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Carlos A. Lazcano, L.M. Pike, and K.S. Yoo

A new designer carrot, `BetaSweet', with high levels of anthocyanin, betacarotene, and crispy texture was developed by the Vegetable Improvement Center at Texas A&M Univ. The new carrot contained low levels of low-volatile terpenoids, responsible for the harsh flavor in carrots and high levels of reducing sugars. Carotenoid content increased with carrot maturity and stabilize at 120 days after sowing for orange and maroon genotypes; however, the maroon genotype was 35% higher than the orange cultivar. Anthocyanin, a cancer preventive compound and not detected in ordinary orange carrots, is present in `BetaSweet' maroon carrot with 89.8 mg·100 g-1 of fresh weight. High percentage of soluble solids and succulence in the maroon cultivar seemed to contribute to the favored sweetness perception by consumers. A consumer taste panel showed a significant difference between orange and maroon genotype for sweetness, texture, and overall carrot flavor.

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Carlos A. Lazcano, Fred T. Davies Jr., Sharon A. Duray, Andres Estrada-Luna, and Victor Olalde-Portugal

Mature cladodes of prickly-pear cactus (Opuntia amyclaea Tenore. cv. Reina) were treated with five wounding methods and four concentrations of potassium salt indolebutyric acid (K-IBA) to stimulate adventitious root formation. K-IBA from 4144 to 41,442 μm (1000 to 10,000 mg·L-1) increased root number and root dry weight; however, root length was decreased at 41,442 μm (10,000 mg·L-1). Root number and root dry weight were higher with wounding methods that had larger wounded surface areas. K-IBA altered rooting polarity and stimulated adventitious root formation along the wounded cladode surfaces. Treatments without suberization had a higher percentage of rotted cladodes. This research validates the commercial practice in Mexico of suberizing cladodes early in the propagation cycle. Auxin application could be of commercial benefit for enhanced rooting in the clonal regeneration of new selections for prickly-pear cactus orchards. The wounding methods and auxin treatments utilized make an excellent classroom demonstration for manipulating rooting polarity.

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Carlos A. Lazcano, Fred T. Davies Jr., Andrés A. Estrada-Luna, Sharon A. Duray, and Victor Olalde-Portugal

Mature cladodes of prickly-pear cactus (Opuntia amyclaea Tenore. `Reina') were treated with five wounding methods and four concentrations of potassium salt indole-3-butyric acid (K-IBA) to stimulate adventitious root formation. The wounding method and K-IBA had highly significant effects on root number and root dry mass of cladodes. Interaction between K-IBA and wounding methods showed that greater root number was obtained at the higher auxin concentrations and with wounding methods that had the greatest cut surface area. K-IBA concentrations from 4,144 to 41,442 μm (1,000 to 10,000 mg·L-1) increased root dry mass. Only the wounding method affected rotting of cladodes. Treatments allowing suberization had a higher percentage of nonrotted cladodes. This research validates the commercial practice of allowing cladodes to suberize early in the propagation cycle. K-IBA altered rooting polarity and stimulated adventitious root formation along the wounded cladode surfaces. The vertical nonsuberized wounding methods and auxin treatments are an excellent classroom demonstration for manipulating rooting polarity. Auxin application and wounding could be of commercial benefit for enhanced rooting in the clonal regeneration of new selections for prickly-pear cactus orchards.

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Carlos A. Lazcano, Frank J. Dainello, Leonard M. Pike, Marvin E. Miller, Lynn Brandenberger, and Larry R. Baker

Carrot (Daucus carota Mill. cv. Caropak) was studied under four population densities, and three numbers of seed lines per bed, and was harvested under three root size harvest parameters. Four phases (cutting, grading, peeling, and marketable yield) in the cut-and-peel baby carrot process were evaluated. Root length was most desirable when plots were harvested when 25% to 35% of the roots measured >2 cm in diameter. Roots were longest (14.7 cm) in the treatments containing six seed lines per bed. The harvest criteria of 25% to 35% root diameter >2 cm also produced the highest fresh mass (48.1 t·ha-1), and the highest cut and graded mass (37.7 and 32.3 t·ha-1, respectively). A population density of 321 plants/m2 produced the highest fresh and cut mass. Percent cut waste (21.6% crowns and tips) was not affected by root size at harvest, but percent graded waste was lowest (14.2%) when plants were harvested at the greatest root size. Four seed lines per bed produced the highest graded (18.4%), and total waste (61.2%), but not cut waste. The lowest total waste, estimated at 59.7% and the highest projected marketable yield (19.4 t·ha-1) occurred when roots were harvested using the 25% to 35% root diameter >2-cm parameter. Total waste and marketable yield were obtained using a fixed waste value of 40% in the peeling phase (peeling, polishing, and grading before packing). This percentage could vary depending on the equipment specifications and quality control of a given processing facility. Root size at harvest proved to be the main factor affecting projected marketable yield of cut-and-peel baby carrots at the population densities used in this study.

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Carlos A. Lazcano, Frank J. Dainello, Leonard M. Pike, Marvin E. Miller, Lynn Brandenberger, and Larry R. Baker

Carrot (Daucus carota Mill. cv. Caropak) was studied under four population densities, and three numbers of seed lines per bed, and was harvested under three root size harvest parameters. Four phases (cutting, grading, peeling, and marketable yield) in the cut-and-peel baby carrot process were evaluated. Root length was most desirable when plots were harvested when 25% to 35% of the roots measured > 2 cm in diameter. Roots were longest (14.7 cm) in the treatments containing six seed lines per bed. The harvest criteria of 25% to 35% root diameter >2 cm also produced the highest fresh mass (48.1 t·ha-1), and the highest cut and graded mass (37.7 and 32.3 t·ha-1, respectively). A population density of 321 plants/m2 produced the highest fresh and cut mass. Percent cut waste (21.6% crowns and tips) was not affected by root size at harvest, but percent graded waste was lowest (14.2%) when plants were harvested at the greatest root size. Four seed lines per bed produced the highest graded (18.4%), and total waste (61.2%), but not cut waste. The lowest total waste, estimated at 59.7% and the highest projeced marketable yield (19.4 t·ha-1) occurred when roots were harvested using the 25% to 35% root diameter >2-cm parameter. Total waste and marketable yield were obtained using a fixed waste value of 40% in the peeling phase (peeling, polishing, and grading before packing). This percentage could vary depending on the equipment specifications and quality control of a given processing facility. Root size at harvest proved to be the main factor affecting projected marketable yield of cut-and-peel baby carrots at the population densities used in this study.

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Carlos A. Lazcano, Frank J. Dainello, Leonard M. Pike, Marvin E. Miller, Lynn Brandenberger, and Larry R. Baker

Baby-style carrot Daucus carota Mill. cv. Caropak was studied under four population densities, three different numbers of lines per bed, and harvested under three root size harvest parameters in the Rio Grande Valley of Texas. Four phases in the baby-style carrot process were evaluated. Length of the roots at harvest and projected values for total waste and marketable yield were estimated. Length was affected by root size at harvest, the most desirable root length occurred when harvested at 25%-35% roots diameter >2 cm. The longer roots (16.55 cm) were in the treatments with 6 seed lines per bed and 197 plants/m2. Population density affected the fresh and cut weight in the baby-style carrots process with the highest weight at 321 plants/m2. Percent of cut waste was the same at the three-root size at harvest with 21.65% of crowns and tips cut. The percent of graded waste was lowest when harvested at the biggest root size, 14.23% and four seed lines per bed produced the highest waste with 18.14. Seed lines per bed affected the quality of the roots in the graded step. Based on a 40% peeling waste projection the lowest total waste was estimated at 59.69% and the highest projected marketable yield of 19.4 t/ha of final product when roots were harvested using the 25%-35% root diameter parameter. Root size at harvest is the main factor affecting projected marketable yield of baby-style carrots in South Texas.