2020 | 2 views | 20 Pages | 2.52 MB
wheat canopy from a digital photograph of the crop. At GS 30, it has been shown that each 0.5 unit increase in GAI above a GAI of 1.25 effectively reduces the variety Lodging Resistance Score, described in the HGCA Recommended List, by 1 point. At GS 31, the critical GAI above which lodging risk increases is 1.75.
Introductionwww pgrplus basf comis BASF s new website tailored to managinglodging risk in cerealsI n addition to detailed information about BASF plant growthregulators the website also hosts a new innovative tool for theassessment of lodging risk in wheatsing the CAT Canopy Assessment Tool you can quickly andvery easily obtain a lodging risk assessment of your wheatcrop and a simple yet tailored PGR recommendationhe information provided is also important for estimating thefertiliser requirement of the crop when using methods such asthe RB209 Fertiliser Guide and GrowHow s N Calc SystemAT has been developed trialled and calibrated by ADAS inorder to provide an accurate lodging risk assessment and PGRprogramme according to the in field riskCanopy Assessment Toolo what is the theoryThe size of the wheat canopy in the springtime is a critical indicator for decisions aboutnitrogen and plant growth regulators PGRsize of the wheat canopy is difficult to estimate but it can bemeasured by its Green Area Index GAI the amount of greentissue per m2 of groundhe Canopy Assessment Tool CAT estimates the GAI of thewheat canopy from a digital photograph of the cropt GS 30 it has been shown that each 0 5 unit increase in GAIabove a GAI of 1 25 effectively reduces the variety LodgingResistance Score described in the HGCA Recommended Listby 1 point At GS 31 the critical GAI above which lodging riskincreases is 1 75igher yielding crops have a greater lodging risk as a resultof heavier ears It has been estimated that each tonne perhectare increase in yield above 9 t ha reduces the varietyLodging Resistance Score by 0 5 pointsnowing the GAI at growth stage 30 or 31 together with theLodging Resistance Score of the variety and an estimate of thecrop s yield potential allows the lodging risk to be predictedand the subsequent requirement for a PGR or PGR programmeach unit of GAI is equivalent to a crop N content of 30 kgN haKnowledge of how much N a crop has taken up in the spring isrequired to estimate the N fertiliser requirement of cropsGrowth Stage GuideHow do I know when my crop isat GS 30 or GS 31Growth stage 30The beginning of stem elongation pseudostem and tillers erectFirst internode begins to elongate top of inflorescence at least1 cm above tillering node1cm 1cm 1cm 1cmDistance between base of the plant and the top of the shootapex on the main stem is 1cm or more but the length of the 1stinternode is less than 1cmGrowth Stage GuideGrowth stage 31First node at least 1 cm above tillering nodeFirst node detectable GS 31main shoots splitAn internode of 1cm or more is present but the internode aboveis less than 2cmGrowth Stage GuideGrowth stage 32Node 2 at least 2 cm above node 1Second node detectable GS 32main shoots split2nd node thanSecond and subsequent nodes are counted when the internodebelow them exceeds 2cmAdvantages and benefits of using CATTailored PGR programmesjustification ICMSupport tool to calculatecrop nitrogen requirementQuick and easy to useGuidance on using the CanopyAssessment Tool CATS useo howStep 1 Take a quick CAT scanFrom growth stage 30 up to and including GS 31 take a digitalphoto of the crop which is representative of the fieldNote To gain the most accurate results from the tool digitalphotographs should be taken directly above the crop The areaof crop photographed is not critical and a 1m x 1m is perfectlyadequate It is advisable to avoid taking photographs on sunnydays as this may cause shadowsQuality of the camera is less important A camera phone isperfectly adequateStep 2 Upload the photoGo to www pgrplus basf com and upload the digital photo toStep 3 Wait for the adviceEnter the wheat variety predicted yield date andgeographical areaThe CAT will showThe Green Area Index GAI of your cropResistance to lodging score of your crop 1 9 scale where1 is high lodging riskA BASF PGR programme tailored to that field risk at the time oftaking the photographRisk colour Red high risk Yellow medium riskGreen low riskCalculated crop N content in kg haPhotographs of various GAI scores atcrop Growth Stage 30Photographs of various GAI scores atcrop Growth Stage 30Photographs of various GAI scores atcrop Growth Stage 30Photographs of various GAI scores atcrop Growth Stage 31Photographs of various GAI scores atcrop Growth Stage 31Photographs of various GAI scores atcrop Growth Stage 31