Response of Oil Production and Quality to Hedgerow Design in Super-High-Density Olive cv. Arbequina Orchards

An analysis is presented of the response of olive oil production and quality parameters, viz. fatty acids (palmitic, oleic and linoleic acids), phenolic compounds and oxidative stability to hedgerow spacing and orientation in 1-m wide super-high-density orchards of cv. Arbequina. Data reveal strong linear relationships between concentrations of fatty acids and internal irradiance within hedgerows, positive for palmitic and linoleic but negative for oleic acid. The result is a significant vertical trend in oil composition within hedgerows, but small to negligible differences in oil harvested from them in totality. The explanation is found in the small ranges and strongly correlated responses of individual fatty acids that together comprise 98% of oil mass. Phenolic compounds respond more widely and to higher levels of irradiance than fatty acids and did show increases in NS hedgerows grown at wide row spacing. Oxidative stability shows a similar trend in phenolic compounds. A simulation study that extended the known responses to 2-m wide hedgerows showed that the linkage between fatty acid profiles was maintained with no resultant differences in the oil composition of the total simulated oil harvest. Based on the current understanding of internal irradiance within olive hedgerows, there seems to be little opportunity to manage oil quality by orchard structure.

The impact of the conservation tillage “maize into grass cover” on reducing the soil loss due to erosion

Maize (Zea mays L.) belongs among the most important agriculture crops all over the world. The conventional way of cultivating maize with wide row spacing does not have a soil conservation effect and significantly contributes to water erosion and surface run-off. In our research, we tested the soil conservation technology (strip-till into grass cover) which took place in 2016 and 2017 in the location of Central Bohemia. The impact of a strip-till system of maize into grass cover on reducing the soil loss due to erosion was verified on the area of 21 m² using a rainfall simulator. During the research, 70 measurements were realised. The strip-till was compared to fallow land, conventional cultivation and no-till methods. Profound differences were found in the soil loss between the treatments. There was a decrease in the soil loss of about 98% in the strip-till compared to the conventional cultivation. Moreover, the surface run-off was reduced by 79%. The ANCOVA (analysis of covariance) models of the log-transformed soil loss on the surface run-off and treatment were highly significant (P < 10^–15). The measurement results clearly demonstrate the positive effect of the strip-till into the grass on the surface run-off and soil loss. This positive soil conservation effect was observed even in springtime, as well as the rest of the season. Using a grass cover for establishing the maize significantly contributes to the soil conservation on the land threatened by erosion and offers farmers a suitable way of farming when growing maize. Strip-tilling is a technology that has great potential in sustainable farming.

Sowing parameters influenced on proso millet quality and yielding capacity

The aim of the research is to define optimal sowing parameters that ensure the highest yielding capacity and high quality of the proso millet seeds (Panicum miliaceum L.). To achieve a stated goal we established and analyzed multiple-factor interrelations of the formation of highly productive seed sowing of the proso millet by improving sowing methods and sowing rates as well as conditions improving sowing qualities and yielding capacity of seeds with the application of correlation pleiades. We founded that deviation from the recommended sowing rates in production results in the decline of yielding capacity level. We also suggested that the deficit of seed material caused the highest shortfalls in seed yields compared to its over-expenditure; moreover, the seed planted with wide row spacing had the best yielding capacity, while sowing with row spacing of 15 cm and sowing rate at 3.5 million seeds/ha provided the its highest yielding capacity.

Effect of Drill-Seeded Soybean Density and Residual Herbicide on Palmer Amaranth (Amaranthus palmeri) Emergence

Palmer amaranth is the most troublesome weed of soybean in the southern United States. Field experiments were conducted at two Arkansas locations to determine the effect of drill-seeded soybean density on Palmer amaranth emergence. Experimental factors were multiple soybean seeding rates planted on a 19-cm-wide row spacing and the presence or absence of a PRE residual herbicide (flumioxazin plus pyroxasulfone). Soybean groundcover was measured throughout the growing season and daily soil temperature was recorded in selected soybean densities. In the absence of a PRE residual herbicide, at least a 1.7-fold reduction in Palmer amaranth emergence occurred when soybean were present. Differences in Palmer amaranth emergence occurred among soybean densities for both locations, suggesting the value of crop canopy in preventing Palmer amaranth emergence in the absence of an effective residual herbicide. In plots treated with the PRE herbicide, no difference in Palmer amaranth emergence occurred among soybean densities, except for the absence of soybean. Achievement of 95% groundcover by soybean reduced daily soil temperature fluctuations, which in turn reduced Palmer amaranth emergence. For both locations, soybean grain yields were greatest at the highest seeding rate (617,500 seed ha−1). In the presence of flumioxazin plus pyroxasulfone applied PRE, greater grain yields occurred compared to the absence of a PRE herbicide at both Fayetteville and Marianna. Based on this research, an effective PRE-applied residual herbicide has more influence on Palmer amaranth emergence than soybean density, and Palmer amaranth germination and emergence are dependent upon daily soil temperature fluctuations, which is a function of soybean density.

Carrier Volume is More Likely to Impact Trifluralin Efficiency than Crop Residue

PRE herbicides are generally less effective in conservation farming systems because of high levels of crop residue. However, performance can be improved if the herbicides are applied with a high carrier volume. This research investigated the interaction of carrier volume and row spacing or height of crop residue on the control of rigid ryegrass with trifluralin, at Cunderdin and Wongan Hills Western Australia. To create plots with varying residue row spacing in 2011, wheat was seeded in 2010 using a narrow row spacing (25 or 22 cm at Cunderdin and Wongan Hills), wide spacing (50 or 44 cm), or not planted to wheat. Narrow or wide row spacing or no crop plots had an average residue biomass of 4480, 3560, and 2430 kg ha−1at Cunderdin and 1690, 1910, and 1030 kg ha−1at Wongan Hills. To vary residue height, the wheat was harvested to produce tall, medium, or short crop residue (22, 13, and 5 cm at Cunderdin and 27, 22, and 17 cm at Wongan Hills). Rigid ryegrass seeds were broadcast onto each site in 2011 and trifluralin was sprayed using 50, 75, or 100 L ha−1carrier volume (directly prior to seeding). Increased carrier volume increased spray coverage at both sites (average cover of 9, 15, and 26% at 50, 75, and 100 L ha−1), leading to improved control of rigid ryegrass (68, 75, and 82% control at Cunderdin and 23, 41, and 68% control at Wongan Hills). Reduced crop residue height or increased row spacing led to reduced rigid ryegrass density at Cunderdin but had no impact at Wongan Hills. Therefore, carrier volume has a more consistent impact on the performance of trifluralin than crop residue row spacing or height.

Effect of Varied NPK Fertilization on Catalase Activity of Amaranth (Amaranthus Cruentus L.)

A study was carried out on the effect of varied NPK fertilization on catalase activity per gram fresh weight of the leaves of two varieties of amaranth, Rawa and Aztek, at different developmental stages (seedling, five-leaf, flowering and mature seed), as well as in the seeds. Amaranth was grown in a field experiment in southeast Poland, at wide-row spacing on good wheat complex soil. The following combinations of macronutrient levels were applied: I - 50 kg N ・ ha-1, 40 kg P ・ ha-1, 40 kg K ・ ha-1, II - 70 kg N ・ ha-1, 50 kg P ・ ha-1, 50 kg K ・ ha-1, III - 90 kg N ・ ha-1, 60 kg P ・ ha-1, 60 kg K ・ ha-1 and IV - 130 kg N ・ ha-1, 70 kg P ・ ha-1, 70 kg K ・ ha-1. The study showed that catalase activity exhibited a downward trend during the vegetation period of amaranth. The highest catalase activity was noted in the leaves during the first stage, ie the seedling stage. Increasing levels of NPK led to an increase in catalase activity. Leaves of the Rawa variety had higher catalase activity than those of the Aztek variety at every stage of development. The level of catalase activity in the amaranth seeds was also significantly affected by fertilization and the variety of amaranth. Higher levels of the fertilizers caused an increase in catalase activity in the seeds.