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11.
银合欢品系对异木虱抗性的研究 总被引：2，自引：0，他引：2
近年来，银合欢异木虱（HeteropsyllaCrawford）已成为亚太地区银合欢生产中一种最重要的害虫。银合欢品系对异木虱的抗性研究结果表明：灰白银合次K376（Leucanenapalli-da）和异叶银合欢Bray2（LeucaenadiversifoliaCPI#46568）具有高度的抗虫性；柯氏银合欢K740（Leucaenacollinsii）、异叶银合欢K784具有中等抗虫性;热研1号银合欢、K636、K584（均为Leucaenaleucocphala）为高度感虫品系。Brsy2、K740具有抗虫丰产性能，可作为饲用；K636。虽然虫口级数和虫害级数较高，但生长快，再生能力强，生物产量高，属耐虫害品系，适用于饲料生产，只要积极采取生物防治措施，也可望获得高产而优质的饲料。 相似文献
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D. M. Phiri B. Coulman H. A. Steppler C. S. Kamara F. Kwesiga 《Agroforestry Systems》1993,23(1):79-84
The effect of feeding maize husk and leucaena as a mixture on voluntary intake of maize husk was studied over a 40-day period. Ten male goats with an average weight of 15 kg were used. The treatments were: (a) maize husk fed in a mixture with leucaena and (b) maize husk plus leucaena offered in separate troughs but at the same time. The maize husk intake and total dry matter intake for the two feeding methods were about the same. Thus total dry matter intake was not affected (P<0.05) by the method of feeding. There was also no significant difference (P<0.05) between the two methods of feeding in the digestibility values. The data were considered to indicate that there were no significant differences in the intake of maize husk when fed in a mixture withLeucaena leucocephala or when offered separately but at the same time. 相似文献
14.
D. M. Phiri B. Coulman H. A. Steppler C. S. Kamara F. Kwesiga 《Agroforestry Systems》1992,17(2):153-158
The effect of browse supplementation on maize husk (Zea mays) utilization by goats was studied in a 12 week feeding and 2 week digestibility trial. Twenty-four goats were stratified
according to their weight, and then randomly allocated to four treatments. Browse supplementation significantly increased
(P < 0.05) the total dry matter intake, diet dry matter digestibility and diet organic matter digestibility (P < 0.05) but
did not have any significant effect on acid detergent fibre digestibility (P > 0.05). The browse supplemented goats gained
more weight than the non browse supplemented goats. 相似文献
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A possible method of protecting biosphere reserve core zones is to encourage transition and buffer zone activities which are
compatible with the core and which provide sufficient returns to the human population to make entry into the core zone unnecessary.
The AMISCONDE project is promoting block plantations and coffee/tree agroforestry systems to do this, but did not analyze
their financial or economic feasibility. Unprofitable systems will not be adopted without subsidy and are not sustainable
after a project ends. Analyses show internal rates of return exceeding 30% for coffee/tree combinations both with and without
project subsidies. Coffee/tree systems have significantly higher returns than coffee without trees, reduce the risk from coffee
price fluctuations, and reduce the need for chemical fertilizers. Returns from a block plantation of cypress are a small fraction
of coffee and coffee/tree system returns, but still are positive and have the advantage of requiring much smaller initial
investments. The systems analyzed seem likely to be sustainable and to contribute to project conservation and development
objectives.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
16.
A ten-year-study (1983 to 1992) conducted on nine 15 × 90 m runoff plots at 4% slope compared production efficiency of Leucaena
leucocephala and Eucalyptus hybrid based agroforestry as well as monocropping landuse systems in the warm, subhumid climate
of the western Himalayan region of India. Treatments for the first sequence were: monocropping systems of leucaena, eucalyptus,
Chrysopogon fulvus grass and maize – wheat rotation, and alley cropping systems of grass and crops at 4.5 and 10.5 m alley
widths with paired contour tree rows of leucaena and eucalyptus. In the second sequence, alley width increased to 22.5 m in
1989, grass was replaced by turmeric Curcuma longa and paired contour rows of leucaena hedges were introduced in monocropping
systems of grain crops and turmeric. Integration of leucaena and eucalyptus trees with crops caused severe reduction of crop
yields ranging from 21 to 92% for wheat grain, 59 to 69% for maize grain, 60 to 67% for dry grass and about 50% for turmeric
rhizome depending upon the age of trees and alley width. The grain yield of crops stabilized at about 50% reduction with 22.5
m alley width. Total crop biomass (grain + straw) also revealed a similar trend; however, its magnitude of reduction was less
severe than for grain. Production of biomass was much lower near the tree rows than in mid alleys. Managing leucaena as contour
hedgerows eliminated crop yield reduction in alleys. Performance of grass and turmeric in alleys was not found to be satisfactory.
Biomass produced from trees adequately compensated the crop yield reduction. Land equivalent ratios of agroforestry landuses
were comparable or even better than monocropping systems indicating suitability of these systems for the western Himalayan
valley region.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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Attention has increasingly focussed on fast-growing trees as a potential means of slowing high rates of deforestation and as a source of renewable energy. Unfortunately, the analytical tools for determining economic tractability of tree-growing projects lags behind the popular support to implement them. This paper brings the methodology of the Faustmann Principle, which was established for use with longer growing species, to bear on leucaena, a short-rotation, leguminous tree crop. The principle incorporates biological and economic parameters to derive a function relating the present value of net revenue to rotation length. Additionally, a method of incorporating secondary benefits, such as nitrogen fixation, is demonstrated. Results from the model are applied to Kenya. Research on agro-climatic zones in Kenya is used to indicate the potential volume of leucaena production. 相似文献
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Abstract Permethrin applied as a spray to cattle at 0.025% or 0.05% effectively controlled Boophilus microplus (Canestrini) by the third day post‐treatment, but only provided < 60% control within 1 day post‐treatment with both concentrations. Percentage control did not drop below 90% until day 28 for 0.025% and day 31 for 0.05% permethrin; percentage control did not fall below 92% for 0.025% fenvalerate until after day 24–25; and at 0.05%, fenvalerate provided 95% control until day 28. A multiple treatment (spray applied every 2 weeks) with permethrin (0.05%) provided greater than 96% control of B. microplus after the initial treatment and 100% control by day 56. We concluded that although both chemicals have potential in an eradication program, they are not satisfactory for use at a quarantine line because both acaricides provided less than 100% control within 1 day post‐treatment. 相似文献
20.
The effects of leucaena hedgerows, mulching with leucaena foliage (0,50 and 100% of harvested foliage), cowpea intercropping and adition of dairy cattle slurry (55 t ha–1 per maize crop) on the yield of maize from a sandy soil were assessed. The four-year results from five maize crops are reported.Except in the first year, yields of maize grain and stover were significantly reduced by 30% in the presence of leucaena hedgerows. Use of leucaena mulch eliminated this effect; application of all the harvested leucaena mulch (100%) increased the total maize grain yield of the five crops by 44% over sole maize. Hedgerow and mulching management required an additional 36 mandays labour ha–1 which was more than compensated by the increased maize yields. Furthermore leucaena hedgerows substantially depressed the growth of weeds between cropping seasons.Intercropping with cowpea significantly depressed yields of maize grain and stover when both crops were sown together, but not in later seasons when cowpea was sown four weeks after the maize. Application of slurry increased the total yields of maize grain and stover by 35 and 37%, respectively. The grain yield of maize in leucaena hedgerow treatments fertilized with slurry did not respond to application of more than 50% of leucaena foliage, which suggested that half of the foliage could be spared for feeding to livestock. The cumulative yield of maize grain from the highest yielding organic system was 85% of the yield from the fertilizer treatment.The study, which is continuing, demonstrates that large increases in agricultural productivity are possible through the intercropping of maize with woody forage and grain legumes and the integration of dairy cattle production into the system. It thus shows the importance of exploiting crop/livestock interactions. 相似文献