factor were manure doses of 20 and 40 Mg·ha^-1, secondary factor were cultivation methods: A – without weed control (control), B – brush weeder, C – weeding hoe, D – brush weeder plus hiller. The production cost specification included direct and indirect costs. Conducted analysis indicated that the yield of green matter of maize was significantly affected by the applied manure doses. The highest yields were observed when a brush weeder was used three times in maize cultivation. Yields of both the fresh and dry matter of maize fertilized with a dose of 20 Mg·ha^-1 were lower than the yields of maize with the application of 40 Mg·ha^-1. Omission of mechanical cultivation while growing maize, regardless of the manure dose, caused reduction in the green matter yield by about 38% compared to plots where the weeds were controlled mechanically. The most beneficial financial results were possible to achieve after using a brush weeder. This method of weed control also ensured obtaining the lowest unit cost in relation to 1 ton of green matter. Positive financial result without area payments was achieved with the use of technological variants, with a lower manure dose (20 Mg·ha^-1), with the use of a brush weeder, weeding hoe, as well as on plots with the use of a brush weeder plus hiller.

Haploid maize plants are obtained using in vitro androgenesis in anther cultures and isolated microsphores, as well as in vivo, through obtaining maternal haploid lines created as a result of pollination with an inducer. DH lines obtained in vivo are gaining importance in heterosis maize breeding. The aim of this study was to evaluate the genetic variability of 11 maize haploid offspring, derived from intraspecies crossings with an inducer of haploids. Plant material originated from the Institute of Plant Breeding and Acclimatization in Radzików. For the evaluation of genetic variability, Random Amplified Polymorphic DNA (RAPD) markers obtained by PCR were used. Nei’s and Li [1979] genetic distance between the particular lines was calculated on the basis of 84 polymorphic amplicons. The values of genetic distance obtained for doubled haploid lines (DH) were relatively high and ranged from 82% to 98%. Application of RAPD-PCR made it possible to isolate genotypes with the lowest genetic similarity. After testing the general and specific combining ability, the lines can serve as starting material for the creation of new maize hybrids, in which heterosis effect will be used.

The aim of this study was to evaluate weed infestation (the number, biomass and species composition) of husked and naked oats canopy depending on the soil tillage system (conventional, simplified with a catch crop, simplified, direct sowing) and the method of plant cultivation (mechanical and chemical) The study was carried out in 2000-2002, in Alfisols, formed from loess. The subject of the investigation was husked oats (cultivar Borowiak) and naked oats (cultivar Akt III). The largest number of weeds occurred in the canopy of husked (123 pcs·m^-2) and naked (102 pcs·m^-2) oats cultivar after the use of direct sowing, and in the cultivar Akt III also after simplified tillage (68.7 pcs·m^-2). The largest dry matter of weeds was determined after the application of direct sowing (Borowiak – 104.8; Akt III – 100.5 g·m^-2) and simplified tillage (Borowiak – 72.5; Akt III – 64.1 g·m^-2). The smallest number and weight of weeds in canopies of both oats cultivars was found after conventional soil cultivation and after simplified tillage with the use of catch crop. Introducing chemical weed control affected a reduction in number and dry matter of weeds in the range from 16 to 22%, both in the canopy of cultivar Borowiak and Akt III. This was particularly effective in treatments where direct sowing and simplified tillage was used. Among weeds short-lived species predominated, but more of them occurred in the canopy of cultivar Akt III than in the canopy of the cultivar Borowiak. Tillage system and the method for weed control had a similar effect on the weed control in canopies of naked and husked oats cultivars.

Mid-forest meadows have a high natural value, due to preserving unique meadow and ecotone biotopes, similar to the natural state. Due to their dissimilarity, they also had a considerable effect on the functioning of forest ecosystems they border. The aim of the study conducted in 2006-2010 in the Bukówka river valley was to assess the natural values of mid-forest meadows with the Oświt method [2000] based on 140 phytosociological records, to estimate the economic value by evaluating dry matter yield and to calculate the fodder value of sward. Richness and floristic diversity of mid-forest meadows was observed, resulting mainly from the mosaic character of habitats and intensity of use. The studied communities from the classes Phragmitetea, Potametea, Lemnetea, as well as Molinio-Arrhenatheretea generally presented a poor quality, due to a very late time of cutting and excessive moisture of most habitats.

Cereals are exposed to considerable losses caused by harmful insects. In the years of the study of production and economic effects of pest control in winter wheat, leaf beetle larvae damaged from 31.6 to 49.8% of leaf blade area. The aim of this study was to evaluate the effectiveness and economic efficiency of the insecticides applied in leaf beetle larvae control in winter wheat. The assessment of wheat damage by leaf beetle larvae was made by determination of a percentage of leaf blade area damage. Each combination of protection against pests used in this study contributed to a significant reduction of the percentage of leaf blade area damage, in relation to the combination without treatments. Insecticides used to control Oulema spp. larvae showed a good efficiency on the level on average from 70.3 to 90.9%. The value of production saved as a result of applying plant protection treatments ranged from 54 to 532 PLN·ha^-1, on average 221 PLN·ha^-1. Cost of protection of one hectare of winter wheat against leaf beetle larvae was low and ranged from 76 to 118 PLN·ha^-1. Cost covering ratio ranged from 0.6 to 7.0 depending on the year of conducted investigation. Treatment profitability index was on average 1.4, and percentage index of costs ranged from 1.2 to 4.1.