Ismail, Mohd Razi

Mohd Saud, Halimi

Universiti Putra Malaysia Institutional Repository

A9ri~ultura( SciencesPlant Growth-Prol11oting Rhizobacteria For Yield Improvement Of High ValueVegetable Crops Grown On Soilless Culture System Under ProtectedEnvironmentH.allm! Moht! Saut! & Mohd ~%llemal1Faculty of AgricultureVnivcrsiti Putra: Millaysia43400 UPM, Serdang, SelangerMalaysillTelephone Number ojCv'J'T/!spollding Author: OJ-89466967E-mail of Corresponding All/hor: haJimi@agri.llpm.edu.",yKey words: Plant growth promoting rhiz<)hacter1a, vegetables, soilless culture, protected environmentIntroductionIn recent years, a substantial amount of reports have been published extolling the benefits of using Plant Growth-r~motillg Rbizobacteria (PGf>R) as biofetilizer for ll)any different crops. Plants received positive growth benefits fromthe association with PGPR tbrvugh various mechanisms which include enhancementllfnutrient uptake, increasing rootbi~mass, lIupp\ying 11ltn>geno'lls compounds by fixing dinitrogen from the air, disease suppression, as antagonists forplant pathogens and solubilization of immobilized soil phosphorous (Doberiener et at, J9S7). The PGPR tnat h\\\1~been studied includes the genera Azospirillum, Azotobacter, Clostridium,. Baci{(us, Enterobacrer, Klebsiella,Pseudomonas and Serratia (Belandreau, 1983}. Many of these FGf'R will increased plant growth and vigour ana havebeen reported locally to benefit oil palm {Amir et al., 2000), bananas (Mia et al., ZOOl) and pineapples (Halimi et ai,1001),In Malaysi3, the demand for vegetables is increasing annually and it is estimated that the amount required f()tconsumption increased to 60i),OOOtonnes in the year 2000. Most of the vegetable crops supplied to the market areplanted conventionally in Cameron Highlands and other highland areas and in the lowlands using high amount ofchemical fertilizers, frequent\y under protected environment or rain shelter. The amount of chemical fertilizers used isalso increasing to produce higher crop )I\e\d \\)U~ intensifying the problems of environmental pollution from excessiveuse of chemicals. Many CQnsumef'llkeenly felt the problems of soil and ground water pollution from the excessive useof chemical fertilizers and pesticides. Hence there is a growing demand for vegetables grown organicaJly which canfetch a premium price, PGrR inoculants C<J.nbe a viable alternative tJ> using chemical fertilizers and thus this stul1y wascarried out to determine the benefits of usillg POPR for high value vegetable crops that include tomatoes (L)'copersicDnfemulemum), sweet p~ppet (Capsicum annllm} arui Japanese cucumber (CucumiS sativus).Materials and MethodsPGPR inocuiatus: Three species of PGPR inoculant!> wert: used i.e. Azospirillum brasiltensts Sp1. Boci{fu.f sphaericu«VPMBIO and Agrobacterium rhizogenes VPMB 1001. Sp7 and UPMB10 was grown in Okon media using II shakerincubator fot 48 houf'llat 2SoC until it reached a eel! density of I x 1{)1 e.f.u. mL'I, whereas UPMBtOO\ was gr<:JwninnuUient broth under similar conditions to obtain the same cell density prior to use as inQCulant. Estimation of celldensity was maul'. using standard curve and readings using spectrophotometer.Tomatoes. Japanese CUctJi7'lVel" tmd Sweet pepper, Tomatoes and Japanese cucumber were grown (fom '.iee<i~ andtral\sf<:rroo.til I'Qlybags containing soilless culture media. The treatments used in the experiment were single inccnlamsof Sp7, UPMBW and Ul'MR {OO{ and a mixed inoculant of an three bacteria. Additional experiment included theused of different chemical fertilizer c()ncentrati~n of I.S, 3,0 and 6.0 mS cm'\ for tomatoes. For sweet pepper, similarinoculation treatments were given as foJ' tomatoes and la~anese -cu~umber except that an extra treatment was use 10include mycorrhiza and fertilizer concentration was used only at :to mS cm' . For control, p\anl% were not treated withany bacterial or mycorrhizal inoculants but given the standard chemical fertilizer based on Cooper's nutrient solution.Five replicate plants were used for each treatment.Culliva/ion media and growth of plan/.r. All plants were grown in polybags containing three kg of a 3: I peal:c~ir dustadmixture. The plants were p\'Iltt:n ~ ){)Ws inside the glasshouse which was well-ventilated. Watering and fertilizationwas done via drip inigationlfertigation with each po\ybag rew;;eivingIS milMes of watering and the time im:reastd asthe plants rrmture. Plants were harvested when the fruits matured and data were taken based on plant weight, height.root biomass and fruit yield. Other physiological characteristics such as SlomalJl conduclJlnce and chlorophyll contentwere also recorded.101UPM Research Report 1997-2000. Vol II.Section 2-Extended AbstractsResults and DiscussionThe study showed some interactions between inorganic fertilizer concentration and and PGPR on the growth and yieldof tomatoes. The highest plant dry weight was obtained when UPMBIO and Sp7 was used with 3.0 and I.S mS ern" offertilizer respectively, The highest root dry weight was obtained with Sp7 and 3.0 mS ern" fertilizer and UPMB I0 with6_0 mS cm-I of fertilizer. The results showed that the presence of Sp7 and UPMB 10 can promote the growth and yieldof tomatoes. The best fresh fruit yield (S 1.0 g plant") was obtained with Sp7 and 3.0 mS ern" fertilizer concentration.Similarly, fruit yield in Japanese cucumber also showed a positive trend in terms of number and fruit weight whenPGPR was used. Stomata conductance increased in Japanese cucumber whilst photosynthetic activity and chlorophyllcontent in sweet pepper showed a significant increase over control. However the results on fruit yield for sweet peppercould not be properly documented due to a heavy infestation of insects resulting in uneven and premature fruit setting.The leaves were severely attacked and showed viral-like infections. Viral infection via insect vectors was suspected.From these studies we can confirm the beneficial effects of selected microbial inoculants, which has also been reportedfor other plants such as oil palm, bananas and soybean. This study was quite simplistic in its approach since the mainobjective was to determine if any of the PGPR could benefit and showed positive response of vegetables grown underprotected environment using soilless culture media, The use of soilless culture media means that plants are naturallydeprived of the indigenous microbial flora that is present when conventional soil media is used. Hence inoculation withPGPR will alleviate any detrimental effects of depriving vegetable crops of the natural microbial flora. The use ofPGPR is also a means of providing alternative fertilizer source since cultivation of vegetable crops under similarenvironment is dependent on expensive inorganic fertilizer input. The use of PGPR inoculant can also be part of anorganic farming technology for producing organically grown vegetables.ConclusionsPGPR inoculants could enhance the growth of selected high value vegetable crops grown on soilless culture mediaunder protected environment agriculture. PGPR can be a potential biofertilizer to replace or supplement the use ofexpensive inorganic fertilizer.Benefits from the studyThe study has shown that several PGPR isolates can be used as biofertilizers of vegetable crops grown in soillessculture under protected environment. Besides promoting growth. the biofertilzers can reduced the use of chemicalfertilizers and has the potential for used in the cultivation of organically grown high value vegetable crops.Patent(s), if applicable:NilStage of Commercialization, if applicable:NilProject Publications in Refereed Journals:NilProject Publications in Conference ProceedingsI. Halimi Mohd Saud, Raflidah Zakaria and Mohd Razi Ismail (2000). Growth Responses of Tomatoes (Lycopersicon esculentumMill.) Under Protected Environmentto Rhizobacterial Inoculation.Transactions of the Malaysian Societyof Plant PhysiologyVol.9. p235-2392. HalimiMohd Saud. Raflidah Zakaria and Mohd Razi Ismail (2000). Growth Performanceof Tomatoes In Soilless Culture Systemto PGPR Inoculation.MalaysianScience and TechnologyCongress 2000 (Symp.A)& Asia Pacific Symposiumon Food Science&Nutrition2000, Kota Kinabalu,Sabah.p 1413. Ho Mei Kheng, Halimi Mohd Saud and Mohd Razi Ismail (2002). PhysiologicalResponses of Sweet Pepper [Capsicum unnum)Grown in Soilless Culture to Rhizobacterialand Mycorrhizal Inoculation.Programmeand Abstract: Workshop on EnvironmentalStress lmpacton TropicalCrops.p 21102Agricultural SciencesGraduate ResearchNameGraduteof Research Topic Field of Expertise Degree Awarded Graduation YearKhor Sock Khun Identification of aPlant GrowthPromotingRhizobacteria,Bacillus sphaericus(UPMB 10) usingPeR-based DNAFingerprintingTechniqueMolecularidentification usingDNAfingerprintingMaster of Science 2002IRPA Project number: 01-02-04-0318UPM Research ClusterAFF103

Plant growth-promoting rhizobacteria for yield improvement of high value vegetable crops grown on soilless culture system under protected environment

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Plant growth-promoting rhizobacteria for yield improvement of high value vegetable crops grown on soilless culture system under protected environment

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