Responses of different growing media ratios growth performance of spinach (Spinacia oleracea L.) under greenhouse conditions

Abstract

Spinach (Spinacia oleracea) vegetables are an important constituent of the diet of rural communities worldwide. It is a suitable substitute for several indigenous leafy vegetables, as it has more or less the same texture after cooking. Consequently, growers tend to grow spinach in any soil type or mixture available to them without modifying it, leading to reduced growth performance and yields. The use of animal manure is common in South Africa and helps to improve soil fertility when used in the correct ratio mixture. Therefore, the study’s objective was to investigate which of the growing media mixture (GMM) ratios of sand, Hutton soil, and goat manure would improve the growth and yield of S. oleracea under greenhouse conditions. The experiment was laid out in a randomized complete block design (RCBD), with 10 replicates (n=60). Six treatments comprised of different types of GMM namely, sand, Hutton soil, and goat manure at T1 (1:3:0 -control), T2 (1:2:1), T3 (1:1:1), T4 (1:1:2), T5 (2:1:2) and T6 (2:3:2), respectively. Growing media mixture had significant (P ≤ 0.05) effect on plant height (PH), number of leaves (NL), chlorophyll content (CC) and root length (RL) of S. oleracea, contributing 78, 62, 76 and 54% of the total treatment variation (TTV) in the respective variables. Relative to the control (T1), treatment T2, T3, T4, T5 and T6 increased PH by 22.75 cm, 24.03 cm, 27.92 cm, 22.84 cm and 24.35 cm, respectively. Similarly, the NL in all the treatments T2, T3, T4, T5 and T6 was increased by 10.90, 11.70, 11.90, 11.70 and 11.60, respectively, compared to T1. A related trend was observed in the CC, treatments T2, T3, T4, T5 and T6, increased the CC by 14.99, 15.08, 26.45, 21.38 and 15.83, respectively when compared to T1. The GMM treatment T4 obtained the highest 27.92, 11.9, 26.45 and 42.38 in PH, NL, CC and RL. In conclusion, GMM T4 had a positive effect on the growth and yield of S. oleraceae, and it is recommended for use to grow the vegetable crop.