Foliar-Applied Seaweed and Fish Powder Do Not Improve Yield and Fruit Quality of Organically Grown Processing Tomatoes

Abstract

ABSTRACT In a replicated field plot study conducted during 1994 and 1995 in the Sacramento Valley, California, U.S.A., combinations of three levels each of soil-applied organic fertilizing materials and foliar-applied seaweed and fish powder were tested on processing tomato (Lycopersicon esculentum Mill.), cv. Orsetti's Halley 3155 to determine effects on crop yield, fruit quality and economics. The experimental design was a factorial split plot arranged in a randomized complete block with four replicates. Main plot treatments consisted of three soil fertility levels: (1) control, (2) woolypod vetch (Vicia villosa Roth ssp. varia [Host] Corbiere), cv. Lana and (3) Lana vetch and poultry manure compost. Subplot treatments consisted of three foliar spray levels: (1) control, (2) seaweed and fish powder applied at label rate, and (3) seaweed and fish powder applied at twice the label rate. The study was designed to simulate practices used by growers of organic processing tomatoes in the area. No significant differences were found for yield or quality of marketable fruit in any soil and foliar treatment combination in either year. Because no significant differences for yield or fruit quality were detected, no economic benefit for seaweed and fish powder can be inferred under the experimental conditions.