The cultivation and consumption of sweet potato (Ipomoea batatas) are increasing globally. As the usage of chemical fertilizers and pest control agents during its cultivation may lead to soil, water and air pollution, there is an emerging need for environment-friendly, biological solutions enabling increased amounts of healthy crop and efficient disease management. Microbiological agents for agricultural purposes gained increasing importance in the past few decades. Our goal was to develop an agricultural soil inoculant from multiple microorganisms and test its application potential in sweet potato cultivation. Two Trichoderma strains were selected: Trichoderma ghanense strain SZMC 25217 based on its extracellular enzyme activities for the biodegradation of plant residues, and Trichoderma afroharzianum strain SZMC 25231 for biocontrol purposes against fungal plant pathogens. The Bacillus velezensis strain SZMC 24986 proved to be the best growth inhibitor of most of the nine tested strains of fungal species known as plant pathogens, therefore it was also selected for biocontrol purposes against fungal plant pathogens. Arthrobacter globiformis strain SZMC 25081, showing the fastest growth on nitrogen-free medium, was selected as a component with possible nitrogen-fixing potential. A Pseudomonas resinovorans strain, SZMC 25872, was selected for its ability to produce indole-3-acetic acid, which is among the important traits of potential plant growth-promoting rhizobacteria (PGPR). A series of experiments were performed to test the selected strains for their tolerance to abiotic stress factors such as pH, temperature, water activity and fungicides, influencing the survivability in agricultural environments. The selected strains were used to treat sweet potato in two separate field experiments. Yield increase was observed for the plants treated with the selected microbial consortium (synthetic community) in comparison with the control group in both cases. Our results suggest that the developed microbial inoculant has the potential to be used in sweet potato plantations. To the best of our knowledge, this is the first report about the successful application of a fungal-bacterial consortium in sweet potato cultivation.

A field study was conducted in South-East Hungary during the main cropping season of 2016, 2017 and 2018, with the objective of determining the effect of plant spacing on the productivity of sweet potato. Production technology experiments of four repetitions were set up in a randomized block design on sandy soil. The performed treatments consisted of four variations of plant spacing (row distance x plant-to-plant distance): 80 cm x 20 cm, 80 cm x 30 cm, 100 cm x 20 cm, 100 cm x 30 cm. The plant material was the Hungarian registered sweet potato variety ‘Ásotthalmi-12’. Analysis of variance revealed that planting density significantly affected the average yield of storage roots. The highest yield per plant was achieved with the 100 cm x 30 cm (2016, 2017), as well as with the 80 cm x 30 cm (2018) setups. On hectare level, our results showed that the highest plant density of 62,500 plants ha-1 (80 cm x 20 cm setup) could give the highest yield. Comparing the highest tons ha-1 results to those achieved with the plant spacing setups resulting in the highest yield per plant, the differences can be even 13 or 14 tons at hectare level. This finding underlines the importance of choosing the proper planting density towards the higher end.

The aim of the study was to determine the effectiveness of regularly applied biological control by continuous monitoring of pests with the help of color traps (sticky sheets) and flower tests with joint species identification of the useful insect to determine the extent to which native useful insects can settle next to the introduced predatory ones. The latter process is to be facilitated by growing a flowering mixture of annual plants at one of the experimental sites, which provides adequate feeding and hiding place for beneficial insects.The experiment was performed in one pepper forcing period. The main pest insects are: western flower thrips (Frankliniella occidentalis), tobacco thrips (Thrips tabaci).Useful insects in the experiment: predatory mites (Amblyseius spp.) and predatory flower bugs (Orius laevigatus).

The overall objectives of our research program are to examine and to develop the possibilities of use and to expand the national production technology of sweet potato. In 2016, we have set up production technology experiments in many regions, from which we report the results of the experimental field in Deszk here. In our field experiments we obtained results of planting material production, planting and nutrition optimization of sweet potato. Rating the effects of different nutrition doses, between the averages of treatment we didn't experience any significant differencies. On hard soil we set up experimental plots with or without ridges. Based on the result of the harvest the production technology without ridges proved to be more effective. The transplants originating from cuttings from shoots or from tubers did not show significant differences, but it does matter how many tons of sweet potato tubers we harvest per hectare.

The aim of our research program is to develop the production technology and to examine the possibilities of the utilization of sweet potato (Ipomea batatas (L.) Lam.). In 2016 and 2017, production technology experiments were set up with four replications in a randomized block design on an alluvial soil in Deszk, Hungary. In our field experiments, we obtained results of planting material production, planting methods and the optimized fertilization of sweet potato. Experimental plots were set up either with or without ridges. In heavy soils – where usually ridge planting is preferred –, in 2016, the production technology without ridges proved to be more effective. In 2017, however, we got opposite results: based on the result of the harvest, the production technology with ridges proved to be more effective. The transplants originating from cuttings from tubers (primary transplants) or from shoots (secondary transplants) did not show significant differences, however, in both years, yield levels were higher on ridges with secondary transplants. Sweet potato yield may vary widely among producers due to improper ridging and planting orientation. The aim of this study was to establish the proper ridging and planting orientation, so as to enhance constant reliable yields among sweet potato producing farmers.