MINIMISING PLANT LOSSES IN ESTABLISHING ASPARAGUS CROPS
A common reason for reduced asparagus yields is loss of plants from crops. Lost plants leave gaps, and gaps don't produce yield. Most deaths occur during the establishment years and, once plants have been lost, the remaining adjacent plants are unable to compensate by producing extra yield. In this paper we describe two field experiments in which we examined the hypotheses that more plant deaths occur and yields are lower (a) when crops are established with small or variable-sized crowns and (b) when crops are over-harvested in the first two establishment years. Plants were vigorous and 4 to 8% died in the first two years in crops established by planting large, uniform crowns, whether or not the crops were harvested. In contrast, plants were weaker in crops established from small crowns, and up to 25% were lost after being harvested in the first two years. Plant deaths were reduced by about half and vigour was increased if the crops were not harvested. Crops established from crowns of medium or variable size had intermediate losses and vigour. The results showed clearly that plants grown from smaller crowns are less able to tolerate being harvested in the establishment years. The disadvantage of lost plants was balanced by the advantage of yield gained from harvests in the first two years. Over both years, crops established from large crowns produced higher yields than ones grown from crowns that were smaller or of variable size. To minimise the risk of plant losses and thereby assure productivity in the longer term, we conclude that crops should be established by planting large, uniform crowns and harvests restricted to short periods in the first two years.
Sinton, S.M. and Wilson, D.R. (2008). MINIMISING PLANT LOSSES IN ESTABLISHING ASPARAGUS CROPS. Acta Hortic. 776, 117-122
crown size, harvest length, vigour, survival