Effect of nitrogen and potassium fertilizer on growth,herbage and oil yield of irrigated palmarosa (Cymbopogon martinii [roxb.] wats. var. motia burk) in a semi-arid tropical climate

The world's agricultural production is increasing by 1 to 2 per cent annually and has been enough to satisfy the growing world population's need for food. Breeding, fertilisation and crop protection have decidedly contributed to that progress in productivity. But since the 1960s, agriculture has been more and more conceived by the public as an environment-contaminating industry. The public is concerned about water contamination with nitrate as a result of the use of fertilisers, and about harmful effects of chemical plant protection products on soil, water, air, animals and wild plants. The public discussion has not remained without consequences. Sustainability of development has become a central political objective in all spheres of social life, and in all world regions. Sustainable development concerns economic, ecological as well as social objectives, and is also the guideline for a renovation of agriculture. Any concepts and strategies integrating environmental aspects into agricultural production are linked with the objective of sustainable development. Discussion on sustainable agriculture has become more concrete on the basis of the Brundtland Report and Agenda 21 , as well as the various follow-up meetings of the 1992 Conference of Rio. Although efforts towards sustainable development in agriculture encounter widespread scepticism, clear progress is to be noted since that discussion has intensified. Farmers have paid more attention to new farming practices. Environmental aspects now play an important role when extension services advise farmers on fertilisation and crop protection. Research has contributed essentially to the change in agriculture towards sustainable production. Sustainability in agriculture has also been expressed in new legal regulations. Principles of good professional practice in applying fertilisers, as it is required by the Fertilisers Act from the year 1989, have been spelled out more clearly in a legal regulation issued on 26 January 1996 (Federal Law Gazette part I of 06 February 1996, p. 118). Principles of good professional practice in crop protection were published in Bundesanzeiger (Federal Gazette) No. 220 a of 21 November 1998. Principles of integrated crop protection were first discussed by representatives of agriculture, environment protection offices and researchers at a workshop at Biologische Bundesanstalt für Land- und Forstwirtschaft (BBA, Federal Biological Research Centre for Agriculture and Forestry) in Kleinmachnow on 23° March 2000. The debate on sustainability centres around the aspects of economic and social efficiency of measures taken, and their effects on the environment. The following article deals with some basic aspects of efficiency on the one hand, and effects/emission on the environment on the other, of fertilisers and crop protection products as important input factors in agriculture. Crop husbandry always is an interference with nature. The Lüneburger Heide cropping region is a memorial of ecologically out-dated land management. Today, sustainable and at the same time efficient agriculture can only be realised with modern methods based on sound knowledge. This includes mineral fertilisation and chemical crop protection. Cropping permanently draws nutrients from the soil-plant system. They have to be refilled by fertilisation. If no fertilising measures are taken at all, the humus layer of the soil declines and soil degrades. The decline in fertility will result in yield losses of between 70 and 90%. In contrast, combination of organic and mineral fertilisers has continually added to soil fertility. This is reflected in the humus content of the soil, which is by about a quarter higher than it was a hundred years ago. Farmers resorting solely to mineral fertilisation produce yields lower by 5-10% than those combining mineral and organic fertilisers. If only organic fertilisers are used, this may reduce yields by between 10 and 40%, depending on the site. Unwanted side-effects of fertilisation (such as leaching of nitrates) may be reduced to a tolerable level by precise input of nutrients, improved methods such as precise fertiliser input depending on the condition of certain field patches, and by integrated crop protection, which relies on synergetic effects of various measures. Germany has for these reasons witnessed a relaxation of environmental pressure from excessive nutrient input. If crop protection measures were abandoned, pests and diseases would reduce yields by between 40 and 80 per cent. Our own trials about energy input-output proportions have shown a ratio of 1:4.6 with use of fertilisers (100kg N/ha), and a ratio of 1:8.6 with use of fertiliser and chemical plant protection products. The risk potential of modern chemical plant protection products has permanently decreased over the past few decades and is generally about one tenth of the values of 15 years ago. Integrated crop protection, which combines various methods of crop protection and reduces the use of chemical crop protection products to a necessary minimum, is the "optimal solution for the future" and "contributes to the sustainability of agriculture", as it is said in the Agenda 21 programme adopted by the 1992 environmental conference in Rio.     

Impact of seed blend and structured maize refuge on Helicoverpa zea (Lepidoptera: Noctuidae) potential phenological resistance development parameters in pupae and adults

BACKGROUND

Helicoverpa zea, an economic pest in the south-eastern United States, has evolved practical resistance to Bacillus thuringiensis (Bt) Cry toxins in maize and cotton. Insect resistance management (IRM) programs have historically required planting of structured non-Bt maize, but because of its low adoption, the use of seed blends has been considered. To generate knowledge on target pest biology and ecology to help improve IRM strategies, nine field trials were conducted in 2019 and 2020 in Florida, Georgia, North Carolina, and South Carolina to evaluate the impact of Bt (Cry1Ab + Cry1F or Cry1Ab + Cry1F + Vip3A) and non-Bt maize plants in blended and structured refuge treatments on H. zea pupal survival, weight, soil pupation depth, adult flight parameters, and adult time to eclosion.

RESULTS

From a very large sample size and geography, we found a significant difference in pupal mortality and weight among treatments in seed blends with Vip3A, implying that cross-pollination occurred between Bt and non-Bt maize ears. There was no treatment effect for pupation depth, adult flight distance, and eclosion time.

CONCLUSION

Results of this study demonstrate the potential impact of different refuge strategies on phenological development and survival of an important pest species of regulatory concern. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

Profiling glucosinolates and phenolics in vegetative and reproductive tissues of the multi-purpose trees Moringa oleifera L. (horseradish tree) and Moringa stenopetala L

Moringa species are important multi-purpose tropical crops, as human foods and for medicine and oil production. There has been no previous comprehensive analysis of the secondary metabolites in Moringa species. Tissues of M. oleifera from a wide variety of sources and M. stenopetala from a single source were analyzed for glucosinolates and phenolics (flavonoids, anthocyanins, proanthocyanidins, and cinnamates). M. oleifera and M. stenopetala seeds only contained 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate at high concentrations. Roots of M. oleifera and M. stenopetala had high concentrations of both 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate and benzyl glucosinolate. Leaves from both species contained 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate and three monoacetyl isomers of this glucosinolate. Only 4-(alpha-l-rhamnopyranosyloxy)-benzylglucosinolate was detected in M. oleifera bark tissue. M. oleifera leaves contained quercetin-3-O-glucoside and quercetin-3-O-(6' '-malonyl-glucoside), and lower amounts of kaempferol-3-O-glucoside and kaempferol-3-O-(6' '-malonyl-glucoside). M. oleifera leaves also contained 3-caffeoylquinic acid and 5-caffeoylquinic acid. Leaves of M. stenopetala contained quercetin 3-O-rhamnoglucoside (rutin) and 5-caffeoylquinic acid. Neither proanthocyanidins nor anthocyanins were detected in any of the tissues of either species.     

Electricity and water desalination: Separate sites offer value

For the fuel type and water situation in the Middle East, the case is strong for the use of combined cycle technology for power generation and reverse osmosis for potable water production, where each are sited for their maximum economic benefit and interconnected by electric power transmission. Because of the fuel efficiency of Combined Cycle generation technology, its use of liquid/gas fuels and its low need for cooling water, it can be optimized for cost away from cities. Conversely, water desalination by reverse osmosis can be sited in optimal locations to take advantage of its modularity and to minimize water pipeline needs. Electric power transmission provides an inexpensive and flexible means to connect these two technologies. Together these technologies may offer an overall minimum cost approach, better than the combining of electric power and water desalination at one location, where power to water ratios must be fixed, independent of need, for optimum efficiency. The use of reverse osmosis with power generation has other, important ancillary benefits over using distillation and power combinations. These advantages include abatement of environmental pollution, delivery of potable water at reasonable drinking temperatures, lower total energy consumption, more efficient land use and less demanding operator skills.