Technological changes and their consequences for plant cropping

The survey deals with some problems of industralized agriculture development and its conditions. This development was promoted both by economic and biological progress, whereas advances in plant breeding enabled to completely mechanize technology of various crops cultivations claimed to be difficult enough (e.g. maize and sugar beet). It resulted in enormous energetic inputs for agricultural production (machines, fertilizers, pesticides), environment degradation and in many cases lowering of agricultural products quality. Some items associated with energetic inputs for agricultural production in Poland are presented

Studies on variation of root weight of sugar beet plant in a population and its determination in 2(5) factorial field experiment

The aim of the paper is to evaluate the effects of five agrotechnical factors on: a) mean root weight of sugar beet plants per plot and within-plot standard deviation of root weight, b) coefficient of determination for root weight of sugar beet plants by three independent variables x₁, x₂ and х₃ and standardised partial regression coefficients for those independent variables. The factors investigated in a 2⁵ factorial field experiment were: sowing date (A), harvest date (B), N rate (C), N application date (D) and division of N rate (E). Multiple linear regression analysis was carried out using plants from one row of 10 m length for each of 32 experimental plots. The independent variables were: xi - the state of plant development 30 days after sowing (measured by the number of leaves), x₂ - growing space per plant in a population, х₃ - coefficient of location, defined as the ratio of half the distance to its the nearest neighbour within the row to half the distance to its further neighbour within the row. A factorial analysis was carried out using the above parameters concerning a sugar beet population. It was proved that: 1) variation of root weight of sugar beet plants in a population was significantly larger for early sowing compared to late sowing and was larger for late harvest and higher N rate compared to the other levels of these factors, 2) the influence of development stage (x₁) on root weight was significantly larger for early sowing compared to late. A higher N rate increased the influence of the x₁ variable, 3) the effect of growing space (x₂) on root weight was larger for early sowing date and late harvest date, 4) the interactions between factors in a sugar beet population as presented in this paper are complicated and modified by agrotechnical factors and weather conditions, and should be further studied in other experiments