{"title":"Effects of Nitrogen and Phosphorus Fertiliser on Growth and Yield of Ironweed (Vernonia Galamesis)","authors":"G. Mati, M. Mburu, P. Kurji, S. Shibairo","doi":"10.4314/eaafj.v69i2.1812","DOIUrl":null,"url":null,"abstract":"ABSTRACT Ironweed (Vernonia galamensis) is a promising new crop for industrial oil but information on its response to fertiliser is scanty. A field experiment was conducted at the University of Nairobi Field Station farm during 2 seasons (January to May 1998, season 1 and March to August 1998, season 2) to determine the effects of nitrogen (N) and phosphorus (P) fertiliser rates on growth, photosynthetically active radiation (PAR) interception and seed yield of 2 Vernonia galamensis cultivars (ethiopica and gibbosa). N was applied at 0, 75 and 150 kg N/ha, and P at 0, 45 and 90 kg P2O5/ha. The experiment was a 2 × 3 × 3 factorial laid out in a randomized complete block design with 3 replications. N and P application significantly increased total dry matter (TDM), photosynthetically active radiation (PAR) interception and leaf area index (LAI) of both varieties in late vegetative and reproductive stages. Gibbosa had consistently higher TDM, LAI, PAR and was taller compared to ethiopica throughout the growing season. Average seed yield of gibbosa was 2.3 times higher than that of ethiopica in both experiments. The highest TDM, LAI and seed yields were obtained at the highest N and P levels. Gibbosa had a significantly higher number of capsules/plant but a lower harvest index (HI) compared to ethiopica.","PeriodicalId":11421,"journal":{"name":"East African Agricultural and Forestry Journal","volume":"51 1","pages":"109 - 118"},"PeriodicalIF":0.0000,"publicationDate":"2003-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"East African Agricultural and Forestry Journal","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4314/eaafj.v69i2.1812","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
ABSTRACT Ironweed (Vernonia galamensis) is a promising new crop for industrial oil but information on its response to fertiliser is scanty. A field experiment was conducted at the University of Nairobi Field Station farm during 2 seasons (January to May 1998, season 1 and March to August 1998, season 2) to determine the effects of nitrogen (N) and phosphorus (P) fertiliser rates on growth, photosynthetically active radiation (PAR) interception and seed yield of 2 Vernonia galamensis cultivars (ethiopica and gibbosa). N was applied at 0, 75 and 150 kg N/ha, and P at 0, 45 and 90 kg P2O5/ha. The experiment was a 2 × 3 × 3 factorial laid out in a randomized complete block design with 3 replications. N and P application significantly increased total dry matter (TDM), photosynthetically active radiation (PAR) interception and leaf area index (LAI) of both varieties in late vegetative and reproductive stages. Gibbosa had consistently higher TDM, LAI, PAR and was taller compared to ethiopica throughout the growing season. Average seed yield of gibbosa was 2.3 times higher than that of ethiopica in both experiments. The highest TDM, LAI and seed yields were obtained at the highest N and P levels. Gibbosa had a significantly higher number of capsules/plant but a lower harvest index (HI) compared to ethiopica.
铁草(Vernonia galamensis)是一种很有前途的工业用油新作物,但其对化肥的反应资料很少。采用1998年1月至5月(第1季)和1998年3月至8月(第2季)2个季节在内罗毕大学田间站农场进行了田间试验,以确定氮肥和磷肥用量对2个galamensis品种(埃塞俄比亚和gibbosa)生长、光合有效辐射(PAR)拦截和种子产量的影响。施氮量分别为0、75和150 kg N/ha,施磷量分别为0、45和90 kg P2O5/ha。试验采用2 × 3 × 3因子随机完全区组设计,共3个重复。氮磷处理显著提高了两个品种营养后期和生殖后期的总干物质(TDM)、光合有效辐射(PAR)截留量和叶面积指数(LAI)。在整个生长季节,赤眼松的TDM、LAI、PAR均高于埃塞俄比亚。在两个试验中,长臂猿的平均种子产量是埃塞俄比亚的2.3倍。最高氮磷水平下TDM、LAI和种子产量最高。与埃塞俄比亚相比,吉博萨的蒴果数量显著高于埃塞俄比亚,但收获指数(HI)较低。