Variety evaluation, on-farm trials and genotype x environment (G x E) analysis, on semi-temperate vegetable for organic production in four agro-ecological zones of the Cordillera highlands [Philippines]

Few varieties adapted under organic conditions were one of the gaps identified for sustainable vegetable production in the Cordillera highlands particularly the province of Benguet. The research was conducted to evaluate and select varieties of five semi-temperate vegetables (cabbage, carrot, Chinese cabbage, garden pea, and tomato) adapted under organic production systems in four agro-ecological zones of the highlands. Preliminary trails were conducted on the first year of evaluation in La Trinidad (1332 m asl). On the second and third years, selected varieties from the preliminary trials were evaluated in four agro-ecological zones under organic conditions represented by La Trinidad (1332 m asl; low mountain zone); Bonglo, Atok (2,085 m asl; mid-mountain zone) and Topdac, Atok (1,459 m asl; mid-mountain zone); Tuludan, Atok (2,330 m asl high-mountain zone) and Camp 1, Tuba (503 m asl; high hills zone). The trials followed most the requirements of the Philippine National Standards (BAFFPS, 2003). All trials were researcher-managed with the participation of the farmer-cooperators. All experiments in all sites were laid-out following the RCBD. G x E analysis of total yield was done using CropStat (IRRI, 2009). The Additive Main Effects Multiplicative analysis was used in the study. Results of the three year evaluation show that vegetable varieties had varied performance in the four agro-ecological zones during the wet and dry season trials. For cabbage, the best performing varieties were Rare Ball, Lucky Ball and Scorpio. G x E analysis showed Lucky Ball as the most stable. For Carrot, Chuntung and Teracota were the highest yielders across locations. G x E analysis revealed Kuroda as the most stable during the dry season while Chunhong in the wet season. For Chinese cabbage, Dou Kang 4 and Summer Star were the highest yielders. Zao Xin Bai was stable during the dry season while Dou Kang 4 in the wet season. Garden pea accession CGP34 and Betag produced the highest fresh pod yield in all locations. CGP34 was the most stable. For the table type tomatoes, CLN 2264 S1 consistently had high marketable yield across locations and seasons. CLN 2264 S1, and CLN 2264 S3 also maintained high yields across locations and seasons. G x E analysis showed that TM 10486 was stable. For Cherry-type tomatoes, the native variety had the highest remarkable yield across locations and seasons. Hong Bao Shi S2 was the most stable.