• Authors:
    • Elazegui, D. D.
    • Chupungco, A. R.
    • Nguyen, M. R.
  • Source: Philippine Journal of Crop Science
  • Volume: 36
  • Issue: 2
  • Year: 2011
  • Summary: This study discusses the seed system, production and marketing of eggplant, Solanum melongena L., considered as one of the most important vegetable crops in the Philippines. Data analyzed were obtained from focus group discussions in major eggplant producing provinces of Pangasinan, Batangas and Quezon; key informant interviews with representatives of government agencies and seed companies, and traders; and secondary sources such as government reports and other publications. The eggplant seed system is generally organized, involving public and private sectors. There are different varieties available in the market but seed developers do not opt for seed registration nor plant variety protection because of the rigorous process involved. Instead, seed companies adopt well-established seed production and quality control strategies and vigorous marketing and promotion to improve sales. Commercial growers of eggplant adopt hybrid seeds, while open-pollinated varieties (OPVs) are mainly used for small-scale production. Between 2000 and 2009, eggplant production increased by 21% despite a relatively lower increase (6%) in area planted. Average yield ranged 8-10 mt ha -1. Eggplant production is profitable, but major problems include fruit and shoot borer (FSB) infestation, bacterial wilt, irrigation supply and climate-related problems. Production involves intensive use of pesticides, bearing some implications on human health and environment. This should call the attention of Local Government Units which are in the forefront of providing extension services. Moreover, research and development should continuously receive adequate support to address these concerns. Research and development thrusts could include varietal improvement of eggplant and alternative pest control strategies such as integrated pest management (IPM) technology and intercropping. The current effort on R & D of Bt eggplant addresses the problem of FSB and heavy dependence of farmers on pesticides. With the stringent regulatory system of the Philippines on the commercial propagation of GM crops, adverse impact on human health and environment will be curtailed.
  • Authors:
    • Rao, I. M.
    • Schmidt, A.
    • van der Hoek, R.
    • Bernasconi, S. M.
    • Frossard, E.
    • Douxchamps, S.
    • Oberson, A.
  • Source: Plant and Soil
  • Volume: 341
  • Issue: 1-2
  • Year: 2011
  • Summary: The integration of multipurpose legumes into low-input tropical agricultural systems is needed because they are a nitrogen (N) input through symbiotic fixation. The drought-tolerant cover legume canavalia (Canavalia brasiliensis) has been introduced for use either as forage or as a green manure into the crop-livestock system of the Nicaraguan hillsides. To evaluate its impact on the subsequent maize crop, an in-depth study on N dynamics in the soil-plant system was conducted. Microplots were installed in a 6-year old field experiment with maize-canavalia rotation. Direct and indirect (15)N-labelling techniques were used to determine N uptake by maize from canavalia residues and canavalia-fed cows' manure compared to mineral fertilizer. Litter bags were used to determine the N release from canavalia residues. The incorporation of N from the amendment into different soil N pools (total N, mineral N, microbial biomass) was followed during the maize cropping season. Maize took up an average of 13.3 g N m(-2), within which 1.0 g N m(-2) was from canavalia residues and 2.6 g N m(-2) was from mineral fertilizer, corresponding to an amendment N recovery of 12% and 32%, respectively. Recoveries in maize would probably be higher at a site with lower soil available N content. Most of the amendment N remained in the soil. Mineral N and microbial N were composed mainly of N derived from the soil. Combined total (15)N recovery in maize and soil at harvest was highest for the canavalia residue treatment with 98% recovery, followed by the mineral fertilizer treatment with 83% recovery. Despite similar initial enrichment of soil microbial and mineral N pools, the indirect labelling technique failed to assess the N fertilizer value of mineral and organic amendments due to a high N mineralization from the soil organic matter.
  • Authors:
    • Nagih, A.
    • Lemalade, J. L.
    • Alfandari, L.
    • Plateau, G.
  • Source: Annals of Operations Research
  • Volume: 190
  • Issue: 1
  • Year: 2011
  • Summary: We propose a Mixed-Integer Linear Programming model for a class of multi-period crop rotation optimization problems with demand constraints and incompatibility constraints between cultivation and fallow state on a land plot. This model is applied to a case study on Madagascan farms in the scope of a sustainable development campain against deforestation, where the objective is to better control agricultural space while covering seasonal needs of farmer. We propose an efficient upper bound computation and study the variation of the minimum number of plots and total space needed in function of the unitary surface area of a plot. Numerical results associated with the Madagascan case are reported.
  • Authors:
    • Peluzio, J. M.
    • Almeida, R. D. de
    • Afférri, F. S.
  • Source: Revista Ciência Agronômica
  • Volume: 42
  • Issue: 1
  • Year: 2011
  • Summary: The aim of this work was to evaluate the genetic divergence among twelve soybean cultivars under irrigated lowland conditions in south Tocantins State, Brazil, in the Companhia Brasileira de Agropecuaria (COBRAPE), at Formoso do Araguaia, TO, in the inter-cropping 2005. The experimental design employed was randomized blocks with twelve treatments and tree replications. The treatments consisted on the following cultivars: DM Vitoria, MG/BR 46 (Conquista), Suprema, BRS Pintado, DM 247, BRS/MG 68, BRS/MG Lideranca, BRS MG Seguranca, DM 339, BRS/MG Garantia, A 7002, and DM 309. The following characteristics were evaluated: grain yield, weight of hundred seeds, number of seeds per pod, number of pods per plant, number of days for flowering; number of days for maturation, plant height and height insertion of the primary pod. Genetic divergence was evaluated by multivariate procedures: generalized Mahalanobis distance, Tocher's agglomerative method of Tocher and nearest neighbor. The Tocher's method and nearest neighbor agreed among themselves. Number of days for the maturation (39.49%), weigh of hundred seeds (26.56%) and number of days for flowering (13.59%) were the traits that most contributed to the genetic dissimilarity. The presence of genetic variability allowed the identification of dissimilar cultivars with high average for the traits studied. BRS/MG Garantia * DM 339 and BRS/MG Garantia * MG/BR 46 (Conquista) hybridizations are promising for obtaining segregate populations with higher variability.
  • Authors:
    • WCI
  • Volume: 2010
  • Year: 2010
  • Summary: Welcome to the Western Climate Initiative (WCI). The WCI is a collaboration of independent jurisdictions working together to identify, evaluate, and implement emissions trading policies to tackle climate change at a regional level. This is a comprehensive effort to reduce greenhouse gas pollution, spur investment in clean-energy technologies that create green jobs and reduce dependence on imported oil.
  • Authors:
    • Liang,Biqing
    • Lehmann,Johannes
    • Sohi,Saran P.
    • Thies,Janice E.
    • Luizão,Flavio J.
    • Trujillo,Lucerina
    • Gaunt,John
    • Solomon,Dawit
    • Grossman,Julie
    • Neves,Eduardo G.
    • O'Neill,Brendan
  • Source: Organic Geochemistry
  • Volume: 41
  • Issue: 2
  • Year: 2010
  • Summary: Black carbon (BC) is an important fraction of many soils worldwide and plays an important role in global C biogeochemistry. However, few studies have examined how it influences the mineralization of added organic matter (AOM) and its incorporation into soil physical fractions and whether BC decomposition is increased by AOM. BC-rich Anthrosols and BC-poor adjacent soils from the Central Amazon (Brazil) were incubated for 532 days either with or without addition of 13C-isotopically different plant residue. Total C mineralization from the BC-rich Anthrosols with AOM was 25.5% (P < 0.05) lower than with mineralization from the BC-poor adjacent soils. The AOM contributed to a significantly (P < 0.05) higher proportion to the total C mineralized in the BC-rich Anthrosols (91–92%) than the BC-poor adjacent soils (69–80%). The AOM was incorporated more rapidly in BC-rich than BC-poor soils from the separated free light fraction through the intra-aggregate light fraction into the stable organo-mineral fraction and up to 340% more AOM was found in the organo-mineral fraction. This more rapid stabilization was observed despite a significantly (P < 0.05) lower metabolic quotient for BC-rich Anthrosols. The microbial biomass (MB) was up to 125% greater (P < 0.05) in BC-rich Anthrosols than BC-poor adjacent soils. To account for increased MB adsorption onto BC during fumigation extraction, a correction factor was developed via addition of a 13C-enriched microbial culture. The recovery was found to be 21–41% lower (P < 0.05) for BC-rich than BC-poor soils due to re-adsorption of MB onto BC. Mineralization of native soil C was enhanced to a significantly greater degree in BC-poor adjacent soils compared to BC-rich Anthrosols as a result of AOM. No positive priming by way of cometabolism due to AOM could be found for aged BC in the soils.
  • Authors:
    • Singh, A.
    • Kumar, R.
    • Pathak, H.
    • Jain, N.
    • Sasmal, S.
    • Bhatia, A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 136
  • Issue: 3
  • Year: 2010
  • Summary: No-till farming in wheat is being practiced in the rice-wheat system of the Indo-Gangetic plains of south Asia for resource conservation. No-tillage leads to mitigation of carbon dioxide emission, but may emit more nitrous oxide (N2O) as compared to conventional tillage reducing mitigation benefit. The aim of this study was assessment of N2O emission in wheat grown under conventional and no-tillage and its mitigation using two new nitrification inhibitors, viz. S-benzylisothiouronium butanoate (SBT-butanoate) and S-benzylisothiouronium furoate (SBT-furoate). Cumulative emission of N2O-N was higher under no-tillage by 12.2% with urea fertilization and from 4.1 to 4.8% for the inhibitor treatments as compared to the conventional tillage. In no-tillage total emission of N2O-N reduced from 0.43% of applied N with urea to 0.29% of applied N with SBT-furoate treatment. The N2O-N emissions in SBT-butanoate treatment were at par with the standard dicyandiamide (DCD) inhibitor treatment. Water-filled pore space (WFPS) was higher on most days under no-tillage, with the largest emissions (>1000 mu g N2O-N m(-2) day(-1)) coming with nitrification of ammonium-N present in soil below 60% WFPS. Carbon efficiency ratio was highest (48.1) from SBT-furoate treatment under conventional tillage. The nitrification inhibitors used in the study increased yield of wheat, reduced global warming potential by 8.9-19.5% over urea treatment and may be used to mitigate N2O emission.
  • Authors:
    • Delve, R. J.
    • Zingore, S.
    • Nyawasha, R. W.
    • Nyamangara, J.
    • Masvaya, E. N.
    • Giller, K. E.
  • Source: Nutrient Cycling in Agroecosystems
  • Volume: 88
  • Issue: 1
  • Year: 2010
  • Summary: This paper examines a number of agronomic field experiments in different regions of sub-Saharan Africa to assess the associated variability in the efficiencies with which applied and available nutrients are taken up by crops under a wide range of management and environmental conditions. We consider N and P capture efficiencies (NCE and PCE, kg uptake kg(-1) nutrient availability), and N and P recovery efficiencies (NRE and PRE, kg uptake kg(-1) nutrient added). The analyzed cropping systems employed different soil fertility management practices that included (1) N and P mineral fertilizers (as sole or their combinations) (2) cattle manure composted then applied or applied directly to fields through animal corralling, and legume based systems separated into (3) improved fallows/cover crops-cereal sequences, and (4) grain legume-cereal rotations. Crop responses to added nutrients varied widely, which is a logical consequence of the wide diversity in the balance of production resources across regions from arid through wet tropics, coupled with an equally large array of management practices and inter-season variability. The NCE ranged from 0.05 to 0.98 kg kg(-1) for the different systems (NP fertilizers, 0.16-0.98; fallow/cover crops, 0.05-0.75; animal manure, 0.10-0.74 kg kg(-1)), while PCE ranged from 0.09 to 0.71 kg kg(-1), depending on soil conditions. The respective NREs averaged 0.38, 0.23 and 0.25 kg kg(-1). Cases were found where NREs were > 1 for mineral fertilizers or negative when poor quality manure immobilized soil N, while response to P was in many cases poor due to P fixation by soils. Other than good agronomy, it was apparent that flexible systems of fertilization that vary N input according to the current seasonal rainfall pattern offer opportunities for high resource capture and recovery efficiencies in semi-arid areas. We suggest the use of cropping systems modeling approaches to hasten the understanding of Africa's complex cropping systems.
  • Authors:
    • Onwugbuta-Enyi, J.
    • Offor, U. S.
  • Source: Journal of Agriculture and Social Research (JASR)
  • Volume: 10
  • Issue: 1
  • Year: 2010
  • Summary: The work was carried out to study the effects of Palm Bunch Ash (PBA) on seed germination, seedling growth and biochemical parameters of Soybean. Soybean seeds were raised in petri-dishes and irrigated with different concentrations of PBA (0-control, 10, 25,40,65,80 and 100%). At lower concentrations, PBA had promotory effects on all the parameters studied while 100% concentration had inhibitory effects.
  • Authors:
    • Sujatha, S.
    • Bhat, R.
  • Source: Agricultural Water Management
  • Volume: 97
  • Issue: 7
  • Year: 2010
  • Summary: A 5-year field trial to assess the impact of microsprinkler irrigation and nutrition on vanilla grown as intercrop in arecanut plantation was conducted on a laterite soil. Pooled analysis indicated that microsprinkler irrigation at 1.0 Epan resulted in significantly higher green bean yield (842 kg ha -1) than 0.75 Epan (579 kg ha -1). Organic manure application in the form of vermicompost (720 kg ha -1) and FYM (768 kg ha -1) and recommended NPK (718 kg ha -1) produced green bean yield at par with recycling of gliricidia prunings (625 kg ha -1). Irrigation at 1.0 Epan proved superior by registering maximum benefit:cost (B:C) ratio of 2.25 compared to 1.62 at 0.75 Epan. The highest B:C ratio was obtained with recommended NPK (2.27) followed by recycling of gliricidia prunings (2.10), vermicompost (1.87), vermicompost+arecanut husk mulching (1.80) and FYM (1.64). The soil pH increased by 0.4 units in 2008 compared with the pre-experimental soil pH of 5.6 in 2004. Nutrition alone and in combination with irrigation had significant impact on soil pH. Organic manure application increased the soil pH (6.1-6.2) significantly over recommended NPK (5.6) at the end of experiment in 2008. Significant variation in soil organic carbon (SOC) was noticed due to different nutrition treatments. Application of vermicompost and FYM significantly increased the SOC content by 38-54% in 2008 over initial levels in 2004. Bray's P availability was influenced by nutrition and its interaction with irrigation. Application of FYM continuously for 4 years has resulted in significant increase in Bray's P content (41.3 mg kg -1) compared to other nutrition treatments (9.4-17.2 mg kg -1). Irrigation equivalent to 0.75 Epan (223 mg kg -1) increased the K availability significantly over 1.0 Epan (172 mg kg -1). The K availability was significantly higher in recommended NPK (416 mg kg -1) than in other organic treatments (98-223 mg kg -1) at 0-30 cm soil depth. Overall, vanilla responded well to irrigation and nutrition in arecanut-based cropping system with a better economic output and improved soil fertility.