In Illinois , lucerne plants are the quarry of a trouble that might be deceive to a farmer ’s first glimpse . The alfalfa leaves are turning a reddish - yellow in the top raw growth of the plants while the elderly leave continue gullible . At a first flavour , it appears the plants have leafhopper damage , but that occurs later on in the season . What the Medicago sativa plant are in reality suffering from , according to Fabián Fernández , assistant professor of craw skill at University of Illinois , is boron deficiency .
“ An well-off manner to recognize between the two problem is to look for flowers , ” Fernández says . “ Alfalfa will flower if the job is get by leafhoppers , but probably will not if it is due to B deficiency . ”
However , it ’s unusual to see symptom of atomic number 5 deficiency this too soon in the growing time of year , Fernández take down . The problem usually appear on the second or third cuttings of lucerne , specially during drouth periods .
“ I surmise that the reason we are seeing atomic number 5 want in some fields so betimes this growing time of year , especially in sandy soils that have humiliated capacity to retain water , is that it has been unusually dry , ” he says .
Also referred to as “ yellow top , ” alfalfa boron deficiency occurs most usually in sandy soils that are low-toned in organic topic or have a high pH. Often , boron deficiency appears during drought condition because the lack of water reduces the capacity of organic matter to release it . Boron does not translocate easily in the industrial plant , which , Fernández explain , causes the folio discolouration .
Boron deficiency also impress alfalfa cell development , often causing shorter internodes and bunching of the top leaves . If the deficiency is severe , the growing points might go bad .
If boron lack is suspect in an Medicago sativa crop , there are several ways to investigate the problem :
If the investigating shows that remedial legal action is want , boron should be applied . Unless soil tests also show marginal engrossment in area with no seeable deficiency symptoms , the program should be restricted to the affected arena , not applied to the entire battleground . A possible scheme is to apply 30 pounds per Accho of household borax , which contains 3.3 pounds of atomic number 5 .
If the arena needs other food , such as Lucifer or potassium , it might be easier to mix this small amount of atomic number 5 with the other fertiliser .
“ In sandy grease for Medicago sativa output , I suggest yearly applications of 1 to 2 Ezra Loomis Pound of boron per acre , ” Fernández state . For fine - textured soils that have atomic number 5 inadequacy , an software of 3 to 4 pounds of boron per acre in the class of validation will usually correct the job for a few years .
The only carefulness is that if oat accompany lucerne during establishment , the atomic number 5 practical software should be delayed until after the first year to invalidate perniciousness problems for the oat . likewise , to avoid boron toxicity in Indian corn , it should not be use to alfalfa during the year prior to corn planting . Finally , if a foliar handling is preferred , a rate of 0.1 to 0.3 pounds of atomic number 5 per Akka is normally enough to correct the trouble .
