Comparison of Snow Pea (Pisum sativum) Cultivars in Relation to Leafminer (Liriomyza huidobrensis) Infestation and Yield
Universidad del Valle de Guatemala (Guatemala)
Phillip Lamport, Stephen Weller (US); Jorge Luis Sandoval, Guillermo E. Sanchez (Guatemala)
Infestations by leafminer are a major concern for snow pea growers in the Guatemalan highlands. The most common cultivar found in snow pea fields, Oregon Sugar Pod II (OSP) has exhibited high susceptibility to the attack of leafminers. With the objective of comparing leafminer infestations and yields of several snow pea cultivars, field trials were established in Xenimajuy? and Zaragoza, (Department of Chimaltenango), during the dry season of 1998 . Treatments consisted of cultivars OSP (as control), Snowflake, Sugar Lace, SP6 and SP18. Treatments were replicated four times following a randomized complete block design. The factors evaluated in this study were snow pea export-quality yield and leafminer larval populations at 35, 60 and 85 days after planting. Leafminer populations were monitored twice a week and insecticide sprayings based on a 10 adult leafminers per meter threshold
The objective of this study was to compare leafminer infestations and yields of several snow pea cultivars.
The 5 cultivars under study exhibited significant differences (p<0.01) in the levels of leafminer larval infestations. The most susceptible variety to leafminer larvae infestation was SP6 (257 total larval count) in Xenimajuyu and OSP (230 larvae) in Zaragoza. The most consistent cultivar was SP18 which exhibited the lowest levels of infestation at both sites, significantly different (p<0.05) from the control. Regarding the yields obtained from the different cultivars, it was evident at Xenimajuy? that the most productive cultivar was Snowflake with 2142 kg/ha more production than the control variety, OSP (7674 kg/ha). Other than Sugar Lace, with statistically significant less production (5753 kg/ha) than the control, the remaining cultivars (SP 16 and SP 18) showed similar yields to that of OSP. At Zaragoza the best yielding cultivar was Snowflake, at 9470 kg/ha, compared to 8060 kg/ha for the control. The other cultivars under study yielded significantly less than Oregon Sugar Pod II.