Zoran Šindrak

Quality of strawberries produced applying two different growing systems

The quality of strawberry fruits (cv. “Clery” and cv. “Asia”) was studied and compared under the conditions of two different growing systems (under a high plastic tunnel and in the open field). Several chemical parameters were determined in the harvested fruits: dry matter, soluble solids, total acidity, ratio between sugars and acids, vitamin C, total phenols, non-flavonoid phenolic compounds, total anthocyanins, reducing sugars, sucrose, colour of fruits, and HPLC analysis of flavonols, flavanols, and phenolic acids content. The fruits of cultivar “Clery” had more antioxidant compounds than the fruits of cultivar “Asia” when grown in the open field. The fruits of both cultivars grown under a tunnel generally had good properties; however, the total phenol content and the non-flavonoid fraction were somewhat lower. Among the phenolic compounds, (+)-catehin, (−)-epicatehin, ellagic, p-coumaric acid, quercetin, and kaempferol were identified and quantified using HPLC equipped with Photo Diode Array detection. The highest content of phenolic compounds was found in cv. “Clery” from the open field production. Analysis of antioxidant compounds has not shown statistically significant differences as a result of growing system or grown cultivar. Samples of strawberries grown under a high plastic tunnel, regardless of examined cultivar, had better basic chemical parameters. The mash colour also depends on cultivar and growing system.

High-risk biodegradable waste processing by alkaline hydrolysis.

High-Risk Biodegradable Waste Processing By Alkaline Hydrolysis Biodegradable waste is by definition degraded by other living organisms. Every day, meat industry produces large amounts of a specific type of biodegradable waste called slaughterhouse waste. Traditionally in Europe, this waste is recycled in rendering plants which produce meat and bone meal and fat. However, feeding animals with meat and bone meal has been banned since the outbreaks of bovine spongiform encephalopathy (BSE). In consequence, new slaughterhouse waste processing technologies have been developed, and animal wastes have now been used for energy production. Certain parts of this waste, such as brains and spinal cord, are deemed high-risk substances, because they may be infected with prions. Their treatment is therefore possible only in strictly controlled conditions. One of the methods which seems to bear acceptable health risk is alkaline hydrolysis. This paper presents the results of an alkaline hydrolysis efficiency study. It also proposes reuse of the obtained material as organic fertiliser, as is suggested by the analytical comparison between meat and bone meal and hydrolysate. Oporaba visokorizičnog biorazgradivog otpada metodom alkalne hidrolize Biorazgradivi otpad definira se kao otpad koji razgrađuju živi organizmi. Klaonice i mesna industrija proizvode na dnevnoj bazi velike količine specifičnoga biorazgradivog otpada poznatog kao otpad životinjskog podrijetla. Tradicionalno se u Europi taj otpad reciklira u kafilerijama, pri čemu se proizvode mesno-koštano brašno i mast. No nakon pojave goveđe spongiformne encefalopatije (GSE) zabranjena je prehrana životinja mesno-koštanim brašnom. U potrazi za novim mogućnostima zbrinjavanja otpada životinjskog podrijetla razvijene su nove tehnologije oporabe i omogućena upotreba takvog otpada u energetske svrhe. Određeni dijelovi otpada životinjskog podrijetla, mozak i leđna moždina, pripadaju kategoriji visokorizičnog otpada zbog velike mogućnosti postojanja priona u njima. Njihova oporaba stoga je moguća samo u strogo kontroliranim uvjetima. Jedna od metoda koja se smatra prikladnom za oporabu visokorizičnih otpada jest metoda alkalne hidrolize. U radu su prikazani rezultati analiza mesno-koštanog brašna i hidroliziranog otpada te njegova uporaba kao organskoga gnojiva.

Soil assessment based on botanical composition on habitats of autochthonous populations of red clover (Trifolium pratense L.)

One of the biggest challenges for the safe maize production is the yield stability in a wide range of environments with different soil fertility, weather conditions, prevailing pests and diseases as well as cultural practices. In order to achieve it, new hybrids with higher tolerance to biotic and abiotic stress are continuously being created. In order to compare performance of maize hybrids in environments with different levels and types of stress, and relate it to the stalk lodging incidence, we compared performance of 64 maize hybrids obtained by crossing 16 inbred lines with four inbred testers in three different environments. Two environments at same location (Rugvica) differed in crop rotation, and the third environment at location Botinec was considered as dry because of low water capacity of the soil. Mixed models that included all design elements and genetic background of hybrids were used to analyze the effect of lodging on yield in different environments. The results show that stalk lodging had a significant effect on yield, but significant lodging x environment interaction indicates that this effect was rather environment specific.Sweet pepper Istra F1 hybrid was grown in a greenhouse on K rich soil. For evaluation of K antagonism, two K rates (55 and 85 kg ha-1) were applied in a randomized complete block design with four replications. Total number of fruits, total number of BER affected fruits as well as average fruit mass were recorded for each harvest. Fruit and leaf K and Ca content were determined at three plant growth stages (at the stage of the first, third and fifth fruit cluster). Higher K rate gave higher : average fruit mass (169.45 g), total number of fruits per plant (7.95), number of BER affected fruits per plant (3.82), K in leaves (5.44% DM), K in fruits (6.35% DM), but negatively correlated with Ca concentration in fruits (0.57% DM) and leaves (3.24% DM). This resulted in decreased marketable yield of sweet pepper fruits.

Efficiency of alpha designs in Croatian variety trials

Regulations of variety trials in Croatia prescribe RCBD as the only possible trial design. This could cause many problems, especially when a large number of varieties have to be tested. In order to explore the possibilities of improving the efficiency of variety trials through the use of alternative trial design, RCBD was substituted by alpha design in a project funded by the Ministry of Agriculture and Forestry.