This 3rd I.A.C.T. trial in Riverside consists of four replicates of 32 hybrids and one, seven and eight replicates of three additional hybrids. The trial was harvested three times per week, with collection of yield and grade records once per week. These data shown in Table 1 are adjusted to a full harvest basis by multiplying observed yields by 7/2 (for Wednesday harvests which reflects spears that reached harvestable size on Tuesday or Wednesday).

Spears were graded as marketable if they had reasonably tight heads, were relatively straight and unblemished.
Export grade spears were defined as follows: Size - between 7/16" (1.11 cm) and 10/16" (1.59 cm) at the base of the spear; Head Tightness - very tight heads with smooth, closely appressed bracts; Color - all green, no white butt or excessive purpling of the base, bracts, or tip; Shape - spear tip should be uniformly tapered, not bulbous or extremely bent. Shaft should be straight and without blemishes.

Small domestic spears were marketable, but lacked a quality attribute essential for export grade and were sized 3/16-10/16" at the base of the spear.

Large domestic spears were marketable, but lacked a quality attribute essential for export grade and were sized >10/16" at the base of the spear.

Trial data underestimate the proportion of marketable yield that will be obtained in commercial plantings because the trial data come from spears harvested 2 or 3 days after the previous harvest. This will increase the proportion of unmarketable spears in comparison with typical commercial harvests. High temperatures during much of the 2004 harvest season probably further reduced the proportion of marketable spears this year. However, hybrids having a high proportion of marketable or export spears in trials should also have a high proportion of marketable or export spears in commercial production.

Note on 2004 harvest:

Stand and vigor remained excellent in 2004 (Table 1). This trial was harvested for the first time in 2004, with each plot was harvested for at least seven weeks, with harvest termination determined by an index based on 2003 fern vigor and 2004 adjusted total yield. The highest marketable and export yields were from UC115. Atlas also had high marketable yield, but most spears were too large for export quality. Surprisingly, Pacific Purple and Purple Passion had the next highest marketable yields, followed by Grande and Plaverd. NJ953, NJ1019, Gijnlim (36), and Jersey Giant had high total yields, but relatively low marketable yields. Early lines included Ravel, Jersey King, Atlas, NJ1019, NJ956, UC115, and NJ953. The trial was harvested again in 2005, but the data have not yet been analyzed.

Note on 2005 harvest:

Stand and vigor remained excellent in 2005. This trial was harvested for the second year in 2005, with each plot being harvested for at least ten weeks, with harvest termination determined by an index based on 2004 fern vigor and 2005 adjusted total yield. The highest cumulative (2004+2005) marketable and export yields were from DePaoli and NJ953. Although NJ953 had higher total yield, DePaoli had significantly higher export quality spears and percent marketable yield. Atlas also had high marketable yield, but most spears were too large for export quality. Two other New Jersey hybrids, NJ953 and NJ1019, also had high total marketable and export yield with moderate spear sizes. All of the top producing lines were also the earliest. We expect to harvest this trial again in 2006. Please note that the variety previously named UC115 has been released, and renamed as DePaoli.

Note on 2006 harvest and cumulative data:

Stand and vigor remained excellent in 2006.This trial was harvested for the third year in 2006, with each plot being harvested for about 75 days, with harvest termination determined by an index based on 2005 fern vigor and 2006 adjusted total yield. The highest cumulative (2004+2005+2006) marketable and export yields were from DePaoli and NJ1019. DePaoli had significantly higher marketable yield, export quality spears, early yield and percent marketable yield than NJ1019. Grande, Atlas, and all of the green New Jersey hybrids with the exception of NJ977 had higher marketable and total yield than UC157. All of the top producing lines were also the earliest.

Yield (lbs/ac)

Yield (lbs/ac)

Yield (lbs/ac)

Yield (lbs/ac)