Growth, Yield, and Nutrient Uptake of Transplanted Fresh-market Tomatoes as Affected by Plastic Mulch and Initial Nitrogen Rate

Abstract

Two field experiments were conducted with two cultivars of transplanted tomatoes (Lycopersicon esculentum Mill.) with and without plastic mulch, varying the initial rate of N fertilizer, but maintaining the total N rate at 168 kg·ha–1 by sidedressing. In 1982, 0 and 112 kg·ha–1 initial N rates, and bare ground, black mulch, and clear plastic mulch were compared on a gravelly loam soil. In 1983, initial N rates used were 34, 67, 101, or 134 kg·ha–1, with bare ground and clear mulch on a silt loam soil. Effects of the plastic mulch dominated both experiments. Mulching increased rate of basal branch appearance and led to early flowering on branches. Total plant growth, as measured by vine weights at final harvest, was increased by mulch in both years. Mulching increased early yield only in 1983, but increased total yields by 13% and 79% in 1982 and 1983, respectively. Initial N fertilizer rates did not influence total yields significantly in either experiment, although high initial N rate, combined with clear plastic mulch, led to a significant decrease in percent marketable fruit in 1982. In 1983, mulching increased shoot concentrations of N, NO3-N, P, K, Ca, Mg, Cu, and Β (P = < 0.01) in spite of the fact that mulched plants were larger than unmulched plants at sampling time, 24 days after transplanting. Nitrogen fertilizer increased only the N and P concentrations and to a lesser extent than did the mulch.

Increasing Yield of Tomatoes with Plastic Mulch and Apex Removal

“…Although flowering started earliest in untopped plants, by 41 or 42 days after transplanting, topped plants had the highest numbers of flowering clusters. In both years, use of clear plastic mulch also increased rate of basal branching and early flower cluster number (Table 2), confirming results of experiments reported previously (19,20). Since the early part of the growing season was significantly cooler in 1985 than in 1984 (20), branch and flower cluster numbers increased more slowly in 1985 than in 1984.…”

“…Mulching with clear plastic increased concentrations of P, K, Ca, and N 0 3-N and decreased the concentration of Na in tomato leaves, as previously reported for 'Pik-Red' tomatoes grown on a fine-textured silt loam in 1983 (19). We have consistently obtained an increase in P concentration using clear plastic mulch and usually an increase in K concentration, but the effects of mulch on N 0 3-N concentrations varied depending on year, planting dates, soil, and environmental conditions.…”

“…'Springset' and 'NY 903' showed similar responses to mulch in 1984. In a mulching experiment in 1983, early yield was increased more by mulch for 'Pik-Red' than 'Springset', while total yield was stimulated more for 'Springset' than for 'Pik-Red' tomato (19). Other workers have noted enhanced response of tomato cultivare to mulch in early yield (3) and in total yield Since various investigators ascribe stimulation in plant growth and yield by plastic mulch to increases in soil temperature, maintainance of soil moisture, increases in soil C 0 2 level, or a combination of these and other factors (2,3,7,17), the precise cause of cultivar differences is hard to identify.…”

“…Nondestructive counts of branches > 5 cm and flower clusters (any raceme with at least one flower at or past anthesis) were made at times noted in Table 1. Leaves were sampled for nutrient analysis for this experiment only, using methods previously described (19). Ripe fruits were harvested at weekly intervals and divided into US No.…”

Response of Fresh-market Tomatoes to Nitrogen Fertilizer and Plastic Mulch in a Short Growing Season

“…Experiments in 1982 and 1983 demonstrated that timing of application of 168 kg N/ha had little influence on early and total yields of the early cultivars Springset and Pik-Red fresh-market tomatoes (13). Mulching increased early and total yields, but there was no interaction between mulch and fertilizer timing on yields.…”