ABSTRACT Global demand for bio-based energy is on the rise and so is research on bioenergy feedst... more ABSTRACT Global demand for bio-based energy is on the rise and so is research on bioenergy feedstock productivity. In this study, seven cultivars of grain sorghums (‘301/41,’ ‘304/5,’ ‘319/8,’ ‘319/22,’ ‘341/10,’ ‘341/120,’ and ‘366/58’) which developed in the drylands of Texas-US were evaluated in the Mid-Atlantic, a relatively wet region. The objective of the study was to evaluate crop response to phosphorus, productivity in the Mid-Atlantic, and its potential for bioethanol production. Seed yield, starch, and element content, stover biomass, forage quality, and whole-plant bioethanol yield were determined. Phosphorus had no effect, and only cultivars were compared. Cultivar showed differences in seed and stover yield, seed quality attributes, and potential bioethanol yield. Cultivar ‘366/58’ produced the greatest seed yield averaged at 4934 kg ha −1 yr −1 while ‘301/41’ and ‘341/10’ produced the least averaged at 2,743 and 2,968 kg ha −1, respectively, Stover yield across years ranged from 6,798 to 13,365 kg ha −1, and the whole plant estimated bioethanol ranged from 3,159 to 5,770 L ha −1. The stover had appreciable forage quality, including a 49 g kg −1 crude protein, sufficient for animal maintenance needs. Up to 96 kg N ha −1 and 211 kg K ha −1 were removed from harvested stover, an issue of concern for crop fertilizer management strategy and sustained production.
Economically feasible and effective hop drying strategies are urgently needed to respond to the i... more Economically feasible and effective hop drying strategies are urgently needed to respond to the increasing number of microbrewers in US. In this study, hops were dried by dehydrator-drying (52 °C), oven-drying (52 °C) and freeze-drying (25 °C) until the final moisture content reached 8-10%. Headspace solid-phase microextraction-gas chromatography-mass spectrometry-olfactometry (HS-SPME-GC-MS-O) was employed to analyze the aroma profiles in all dried hops. Methyl octanoate, β-myrcene, trans-α-bergamotene, linalool and geraniol were perceived as high-intensity aromas in all samples. Generally, dehydrator-dried hops contained the highest contents of aroma compounds among all groups, showing an increase of 5-23% and 6-37% when compared to freeze- and oven-dried hops, respectively. Principal component and hierarchical cluster analyses also revealed aroma content differences from three drying methods. Dehydrator drying at 52 °C was therefore considered as an alternative and promising drying approach for smaller-scale hop processing, which can largely benefit regional producers and local craft breweries.
There are differences in walnut quality through the tree canopy which may be related to water rel... more There are differences in walnut quality through the tree canopy which may be related to water relations and/or light gradients. We have made significant progress on understanding the role of canopy position and light exposure on quality related problems in walnut. The data we have at present suggests that photosynthate reduction early in the season results in shriveled nuts while later restriction results in either yellow or black pellicles, depending on the timing. Some of the yellow nuts occurred in positions where the spur was in a well lit position early in the season but became shaded as the season progressed due to higher limbs coming down on top of them. All of the nuts with yellow and black pellicles had a mushy, wet hull surrounding the nut. The photosynthate reduction can be caused by low light conditions and/or loss of leaves. In addition, it appears that orchards running near the fully watered baseline (in the -4 to -5.5 bar midday stem water potential range) have a decr...
Drought stress is an environmental factor that causes severe yield loss in agriculture. Identifyi... more Drought stress is an environmental factor that causes severe yield loss in agriculture. Identifying new genetic resources is key to improving crop drought tolerance. Purslane (Portulaca spp.) is a xerophyte that grows in extreme drought conditions worldwide. Here, we report genetic variation in drought tolerant phenotypes, and AFLP-based genetic diversity among purslane accessions collected from geographically diverse regions. Variations among different purslane accessions occurred at seed germination, seedling and adult stages with Tokombiya identified as the most drought tolerant accession at adult stage. Genetic diversity among purslane accessions was evaluated by AFLP fingerprinting. Using the average genetic similarity as cut-off value, four distinct groups were classified by UPGMA-cluster analysis, and Tokombiya was found to be distinct from all other purslane accessions. Together, these results suggest that significant genetic variations exist among purslane accessions and To...
Abstract. Soil and whole plant samples were collected from two natural populations of Appalachian... more Abstract. Soil and whole plant samples were collected from two natural populations of Appalachian black cohosh (Actaea racemose L.) to assess soil-plant-microbe interactions and determine seasonal mineral acquisition by the species. A. racemosa is one among medicinal forest plants subject to excessive harvesting, and there is increasing concern over the sustainability of natural populations. Following standard procedures, mineral content and chemistry of soils sampled from the two sites were determined, and monthly (May to August) A. racemosa root, stem, and leaf mineral content were analyzed. Fresh tissue samples were processed for isolation and genotyping of associated endophytic organisms, and classical root staining was used to assess presence and extent of the arbuscular mycorrhizal (AM) symbiosis. Results showed that forest soils in the natural habitat of A. racemosa are slightly acidic (pH 4.5–6.0; 40–70% base saturation) with high organic matter (6–25%) and microelement cont...
The Pacific Northwest grows the majority of hops in the United States; however, the region is exp... more The Pacific Northwest grows the majority of hops in the United States; however, the region is experiencing an increase in the number of days with high heat. In addition, there is an increased interest in growing hops in other warmer regions of the United States. To understand how hop plants respond to high temperatures, we measured several physiological traits of six hop cultivars under a range of temperatures from 15 to 45 °C. We found that hop plants achieved maximal carbon assimilation at temperatures of 21 to 39 °C when given sufficient water. At temperatures of 41 °C and higher, all cultivars experienced declines in carbon assimilation. This was likely due to multiple effects on the cell, including damage to photosystem II (PSII), as reflected in declines in FV/FM, damage to membrane integrity as reflected in electrolyte leakage at high temperatures, and declines in Rubisco activity likely due to degradation of Rubisco activase, as reflected in declines in Vc,max. ‘Cascade’, ‘W...
The French American hybrid grape cultivars Corot noir and Arandell (Vitis sp.), and Vidal blanc a... more The French American hybrid grape cultivars Corot noir and Arandell (Vitis sp.), and Vidal blanc and Petit Manseng (Vitis vinifera), along with different spray programs, were evaluated for potential organic production in Virginia from 2013 to 2014. Results obtained in the study demonstrate that organic wine grape production in Virginia can be achieved by using select grape cultivars and spray programs. With the exception of Vidal blanc, disease severity and disease incidence were below the threshold for maintaining healthy vines in all organically managed grape cultivars. ‘Vidal blanc’ was not sufficiently resistant to downy mildew (Plasmopara viticola), precluding it from potential organic management in Virginia. The study also demonstrated significant disease resistance in Virginia of the cultivar Arandell, released by Cornell University (Ithaca, NY) in 2013. The results suggest that the organically registered fungicide Bacillus subtilis is effective in reducing the severity and in...
ABSTRACT Global demand for bio-based energy is on the rise and so is research on bioenergy feedst... more ABSTRACT Global demand for bio-based energy is on the rise and so is research on bioenergy feedstock productivity. In this study, seven cultivars of grain sorghums (‘301/41,’ ‘304/5,’ ‘319/8,’ ‘319/22,’ ‘341/10,’ ‘341/120,’ and ‘366/58’) which developed in the drylands of Texas-US were evaluated in the Mid-Atlantic, a relatively wet region. The objective of the study was to evaluate crop response to phosphorus, productivity in the Mid-Atlantic, and its potential for bioethanol production. Seed yield, starch, and element content, stover biomass, forage quality, and whole-plant bioethanol yield were determined. Phosphorus had no effect, and only cultivars were compared. Cultivar showed differences in seed and stover yield, seed quality attributes, and potential bioethanol yield. Cultivar ‘366/58’ produced the greatest seed yield averaged at 4934 kg ha −1 yr −1 while ‘301/41’ and ‘341/10’ produced the least averaged at 2,743 and 2,968 kg ha −1, respectively, Stover yield across years ranged from 6,798 to 13,365 kg ha −1, and the whole plant estimated bioethanol ranged from 3,159 to 5,770 L ha −1. The stover had appreciable forage quality, including a 49 g kg −1 crude protein, sufficient for animal maintenance needs. Up to 96 kg N ha −1 and 211 kg K ha −1 were removed from harvested stover, an issue of concern for crop fertilizer management strategy and sustained production.
Economically feasible and effective hop drying strategies are urgently needed to respond to the i... more Economically feasible and effective hop drying strategies are urgently needed to respond to the increasing number of microbrewers in US. In this study, hops were dried by dehydrator-drying (52 °C), oven-drying (52 °C) and freeze-drying (25 °C) until the final moisture content reached 8-10%. Headspace solid-phase microextraction-gas chromatography-mass spectrometry-olfactometry (HS-SPME-GC-MS-O) was employed to analyze the aroma profiles in all dried hops. Methyl octanoate, β-myrcene, trans-α-bergamotene, linalool and geraniol were perceived as high-intensity aromas in all samples. Generally, dehydrator-dried hops contained the highest contents of aroma compounds among all groups, showing an increase of 5-23% and 6-37% when compared to freeze- and oven-dried hops, respectively. Principal component and hierarchical cluster analyses also revealed aroma content differences from three drying methods. Dehydrator drying at 52 °C was therefore considered as an alternative and promising drying approach for smaller-scale hop processing, which can largely benefit regional producers and local craft breweries.
There are differences in walnut quality through the tree canopy which may be related to water rel... more There are differences in walnut quality through the tree canopy which may be related to water relations and/or light gradients. We have made significant progress on understanding the role of canopy position and light exposure on quality related problems in walnut. The data we have at present suggests that photosynthate reduction early in the season results in shriveled nuts while later restriction results in either yellow or black pellicles, depending on the timing. Some of the yellow nuts occurred in positions where the spur was in a well lit position early in the season but became shaded as the season progressed due to higher limbs coming down on top of them. All of the nuts with yellow and black pellicles had a mushy, wet hull surrounding the nut. The photosynthate reduction can be caused by low light conditions and/or loss of leaves. In addition, it appears that orchards running near the fully watered baseline (in the -4 to -5.5 bar midday stem water potential range) have a decr...
Drought stress is an environmental factor that causes severe yield loss in agriculture. Identifyi... more Drought stress is an environmental factor that causes severe yield loss in agriculture. Identifying new genetic resources is key to improving crop drought tolerance. Purslane (Portulaca spp.) is a xerophyte that grows in extreme drought conditions worldwide. Here, we report genetic variation in drought tolerant phenotypes, and AFLP-based genetic diversity among purslane accessions collected from geographically diverse regions. Variations among different purslane accessions occurred at seed germination, seedling and adult stages with Tokombiya identified as the most drought tolerant accession at adult stage. Genetic diversity among purslane accessions was evaluated by AFLP fingerprinting. Using the average genetic similarity as cut-off value, four distinct groups were classified by UPGMA-cluster analysis, and Tokombiya was found to be distinct from all other purslane accessions. Together, these results suggest that significant genetic variations exist among purslane accessions and To...
Abstract. Soil and whole plant samples were collected from two natural populations of Appalachian... more Abstract. Soil and whole plant samples were collected from two natural populations of Appalachian black cohosh (Actaea racemose L.) to assess soil-plant-microbe interactions and determine seasonal mineral acquisition by the species. A. racemosa is one among medicinal forest plants subject to excessive harvesting, and there is increasing concern over the sustainability of natural populations. Following standard procedures, mineral content and chemistry of soils sampled from the two sites were determined, and monthly (May to August) A. racemosa root, stem, and leaf mineral content were analyzed. Fresh tissue samples were processed for isolation and genotyping of associated endophytic organisms, and classical root staining was used to assess presence and extent of the arbuscular mycorrhizal (AM) symbiosis. Results showed that forest soils in the natural habitat of A. racemosa are slightly acidic (pH 4.5–6.0; 40–70% base saturation) with high organic matter (6–25%) and microelement cont...
The Pacific Northwest grows the majority of hops in the United States; however, the region is exp... more The Pacific Northwest grows the majority of hops in the United States; however, the region is experiencing an increase in the number of days with high heat. In addition, there is an increased interest in growing hops in other warmer regions of the United States. To understand how hop plants respond to high temperatures, we measured several physiological traits of six hop cultivars under a range of temperatures from 15 to 45 °C. We found that hop plants achieved maximal carbon assimilation at temperatures of 21 to 39 °C when given sufficient water. At temperatures of 41 °C and higher, all cultivars experienced declines in carbon assimilation. This was likely due to multiple effects on the cell, including damage to photosystem II (PSII), as reflected in declines in FV/FM, damage to membrane integrity as reflected in electrolyte leakage at high temperatures, and declines in Rubisco activity likely due to degradation of Rubisco activase, as reflected in declines in Vc,max. ‘Cascade’, ‘W...
The French American hybrid grape cultivars Corot noir and Arandell (Vitis sp.), and Vidal blanc a... more The French American hybrid grape cultivars Corot noir and Arandell (Vitis sp.), and Vidal blanc and Petit Manseng (Vitis vinifera), along with different spray programs, were evaluated for potential organic production in Virginia from 2013 to 2014. Results obtained in the study demonstrate that organic wine grape production in Virginia can be achieved by using select grape cultivars and spray programs. With the exception of Vidal blanc, disease severity and disease incidence were below the threshold for maintaining healthy vines in all organically managed grape cultivars. ‘Vidal blanc’ was not sufficiently resistant to downy mildew (Plasmopara viticola), precluding it from potential organic management in Virginia. The study also demonstrated significant disease resistance in Virginia of the cultivar Arandell, released by Cornell University (Ithaca, NY) in 2013. The results suggest that the organically registered fungicide Bacillus subtilis is effective in reducing the severity and in...
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