The application of mulch films for preserving soil moisture and preventing weed growth has been a... more The application of mulch films for preserving soil moisture and preventing weed growth has been a part of agricultural practice for decades. Different materials have been used as mulch films, but polyethylene plastic has been considered most effective due to its excellent mechanical strength, low cost and ability to act as a barrier for sunlight and water. However, its use carries a risk of plastic pollution and health hazards, hence new laws have been passed to replace it completely with other materials over the next few years. Research to find out about new biodegradable polymers for this purpose has gained impetus in the past few years, driven by regulations and the United Nations Organization’s Sustainable Development Goals. The primary requisite for these polymers is biodegradability under natural climatic conditions without the production of any toxic residual compounds. Therefore, biodegradable polymers developed from fossil fuels, microorganisms, animals and plants are viabl...
The faba bean (Vicia faba L.) crop often experiences drought during its growth and development su... more The faba bean (Vicia faba L.) crop often experiences drought during its growth and development such that soil moisture deficits constrain its production. As droughts are predicted to increase in both frequency and intensity due to climate change, a better understanding of drought response patterns and associated traits is essential for obtaining yield stability in water-limited environments. This review deals with adaptation mechanisms associated with drought avoidance, escape and tolerance, with an emphasis on physiological traits such as stomatal conductance, carbon isotope discrimination and leaf temperature. Leaf temperature is considered an effective surrogate measure for other measures of stomatal characteristics. Drought tolerance through osmotic adjustment has not yet been demonstrated in faba bean although it is found in many other legumes including chickpea and pea. Deeper root growth, leading to uptake of otherwise unavailable water, helps the plant to avoid drought by delaying dehydration, but genetic variation and heritability of the trait are essentially unknown for faba bean. Crop management strategies, such as early planting, and appropriate phenology, are particularly important for drought escape in regions where terminal drought is common. Disease resistance is especially important in drought-prone areas to reduce the need for expensive control measures when yields are uncertain. The relevance of soil fertility status and nutrient availability are also covered. Drought escape and ascochyta blight resistance are important breeding objectives for terminal drought regions. Some form of drought resistance is necessary for the transient droughts experienced in most regions, and drought avoidance can be screened by a combination of leaf temperature or other rapid test of stomatal characteristics followed by carbon isotope discrimination in the most valuable materials. No single trait is adequate to improve yield in drought-prone environments, rather, a combination of characteristics is needed.
Biodegradable mulches are considered a promising alternative to polyethylene-based, nonbiodegrada... more Biodegradable mulches are considered a promising alternative to polyethylene-based, nonbiodegradable mulch for sustainable agriculture. In the present study, a bioactive 2-methyl-4cholorophenoxyacetic acid/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (MCPA-PHBV) conjugate blended with biodegradable poly(butylene adipate-co-terephthalate/polylactide (PBAT/PLA) was developed and used as mulch under controlled condition greenhouse pot experiment with fava bean (Vicia faba) as the nontarget crop species. The objectives were to examine the effectiveness of sustained-release of MCPA herbicide from biodegradable mulch for broadleaf weed suppression and to assess any adverse effects of the herbicide on the nontarget species (fava bean). The energy-dispersive X-ray spectroscopy analysis (EDS) suggests that a substantial quantity of the herbicide was released from the biodegradable mulch which effectively killed the broadleaf weed species even at 1% MCPA concentration. However, the higher concentrations of the herbicide adversely affected several physiological parameters of fava bean growth and development. Stomatal conductance decreased, while leaf temperature subsequently rose (at MCPA concentrations 5, 7.5, and 10%). The quantum yield of the Photosystem II (PSII) indicates that the photosynthetic efficiency was also restricted at concentrations 7.5% and 10%. Evidently, this slow-release herbicide system worked efficiently for broadleaf weed control but at higher concentrations, resulted in adverse physiological effects on the nontarget crop species. This study has demonstrated that biodegradable mulches containing MCPA herbicide are able to effectively inhibit the growth of broad leaf weed species and may be of potential importance in a wide variety of horticultural and agricultural applications.
Isoproturon and Methabenzthiazuron and Post-emergence herbicides; Fomesafen, Fluazifopbutyl and M... more Isoproturon and Methabenzthiazuron and Post-emergence herbicides; Fomesafen, Fluazifopbutyl and Methabenzthiazuron alone and in combinations were evaluated to know their broad spectrum performance, if any; against a lentil variety Precoz. Hand weeded and weedy plots were kept for comparison of yield and economic gains. Most of the herbicides applied and hand weeded plots controlled the weeds density per unit area by 19 and 100% and significantly increased grain yield by 9 to 113% (440 kg/ha to 936 kg/ha). Among the pre-emergence weedicides, Oxadiazon gave the highest grain yield of 764 kg/ha and earned net return/per rupee investment of Rs. 1:2.15, while post-emergence treatment hand-free check (twice) gave the highest yield of 936 kg/ha or 113% increase over control (440 kg/ha) and earned net return of Rs. 1:2.86, whereas mixture of Fluzifopbuty+ Fomesafen at given rates of 0.50+0.13 a.i/ha and 0.75+0.13 a.i/ha produced 635 and 849 kg/ha respectively by controlling grasses and broad-leaved weeds to the extent of 69/100 and 75/94% and earned net returns of Rs. 1:2.14 and 1: 3.22 respectively.
The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-c... more The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was prepared via a melt transesterification route. The resultant bioactive oligomer was then mixed with a blend of polylactide (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with different loadings to manufacture films to be used as a bioactive, biodegradable mulch to deliver the herbicide to target broadleaf weed species. The biological targeting of the MCPA-PHBV conjugate in the mulch film was investigated under glasshouse conditions using faba bean (Vicia faba) as a selective (nontarget) model crop species having broadleaf morphology. The presence of the MCPA-PHBV conjugate in the biodegradable PBTA/PLA blend was shown to completely suppress the growth of broadleaf weed species while displaying only a mild effect on the growth of the model crop. The degradation of the mulch film under glasshouse conditions was quite slow. The release of the MCPA-P...
The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-c... more The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was prepared via a melt transesterification route. The resultant bioactive oligomer was then mixed with a blend of polylactide (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with different loadings to manufacture films to be used as a bioactive, biodegradable mulch to deliver the herbicide to target broadleaf weed species. The biological targeting of the MCPA-PHBV conjugate in the mulch film was investigated under glasshouse conditions using faba bean (Vicia faba) as a selective (nontarget) model crop species having broadleaf morphology. The presence of the MCPA-PHBV conjugate in the biodegradable PBTA/PLA blend was shown to completely suppress the growth of broadleaf weed species while displaying only a mild effect on the growth of the model crop. The degradation of the mulch film under glasshouse conditions was quite slow. The release of the MCPA-P...
Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Product... more Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Productivity is often limited by periods of water deficit and in a number of regions zinc deficiency occurs, but the interaction between zinc nutrition and water stress has not been studied extensively. This interaction was examined in two glasshouse experiments. Chickpea was grown under deficient (no applied Zn) or adequate (2.5 µg Zn/g soil) levels of zinc in pots for either 53 days (Experiment 1) or 40 days (Experiment 2) before being exposed to a single period of water stress that lasted for 12 days (Experiment 1) or 23 days (Experiment 2). In one experiment four genotypes (Tyson, ICC-4958, T-1587 and NIFA-88) differing in their sensitivity to zinc deficiency were compared during a single drying cycle, and in the second experiment a single cultivar (Tyson) was compared under well-watered and water stress conditions. Water stress was induced by allowing the soil to dry gradually and the responses in shoot biomass, water use, plant water relations and carbon isotope discrimination ( , ) were measured. Shoot biomass, water use and water use efficiency were reduced by zinc deficiency. Stomatal conductance was lower in zinc-deficient plants as well. Zinc deficiency reduced by about 1 and there were significant differences in between genotypes which were independent of the level of zinc nutrition. At an adequate level of zinc there was a significant negative correlation between and shoot biomass and between and water use efficiency among the four chickpea genotypes, but these correlations were not significant under zinc deficiency. Osmotic potential was lower and turgor higher in the leaves of zinc-deficient plants, but the ability to adjust osmotically was reduced by zinc deficiency as stress developed. In conclusion, zinc-deficiency reduced the efficiency with which the water was used for biomass production and compromised the plant's capacity to respond to water stress by osmotic adjustment.
Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Product... more Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Productivity is often limited by periods of water deficit and in a number of regions zinc deficiency occurs, but the interaction between zinc nutrition and water stress has not been studied extensively. This interaction was examined in two glasshouse experiments. Chickpea was grown under deficient (no applied Zn) or adequate (2.5 µg Zn/g soil) levels of zinc in pots for either 53 days (Experiment 1) or 40 days (Experiment 2) before being exposed to a single period of water stress that lasted for 12 days (Experiment 1) or 23 days (Experiment 2). In one experiment four genotypes (Tyson, ICC-4958, T-1587 and NIFA-88) differing in their sensitivity to zinc deficiency were compared during a single drying cycle, and in the second experiment a single cultivar (Tyson) was compared under well-watered and water stress conditions. Water stress was induced by allowing the soil to dry gradually and the responses in shoot biomass, water use, plant water relations and carbon isotope discrimination ( , ) were measured. Shoot biomass, water use and water use efficiency were reduced by zinc deficiency. Stomatal conductance was lower in zinc-deficient plants as well. Zinc deficiency reduced by about 1 and there were significant differences in between genotypes which were independent of the level of zinc nutrition. At an adequate level of zinc there was a significant negative correlation between and shoot biomass and between and water use efficiency among the four chickpea genotypes, but these correlations were not significant under zinc deficiency. Osmotic potential was lower and turgor higher in the leaves of zinc-deficient plants, but the ability to adjust osmotically was reduced by zinc deficiency as stress developed. In conclusion, zinc-deficiency reduced the efficiency with which the water was used for biomass production and compromised the plant's capacity to respond to water stress by osmotic adjustment.
D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables... more D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables could be measured in pot-grown plants at adequate water supply and may serve as indirect selection criteria to pre-screen genotypes.
Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-... more Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-efficient genotypes on Zn-deficient soil is a benign approach of universal interest. Response of 13 chickpea genotypes (10 desi and 3 kabuli) to Zn nutrition was studied in a pot experiment under glasshouse conditions. Plants were grown in a Zn-deficient siliceous sand for 6 weeks and fertilized with 0 (Zn ) and 2.5 mg Zn per kg soil (Zn+). When grown with no added Zn, Zn deficiency symptoms (chlorosis of younger leaves and stipules followed by necrosis of leaf margins) appeared 3-4 weeks after planting and were more apparent in cultivars Tyson, Amethyst and Dooen than Kaniva and T-1587. Zn deficiency reduced shoot growth, but it was less affected in breeding lines T-1587 and CTS 11308 than cultivars Tyson, Dooen, Amethyst and Barwon. Among all genotypes, Tyson produced the lowest root dry weight in Zn-treatment. Zinc efficiency based on shoot dry weight showed marked differences among genotypes; breeding lines CTS-60543, CTS-11308 and T-1587 were 2-fold more Zn-efficient than cultivars Tyson and Dooen. A higher Zn accumulation per plant and higher Zn uptake per g. of root dry weight were recorded in T-1587 and CTS-11308 when compared with Tyson. Root:shoot ratio was increased and proportionally more Zn was transported to the shoot when the soil was deficient. Cultivars that were very sensitive to Zn deficiency tended to have their root:shoot ratio increased by Zn deficiency more than less sensitive cultivars. The insensitive lines T-1587 and CTS-11308 transported more than 70% of the total absorbed Zn to the shoot. It is concluded that chickpea genotypes vary in their sensitivity to Zn deficiency. Advanced breeding lines T-1587 and CTS-11308 are relatively more Zn-efficient compared with Australian chickpea cultivar Tyson. Zn efficiency in chickpea genotypes is probably related to an efficient Zn absorption coupled with a better root to shoot transport.
... Diego Rubiales1,∗ , Alejandro Pérez-de-Luque1, Mónica Fernández-Aparico1, Josefina C. Sillero... more ... Diego Rubiales1,∗ , Alejandro Pérez-de-Luque1, Mónica Fernández-Aparico1, Josefina C. Sillero2, Belén Román2, Mohamed Kharrat3, Shaban Khalil4, Daniel M. Joel5 & Charlie Riches6 1Instituto de Agricultura Sostenible, CSIC, Apdo. ...
Chickpea (Cicer arietinum L.) is extensively grown in areas where soils are deficient in zinc (Zn... more Chickpea (Cicer arietinum L.) is extensively grown in areas where soils are deficient in zinc (Zn). To determine the response of chickpea to Zn nutrition and to diagnose Zn status in plant tissue, two glasshouse experiments were conducted using Zn-deficient siliceous sandy soil. In Experiment 1, two genotypes of desi chickpea (Dooen and Tyson) were grown at five Zn levels (0, 0.04, 0.2, 1.0 and 5.0 mg kg 1 of soil). After 4 weeks, no difference in growth and no visible symptoms of Zn deficiency were detected. After 6-8 weeks of growth, chlorosis of younger leaves and stipules occured in the Zn 0 treatment, with shoot dry weight being only 24% of that recorded at the highest Zn level. Root growth increased from 0.52 g/plant when no Zn was applied to 1.04 g/plant in the treatment with 0.2 mg Zn kg 1 of soil; no response to further increase of Zn fertilization occurred. Zinc concentration in the whole shoot increased significantly with increased in Zn application. The critical Zn concentration in the shoot tissue, associated with 90% of maximum growth, was 20 mg kg 1 for both genotypes at flowering stage.
In a number of the major chickpea-growing areas in the world, rainfed crops of chickpeas are ofte... more In a number of the major chickpea-growing areas in the world, rainfed crops of chickpeas are often grown on soils with low available zinc (Zn). Consequently, chickpea crops can be challenged by soil water deficits and Zn deficiency coincidentally during the growing season. The interaction between these stresses was examined in two glasshouse experiments using genotypes differing in Zn efficiency. Water stress was imposed during podding. Increasing the level of Zn resulted in large and significant increases in vegetative growth up to podding. Applying Zn increased grain yields when the plants were well watered, but not under water stress, except for the Zn-efficient and drought-resistant genotype ICC-4958. Harvest indices were generally reduced as the supply of Zn and water increased. Applying Zn increased water use and water use efficiency of chickpea. Yields were reduced by water stress, largely due to fewer pods set per plant. Losses from water stress were greatest at the highest level of Zn, which was attributed to the limited soil volume afforded by the pots and the rapid development of stress in the larger plants grown at adequate levels of Zn. However, at each level of Zn, the loss in yield from water stress tended to be less in a Zn-efficient genotype. The major factor determining the distribution of Zn in the plant was the supply of Zn, while differences due to water stress and genotype were relatively small. Two-thirds of the Zn present in the plant at maturity was accumulated after the start of podding and this was little affected by water stress. The proportion of Zn in the roots of Zn-deficient plants was less than that in Zn-adequate plants. As the Zn supply increased, Zn accumulation was higher in leaves than in the stem and reproductive parts, due to combined effect of both higher Zn concentration and higher dry matter. At maturity, senesced leaves and pod walls had relatively lower concentrations of Zn compared to leaves and pods at the start of podding in all Zn treatments. In contrast, the Zn content in the stem either increased or remained unchanged. At maturity, Zn accumulation in plant organs generally increased with increasing Zn supply, but the largest proportion of Zn was found in the seeds, which is a beneficial nutritional trait for human nutrition. * FAX No: +61-8-8303-7109.
Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-... more Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-efficient genotypes on Zn-deficient soil is a benign approach of universal interest. Response of 13 chickpea genotypes (10 desi and 3 kabuli) to Zn nutrition was studied in a pot experiment under glasshouse conditions. Plants were grown in a Zn-deficient siliceous sand for 6 weeks and fertilized with 0 (Zn ) and 2.5 mg Zn per kg soil (Zn+). When grown with no added Zn, Zn deficiency symptoms (chlorosis of younger leaves and stipules followed by necrosis of leaf margins) appeared 3-4 weeks after planting and were more apparent in cultivars Tyson, Amethyst and Dooen than Kaniva and T-1587. Zn deficiency reduced shoot growth, but it was less affected in breeding lines T-1587 and CTS 11308 than cultivars Tyson, Dooen, Amethyst and Barwon. Among all genotypes, Tyson produced the lowest root dry weight in Zn-treatment. Zinc efficiency based on shoot dry weight showed marked differences among genotypes; breeding lines CTS-60543, CTS-11308 and T-1587 were 2-fold more Zn-efficient than cultivars Tyson and Dooen. A higher Zn accumulation per plant and higher Zn uptake per g. of root dry weight were recorded in T-1587 and CTS-11308 when compared with Tyson. Root:shoot ratio was increased and proportionally more Zn was transported to the shoot when the soil was deficient. Cultivars that were very sensitive to Zn deficiency tended to have their root:shoot ratio increased by Zn deficiency more than less sensitive cultivars. The insensitive lines T-1587 and CTS-11308 transported more than 70% of the total absorbed Zn to the shoot. It is concluded that chickpea genotypes vary in their sensitivity to Zn deficiency. Advanced breeding lines T-1587 and CTS-11308 are relatively more Zn-efficient compared with Australian chickpea cultivar Tyson. Zn efficiency in chickpea genotypes is probably related to an efficient Zn absorption coupled with a better root to shoot transport.
D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables... more D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables could be measured in pot-grown plants at adequate water supply and may serve as indirect selection criteria to pre-screen genotypes.
The application of mulch films for preserving soil moisture and preventing weed growth has been a... more The application of mulch films for preserving soil moisture and preventing weed growth has been a part of agricultural practice for decades. Different materials have been used as mulch films, but polyethylene plastic has been considered most effective due to its excellent mechanical strength, low cost and ability to act as a barrier for sunlight and water. However, its use carries a risk of plastic pollution and health hazards, hence new laws have been passed to replace it completely with other materials over the next few years. Research to find out about new biodegradable polymers for this purpose has gained impetus in the past few years, driven by regulations and the United Nations Organization’s Sustainable Development Goals. The primary requisite for these polymers is biodegradability under natural climatic conditions without the production of any toxic residual compounds. Therefore, biodegradable polymers developed from fossil fuels, microorganisms, animals and plants are viabl...
The faba bean (Vicia faba L.) crop often experiences drought during its growth and development su... more The faba bean (Vicia faba L.) crop often experiences drought during its growth and development such that soil moisture deficits constrain its production. As droughts are predicted to increase in both frequency and intensity due to climate change, a better understanding of drought response patterns and associated traits is essential for obtaining yield stability in water-limited environments. This review deals with adaptation mechanisms associated with drought avoidance, escape and tolerance, with an emphasis on physiological traits such as stomatal conductance, carbon isotope discrimination and leaf temperature. Leaf temperature is considered an effective surrogate measure for other measures of stomatal characteristics. Drought tolerance through osmotic adjustment has not yet been demonstrated in faba bean although it is found in many other legumes including chickpea and pea. Deeper root growth, leading to uptake of otherwise unavailable water, helps the plant to avoid drought by delaying dehydration, but genetic variation and heritability of the trait are essentially unknown for faba bean. Crop management strategies, such as early planting, and appropriate phenology, are particularly important for drought escape in regions where terminal drought is common. Disease resistance is especially important in drought-prone areas to reduce the need for expensive control measures when yields are uncertain. The relevance of soil fertility status and nutrient availability are also covered. Drought escape and ascochyta blight resistance are important breeding objectives for terminal drought regions. Some form of drought resistance is necessary for the transient droughts experienced in most regions, and drought avoidance can be screened by a combination of leaf temperature or other rapid test of stomatal characteristics followed by carbon isotope discrimination in the most valuable materials. No single trait is adequate to improve yield in drought-prone environments, rather, a combination of characteristics is needed.
Biodegradable mulches are considered a promising alternative to polyethylene-based, nonbiodegrada... more Biodegradable mulches are considered a promising alternative to polyethylene-based, nonbiodegradable mulch for sustainable agriculture. In the present study, a bioactive 2-methyl-4cholorophenoxyacetic acid/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (MCPA-PHBV) conjugate blended with biodegradable poly(butylene adipate-co-terephthalate/polylactide (PBAT/PLA) was developed and used as mulch under controlled condition greenhouse pot experiment with fava bean (Vicia faba) as the nontarget crop species. The objectives were to examine the effectiveness of sustained-release of MCPA herbicide from biodegradable mulch for broadleaf weed suppression and to assess any adverse effects of the herbicide on the nontarget species (fava bean). The energy-dispersive X-ray spectroscopy analysis (EDS) suggests that a substantial quantity of the herbicide was released from the biodegradable mulch which effectively killed the broadleaf weed species even at 1% MCPA concentration. However, the higher concentrations of the herbicide adversely affected several physiological parameters of fava bean growth and development. Stomatal conductance decreased, while leaf temperature subsequently rose (at MCPA concentrations 5, 7.5, and 10%). The quantum yield of the Photosystem II (PSII) indicates that the photosynthetic efficiency was also restricted at concentrations 7.5% and 10%. Evidently, this slow-release herbicide system worked efficiently for broadleaf weed control but at higher concentrations, resulted in adverse physiological effects on the nontarget crop species. This study has demonstrated that biodegradable mulches containing MCPA herbicide are able to effectively inhibit the growth of broad leaf weed species and may be of potential importance in a wide variety of horticultural and agricultural applications.
Isoproturon and Methabenzthiazuron and Post-emergence herbicides; Fomesafen, Fluazifopbutyl and M... more Isoproturon and Methabenzthiazuron and Post-emergence herbicides; Fomesafen, Fluazifopbutyl and Methabenzthiazuron alone and in combinations were evaluated to know their broad spectrum performance, if any; against a lentil variety Precoz. Hand weeded and weedy plots were kept for comparison of yield and economic gains. Most of the herbicides applied and hand weeded plots controlled the weeds density per unit area by 19 and 100% and significantly increased grain yield by 9 to 113% (440 kg/ha to 936 kg/ha). Among the pre-emergence weedicides, Oxadiazon gave the highest grain yield of 764 kg/ha and earned net return/per rupee investment of Rs. 1:2.15, while post-emergence treatment hand-free check (twice) gave the highest yield of 936 kg/ha or 113% increase over control (440 kg/ha) and earned net return of Rs. 1:2.86, whereas mixture of Fluzifopbuty+ Fomesafen at given rates of 0.50+0.13 a.i/ha and 0.75+0.13 a.i/ha produced 635 and 849 kg/ha respectively by controlling grasses and broad-leaved weeds to the extent of 69/100 and 75/94% and earned net returns of Rs. 1:2.14 and 1: 3.22 respectively.
The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-c... more The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was prepared via a melt transesterification route. The resultant bioactive oligomer was then mixed with a blend of polylactide (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with different loadings to manufacture films to be used as a bioactive, biodegradable mulch to deliver the herbicide to target broadleaf weed species. The biological targeting of the MCPA-PHBV conjugate in the mulch film was investigated under glasshouse conditions using faba bean (Vicia faba) as a selective (nontarget) model crop species having broadleaf morphology. The presence of the MCPA-PHBV conjugate in the biodegradable PBTA/PLA blend was shown to completely suppress the growth of broadleaf weed species while displaying only a mild effect on the growth of the model crop. The degradation of the mulch film under glasshouse conditions was quite slow. The release of the MCPA-P...
The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-c... more The herbicide 2-methyl-4-chlorophenoxyacetic acid (MCPA) conjugated with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was prepared via a melt transesterification route. The resultant bioactive oligomer was then mixed with a blend of polylactide (PLA) and poly(butylene adipate-co-terephthalate) (PBAT) with different loadings to manufacture films to be used as a bioactive, biodegradable mulch to deliver the herbicide to target broadleaf weed species. The biological targeting of the MCPA-PHBV conjugate in the mulch film was investigated under glasshouse conditions using faba bean (Vicia faba) as a selective (nontarget) model crop species having broadleaf morphology. The presence of the MCPA-PHBV conjugate in the biodegradable PBTA/PLA blend was shown to completely suppress the growth of broadleaf weed species while displaying only a mild effect on the growth of the model crop. The degradation of the mulch film under glasshouse conditions was quite slow. The release of the MCPA-P...
Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Product... more Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Productivity is often limited by periods of water deficit and in a number of regions zinc deficiency occurs, but the interaction between zinc nutrition and water stress has not been studied extensively. This interaction was examined in two glasshouse experiments. Chickpea was grown under deficient (no applied Zn) or adequate (2.5 µg Zn/g soil) levels of zinc in pots for either 53 days (Experiment 1) or 40 days (Experiment 2) before being exposed to a single period of water stress that lasted for 12 days (Experiment 1) or 23 days (Experiment 2). In one experiment four genotypes (Tyson, ICC-4958, T-1587 and NIFA-88) differing in their sensitivity to zinc deficiency were compared during a single drying cycle, and in the second experiment a single cultivar (Tyson) was compared under well-watered and water stress conditions. Water stress was induced by allowing the soil to dry gradually and the responses in shoot biomass, water use, plant water relations and carbon isotope discrimination ( , ) were measured. Shoot biomass, water use and water use efficiency were reduced by zinc deficiency. Stomatal conductance was lower in zinc-deficient plants as well. Zinc deficiency reduced by about 1 and there were significant differences in between genotypes which were independent of the level of zinc nutrition. At an adequate level of zinc there was a significant negative correlation between and shoot biomass and between and water use efficiency among the four chickpea genotypes, but these correlations were not significant under zinc deficiency. Osmotic potential was lower and turgor higher in the leaves of zinc-deficient plants, but the ability to adjust osmotically was reduced by zinc deficiency as stress developed. In conclusion, zinc-deficiency reduced the efficiency with which the water was used for biomass production and compromised the plant's capacity to respond to water stress by osmotic adjustment.
Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Product... more Chickpea (Cicer arietinum) is an important dryland pulse crop in many parts of the world. Productivity is often limited by periods of water deficit and in a number of regions zinc deficiency occurs, but the interaction between zinc nutrition and water stress has not been studied extensively. This interaction was examined in two glasshouse experiments. Chickpea was grown under deficient (no applied Zn) or adequate (2.5 µg Zn/g soil) levels of zinc in pots for either 53 days (Experiment 1) or 40 days (Experiment 2) before being exposed to a single period of water stress that lasted for 12 days (Experiment 1) or 23 days (Experiment 2). In one experiment four genotypes (Tyson, ICC-4958, T-1587 and NIFA-88) differing in their sensitivity to zinc deficiency were compared during a single drying cycle, and in the second experiment a single cultivar (Tyson) was compared under well-watered and water stress conditions. Water stress was induced by allowing the soil to dry gradually and the responses in shoot biomass, water use, plant water relations and carbon isotope discrimination ( , ) were measured. Shoot biomass, water use and water use efficiency were reduced by zinc deficiency. Stomatal conductance was lower in zinc-deficient plants as well. Zinc deficiency reduced by about 1 and there were significant differences in between genotypes which were independent of the level of zinc nutrition. At an adequate level of zinc there was a significant negative correlation between and shoot biomass and between and water use efficiency among the four chickpea genotypes, but these correlations were not significant under zinc deficiency. Osmotic potential was lower and turgor higher in the leaves of zinc-deficient plants, but the ability to adjust osmotically was reduced by zinc deficiency as stress developed. In conclusion, zinc-deficiency reduced the efficiency with which the water was used for biomass production and compromised the plant's capacity to respond to water stress by osmotic adjustment.
D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables... more D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables could be measured in pot-grown plants at adequate water supply and may serve as indirect selection criteria to pre-screen genotypes.
Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-... more Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-efficient genotypes on Zn-deficient soil is a benign approach of universal interest. Response of 13 chickpea genotypes (10 desi and 3 kabuli) to Zn nutrition was studied in a pot experiment under glasshouse conditions. Plants were grown in a Zn-deficient siliceous sand for 6 weeks and fertilized with 0 (Zn ) and 2.5 mg Zn per kg soil (Zn+). When grown with no added Zn, Zn deficiency symptoms (chlorosis of younger leaves and stipules followed by necrosis of leaf margins) appeared 3-4 weeks after planting and were more apparent in cultivars Tyson, Amethyst and Dooen than Kaniva and T-1587. Zn deficiency reduced shoot growth, but it was less affected in breeding lines T-1587 and CTS 11308 than cultivars Tyson, Dooen, Amethyst and Barwon. Among all genotypes, Tyson produced the lowest root dry weight in Zn-treatment. Zinc efficiency based on shoot dry weight showed marked differences among genotypes; breeding lines CTS-60543, CTS-11308 and T-1587 were 2-fold more Zn-efficient than cultivars Tyson and Dooen. A higher Zn accumulation per plant and higher Zn uptake per g. of root dry weight were recorded in T-1587 and CTS-11308 when compared with Tyson. Root:shoot ratio was increased and proportionally more Zn was transported to the shoot when the soil was deficient. Cultivars that were very sensitive to Zn deficiency tended to have their root:shoot ratio increased by Zn deficiency more than less sensitive cultivars. The insensitive lines T-1587 and CTS-11308 transported more than 70% of the total absorbed Zn to the shoot. It is concluded that chickpea genotypes vary in their sensitivity to Zn deficiency. Advanced breeding lines T-1587 and CTS-11308 are relatively more Zn-efficient compared with Australian chickpea cultivar Tyson. Zn efficiency in chickpea genotypes is probably related to an efficient Zn absorption coupled with a better root to shoot transport.
... Diego Rubiales1,∗ , Alejandro Pérez-de-Luque1, Mónica Fernández-Aparico1, Josefina C. Sillero... more ... Diego Rubiales1,∗ , Alejandro Pérez-de-Luque1, Mónica Fernández-Aparico1, Josefina C. Sillero2, Belén Román2, Mohamed Kharrat3, Shaban Khalil4, Daniel M. Joel5 & Charlie Riches6 1Instituto de Agricultura Sostenible, CSIC, Apdo. ...
Chickpea (Cicer arietinum L.) is extensively grown in areas where soils are deficient in zinc (Zn... more Chickpea (Cicer arietinum L.) is extensively grown in areas where soils are deficient in zinc (Zn). To determine the response of chickpea to Zn nutrition and to diagnose Zn status in plant tissue, two glasshouse experiments were conducted using Zn-deficient siliceous sandy soil. In Experiment 1, two genotypes of desi chickpea (Dooen and Tyson) were grown at five Zn levels (0, 0.04, 0.2, 1.0 and 5.0 mg kg 1 of soil). After 4 weeks, no difference in growth and no visible symptoms of Zn deficiency were detected. After 6-8 weeks of growth, chlorosis of younger leaves and stipules occured in the Zn 0 treatment, with shoot dry weight being only 24% of that recorded at the highest Zn level. Root growth increased from 0.52 g/plant when no Zn was applied to 1.04 g/plant in the treatment with 0.2 mg Zn kg 1 of soil; no response to further increase of Zn fertilization occurred. Zinc concentration in the whole shoot increased significantly with increased in Zn application. The critical Zn concentration in the shoot tissue, associated with 90% of maximum growth, was 20 mg kg 1 for both genotypes at flowering stage.
In a number of the major chickpea-growing areas in the world, rainfed crops of chickpeas are ofte... more In a number of the major chickpea-growing areas in the world, rainfed crops of chickpeas are often grown on soils with low available zinc (Zn). Consequently, chickpea crops can be challenged by soil water deficits and Zn deficiency coincidentally during the growing season. The interaction between these stresses was examined in two glasshouse experiments using genotypes differing in Zn efficiency. Water stress was imposed during podding. Increasing the level of Zn resulted in large and significant increases in vegetative growth up to podding. Applying Zn increased grain yields when the plants were well watered, but not under water stress, except for the Zn-efficient and drought-resistant genotype ICC-4958. Harvest indices were generally reduced as the supply of Zn and water increased. Applying Zn increased water use and water use efficiency of chickpea. Yields were reduced by water stress, largely due to fewer pods set per plant. Losses from water stress were greatest at the highest level of Zn, which was attributed to the limited soil volume afforded by the pots and the rapid development of stress in the larger plants grown at adequate levels of Zn. However, at each level of Zn, the loss in yield from water stress tended to be less in a Zn-efficient genotype. The major factor determining the distribution of Zn in the plant was the supply of Zn, while differences due to water stress and genotype were relatively small. Two-thirds of the Zn present in the plant at maturity was accumulated after the start of podding and this was little affected by water stress. The proportion of Zn in the roots of Zn-deficient plants was less than that in Zn-adequate plants. As the Zn supply increased, Zn accumulation was higher in leaves than in the stem and reproductive parts, due to combined effect of both higher Zn concentration and higher dry matter. At maturity, senesced leaves and pod walls had relatively lower concentrations of Zn compared to leaves and pods at the start of podding in all Zn treatments. In contrast, the Zn content in the stem either increased or remained unchanged. At maturity, Zn accumulation in plant organs generally increased with increasing Zn supply, but the largest proportion of Zn was found in the seeds, which is a beneficial nutritional trait for human nutrition. * FAX No: +61-8-8303-7109.
Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-... more Zinc (Zn) deficiency is common in most of the chickpea growing areas of the world and growing Zn-efficient genotypes on Zn-deficient soil is a benign approach of universal interest. Response of 13 chickpea genotypes (10 desi and 3 kabuli) to Zn nutrition was studied in a pot experiment under glasshouse conditions. Plants were grown in a Zn-deficient siliceous sand for 6 weeks and fertilized with 0 (Zn ) and 2.5 mg Zn per kg soil (Zn+). When grown with no added Zn, Zn deficiency symptoms (chlorosis of younger leaves and stipules followed by necrosis of leaf margins) appeared 3-4 weeks after planting and were more apparent in cultivars Tyson, Amethyst and Dooen than Kaniva and T-1587. Zn deficiency reduced shoot growth, but it was less affected in breeding lines T-1587 and CTS 11308 than cultivars Tyson, Dooen, Amethyst and Barwon. Among all genotypes, Tyson produced the lowest root dry weight in Zn-treatment. Zinc efficiency based on shoot dry weight showed marked differences among genotypes; breeding lines CTS-60543, CTS-11308 and T-1587 were 2-fold more Zn-efficient than cultivars Tyson and Dooen. A higher Zn accumulation per plant and higher Zn uptake per g. of root dry weight were recorded in T-1587 and CTS-11308 when compared with Tyson. Root:shoot ratio was increased and proportionally more Zn was transported to the shoot when the soil was deficient. Cultivars that were very sensitive to Zn deficiency tended to have their root:shoot ratio increased by Zn deficiency more than less sensitive cultivars. The insensitive lines T-1587 and CTS-11308 transported more than 70% of the total absorbed Zn to the shoot. It is concluded that chickpea genotypes vary in their sensitivity to Zn deficiency. Advanced breeding lines T-1587 and CTS-11308 are relatively more Zn-efficient compared with Australian chickpea cultivar Tyson. Zn efficiency in chickpea genotypes is probably related to an efficient Zn absorption coupled with a better root to shoot transport.
D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables... more D 13 C are promising physiological indicators for drought tolerance in faba bean. These variables could be measured in pot-grown plants at adequate water supply and may serve as indirect selection criteria to pre-screen genotypes.
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