This study was conducted on a Clear Lake clay soil (Fine, montmorillonitic, thermic, Typic Pelloxerert) planted to peppers in 1994 and tomatoes in 1993. Compost made from municipal yardwaste and manure was applied at five levels on 1 Dec 1994. It was spread onto rough-shaped beds with a manure spreader and then lillistoned into the top 2-3 in. of soil the same day. Preplant fertilizer (600 lbs of -12-12) was applied on 2 Dec. The field remained in rough beds through the winter. The field was planted on 24 Feb with the variety Discovery. The plots had three splits of various fertilizer treatments, but for clarity, only the treatment that represented the growers standard fertilization practices were analyzed and presented in this paper. The trial was designed as a randomized complete block design with six replications. Counts of the number of roots with pink root were made on 20 bulbs per plot on 7 Jul. Onions from the middle 18 ft of each plot were harvested and graded for size and presence of Fusarium basal plate rot symptoms on 1 Aug. the data were subjected to analysis of variance and treatments were compared using an LSD test.
Only the 5.0 T/A compost treatment had a significantly greater marketable yield than the untreated control. The 5.0, 10.0 and 20.0 T/A treatments had significantly fewer tons of Fusarium infected bulbs and a lower percent of infected bulbs. Compost had no effect on the number of roots infected by Pink root.
| Yield (T/A) | ||||||||
| Compost Treatment (T/A) |
Total Market Yield |
Jumbo | Med. | Pre-pack | Culls | Basal Rot | Basal Rot % | No. of roots infected with pink root |
| 0 | 18.0 | 3.9 | 12.8 | 1.3 | 0.2 | 5.2 | 22.2 | 2.8 |
| 2.5 | 22.8 | 2.8 | 18.5 | 1.6 | 0.3 | 2.9 | 10.9 | 3.4 |
| 5.0 | 24.8 | 6.8 | 15.9 | 2.0 | 0.4 | 1.8 | 6.6 | 2.3 |
| 10.0 | 21.0 | 4.0 | 15.5 | 1.5 | 0.1 | 2.4 | 10.3 | 2.5 |
| 20.0 | 24.2 | 4.0 | 18.8 | 1.5 | 0.2 | 1.5 | 6.1 | 1.8 |
| LSD (P=0.05) | 6.6 | ns | 6.1 | ns | ns | 2.7 | 11.2 | ns |