| Abstract: In order to screen out the seedling substrates suitable for lettuce in nutrient film technique, the effects of six commercial seedling substrates (flower puree 30, peat block 38, peat block 30, coconut bran
block 30, rock wool block 36, rock wool block 25) on the growth of buttered lettuce 'Flandria' were studied and compared. The results showed that when sowing, planting, and harvesting at the same time, peat block 38, peat block 30 and coconut bran block 30 were more conducive to the growth of lettuce in the seedling stage and after planting, rock wool block 36 and rock wool block 25 had the second effect, and flower puree 30 had the worst seedling effect. When sowing at the same time, planting with the same number of leaves, and harvesting with the same weight, the growth time of lettuce grown with peat block 38 and peat block 30 was the shortest, followed by coconut bran block 30, rock wool block 36 and rock wool block 25. The growth time of lettuce using flower puree 30 seedlings was the longest. On the whole, for lettuce in nutrient film technique, peat block 38, peat block 30 and coconut bran block 30 were better than other substrates, the growth of luttce were good at seedling stage and after planting, and growth cycle were short. But considering the cost of raising seedlings, it was recommended to use peat block 30 or coconut bran block 30. |