Commercial hybrid yield of green asparagus ( Asparagus officinalis L. var. altilis) processed in two spear-lengths, during the stable productivity stage, in the Province of Buenos Aires, Argentina

The perennial crop asparagus reaches maximum yield in its fifth season, exhibits marked genotype-environment interaction and requires productivity evaluation of its hybrids. To determine the behavior of green asparagus genotypes, a randomized complete block design trial (begun 16/11/11, density 23810 pl ha(-1), area 1690 m2) was carried out in Azul (36 degrees 48' S, lat. 59 degrees 51' W, long.) within the framework of the ISHS's Fourth International Asparagus Cultivar Trial, in which the following hybrids were harvested between 5/8/17 and 26/10/17 and evaluated for agronomic performance: 'Italo', 'Vittorio', 'Eros', 'Ercole', 'Giove', 'Franco', 'Chino', 'Early-California', 'UC-157', 'Patron', 'NJ-1189', 'NJ-1123' and 'NJ-1192'. Their response to pre-harvest diammonium phosphate (DAP) fertilisation was also evaluated (100 kg ha(-1) vs. control). Harvested spears were cut, conditioned to two lengths (long 22 cm, short 17 cm), weighed, counted, washed and calibrated. The following characters were evaluated: total fresh commercial productivity (TFP) and that of long and short commercial spears (CFP-L and CFP-S); total commercial spear number (TSN) and that of long and short commercial spears (CSN-L and CSN-S); mean spear weight (MSW); calibre distribution (CD): ( J: Jumbo; XL: Extra-Large; L: Large; M: Medium; S: Small and A: Asparagine). ANOVA-LSD test P=0.05 was employed. DAP fertilisation raised yield by 3-10%, though not significantly. The following mean values were obtained: TFP: 8678.46 kg ha(-1); TSN: 440298 spears ha(-1); MSW: 20 g; CFP-L: 3109; CFP-S: 1945 kg ha(-1); CSN-L: 165857 and CSN-S: 130467 spears ha(-1). The following hybrids performed well: for CFP-L: 'Vittorio': 4379(a); 'Franco': 4033(ab); 'NJ-1123': 3849(abc); for CFP-C: 'NJ-1123': 2726(a); 'Ercole': 2483( ab); 'Vittorio': 2325(abc); for CSN-L: 'NJ-1123': 225260(a); 'Franco': 214161(a); 'Vittorio': 204358( ab); 'Giove': 200229(abc); for CSN-C: 'NJ-1123': 2725(a); 'Ercole': 2482( ab); 'Vittorio': 2325(abc); for CD: J: 'UC-157': 12767(a); 'Eros': 9882(ab); 'NJ-1123': 9005(abc); for XL: 'NJ-1123': 41124(a); 'Franco': 38958(ab); 'NJ-1192': 37644(ab); for L: 'Ercole': 85083(a); 'NJ-1123': 84700(a); 'Franco': 83872(a); 'Italo': 83095(a); for M: 'NJ-1123': 118198(a); 'Franco': 116369(a); 'Vittorio': 109645(ab); 'Ercole': 105984(ab); for S: 'Giove': 102748(a); 'NJ-1123': 80530(ab). In summary, 'NJ-1123' would be chosen for spear number productivity and 'Vittorio' and 'Franco' for yield.