Improvement of Sugarbeet Seed Emergence with Dilute Acid and Growth Regulator Treatments

Abstract

Poor emergence of sugarbeet seedling under moisture, temperature, and impedance stress conditions can limit satisfactory stand establishment. The objective of this study was to permeate seeds with dilute acid, growth regulators, and other chemicals, alone and in combinations, and to determine the effect of these treatments on emergence under favorable and unfavorable conditions. Commercially processed seed was treated with 1.0 N hydrochloric acid, propylene, ethylene, 10 and 100 ppm gibberillic acid (GA3), 10 and 100 ppm kinetin, 10 and 100 ppm 6‐benzyl‐aminopurine (6‐BA), 1% sodium hypochlorite, 0.01 M pH 6.7 and 11.4 phosphate buffers, and fermentation, alone and in combination.Effects of treatments on emergence of ‘GWH 58’ were evaluated in laboratory tests with combinations of moisture, temperature, and impedance stress and in field trials in 1977, 1978, and 1979. Laboratory tests showed that the acid treatment stimulates emergence under moisture and temperature, but not impedance stress conditions. The growth regulators ‐ GA3, kinetin, ethylene, and propylene stimulated emergence under combined moisture, temperature, and impedance stress. Under these conditions, acid and growth regulator treatment effects were additive.In field tests, the growth regulator seed treatments stimulated emergence only in combination with acid pretreatment. The acid + 100 ppm GA3 treatment gave the most consistent positive results (significant at 0.05 in 69% of trials) and greatest average improvement in emergence (9.3% of seeds planted) over the control. Significant improvements in field emergence were also obtained with acid + 10 ppm GA3, acid + 10 and 100 ppm kinetin, acid + 10 and 100 ppm 6‐BA, and acid + 100% propylene. Combinations of growth regulators gave no improvement in emergence over that of the individual growth regulators. The acid seed treatment improved emergence only under moisture stress conditions. Cultivars differed in their response to acid + 100 ppm GA, and acid + I00 ppm kinetin treatments in laboratory and field emergence trials conducted in 1980.