CHLOROSIS AND MERISTEM DIEBACK IN GREENHOUSE-GROWN ASPARAGUS TRANSPLANTS

Following observation of severe chlorosis and dieback of meristem tiss ue in asparagus seedlings started in the greenhouse in a soilless medi a, a study was conducted to determine if the growth patterns were asso ciated with one or more of the media components. Asparagus seedling gr owth using several potting media was compared. Treatments included sin gle component media, washed sand, perlite, peat, Plainfield loamy sand [a local soil (PLS)], plus 1:1' mixtures of peat/perlite, washed sand /peat, PLS/perlite, washed sand/peat, and PLS/peat. Abnormal growth pa tterns were observed in several of the media. Chlorosis was associated with high pH which occurred in perlite, washed sand, and their combin ations. Chlorotic plants were characterized by low root and fem dry we ights and low fem to root ratios. Meristem dieback occurred in several media treatments and did not appear to be pH related. Plants exhibiti ng dieback had fem to root ratios approaching 1 if they were not also affected by chlorosis. Nutrient availability was suspected to be a cau se but this hypothesis was not substantiated by data collected in this experiment. Asparagus growth in a mixture of Plainfield loamy sand an d peat was the highest and was similar to that of field gown seedlings .