Marisol Berti

Zinc Fertilization Effects on Seed Cadmium Accumulation in Oilseed and Grain Crops Grown on North Dakota Soils

The Cd concentration in the seed of crops depends on various soil factors including parent material, texture, pH, soil redox, and salinity. Cadmium accumulation also varies among crop species and cultivars within a species. Cadmium and Zn may have either an antagonistic or a synergistic effect on plant uptake that can be influenced by the soil Cd and Zn concentrations. The objective was to determine the effect of Zn fertilizer additions on the seed Cd of nine crops commonly grown in North Dakota, USA. Studies were conducted at five North Dakota locations representing different soil series during 1994 and 1995. In Experiment 1, nine crops common in North Dakota were grown with and without the addition of 25 kg ha-1 Zn fertilizer. Among crops evaluated, the greatest seed Cd accumulation occurred in flax ( Linum usitatissimum L.) followed by sunflower ( Helianthus annuus L.), soybean ( Glycine max [L.] Merr.), and durum wheat ( Triticum turgidum L. var. durum). In Experiment 2, two durum wheats and one flax cultivar were grown under three Zn treatments of 0, 5, and 25 kg ha-1. In Experiment again flax had the higher seed Cd level compared with the two durum varieties. Based on the results from both studies, addition of Zn fertilizer did not consistently reduce seed Cd content, and even when statistically significant, the level of reduction was small and not likely to impact marketability of Cd accumulating crops such as flax, sunflower, soybean, and durum.

Borage (Borago officinalis L.) Response to N, P, K, and S Fertilization in South Central Chile

Borage (Borago officinalis L.) is an oilseed with a high gamma-linolenic acid (GLA) content in its seed. The objective of this study was to determine the response of borage seed yield, oil content, and fatty acid composition to N, P, K, and S fertilizer treatments. Three experiments were conducted in Osorno (40o22’ S, 73o04’ W; 72 m.a.s.l.), Chile. The first experiment was conducted during the 2005-2006 growing season, with four N rates (0, 100, 200, and 300 kg N ha -1 ), three P rates (0, 60, and 120 kg P2O5 ha -1 ) and two K rates (0 and 150 kg K2O ha -1 ). The second experiment was conducted in 2006-2007 and evaluated only the effect of four N rates (0, 50, 100 and 150 kg N ha -1 ) was evaluated because there was no response to P and K in the first experiment. The third experiment was conducted in the 2005-2006 and 2006-2007 and evaluated only two rates of S, 0 and 40 kg S ha -1 were evaluated. Seed yield was not affected by N, P, K, or their interactions in any of the experiments. As N rates increased GLA content increased. Mean seed yield increased to 98 kg ha -1 when appliying of 40 kg S ha -1 . Results indicate that borage has a higher response to S applications than N. Further research is needed to determine the interactions between N and S applications, given that the experiments were conducted on soils with high levels of P and K levels.

Genotype × Environment Interaction in Canola (Brassica napus L.) Seed Yield in Chile

Genotype x environment (G × E) interaction in canola ( Brassica napus L.) cultivar seed yield is unknown in Chile. The interaction was performed with the SREG (Sites Regression) model. Two experiments were conducted in five and thirteen environments in the 2008-2009 season in Central South Chile. The experimental design was a randomized complete block (RCBD) in each environment with four replicates and 26 open-pollinated or hybrid canola genotypes in Experiment 1, and RCBD with three replicates and 17 genotypes in Experiment 2. ANOVA was used to determine the significance of the G × E interaction. Biplots were used to graphically interpret and determine the best cultivar in each environment and the corresponding mega-environments. The G × E interaction was significant for seed yield in many locations in one cropping season. Most of the analyzed seed yield variation was due to environment and G × E effects. Principal components (PC1 and PC2) of the Sites Regression (SREG) model, with five and eight environments, accumulated 74.5% and 61.1% of the total variation, respectively. Two mega-environments were formed; the first being the Chillan environment while the second included the remaining environments. Six of the evaluated cultivars, all hybrids except ‘Goya’, were superior. The mean vs. stability analysis indicated that the Monalisa hybrid had the highest yield and was the most stable cultivar across all environments. Although the information is for only 1 yr, results could change with data from several years of experimentation. Hence, the study was carried out in many locations in order to provide validity to the results.

Calidad de Cardo Mariano (Silybum marianum (L.) Gaertn.) Cosechado en Diferentes Estados Fenológicos

Two milk thistle genotypes (Silybum marianum (L.) Gaertn.), German and Chilean, were cultivated to determine the most suitable moment of harvest. A randomized complete block design with a split plot arrangement and four replicates was used. The main plot was harvested timeliness (2, 4, 6 y 10 mature capitula in 50% of the plants) and the subplot was the genotype. For the harvest, the weight of 1000 seeds, the percentage of mature seeds and the silymarin content were evaluated. Always the German genotype showed higher mature seed proportion and with higher weight than the Chilean one. However, the Chilean genotype seeds showed higher silymarin content. This study concluded that the most adequate moment for harvest is the physiological state of four mature capitula for both genotypes.

Cuphea Production and Management

The genus Cuphea (Lythraceae) is quite unique in that most of its 265 different species synthesize and store primarily medium-chain fatty acids (MCFA) in their seeds, and many flourish in temperate climates. Presently, the United States and other developed countries import millions of tons of tropical plant-related oils to provide MCFA for industrial chemical manufacturing. Cuphea can serve as an additional source for these fatty acids. Since about the early 1980s, a concerted effort in the United States has been made to domesticate cuphea as a commercial, temperate climate crop source of MCFA for the manufacturing of a myriad of industrial chemicals. The biggest breakthrough came in the 1990s when more agronomically friendly genotypes were developed through the interspecific hybridization of C. viscosissima and C. lanceolata. Since that time, significant strides have been made in developing best agricultural management practices for the commercial production of cuphea. Currently, small-scale seed production has taken place in the northern Corn Belt region of the United States for high-end value products such as those manufactured by the cosmetic industry. This review primarily focuses on advancements that have been made over the past decade in developing agricultural management for cuphea production.

Integration of Annual and Perennial Cover Crops for Improving Soil Health

Abstract Use of annual and perennial cover crops in rotation is a primary tool in agricultural systems, especially for improving soil health. Environmental benefits include erosion control and nutrient capture to protect water resources. On a field scale, cover crops are used to build physical, chemical, and biological soil properties. Annual grasses, brassicas, and legumes improve soil infiltration and reduce compaction through both fibrous and large tap root development. Nutrient capture, nutrient cycling efficiency, and associations with microbial communities are also benefits of including cover crops in rotation. Perennial grass and legume phases in rotation contribute to soil health through specific uses such as salinity management and general uses such as building nitrogen reserves for following cash crops. Overall, the research and agricultural communities continue to explore the many benefits of cover crops for soil health.