Genotype-dependent responses of apples to drought stress were evaluated between commercial and traditional apple cultivars. The results indicate different mechanisms of tolerance to investigated drought stress conditions. Chlorophyll fluorescence induction (OJIP) parameters, chlorophyll and carotenoid content, malondialdehyde (MDA), hydrogen peroxide (H₂O₂), proline, phenols and leaf water content (WC) were measured. The traditional cultivar “Crvenka” confirmed the best tolerance to a drought stress condition, presenting higher photosynthetic efficiency, higher leaf water content, higher levels of chlorophyll content and lower lipid peroxidation with greater membrane stability. The commercial cultivar “Golden Delicious Reinders” showed decreased water content in leaves, increased lipid peroxidation levels and photoinhibition. Considering all results, the commercial cultivar “Golden Delicious Reinders” was adversely affected by drought, while traditional cultivars exhibited better tolerance to drought stress.

This four-year study with four elite soybean lines with different maturities was conducted to investigate the impact of deficit (a field water capacity, or FWC, of 60%) and full irrigation (an FWC of 80–100%) on soybean grain yield and grain quality (grain protein and oil contents and crude protein and oil yields), depending on the environmental conditions and genotype. Overall, the irrigation effect was positive for the grain yield and grain protein content but negative for the grain oil content. The differences between the full and deficit irrigation were only 2.9% for the grain yield, 2.8% for the crude protein yield and 1.7% for the crude oil yield. The results indicate that deficit irrigation could be the best option for optimizing soybean production in environments similar to the tested one. In such conditions, further rationalization of soybean production could be achieved by choosing the C2 genotype (0 maturity group), which, combined with deficit irrigation, had the highest grain, crude protein and crude oil yields.

Repetitive heat and drought stress conditions have a significant impact on quantity and quality of barley (Hordeum vulgare L.) production in most regions of the world. Objective of this study was to determine the relationships between photosynthetic performance index (PI ABS), water use (WU), grain yield-based water use efficiency (WUE G), and grain yield per pot (GYP) of winter barley cultivars grown in a pot trial under short-term drought stress conditions and grain yield and its stability from the multi-environmental field trials. Ten winter barley cultivars were examined in two water treatments. One treatment was well watered, while the second treatment was subjected to short-term stress caused by deficiency of water in the stages of full tillering, beginning of heading, and grain filling. PI ABS was measured at full tillering stage while WU, WUE G , and GYP of barley cultivars were estimated after the whole vegetative cycle. Also, multi-environmental field trials with the same winter barley cultivars were carried out during 4 yr (2004-2007) and 3 yr (2009-2011) with two sowing densities (300 and 450 seeds m-2) on multiple locations in the lowland part of the Republic of Croatia. ANOVA showed highly significant (P ≤ 0.001) cultivar effect for all of the examined traits in the pot trial. PI ABS of cultivars in both treatments was in a negative nonsignificant correlation with grain yield and grain yield stability (ecovalence) of the same cultivars in multi-environmental field trials. Winter barley cultivars with higher WU and WUE G also had higher values of grain yield, and harvest index observed on the basis of the pot trial. WU, WUE G , and GYP of 10 barley cultivars in pot trial showed highly positive phenotypic correlation with grain yield of all eight and 10 barley cultivars in the multi-environmental field trials. These results suggests that WU and WUE G could be good indicators for preliminary selection of modern, high yielding, and stable winter barley genotypes which have better water management capabilities.

In the decade from 2000 to 2009, the yield of maize grain in Croatia varied from 4.2 t ha⁻¹ (2003) to 8.0 t ha⁻¹ (2008). The yield variation was mainly caused by weather conditions unfavourable for maize production, meaning lack of precipitation, unevenly distributed during the vegetation season, and mean air temperatures above the long-term mean. Irrigation has become a justified and essential agrotechnical measure that minimizes the damage caused by water deficit during critical plant growth stages and ensures high yields with good quality. In this paper two vegetation seasons (2006 and 2007) with quite different weather conditions for maize production were analysed in order to examine the importance of irrigation in terms of yield increase, irrigation water use efficiency (IWUE), irrigation efficiency (IE) and irrigation water use index (IWUI) in years favourable (2006) or too dry (2007) for maize production. The yield surpluses achieved with irrigation ranged from 8.54 t ha⁻¹ to 9.62 t ha⁻¹ in the average crop year (2006) and from 8.43 t ha⁻¹ to 10.7 t ha⁻¹ in the dry year (2007), depending on the irrigation method. In the dry year the values of IWUE where higher than in the average year (6.16 and 13.75 kg ha⁻¹/mm, respectively, averaged over the hybrids).

European corn borer (ECB) creates tunnels inside the plant stalks, causing damage, which could significantly decrease yield loss. This study aimed to determine the relationship between damage caused by ECB larval feeding and different irrigation and nitrogen fertilization rates on different maize genotypes. We conducted a field experiment in Croatia from 2012 to 2014. Increased plant nitrogen adsorption was observed under irrigation only in drought years, and it was decreased in optimal or extremely wet years. We found a weak or a moderate relationship between ECB damage and nitrogen concentration, but the greatest ECB damage was in all years recorded in treatments with the highest fertilization rates. However, the highest plant nitrogen concentration was observed in the hybrid with the lowest damage from ECB larvae. The maize damage caused by ECB larval feeding was negatively affected by high plant nitrogen concentrations only when plants were under drought stress. Nitrogen uptake was increased in irrigated plots. We did not find a strong relationship between the C/N ratio or irrigation and intensity of ECB damage. In 2012, when the narrowest C/N ratio was calculated, the greatest damage by ECB was measured. Further studies are needed since we detected the significant impact of drought on intensive ECB larval feeding.

U procesu proizvodnje kvalitetnog sjemena lucerne potrebno je proizvesti sjeme te ga adekvatno doraditi i skladištiti u skladu sa zakonskim aktima i pravilima struke. Stoga je i cilj ovog istraživanja bio utvrditi koji su dijelovi...