Maize is the third most important cereal crop in the world and many subsistence farmers are practicing intercropping of it with legumes due to land scarcity and in order to enhance production. Intercropping system is being practiced in may areas of South Africa mainly in the Limpopo province. The objective of the study was to evaluate the crop responses to intercropping maize with different growth length cowpea cultivars. The effects of intercropping on weed growth, maize and cowpea growth and yield components were investigated. The experiment was conducted during the 2005/06 and 2006/07 seasons at Bethlehem and Potchefstroom. Treatments were: maize sole, maize+PAN311 (short duration cowpea cultivar), maize+Glenda (medium duration cowpea cultivar), maize+Agrinawa (long duration cowpea cultivar) and sole plots of all cowpea varieties. Each plot was divided into two weed levels where all the plots were kept weed free for one month after planting, after which one half was left weedy and the other half weed free. Weed sampling was done within each weed treatment. Intercropping reduced maize LAI and plant height while time to physiological maturity was also reduced by weed infestation, especially under drier and warmer environments. Glenda and Agrinawa intercrops produced more nodules per plant under cooler and wetter conditions. Agrinawa produced the highest leaf and total DMY under sole crop conditions and this was significantly reduced by weed infestation. Different growth duration cultivars did not differ in their N2-binding abilities. Maize intercropping, especially with Glenda and Agrinawa, significantly reduced weed biomass. Maize sole crop under zero weeds had high grain yield compared to intercropping. PAN311 and Glenda sole crops under zero weeds produced higher yields under dry and warmer conditions, and cooler and wetter conditions, respectively, compared to intercropping. High cowpea grain yields were strongly correlated to more seeds per pod and larger pod lengths and number of pods per plant especially for Glenda. No intercropping advantage compared to sole cropping was observed (total LER < 1). This implies that maize and cowpeas must rather be planted as sole crops for better yields under wetter and cooler, and warmer and drier conditions. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2009. / Plant Production and Soil Science / unrestricted

The work is focused on spring application of plant growth regulators and the operating conditions of agricultural society Kosova Hora, as Preparations were applied during the growth phase stands 32-33 BBCH scale, with 2 types of varieties - a line of hybrid canola varieties. 3 preparations were evaluated (Galleko, Toprex, Caryx) and one untreated area for control of the comparison of products. During the vegetation period were gradually on individual plots monitored the main elements of the plant yield (number of plants, number of pods, HTS, the number of branches). After harvesting canola yield was determined at the experimental plot. Results showed a positive reaction to stand on the treated area CARYX product. Attainment and income (4, 53 t / ha) on the experimental plot was achieved on a plot of hybrid rape. Difference treated variants compared to the control side were 0, 28 t / ha. This result is not statistically provable. The results are largely influenced the course of weather throughout the growing season. For better statistical power experiment would be preferable to multi attempts.

In this thesis, the effects of year, variety and size of seed tubers on yield and quality of potato tubers were evaluated. In the two years (2011 and 2012), four potato varieties (Velox, Marabel, Adéla and Laura) were used. Size of seed tubers for all varieties was split into three size fractions: A < 35 mm, B 35-60 mm and C > 60 mm. In both years of observation were monitored following parameters: total and marketable yield, average number of stems per plant, number of tubers per plant, number of tubers per stem, the average weight of tuber, proportion of tuber size in harvested tubers, content of dry matter and starch in tubers fresh matter. Year contributed most to the total variability in total and market tuber yield (51.2%. And 54.4%, respectively). Size of seed tubers showed the highest proportion in the total variability of number of stems per plant (94.7%). Declared cooking type in all evaluated varieties was kept. Table value was significantly affected only by variety.

Some microorganisms are known to form mutualistic symbiosis with plant roots and by their impact they can improve some plant parameters. These symbiotic microorganisms, which are able to improve some plant parameters, include especially mycorrhizal fungi, plant growth promoting bacteria and some saprotrophic mycoparasitical fungi. Mechanisms of changes of these parameters, as influenced by symbiotic microorganisms, are known only in part and nowadays are being actively researched. Aims of this work were to find out if selected microbial treatments influence selected growth, physiological and yield parameters of plants and contents of selected substances in fruits. Within this work were made three pot greenhouse experiments (experiments 1, 2 and 3) and three pilot greenhouse experiments (experiments 4, 5 and 6), performed on tomato (Solanum lycopersicum) and cucumber (Cucumis sativus) plants. Plants were grown in hydroponics using a carrier of rockwool and they were watered by nutrient solution. As microbial treatments for plants in experiments have been used a mixture of arbuscular mycorrhizal fungi (AM), mixture of plant growth promoting bacteria (PGPB), saprotrophic mycoparasitical fungus Trichoderma harzianum (Th) and various mutual combinations of these treatments. There have been observed...