Growth and canopy characteristics of field-grown tomato

Although detailed growth studies and yield analysis are common for agronomi c crops, their application to horticultural crops is limited. Detailed grow th measurements of field-grown tomato (Lycopersicon esculentum Mill.) were conducted at four Florida locations for two irrigation methods. Maximum rat e of main-stem node development was approximate to 0.5 nodes d(-1) and leaf area index (LAI) increased exponentially with main-stem node number. Maxim um LAI was attained 11 wk after transplanting, with values ranging from 1.5 to 3.0 and from 3.2 to 6.0 for drip-irrigated and subirrigated crops, resp ectively. Lower LAI values with drip irrigation were only partially related to wider row spacings. Final biomass (dry weight) ranged from 6 to 12 Mg h a(-1) and fruit dry weight harvest indices (fruit biomass/total above-groun d biomass) ranged from 0.53 to 0.71. Average dry matter accumulation by roo ts, stems, and leaves accounted for approximate to 3, 23, and 17% of final biomass, respectively. Estimated radiation use efficiency (RUE) for tomato averaged 1.05 g dry weight MJ(-1) m(-2), with 50 to 60% light interception in the crop production area at LAI values of 4 to 5. At 11000 plants per ha , the rate of dry matter accumulation averaged 17.8 g d(-1) m(-2) during th e linear growth phase, with instantaneous dry matter partitioning to fruits averaging 0.70 during the fruit-growth phase. Relationships between degree days, estimated cumulative intercepted radiation, and fruit yield accounte d for much of the variation in fruit yields for these different seasons and locations throughout Florida.